应用木质素示踪楚科奇海表层沉积物中有机碳的来源和降解程度

埋藏在海洋沉积物中的有机碳是大气二氧化碳的净汇,而埋藏过程主要发生在陆架区。北冰洋拥有全球最大的陆架,接收大量来自河流和沿岸侵蚀输运的陆源有机碳,楚科奇海作为北冰洋的边缘海,是有机碳埋藏的重要海区之一。本研究选用楚科奇海和海台的表层沉积物（陆架区33~82.69 m,陆坡区164.63~3 763 m）,通过木质素,结合粒度、比表面积、有机碳百分含量（OC%）、有机碳稳定同位素（δ13C）等指标来示踪楚科奇海沉积物有机碳的来源和降解程度。结果表明,有机碳载荷从陆架到陆坡有明显的降低趋势;δ13C的范围指示有机碳可能来自苔藓、草本裸子植被、浮游植物和冰藻等;木质素丁香基酚（S）与香草基酚（V）的比值（S/V）和肉桂基酚（C）与香草基酚（V）的比值（C/V）表明裸子植物的草本组织贡献了更多的陆源有机碳;此外,较高含量的C9DA二酸（干酪根氧化产物）表明干酪根也可能是楚科奇海表层沉积物中有机质来源的重要组成。指示降解的参数[（Ad/Al） s、（Ad/Al） v、（Ad/Al） p、3,5-Bd/V]在陆架和陆坡沉积物中的差异表明陆坡沉积物中有机质的降解过程受到水动力分选以及原位降解等因素的影响更为明显。     

多波束UNB数据文件格式的解析及应用

对多波束UNB数据文件格式进行了解析,阐述了UNB文件格式的内部记录结构,即系统参数记录、声速剖面记录、导航记录和测深记录等。设计了能读取UNB文件所包含的船参数、声速剖面、导航信息和多波束各波束信息的原始多波束数据格式读取模,经与CTD实测声速剖面得到的数据进行对比可知,读取的结果准确、可靠。     

甘肃平凉市的旅游气候舒适度评价

利用甘肃省平凉市7县（区）气象观测站1961—2010年50a气象资料,采用温湿指数、风寒指数和着衣指数指标,对平凉7县（区）各月旅游气候舒适度进行了分析。结果显示,平凉市7县（区）旅游气候最舒适期为每年的5～9月,较舒适期在4月和10月,不舒适期静宁、庄浪、华亭为4个月,主要分布在冬季及秋末（1～2月、11—12月）,崆峒、灵台、泾川、崇信为3个月,分布在冬季的1、2、12月。由于地理位置和海拔高度的不同,平凉旅游气候在东西南北方向上有着一定差异,在东西方向上差异尤其明显,一年中舒适度年指数自西向东呈升高趋势。     

GF-5 DPC数据的云检测方法研究

高分五号（GF-5）号卫星所搭载的大气多角度偏振探测仪（DPC）能够对地球进行多波段,多角度和的连续观测,其数据对研究全球大气云分布及云辐射反馈作用提供新的视角。本文通法国多角度偏振载荷POLDER（POLarization and Directionality of the Earth’s Reflectances）云检测算法为参考,结合DPC多波段反射率、偏振反射率、表观压强等信息开发了一个适用于DPC的云检测算法。算法主要分为3个部分：首先是阈值方法对云像元进行检测,同时引入表观压强对不同高度的云（如卷云、层积云等）进行进一步的条件约束,然后利用865 nm波段偏振反射率对海表反射的太阳耀斑区进行识别,修正了反射率阈值识别云像元时受到的太阳耀斑干扰。为了验证算法的准确性,利用2018-10-01的MODIS的MOD06云掩码产品与本文云检测算法结果进行定性分析,从目视判读结果可以看出本文云检测结果与MOD06产品具有较高的吻合度;随后又利用2018-10-01—04的CALIPSO-VFM数据与本文云检测结果和MYDO6云掩码产品进行定量分析,分别计算了中低纬度区域（60°N—60°S）的云/晴空像元命中率和云/晴空像元错误预报率,计算结果显示算法云命中率均值相较MYD06云掩码产品高出13.501%的前提下云错误预报率仅高出3.561%,可表明该算法在全球中低纬度区域有着良好的云检测效果。本文提出的云检测算法,可为后续DPC的云参数、水汽、气溶胶等研究提供重要数据支撑。     

Review of the Research of the 2011 MW9.0 Tohoku-Oki Earthquake

On March 11, 2011, a M_W9.0 earthquake occurred in the Japan Trench, causing tremendous casualties, and attracting extensive concern. Based on the results of related research, this paper analyzes the observations, phenomena and understandings of the earthquake from varied aspects, and obtains four main conclusions. (1) The earthquake, occurring in the subduction zone in the Japan Trench located in the northwest boundary of the pacific plate has two zones of concentrated coseismic slip at different depths, and the slip in the deep zone is relatively small. Though there have been many M7.0 historical earthquakes, slips in the shallow zone are large, but there have been few historical strong earthquakes. (2) Constrained by GPS data, the study of fault movement shows that fault movement in the Japan Trench has a background of widely distributed stability and locking (the locking zone is equivalent that of coseismic rupture zone). Perturbation occurred after the 2008 M8.0 Hokkaido earthquake, several M7.0 events had after slips larger than the coseismic slip, and two obvious slow slip events were recorded in 2008 and 2011. Eventually, the March 9, 2011 M7.0 foreshock and the March 11, 2011 M_W9.0 mainshock occurred. The pre-earthquake changing of the fault movement in the Japan Trench is quite clear. (3) Traditional precursory observation show no obvious anomaly, possibly due to monitoring reason. Anomaly before earthquake consists of high stress state in focal zone reflected by some seismic activity parameters, short period anomaly in regional ground motion, etc. (4) The analysis of physical property in focal zone aroused more scientific issues, for example, is there obvious difference between physical property in focal zone and its vicinity? Does frictional property of fault determine seismogenic ability and rupture process? Whether pre-earthquake fault movement include pre-slips? Could deep fluid affect fault movement in focal zone? Experience is the best teacher, and authors hope this paper could be a modest spur to induce others in basic research in earthquake forecast and prediction.     

Seismic Response Analysis of Portal Water Injection Sheet Pile

1 Introduction The portal water injection sheet pile (PWISP) is a new type of space-retaining structure developed for the Shengli Oil Company. It was developed based on the combination of the practical needs of hydraulic projects and the technical principle of jet-drilling in the oil indus-try and has been successfully used for disaster prevention and hydraulic projects (Guo, 2002, 2005). It consists of the double-row parallel-prefabricated reinforced concrete sheet piles and the connectio…     

滨州市海域海冰的时空分布和冰级特征

文章根据2005—2017年滨州市海域冬季各类海冰监测数据资料,对冰日、冰期、冰型、冰厚、浮冰密集度和结冰范围等冰情要素进行分析,总结海冰的时空分布和冰级特征,为进一步开展相关海域的海冰灾害研究和防灾减灾工作提供必要的参考。研究表明,滨州市海域的总冰期一般为60~80d,其中严重冰期约为25d,河口和浅滩等近岸海域冰情较重;冰型、冰厚和结冰范围等在不同冰期和冰级具有不同特点,对海上设施和海上活动造成不同程度的影响。     

The Late Quaternary Coastal Geo-Environment Evolution and Modern Process of Bohai Bay, China

<正>Paleoenvironmental reconstruction is fundamental to understand the modern environmental changes and to predict future environment,which is especially critical to understand the evolution of land and sea during geological periods.However,the basic geological research on China’s muddy coastal zone is not enough to provide     

主TIN模式下面向拓扑的三维地质块体构建方法

当前普遍采用主TIN模式对层状地质体进行三维结构建模,然而在地质块体的构建方面还有所欠缺。考虑到由于尖灭、出露等现象引起的各地质块体间空间位置关系的复杂性,根据主TIN建模的特点,处理完地层相交与高程调整之后,通过对地层面中某个区域内的三角网与上下地层中对应区域内的三角网的重叠次数的不同,设置子面类型标记,从而分离出一个地层面中不同类型的子面。依据子面的类型可以快速建立地质块体与被引用的各子面之间的对应关系,最终自动分离出地层中的各个地质块体,并保证相邻块体在邻接处有唯一的公共子面,由此可建立各地质块体间的空间拓扑关系。     

行波效应对铁路大跨长联连续刚构桥地震反应的影响

介绍了多点激励下结构运动方程的求解方法。以某大跨度铁路连续刚构桥为工程背景,用有限元软件MIDAS建立了结构有限元模型,选取地震波波速为主要参数,对某铁路大跨长联连续刚构桥进行了考虑行波效应的时程反应分析,并与一致激励下的结果进行了对比。结果表明:考虑行波效应后,跨中截面的弯矩增大,而墩底截面的弯矩减小。在梁部结构的抗震设计中应考虑行波效应的影响。