南海北部水合物富集区水道特征对比与成因分析

天然气水合物作为现今乃至未来的重要清洁能源之一,其沉积环境和成矿条件的研究一直是国内外地质学家关注的热点问题,我国2007年、2013年及2015年已先后在神狐、和东沙海域多次成功钻获了天然气水合物实物样品。由此南海北部陆坡成为探讨天然气水合物沉积成因与成矿条件的重要试验区。然而,南海北部陆坡区的神狐、东沙及琼东南三个海域均有不同程度的天然气水合物发现,其各自的水深、沉积特征、气源成因及水合物成矿条件各有特点。本文利用地震沉积学原理,结合不同沉积相和沉积演化和古地貌、海平面变化和构造运动等因素,识别出不同类型的地震相。通过对比南海北部陆坡区域的水道系统的MTDs,认为其发育位置、展布和控制因素的不同影响了沉积展布。其中东沙区域位于近物源的上陆坡,神狐区域位于正常的缓陆坡区域,琼东南区域位于远离物源的海底平原区域。并且,水道系统可以分成侵蚀型,侵蚀-加积型和加积型,MTDs也可以分成头部拉张型,中部过渡型和趾部挤压型。     

渤海夏季环流的高分辨率海浪-潮汐-环流耦合模式研究

The Bohai Sea is a shallow semi-enclosed inner sea with an average depth of 18 m and is located at the west of the northern Yellow Sea. The climatological circulation pattern in summer of the Bohai Sea is studied by using a wave-tide-circulation coupled model. The simulated temperature and the circulation agree with the observation well. The result shows that the circulation pattern of the Bohai Sea is jointly influenced by the tidal residual current, wind and baroclinic current. There exists an obvious density current along the temperature front from the west part of the Liaodong Bay to the offshore area of the Huanghe Estuary. In the Liaodong Bay there exists a clockwise gyre in the area north to the 40°N. While in the area south to the 40°N the circulation shows a two-gyre structure, the flow from the offshore area of the Huanghe Estuary to the Liaodong Bay splits into two branches in the area between 39°N and 40°N. The west branch turns into north-west and forms an anti-clockwise gyre with the south-westward density current off the west of the Liaodong Bay. The east branch turns to the east and forms a clockwise gyre with the flow along the east coast of the Liaodong Bay. The forming mechanism of the circulation is also discussed in this paper.     

基于GPT2w模型化加权平均温度反演可降水量

提出一种基于GPT2w模型化加权平均温度反演大气可降水量的方法,并分析附加系统偏差改正的模型化加权平均温度对可降水量的影响。结果表明,基于GPT2w模型化加权平均温度反演的大气可降水量的精度与基于Bevis公式计算的加权平均温度反演的大气可降水量的精度相当;对GPT2w模型化加权平均温度进行系统偏差改正后,大气可降水量的精度有一定改善,但改善率不到1%。     

Analyses of the long-term salinity variability in the Bohai Sea and the northern Huanghai(Yellow) Sea

Based on the comprehensive collection of the field observed salinity of the Bohai Sea (BHS) and the northern Huanghai Sea (NHS) from the 1950s to the present,the patterns of 10-years-averaged salinity at the different layers in the recent five decades (the 1950s,the 1960s,the 1970s,the 1980s and the 1990s) are obtained by the spatial-temporal interpolation technique with the scrupulous data quality control in this study.Then,by combining the spatial-temporal interpolation technique with successive correction method,the annual distributions of salinity both in the BHS and in the NHS are obtained as well.The data analyses indicate that the overall salinity in the BHS and the NHS increases from the 1960s till the present,with the increase of annual mean salinity of 0.04 psu from the 1950s,and the maximum increase rate of salinity is about 0.14 psu/a in the Bohai Bay.The high salinity tongue extended significantly from the NHS into the BHS.The intensified eastern wind field is related to the western intrusion of the NHS warm current,which probably leads to the moving forward of the high salinity water mass into the BHS.However,it is rather different from the salinity distribution characteristics between the 1950s and the 1960s.The extensive precipitation in the 1960s could lead to an increase in the discharge of the Huanghe River,which might result in the decrease of salinity in the BHS.But the salinity isoline of 32 in the NHS still extended significantly into the BHS in the 1960s.Since the 1980s,the patterns of salinity distribution have changed thoroughly.The salinity in the central area of the BHS was low,while the salinity in the Bohai Bay and the Liaodong Bay was higher than the other regions with its horizontal salinity gradient decreasing in the 1980s.The Empirical Orthogonal Function Analysis (EOF) is also conducted to study the interannual salinity variability of the BHS and the NHS.The correlation coefficient between the time coefficient series of the main mode and the Huanghe River discharge can reach -64.57%.It can be concluded that salinity variation of the BHS and the NHS has strong negative correlation with the Huanghe River discharge.     

1932年以来北京主城区土地利用空间扩张特征与机制分析

基于历史地图、地形图和遥感影像提取1932年以来,北京主城区城市空间扩张,以及建筑密度空间信息。从城市土地利用扩张特征、建筑密度变化特征以及驱动机制三个方面分析北京城市土地利用扩张过程。研究表明:1984年前,北京城市呈现缓慢增长趋势。1984-1992年在市场经济驱动下,北京进入了第一次大规模快速的扩张阶段。1992-2000年间,由于我国出台了最为严格的耕地保护政策,这一时段城市空间扩张有所放缓。2000-2007年受北京城市建设规划、2008年奥运会场馆建设的影响,北京城市进入了有史以来,最快的扩张阶段。北京城市呈现单中心低密度蔓延,1982年前,城市扩张形态以相对较高的建筑密度紧凑扩张模式为主,1982年以来,呈现严重的低密度蔓延态势,特别是2000-2007年城市在5-6环之间"摊大饼"式与"遍地开花"式低密度蔓延问题更为突出。北京城市空间扩张是重大事件与人口、社会经济等因素共同驱动的结果。而且重大事件驱动对于长时间序列城市空间扩张作用更为突出。     

潮流对老虎石海滩养护工程响应的数值预测

为研究老虎石海滩养护工程对老虎石浴场及周围岬湾的水动力环境的影响,利用MIKE 21建立工程区海域二维潮流数学模型,通过实测流速、流向对模型进行验证,将验证后模型参数运用到工程设计方案下潮流场的模拟,比较分析工程前后水动力环境的变化。潮流场比较结果表明,修建潜坝会使得工程及其附近的潮流场发生小幅变化,但对该海域整体的潮流动力环境影响甚微。工程后老虎石海域的潮流动力仍然很弱,对保存海滩上人工养护的泥沙是非常有利的。     

专题地图制图决策系统规则库的设计

在分析已有的专题地图制图决策支持系统的有关理论的基础上,总结相关制图知识,提出规则库设计的方法并设计部分规则实例,最后对规则库如何映射到关系数据库做了一些探讨,并建立了模型。     

若尔盖与西秦岭地震反射岩石圈结构和盆山耦合

松潘地块北缘的若尔盖盆地与西秦岭造山带相接触,构成青藏高原东北缘典型的新生代盆山构造.其岩石圈结构与深部构造关系,记录了青藏高原东北缘板块碰撞的深部过程,同时又关联着若尔盖盆地油气远景的评价.2004年秋冬季,我们完成了第一条跨越若尔盖盆地和西秦岭造山带的深地震反射剖面.整个剖面全长254 km,分5段完成,其中第2段剖面（简称SP04_2）横过盆山结合部位.SP04_2剖面首次揭示若尔盖盆地－西秦岭造山带盆山结合部位的岩石圈结构,发现了若尔盖盆地和西秦岭造山带下地壳均以北倾为主的强反射特征,提供出若尔盖盆地下地壳整体向西秦岭造山带俯冲的地震学证据,揭示了若尔盖盆地和西秦岭造山带在挤压构造体系下形成的深部构造关系.而近于平的Moho反射特征又反映出两者在造山后期经历了强烈的伸展作用.     

一种基于OpenMP的高效GPS卫星钟差实时估计方法

提出基于单观测值的Kalman滤波快速计算方法,并引入共享存储并行编程（OpenMP）技术实现协方差快速更新,从而实现非差GPS卫星钟差的快速实时计算。均匀选取55个IGS参考站,计算2017-03-20~03-30采样率为60 s的卫星钟差。与IGS事后30 s钟差相比,两者具有很好的一致性,RMS互差优于0.5 ns。选取未参与钟差解算的10个IGS参考站进行精密单点定位,结果表明,实时静态PPP水平方向精度优于2 cm,高程方向精度为2~4 cm;实时动态PPP水平方向精度为2～4 cm,高程方向精度为4～6 cm,能够满足实时PPP的精度要求。该方法在主频1.2 GHz服务器上8线程并行模式下单历元耗时4 s,相比串行模式效率提升1/3。     

The System Analysis and Reliability Evaluation of Rock Slopes

The principal of preferred plane analysis is a new research view and model of rock slope engineering geology. It advocates that the rock slope stability, boundary conditions and failure model are controlled by preferred planes. Therefore, the problem of slope stability evaluation can be converted into the search for preferred planes and determination of preferred separating bodies. The organic combination of the deterministic model and the indeterministic model can be realized by applying the systems engineering principle and the research model and method of reliability analysis in the quantitative evaluation and prediction of rock slope stability. Finally, the paper presents the case studies of slopes of the Yangtze Gorge Project and the Ma'anshan openpit mine.