Precipitation variability during the past 400?years in the Xiaolong Mountain (central China) inferred from tree rings

We developed the first tree-ring chronology, based on 73 cores from 29 Pinus tabulaeformis trees, for the Xiaolong Mountain area of central China, a region at the boundary of the Asian summer monsoon. This chronology exhibits significant (at 0.01 level) positive correlations with precipitation in May and June, and negative correlations with temperature in May, June and July. Highest linear correlation is observed between tree growth and the seasonalized (April–July) precipitation, suggesting that tree rings tend to integrate the monthly precipitation signals. Accordingly, the April–July total precipitation was reconstructed back to 1629 using these tree rings, explaining 44.7?% of the instrumental variance. A severe drought occurred in the area during the 1630s–1640s, which may be related to the weakened Asian summer monsoon caused by a low land-sea thermal gradient. The dry epoch during the 1920s–1930s and since the late 1970s may be explained by the strengthened Hadley circulation in a warmer climate. The dry (wet) epochs of the 1920s–1930s (the 1750s and 1950s) occurred during the warm (cold) phases of the El Ni?o-Southern Oscillation and the Pacific Decadal Oscillation that are often associated with weakened (strengthened) East Asian summer monsoon. These relationships indicate significant teleconnections operating over the past centuries in central China related to large-scale synoptic features.     

东北地区水稻障碍型低温冷害变化对区域气候增暖的响应

利用东北地区153个气象站1961—2010年逐日气温资料,采用统计学方法分析了水稻障碍型低温冷害的气候变化特征及其对区域气候变暖的响应情况。结果表明,东北大部地区水稻障碍型低温冷害事件呈减少趋势,但区域性较为明显;障碍型低温冷害对关键发育期气温变化响应较为敏感,二者呈显著的负相关关系,表现为气温每升高1 ℃,东北地区冷害减少35个站次。东北地区关键发育期气温均呈上升趋势,但吉林西部地区障碍型冷害却随之增加,分析了关键发育期气温变率和气候变率,将其解释为局地障碍型冷害增加主要受气候变率增大的影响,逐日气温变率对其影响不大。     

盐城市雾发生规律及其预报

依据盐城市１９８０￣１９９６年的雾资料进行了气候分析,将雾发生的天气形势归纳为弱高压和气旋倒槽两种类型;在此基础上,对单站要素进行了指标分析,由给出的５条指标采用概率加法原理进行雾发生的分析判断;并在气象信息综合分析处理系统（Ｍｉｃａｐｓ）上建立了春运期间雾预报系统,在实际应用中取得了较好的效果。     

跨越断层埋地管线地震反应研究述评

本文论述了跨越断层埋地管线地震反应研究工作概况,包括理论研究和实验研究的进展,并介绍了不同情况下采用的研究方法和建立的相应的研究模型,通过对数据结果进行整理分析,得出跨越断层埋地管线地震反应规律。同时,本文还对埋地管线研究中的一些重要参数对研究结果的影响作了详尽的阐述,提出了需进一步研究的问题和今后可能的研究发展方向。     

小口径割管器的设计与应用

某盐井施工时,在245．00—270．00m孔段有25m钻具被水泥固结,进行透孔作业时,扫至孔深250．60m时,扫孔用岩心管被扫落的钻杆接头碎块卡住拧断,透孔时发现孔内遗留3．2m断岩心管、钻头等物。根据钻孔结构与遗留钻具的特点．自行设计一种主要由活塞柱、割刀片和复位弹簧组成的小口径割管器,将水泥固结钻具割断,并将钻具和多种残留管材打捞出孔。从割断后打捞上来的钻杆分析,钻杆切割面光滑、平整,钻杆被完全切透,说明此种割管器设计合理,各部件动作有效。     

青海东昆仑哈陇休玛钼多金属矿床成矿流体特征及成矿模式

哈陇休玛钼多金属矿床是东昆仑成矿带东段目前仅有的中型斑岩型矿床。为了查明其成矿流体性质及成矿物质来源,构建矿床成矿模式,本文进行了详细的流体包裹体和H-O-S同位素研究。流体包裹体显微测温显示,哈陇休玛矿床发育气液两相和含CO₂三相两种类型包裹体,成矿流体呈现中高温(集中于280～340℃)、高盐度(w(NaCl),集中于6.00%～18.00%)和中等密度(集中于0.64～0.92 g/cm³)特点,成矿深度为2.4～4.1 km,形成于中浅成环境。H-O同位素显示,成矿流体具有岩浆水和大气降水混合的特征,但主体以岩浆水为主;S同位素显示,成矿物质主要来自于深部岩浆。结合区域构造演化认为,哈陇休玛矿床成矿模式为印支晚期东昆仑地区发生强烈壳幔混合作用,形成富含成矿元素的混合岩浆,含矿流体在随混合岩浆上升的过程中发生流体沸腾,并与大气降水混合冷却,导致成矿物理化学条件发生变化,促使成矿物质沉淀成矿。     

广西前汛期旱涝特征及成因分析

利用 EOF分解和 Z指数对广西前汛期 (4～ 6月 )降水进行型态分布及旱涝等级的划分 ,研究旱涝的空间分布、年际变化及年代际变化 ,并对旱涝成因进行了分析。结果表明 :广西前汛期降水的一致性较好 ;6 0年代和 90年代为旱涝多发年代 ,70年代以涝为主要特征 ,80年代以旱为主要特征。影响广西前汛期降水的环流因子主要有中高纬环流经向度、北半球极涡、印缅槽及副热带高压 ;中低纬太平洋海区对广西前汛期降水多少的影响亦较明显     

Three-dimensional analysis of ozone and PM<Subscript>2.5</Subscript> distributions obtained by observations of tethered balloon and unmanned aerial vehicle in Shanghai,China

A lightweight unmanned aerial vehicle (UAV) and a tethered balloon platform were jointly used to investigate three-dimensional distributions of ozone and PM_2.5 concentrations within the lower troposphere (1000 m) at a localized coastal area in Shanghai, China. Eight tethered balloon soundings and three UAV flights were conducted on May 25, 2016. Generalized additive models (GAMs) were used to quantitatively describe the relationships between air pollutants and other obtained parameters. Field observations showed that large variations were captured both in the vertical and horizontal distributions of ozone and PM_2.5 concentrations. Significant stratified layers of ozone and PM_2.5 concentrations as well as wind directions were observed throughout the day. Estimated bulk Richardson numbers indicate that the vertical mixing of air masses within the lower troposphere were heavily suppressed throughout the day, leading to much higher concentrations of ozone and PM_2.5 in the planetary boundary layer (PBL). The NO and NO₂ concentrations in the experimental field were much lower than that in the urban area of Shanghai and demonstrated totally different vertical distribution patterns from that of ozone and PM_2.5. This indicates that aged air masses of different sources were transported to the experimental field at different heights. Results derived from the GAMs showed that the aggregate impact of the selected variables for the vertical variations can explain 94.3% of the variance in ozone and 94.5% in PM_2.5. Air temperature, relative humidity and atmospheric pressure had the strongest effects on the variations of ozone and PM_2.5. As for the horizontal variations, the GAMs can explain 56.3% of the variance in ozone and 57.6% in PM_2.5. The strongest effect on ozone was related to air temperature, while PM_2.5 was related to relative humidity. The output of GAMs also implied that fine aerosol particles were in the stage of growth in the experimental field, which is different from ozone (aged air parcels of ozone). Geographical parameters influenced the horizontal variations of ozone and PM_2.5 concentrations by changing underlying surface types. The differences of thermodynamic properties between land and sea resulted in quick changes of PBL height, air temperature and dew point over the coastal area, which was linked to the extent of vertical mixing at different locations. The results of GAMs can be used to analyze the sources and formation mechanisms of ozone and PM_2.5 pollutions at a localized area.     

天文观测科学实践中心技术实现

天文观测科学实践中心是一个以天文观测为核心的网络实践体验中心,以网站的形式向公众提供服务。网站建设使用HTML、CSS、JavaScript和JSP/JaveBean等技术;基于B/S结构实现望远镜远程控制;采用Windows Media技术实现视频发布。建成的网站为用户提供了全新的天文观测实践体验机会,达到了传播天文知识的目的。     

南海夏季风爆发日期和强度的短期气候预测方法研究

利用合成及相关统计方法，研究冬季南海季风指数与850hPa风场、500hPa高度、海表温度、OLR等环境场的相互关系及其影响南海夏季风活动的可能机制。指出冬季南海季风指数及环境场的异常特征可以作为预测南海夏季风活动的前兆信号。在此基础上建立了预测南海夏季风爆发日期和强度的概念模型，1998－2001年的预测试验取得了较好成绩。