两个同源地不同路径热带气旋的大尺度场对比分析

本文利用NCEP/NCAR再分析格点资料,着重对8903号"BRENDA"和0601号"珍珠"两个同源地进入南海后不同路径的典型热带气旋的大尺度环境场进行对比分析。结果表明:西风槽的强弱和东移的快慢、西太平洋副高的形状变化和东退西进、冷空气的强弱和南下路径及热带气旋内部的不对称结构是造成二者移动路经差异的主要原因。另,印缅槽的变化也对其路径差异有一定的作用。     

中国南阳伏牛山世界地质公园地质灾害评价

中国南阳伏牛山世界地质公园位于豫西南山区。地貌类型以中、低山为主,地表多出露变质岩及侵入岩,岩体风化强烈,多赋存基岩裂隙水,地质构造发育,人类工程活动强烈,园区地质环境条件复杂。通过野外调查及评价,园区处于地质灾害高易发区,主要地质灾害有崩塌、滑坡和泥石流。针对地质公园这一特色旅游,提出地质灾害防治对策,保障当地旅游经济可持续发展。     

Early Jurassic rift structures associated with the Soapaga and Boyacá faults of the Eastern Cordillera, Colombia: Sedimentological inferences and regional implications

The NW-trending Bucaramanga fault links, at its southern termination, with the Soapaga and Boyacá faults, which by their NW trend define an ample horsetail structure. As a result of their Neogene reactivation as reverse faults, they bound fault-related anticlines that expose the sedimentary fill of two Early Jurassic rift basins. These sediments exhibit the wedge-like geometry of rift fills related to west-facing normal faults. Their structural setting was controlled further by segmentation of the bounding faults at approximately 10 km intervals, in which each segment is separated by a transverse basement high. Isopach contours and different facies associations suggest these transverse anticlines may have separated depocenters of their adjacent subbasins, which were shaped by a slightly different subsidence history and thereby decoupled. The basin fill of the relatively narrow basin associated with the Soapaga fault is dominated by fanglomeratic successions organized in two coarsening-upward cycles. In the larger basin linked to the Boyacá fault, the sedimentary fill consists of two coarsening-upward sequences that, when fully developed, vary from floodplain to alluvial fan deposits. These Early Jurassic rift fills temporally constrain the evolution of the Bucaramanga fault, which accommodated right-lateral displacement during the early Mesozoic rift event.     

嵌入式跨平台GIS应用中间件设计

为了解决嵌入式GIS跨平台的软件开发问题,针对嵌入式环境的资源有限性和平台多样性特点,设计了一种嵌入式GIS应用中间件——EGIS_MW平台,该平台能够有效屏蔽不同嵌入式软硬件环境的差异,为上层应用程序提供统一高效并且适合嵌入式GIS应用的编程接口。EGIS_MW平台已经在一款支持多种不同软硬件环境的嵌入式导航系统中得到了应用。应用表明该中间件能够很好地满足嵌入式GIS跨平台软件开发的技术需求。     

1961—2020年郑州主城区大气自净能力变化特征分析

利用郑州市主城区1961—2020年气象观测资料和2014—2018年空气质量监测数据,分析了郑州主城区大气自净能力指数的长期变化趋势与影响因子以及2014—2018年主城区大气自净能力与PM_2.5的关系。结果表明：郑州主城区大气自净能力指数30 a气候均值为4.42 t·(d·km²)^-1,春季大气自净能力最强,为5.20 t·(d·km²)^-1;秋季大气自净能力最弱,为3.88 t·(d·km²)^-1,不利于对大气污染物的清除。1961—2020年郑州主城区大气自净能力呈显著的减弱趋势,其中1969年最强为6.85 t·(d·km²)^-1,2020年最弱为3.06 t·(d·km²)^-1。影响因子中,1961—1980年混合层厚度与大气自净能力指数呈正相关;日平均风速≥2.5 m·s^-1的日数和小风日数与大气自净能力分别呈...     

The crustal fluid evolution and the causes of earthquakes(Ⅲ)

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关于A型花岗岩判别过程中若干问题的讨论

自A型花岗岩提出(1979年)30年来,其内涵和外延相对于原始定义而言已发生了很大的变化.主要针对A型花岗岩的各种判别方法(尤其是判别图解)的有效性和局限性进行了讨论.这些判别方法对于A型花岗岩的判定并不总是奏效,所以在实践过程中不能过于依赖判别图解,否则就很容易得出错误的结论.实际上,A型花岗岩最本质的特征很可能在于它是一种高温花岗岩(相时于I型争S型花岗岩),因此较高地温梯度下的各种地球动力学背景均有利于这一类型花岗岩的发育.     

北斗Ⅱ载波相位差分定位法在高填方变形监测中的应用

通过对北斗Ⅱ载波相位差分定位技术在高填方变形监测中的应用研究,包括实时动态差分定位(RTK)和静态相对定位,构建了完整的北斗Ⅱ高填方变形监测软硬件系统。该系统采用基于贯序极限学习机的卫星信号周跳探测与修复方法进行数据预处理,并利用基于卫星历元数的分层置信滤波算法对静态相对定位结果进行修正,提高了定位结果的准确性和可靠性。通过自制的精度测试装置,以百分表和钢尺测量的位移变化量为相对真值,完成了上述变形监测系统的精度试验。试验结果表明:该系统的RTK高程测量精度优于2 cm,静态高程测量精度优于2 mm,静态水平位移测量精度优于1.5 mm,可有效抑制卫星信号周跳和卫星历元数量较少等因素的影响。     

TURBULENCE STRUCTURE IN A STRATIFIED BOUNDARY LAYER UNDER STABLE CONDITIONS

Turbulence structure in stably stratified boundary layers isexperimentally investigated by using a thermally stratified wind tunnel. Astably stratified flow is created by heating the wind tunnel airflow to atemperature of about 50 °C and by cooling the test-section floor to asurface temperature of about 3 °C. In order to study the effect ofbuoyancy on turbulent boundary layers for a wide range of stability, thevelocity and temperature fluctuations are measured simultaneously at adownwind position of 23.5 m from the tunnel entrance, where the boundarylayer is fully developed. The Reynolds number, Re, ranges from 3.14× 104 to 1.27 × 105, and the bulk Richardson number, Ri,ranges from 0 to 1.33. Stable stratification rapidly suppresses thefluctuations of streamwise velocity and temperature as well as the verticalvelocity fluctuation. Momentum and heat fluxes are also significantlydecreased with increasing stability and become nearly zero in the lowest partof the boundary layer with strong stability. The vertical profiles ofturbulence quantities exhibit different behaviour in three distinct stabilityregimes, the neutral flows, the stratified flows with weak stability(Ri = 0.12, 0.20) and those with strong stability (Ri= 0.39,0.47, 1.33). Of these, the two regimes of stratified flows clearly showdifferent vertical profiles of the local gradient Richardson number Ri,separated by the critical Richardson number Ri cr of about 0.25. Moreover,turbulence quantities in stable conditions are well correlated with Ri.     

构造体制转换与流体多层循环成矿动力学

基于成矿系统动力学研究进展的综合分析, 认为构造体制转换与流体多层循环成矿动力学研究是地球科学跨世纪的重要前沿领域之一, 进而提出这一领域的研究主题和关键问题、研究思路及方法, 阐释其重要意义, 指出构造体制转换与流体多层循环成矿动力学研究以构造演化、流体活动及区域地球化学和地球物理不均一性为基础, 通过变形-流动高温高压实验及计算机数值模拟再现成矿作用过程和机理, 解析构造体制转换与流体多层循环成矿动力学特征, 揭示成矿界面时-空演化规律, 建立成矿系统物质和能量交换-反馈耦合成矿的定量模型.这是深化矿床成因认识的重要基础和实现科学找矿的有效途径, 对地球系统科学和大陆动力学的研究也具有重要意义.