Climate change feedbacks on future oceanic acidification   总被引：1，自引：0，他引：1  

BEN I. MCNEIL  RICHARD J. MATEAR 《Tellus. Series B, Chemical and physical meteorology》2007,59(2):191-198

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平面四孔六边形格网系统编码运算   总被引：2，自引：2，他引：0  

王蕊  贲进  杜灵瑀  周建彬  李祝鑫 《测绘学报》2018,47(7):1018-1025

全球离散格网系统是支持多源地球空间信息融合处理的新型数据模型。六边形格网系统具有优良的几何属性,相关研究已引起学术界的关注,单元层次关系描述与编码方案设计是其研究难点。本文根据平面四孔六边形格网系统结构特点,设计“格点四叉树”层次编码结构,定义编码运算并归纳运算规律,据此实现二维直角坐标与单元编码的相互转换。与同类成果相比,格点四叉树从原理上克服了奇（偶）分层编码、单元中心与顶点混合编码导致的诸多缺陷,且编码运算规律简明,易于算法实现。试验结果表明,格点四叉树编码加法运算的效率约是PYXIS的6倍、HQBS的5倍;直角坐标转换到编码的效率约为HQBS的5倍,编码转换到直角坐标的效率约为HQBS的3倍。  相似文献   

Palaeo‐climate controlled diagenesis of the Westphalian C & D fluvial sandstones in the Campine Basin (north‐east Belgium)     

PIETER BERTIER  RUDY SWENNEN  DAVID LAGROU  BEN LAENEN  RAYMOND KEMPS 《Sedimentology》2008,55(5):1375-1417

The Westphalian C and D fluvial sandstones in the Campine Basin (north‐east Belgium) are potential reservoirs for the sequestration of CO₂ and interesting analogues of the hydrocarbon reservoirs in the Southern North Sea. Although these sandstones were deposited in a relatively short period of time, their reservoir properties and mineralogical compositions are very different. A petrographic study complemented with stable isotope analyses, fluid inclusion microthermometry and X‐ray diffraction analyses of the clay fractions of the sandstones, which were sampled from deep boreholes (>1000 m) in the Campine Basin, revealed that these differences are related mainly to the climate at the time of deposition. The most important eogenetic processes affecting the Westphalian sandstones were the generation of a pseudomatrix by physical compaction of Al‐silicates and lithic fragments that were strongly altered by extensive meteoric leaching, kaolinitization of unstable silicates and precipitation of siderite. These processes had a detrimental influence on the reservoir properties of Westphalian C sandstones, but their impact on the Westphalian D sandstones was minimal. The difference is assumed to be related to the climate at the time of deposition, which changed from tropical humid in the Westphalian C to semi‐arid/arid during the Late Westphalian D. Both the Westphalian C and D sandstones were affected by similar mesogenetic processes. Mesogenetic quartz cementation resulted from chemical compaction and illitization of kaolinite, K‐feldspar and smectitic clays. Illitization of kaolinite was controlled by the available quantities of co‐existing kaolinite and K‐feldspar and mainly affected the Westphalian D sandstones. Illitization of K‐feldspar was controlled by the K‐feldspar content. It had a much larger impact on the reservoir properties of the Westphalian D as, in these sandstones, K‐feldspar was less affected by eogenetic alteration. The illitization of smectitic clays resulted in illite, quartz and ankerite cementation in both reservoirs. This process had a more important impact on the Westphalian C reservoir, since cementation here also resulted from smectite to illite conversion in the interbedded and underlying shales. The effect of mesogenetic alterations on the reservoir properties was much less drastic than the impact of eodiagenesis. Mesogenetic alterations do exert a significant control on the properties of the Westphalian D. The vast impact of eodiagenesis on the Westphalian C sandstones made them less susceptible to mesogenetic alteration. The effect of telogenetic processes on the porosity and permeability of the Westphalian sandstones was small and restricted to the top reservoir intervals that directly underlie the Cimmerian Unconformity. No significant telogenetic alterations related to the Variscan Unconformity were observed.  相似文献   

不同模式扰动方案在风暴尺度集合预报中的对比试验研究   总被引：2，自引：0，他引：2  

刘畅  闵锦忠  冯宇轩  贲海荣  王世璋 《气象学报》2018,76(4):605-619

由于适用于中长期集合预报的模式扰动技术在风暴尺度集合预报系统中的影响并不明确,为探究不同模式扰动方案在风暴尺度集合预报中的效果,基于WRF模式设计了3组模式扰动方案:多物理扰动（MP）方案、随机物理倾向扰动（Stochastically Perturbed Parameterization Tendencies,SPPT）方案以及由MP方案与SPPT方案组合构建的一种新混合扰动（SPMP）方案。对2013年7月5—6日发生在江淮流域的一次强对流天气过程进行了数值模拟。结果表明:MP方案在积分前期的降水概率评分较高,对高层大气的扰动效果更为合理;SPPT方案主要作用于积分中后期,对大气低层及近地面的扰动效果最为理想,尤其是对于地面水汽场的模拟;SPMP方案能显著提高大气中高层各预报变量的离散度,降低均方根误差,提升集合成员的可信度,有效弥补降水预报评分在单独使用MP方案和SPPT方案不同积分时段的不足。在扰动水平传播方向上,SPMP方案的扰动形态主要受MP方案主导;垂直方向上,SPMP方案在低层的扰动形态与SPPT方案一致,在高层受MP方案控制。波谱能量分析表明3组方案的扰动能量随积分时间均有向大尺度传播的趋势,SPMP方案能有效补偿两种方案能量在各尺度的耗散。   相似文献   

基于skyline的城市地下三维管线建立研究     

张玉红  任东风  贲忠奇  李琳  张新月 《测绘工程》2016,25(2):71-76

传统二维管线系统难以直观地反映各管线之间的立体空间位置关系。旧管线更新、新管线规划、管线设计施工、土建工程的破土动工等都需要准确掌握地下管线的现状信息,如果盲目开挖就可能引起自来水管爆裂、煤气泄露、停电、通信信号中断等事故。以地下管线为研究对象,以skyline为平台,C#为开发语言建立城市三维管网系统,在地下错综复杂的条件下,展现各管线之间以及管线与周边地物之间的空间位置关系,实现管线的查询和分析功能,有利于决策者做出更好的决定。  相似文献   

SH波在多个浅埋圆形孔洞附近的多个含孔半圆形凸起地形处的散射     

李敏  冯云亭  贲伟 《地震工程与工程振动》2008,28(4)

为研究地震时局部地形与附近浅埋结构的作用,文中使用"分区"思想,复变函数法和移动坐标的方法,建立多个浅埋圆形孔洞附近的多个含孔半圆形凸起地形对SH波的散射的数学模型,并通过算例给出含孔半圆形凸起地形的地表位移,讨论了浅埋圆孔的深度、含孔半圆形凸起间距及浅埋圆孔间距对地表位移影响。  相似文献   

The (Post)colonial Landscape of Cathedral Square: Urban Redevelopment and Representation in the “Cathedral City”1     

BEN McBRIDE 《New Zealand geographer》1999,55(1):3-11

Recent urban redevelopments in central Christchurch draw on the city's colonial origins to develop a market for tourist consumption. This article introduces literature from both the ‘landscape school’ of cultural geography and (post)colonialism, combined with the grounded theory research method, to examine representation in the changing landscape of Cathedral Square. It finds that redevelopment plans, which articulate the traditional colonial representation of the city, are dominated by market and consumption activities such that participation in the central city has become contingent on the ability to consume.  相似文献   

时间域航空电磁系统姿态变化影响研究          下载免费PDF全文

贲放  黄威  吴珊  孟庆敏  刘云鹤  廖桂香  西永在 《地球物理学报》2018,61(7):3074-3085

航空电磁系统的收发线圈受外界因素影响会发生姿态变化,使测量结果产生一定偏差.传统的数据处理方法考虑姿态变化情况单一,且主要以频率域系统为主,而目前复杂姿态变化对时间域航空电磁系统全时响应的影响尚未有系统研究.本文在前人研究基础上拓宽思路,不仅研究姿态的角度变化,同时改进前人计算方法,研究线圈发生位置变化的影响,并将线圈与大地的耦合感应效应考虑在内.本文通过定义姿态变化前后两种坐标系,确定姿态变化的角度和旋转矩阵,并将一维层状半解析解与姿态角度变化和位置变化进行整合,推导出收发线圈任意姿态变化的表达式.以直升机吊舱分离装置为例,对时间域航空电磁系统收发线圈任意姿态变化进行细致分析.基于重叠偶极子的假设,给出可应用于实际工作中的姿态校正因子,以提高实测数据的处理效率与精度.  相似文献   

球面等积六边形离散网格的生成算法及变形分析   总被引：10，自引：4，他引：6  

贲进  童晓冲  张永生  张衡 《地理与地理信息科学》2006,22(1):7-11

球面离散网格模型是管理海量数据的有效途径,如何构建球面网格是这类模型的基础问题。利用施奈德等积投影建立平面与球面的对应关系,并在此基础上设计了3种球面等积六边形离散网格的生成算法。结合实验分析这3种网格的最大/最小边长比和单元周长均方差两项指标,结果表明全部网格的指标均收敛,其中C-Ⅰ网格的性质最优。  相似文献   

基于GIS的城镇土地分等定级研究   总被引：5，自引：1，他引：4  

李红玲  谭海樵  贲旭东 《测绘与空间地理信息》2005,28(5):46-49

基于GIS空间技术,采用Delphy法进行评价因素、因子的选取及权重的确定,运用空间分析模型确定土地分等定级单元,并加权得到各单元的总分值,最后采用总分值频率直方图法进行土地等级的综合评定.  相似文献