自动气象站的雷电防护

针对自动气象站安装在室外易遭雷击以及微电子装置的脆弱性，结合河南省自动气象站实际情况及设备的维护维修经验，探讨如何做好自动气象站雷电防护工作。     

长江下游镇江段造床流量计算及特性分析

造床流量是河床形态塑造的关键因素,也是河道整治、水工计算设计的主要参数。根据实测水文数据,分别采用三种常用造床流量计算方法,对长江下游镇江河段的造床流量进行求解计算,结果分析对比,表明Makovieve法更适用于镇江段造床流量的计算。基于算例结果建立长江下游河段造床流量经验方法,精度分析表明经验方法具有较高的精度。给出了推荐值。建立了适用于镇江河段造床流量计算的经验公式。     

多腔扁钢管混凝土斜折柱抗震性能试验研究

大连国际会议中心结构幕墙柱中,采用了一种扁钢管混凝土斜折柱.文中结合该工程设计,进行了2个1/3缩尺的扁钢管混凝土斜折柱试件的低周反复荷载试验,1个试件为普通扁钢管混凝土斜折柱,1个试件为多腔扁钢管混凝土斜折柱.比较分析了两个试件的承载力、刚度、延性、滞回特性及破坏特征.研究表明:多腔扁钢管混凝土斜折柱与普通扁钢管混凝...     

地质调查支撑服务福建生态文明试验区理论与方法探索

为探索地质调查支援服务生态文明建设的理论与方法,为新时代地质工作转型升级提供经验,中国地质调查局组织实施了"福建生态文明试验区综合地质调查工程".通过省、市、县、流域等不同层级综合地质调查及专题评价试点,取得了一些理论方法及技术应用成果:①揭示了我国典型红壤区地质要素对水土流失的控制作用,总结了不同岩性控制区水土流失地...     

内蒙古克什克腾旗林西组碎屑锆石LA-ICP-MS年代学及其地质意义

内蒙古克什克腾旗位于西拉木伦河以北,属锡林浩特地块南缘。本文对出露于克什克腾旗北东约5 km的一套变质粉砂岩进行了锆石LA-ICP-MS U-Pb测年,其年龄结果主要分为4个区间:258~298 Ma(峰值为285 Ma)、377~474 Ma(峰值为430 Ma)、1261~1727 Ma、1853~2513 Ma,此外还含有321 Ma和937 Ma的锆石各一颗。锆石CL图像显示:258~298 Ma的锆石以岩浆锆石为主,响应兴蒙造山带的晚古生代岩浆活动;377~474 Ma的锆石中既有岩浆锆石又有变质锆石,表明其源区既有奥陶纪-泥盆纪岩浆岩,又有古生代的变质岩;1261~1727 Ma的锆石以岩浆锆石为主,少数为变质锆石,暗示中元古代的岩浆岩和变质岩也为该组提供物源;1853~2513 Ma的锆石以岩浆锆石为主,反映了华北板块基底的年龄信息。该变质粉砂岩中碎屑锆石的最小谐和年龄是258 Ma,限定了其沉积时代的下限为晚二叠世,应属于林西组。年龄峰值既对应华北板块的重要构造热事件,又有与兴蒙造山带地质事件相关的年龄信息,表明林西组具有南北两个物源区,同时也暗示在其形成时华北板块与西伯利亚板块已经拼合。     

低植被覆盖区斑岩铜矿遥感找矿模型及其应用——以环巴尔喀什-西准噶尔成矿带为例

针对遥感找矿过程中所面临的干扰因素多、地表覆盖类型多样导致的遥感找矿困难的问题,提出了低植被覆盖区斑岩铜矿"小型侵入岩体异常+线性构造异常+蚀变矿物异常"的多尺度遥感找矿模型,并系统总结了该模型的基本原理和技术流程。以环巴尔喀什-西准噶尔成矿带为研究区,分析了研究区的成矿地质背景;在遥感找矿模型的指导下,依据遥感找矿技术流程提取了研究区的岩性、构造和蚀变矿物等控矿要素;结合野外地表验证情况,综合多源数据,圈定了5处重点远景区;结合大比例尺遥感蚀变矿物填图、地质、地球物理、地球化学和探槽取样的分析结果,圈定3处遥感找矿靶区。     

Sensitivity and areal differentiation of vegetation responses to hydrothermal dynamics on the northern and southern slopes of the Qinling Mountains in Shaanxi province

The Qinling Mountains, located at the junction of warm temperate and subtropical zones, serve as the boundary between north and south China. Exploring the sensitivity of the response of vegetation there to hydrothermal dynamics elucidates the dynamics and mechanisms of the main vegetation types in the context of changes in temperature and moisture. Importance should be attached to changes in vegetation in different climate zones. To reveal the sensitivity and areal differentiation of vegetation responses to hydrothermal dynamics, the spatio-temporal variation characteristics of the normalized vegetation index(NDVI) and the standardized precipitation evapotranspiration index(SPEI) on the northern and southern slopes of the Qinling Mountains from 2000 to 2018 are explored using the meteorological data of 32 meteorological stations and the MODIS NDVI datasets. The results show that: 1) The overall vegetation coverage of the Qinling Mountains improved significantly from 2000 to 2018. The NDVI rise rate and area ratio on the southern slope were higher than those on the northern slope, and the vegetation on the southern slope improved more than that on the northern slope. The Qinling Mountains showed an insignificant humidification trend. The humidification rate and humidification area of the northern slope were greater than those on the southern slope. 2) Vegetation on the northern slope of the Qinling Mountains was more sensitive to hydrothermal dynamics than that on the southern slope. Vegetation was most sensitive to hydrothermal dynamics from March to June on the northern slope, and from March to May(spring) on the southern slope. The vegetation on the northern and southern slopes was mainly affected by hydrothermal dynamics on a scale of 3–7 months, responding weakly to hydrothermal dynamics on a scale of 11–12 months. 3) Some 90.34% of NDVI and SPEI was positively correlated in the Qinling Mountains. Spring humidification in most parts of the study area promoted the growth of vegetation all the year round. The sensitivity of vegetation responses to hydrothermal dynamics with increasing altitude increased first and then decreased. Elevations of 800 to 1200 m were the most sensitive range for vegetation response to hydrothermal dynamics. The sensitivity of the vegetation response at elevations of 1200–3000 m decreased with increasing altitude. As regards to vegetation type, grass was most sensitive to hydrothermal dynamics on both the northern and southern slopes of the Qinling Mountains; but most other vegetation types on the northern slope were more sensitive to hydrothermal dynamics than those on the southern slope.     

黄河源区鄂陵湖湖面和湖边草地对流边界层湍流结构特征的大涡模拟研究

为研究黄河源区边界层湍流特征及其对物质和能量输送的影响,本文首次采用大涡模拟的方法,对比分析了黄河源区两种不同下垫面上(鄂陵湖和湖边草地)对流边界层(CBL)中精细的湍流结构特征.使用资料为2012年夏季黄河源区鄂陵湖流域野外观测实验的GPS探空资料、涡动相关观测资料.分析表明,模拟的黄河源区草地和湖上CBL的平均结构...     

乌鲁木齐一次重污染过程及其边界层特征量分析

针对2020年1月5—17日乌鲁木齐出现的重污染天气，利用乌鲁木齐的探空站资料和地面常规气象数据计算了最大混合层高度、平均风速、逆温特性、边界层通风量、能见度、相对湿度等，对最大混合层高度、能见度、相对湿度与PM_2.5质量浓度进行了相关性分析，并利用Hysplit后向气团轨迹模式分析污染形成源。结果表明：此次重污染天气过程大气层结较为稳定，主要表现为逆温层厚(平均577 m)、逆温强度大(平均1.7℃/100 m)、最大混合层高度低(平均400 m)；边界层通风量对局地空气质量影响显著；PM_2.5质量浓度与相对湿度呈弱的正相关，与能见度呈指数相关；Hysplit后向气团轨迹模式分析得出此次污染过程以局地排放为主要形成源。