三种GNSS模糊度解算方法成功率比较

介绍了在航模糊度求解的模型。在航模型每个历元均需要多估计一组坐标矢量,因而降低模糊度求解的精度。用取整法、引导取整法和整数最小二乘法三种模糊度固定方法,比较了在静态模型和在航模型下整周模糊度求解的成功率和需要的初始化时间,为动态平台的糊度解算提供参考。     

斜井泥浆侵入仿真及其阵列侧向测井响应数值模拟

为了研究斜井泥浆侵入储层的井周岩石物理特征,采用广义曲线坐标系统模拟斜井泥浆侵入特性,进而研究泥浆侵入过程的阵列侧向测井响应.数值仿真表明,采用广义曲线坐标系消除了笛卡儿坐标系统在斜井边界处网格划分的锯齿现象;储层非均质造成泥浆侵入不均匀,储层渗透性越好,泥浆滤液侵入越深;泥浆滤液侵入使得井周地层饱和度、孔隙水矿化度的分布发生变化,进而造成斜井井周岩石电阻率分布剖面复杂变化;泥浆侵入过程中阵列侧向视电阻率变化以及深浅视电阻率的幅度差异,有效反映了斜井泥浆侵入特性;文中采用了基于Marquardt方法的阵列侧向测井四参数反演,有效恢复了斜井储层侵入剖面,得到了原状地层电阻率.斜井泥浆侵入特征及其阵列侧向测井响应模拟分析,有助于正确认识斜井井周岩石物理特征和利用阵列侧向测井进行斜井储层评价.     

自然电位测井数值计算中的激励源分布

为实现自然电位测井的高效正演计算,以定量研究各种因素影响,针对自然电位的激励源-偶电层的分布进行了研究。通过对自然电位产生原因及偶电层对自然电位贡献的分析,认为只有泥岩井壁、侵入带中砂泥岩界面和侵入带与原状地层分界面处的偶电层对自然电位测井值有贡献,而研究砂岩层处的自然电位异常,则仅考虑由侵入带与原状地层界面处的偶电层即可。通过直流电场与静电场的类比,推出了偶极源的面电流密度表达式,并通过计算研究了均匀介质中侵入深度的影响。结果显示,自然电位曲线形状随侵入深度增加而变得平缓,异常幅度减小。     

Invasion of Sargassum muticum in intertidal rockpools: Patterns along the Atlantic Iberian Peninsula

Spatial patterns of non-indigenous species show scale-dependent properties. Sargassum muticum is an invasive macroalga widely distributed along the Atlantic Iberian Peninsula. Despite being quite abundant from Norway to South Portugal, there is little information about its patterns of distribution, particularly at a large spatial scale (i.e. thousands of kilometres). Here, we examined the spatial variation in the invasion success of S. muticum from rockpools at multiple spatial scales using a hierarchical design. In addition, we analysed how the richness of native assemblages was related to its invasion success and how this relationship changed over different scales. Most of the variation in the invasion success was found at the smallest scales of pool and plot. Furthermore, the invasibility of native macroalgal assemblages was related to the native species richness, but causes that determined invasion success could not be separated from the effects provoked by the invader. Results suggest that small-scale (centimetres to metres) processes contribute considerably to the heterogeneity of S. muticum invasion success.     

利用阵列感应测井进行储层渗透率评价

钻井过程中储层受到泥浆侵入影响的程度与储层岩性有着密切关系,其中储层渗透率对侵入深度有着较大影响,因此若可以获知泥浆侵入深度,则有望对储层渗透率进行评估.本文首先建立含泥饼增长的泥浆侵入数值模型,然后建立阵列感应测井数值模型,两者的联合正演模拟显示泥浆侵入对地层的影响可以反映在阵列感应测井响应上,利用阻尼最小二乘法对阵列感应测井响应进行反演可以得到侵入深度.对侵入深度和储层渗透率的关系进行分析发现:在渗透率为1～100mD(1mD=0.987×10~(-3)μm～2)数量级的储层中,渗透率的变化可以在侵入深度上得到反映.以储层和井数据进行二维数值模拟发现:利用阵列感应测井响应反演出来的侵入深度曲线反映了渗透率在地层上的变化趋势,采用解释图版的方法可以对储层各层段的渗透率进行粗略估算.     

一种月尺度单站预报方法研究

利用实况资料,分析了2004年12月20日-22日出现在华北地区的大到暴雪天气的干侵入特征,得出：a）此次降雪主要受中层切变线影响,降雪带与切变线相对应,强降雪中心就出现在切变线交汇的东南到东侧.b）此次降雪过程中,干冷空气主要来自对流层高层,分3路持续入侵,与3条切变线密切对应,而中低层西南和南2支暖湿气流在对流层中层耦合加强,与于冷空气交汇,产生强降雪;强降雪落区位于相对湿度梯度最大处的湿区一侧且有强风辐合的区域.c）随着中层切变线的东移发展,湿不稳定增强并向下延伸,高位涡区向东输送并向下传播,从而触发不稳定能量释放,导致强降雪.d）对流层高层持续的干侵入,使得中低层切变线稳定维持,有利于其前方西南急流的稳定加强和对流性不稳定的持续发展,是导致强降雪持续、增幅的重要原因.     

Congruent,decreasing trends of gentoo penguins and Crozet shags at sub-Antarctic Marion Island suggest food limitation through common environmental forcing

Numbers of gentoo penguins Pygoscelis papua and Crozet shags Phalacrocorax [atriceps] melanogenis breeding annually at Marion Island, one of South Africa's Prince Edward Islands in the South-West Indian Ocean, were strongly correlated over 19 split-years from 1994/1995 to 2012/2013. Both species decreased between the mid-1990s and the mid-2000s, exhibited a partial recovery in the late-2000s and then decreased to their lowest recorded levels in 2012/2013. In both instances, the partial recoveries in the late-2000s were associated with improved breeding success. At a colony of gentoo penguins, breeding success was negatively correlated with the date of arrival of adults to breed. Gentoo penguins and Crozet shags are demersal feeders in inshore waters around Marion Island and there is considerable overlap in the composition of their diets. Therefore, trends in their populations may be driven by food availability, which is likely to be influenced by benthic production around the island. We propose that, in South Africa, and based on the current assessment, the Crozet shag, which elsewhere breeds only at the Crozet Islands, is now Critically Endangered, and the more widely ranging gentoo penguin is Endangered.     

科学钻探的意义及其取得的巨大成就

科学钻探是直接获得深部地质资料的技术手段，深海钻探成果证实了板块构造学说及大陆漂移学说的正确性，并且对地震起因，古气候，气象变化的具有重要意义，陆壳科学钻探发现，在地壳深部７００ｍ处有流体循环，使传统的水热矿床形成理论受到挑战。德国ＫＴＢ陆壳超深科学钻探获得９１００ｍ的温度剖面，使人们对地壳深部的状态有了真实的了解。我第一口超深钻的实施将对了解华北板块和扬子板块接触带的演化及高压变质作用有重要意义     

利用套管井补偿中子时间推移测井识别气层及侵入

根据泥浆侵入气层前后补偿中子测井响应值的变化,设计了套管井内补偿中子时间推移测井试验。结果表明,该方法对识别渗透率在(1～3)×10^-3μm²以上的砂岩气层有明显效果,为鄂尔多斯盆地上古生界低渗透砂岩可疑气层、低阻气层、泥浆污染气层的识别和老井资料复查提供了一种新的手段。     

气象信息系统雷电综合防护技术的探讨

分析了雷电对广西气象台站的气象信息系统造成危害的主要原因,并提出了采用接闪、分流、屏蔽、合理布线、等电位连接、共用接地系统、过电压和过电流电涌防护等进行综合防护的主要措施。