激电中梯测量在莒南金矿找矿中的应用

山东省莒南县东书院金矿是胶南隆起上曾开采过的小型金矿床,金矿石类型为黄铁绢英岩化碎裂岩型,矿床工业类型为中低温热液岩浆型矿床。采用激电中梯测量与钻探资料结合,共圈定金矿体3个。其中,AuⅠ矿体为矿区主体,金品位(2.64~4.28)×10~(-6),平均品位3.46×10~(-6)。     

通海台垂直摆受建筑载荷影响的数值模拟研究

针对通海台垂直摆NS和EW测项自2019-04出现同步趋势转折变化,计算2017~2020年NS和EW测项M₂波潮汐因子。结合监测井等地下介质结构资料,构建通海台沿垂向分层的三维有限元物理模型,定量分析不同岩石参数模型下建筑载荷对通海台NS向及EW向位移影响的差异特征。结果表明：1）2019-04后NS测项N倾变化量达到约2 750 ms,而EW测项E倾变化量达到约580 ms,NS测项趋势变化量显著大于EW测项;2）2017~2020年NS和EW测项M₂波潮汐因子较为稳定,NS测项M₂波潮汐因子在0.7左右波动,EW测项M₂波潮汐因子在0.52左右波动,数据的转折变化未能在潮汐频段引起同步变化;3）位于通海台东北部的医院建筑物载荷在通海台附近产生N向和E向位移加载,与垂直摆NS和EW测项在2019-04后出现的N倾和E倾趋势转折变化较为一致,模拟得到的N向位移量约为E向位移量的3倍。     

航海英语语义探源

在世界航海过程中 ,人们创造了众多语言词汇 ,丰富了人类语言。英语中也有许多与航海有关的词语 ,它们语义的产生有其特定的背景 ,在使用过程中被赋予新的含义 ,至今广泛使用。     

宏观生态环境遥感监测系统总体设计与关键技术

宏观生态环境遥感监测系统是基于环境遥感监测应用技术的软件实现.本文重点介绍了宏观生态环境遥感监测系统的总体结构设计、业务流程设计和核心功能设计,以及模型转换与实现技术、实时投影转换技术与以文件和数据库相结合的数据管理技术、基于XML的数据实时交换技术、产品自动化生产技术等关键技术,并给出了系统的应用实例.系统应用结果表...     

基于VOF方法的海底管道溢油扩散数值模拟研究

在海底输油管道运行过程中,管道渗漏、穿孔及破碎都会导致原油泄漏。对溢油运动的轨迹及其扩散范围作出预报可为溢油事故的处理提供及时、准确的信息,指导应急处理的正确实施。基于工程实际需求,采用有限体积法,结合k-ε紊流模型,建立了海流作用下海底输油管道溢油扩散数值模型。采用VOF方法(volume of fluid method)追踪多相流界面。首先,将数值模拟结果与Fan的实验值及Zheng和Yapa的数值结果进行了对比,验证数值模型的可靠性;其次,研究了不同原油溢出速度与环境水深对不同时刻溢油轨迹、到达海面时间、横向漂移距离与海面扩散范围的影响。研究表明:随原油溢出速度增大,溢油到达海面时间逐渐减小,溢油横向漂移距离与海面扩散范围则逐渐增大;随环境水深增大,溢油到达海面时间逐渐增大,且其变化接近线性分布。     

A multi‐proxy sediment record of late Holocene and recent climate change from a lake near Ny‐Ålesund,Svalbard

Jiang, S., Liu, X., Sun, J., Yuan, L., Sun, L. & Wang, Y. 2011: A multi‐proxy sediment record of late Holocene and recent climate change from a lake near Ny‐Ålesund, Svalbard. Boreas, Vol. 40, pp. 468–480. 10.1111/j.1502‐3885.2010.00198.x. ISSN 0300‐9483 The Arctic constitutes a unique and important environment with a significant role in the dynamics and evolution of the earth system. Arctic lake sediments, which accumulate slowly over time, contain abundant information about the biological communities that lived within the water body, as well as in the surrounding catchment. In this study, we collected a sediment core from Ny‐Ålesund, Svalbard, performed multi‐proxy analyses on sediment pigments, mineral magnetic susceptibility, various sediment quality (i. e. organic matter content, CaCO₃ content, carbon and nitrogen isotope), and diatom composition, and reconstructed the history of ecosystem responses to environmental variations, especially regarding aquatic productivity and lake catchment surface processes. Ny‐Ålesund has undergone distinct ecological and climatic changes. During the Little Ice Age, the cold climate was unfavourable for the growth of lake algae, and therefore the lake primary productivity declined. After about AD 1890 and during the 20th century, the warming climate and reduced ice cover led to rapid lithological change and growth of lake algae, enhanced lake primary productivity, and increased input of nutrients derived from increased chemical weathering into the lake. The lake ecosystem on Ny‐Ålesund has had rapid responses to climatic and environmental changes in the Arctic.     

冰岛北部陆架末次冰消期以来基于硅藻的古环境记录

冰岛北部陆架MD99-2271孔沉积硅藻组合呈现暖水硅藻数量增加、冷水硅藻数量减少和这两类硅藻数量周期性此消彼长的特点,反映了气候在趋暖的背景下,冷暖交替的过程。通过该区温度指数Rw/wc值(暖水硅藻种含量与海冰种及暖水种含量总和的比值)的变化,重建了冰岛北部陆架古海洋环境:Blling-Allerd暖期时,暖水硅藻T.nitzschioides含量较高,表明印明格暖流对研究区的影响较强;随着暖水硅藻含量减少,海冰硅藻F.cylindrus和T.bulbosa的显著增加,此时暖流强度减弱,东格陵兰寒流明显增强,冰岛北部海域进入末次冰消期以来最冷的时期——Younger Dryas冷期。11cal.kaBP左右暖水硅藻T.nitzschioides和T.oestrupii数量急剧升高,表明该海域海洋环境发生了明显变化,并逐步向全新世大暖期过渡,此时冰岛北部陆架海域现代海洋格局基本形成。全新世大暖期时,硅藻群落表现为暖水种的显著增多,海冰、极地及冷水硅藻较之前明显减少,说明冰岛北部海域主要受北大西洋暖流的分支——印明格暖流的影响,海洋环境较温暖;6cal.kaBP之后东格陵兰寒流逐渐增强,冰岛北部海洋环境转冷,全新世大暖期结束。     

The transition from the Younger Dryas to the Preboreal: a case study from the Kattegat, Scandinavia

A two-step climatic warming and oceanographic change during the Younger Dryas/Preboreal transition was registered by diatom, foraminiferal, mollusc, lithologic data and sediment accumulation rates in a high resolution sediment core from the Swedish west coast. An abrupt climatic warming in the surface water of the Kattegat occurred at c . 10 200 BP, resulting in a rapid increase in sea surface water temperatures. The attenuation of meltwater discharge into the Kattegat led to an increase in sea surface salinity. Consequently, the difference in salinity through the water column diminished. This change happened within less than 80 years. The warming of bottom water in the deeper parts of the region took place a few hundred years after the surface water warming. The climatic amelioration was recorded by increased meltwater discharge and a slight increase in abundance of relatively warm diatoms around 10 600 BP at the time of the recession of the Fennoscandian ice sheet. An increase in the number of arctic/subarctic benthic foraminifera shows that the bottom water temperature during this period was still relatively low.     

第一代北斗星座卫星对GALILEO卫星导航定位系统增强性能仿真

第一代北斗星座已经于2003年布置完毕，基本实现了中国本土及周边的导航定位功能。中国作为GALILEO卫星导航定位系统开发的重要参与者，研究北斗系统和GALILEO卫星导航定位系统的集成问题十分必要和迫切。本文，就第一代北斗星座对GALILEO卫星导航定位系统的增强性能进行分析，主要对PDOP指标进行了仿真。给出了国内典型城市的PDOP及其一天内的变化曲线。     

环境植物样品中铜铅锌铁锰的测定

将环境植物样品在４００─５００℃灰化，用硝酸、氢氟酸和高氯酸分解，用盐酸（１＋１）提取，控制２％─３％的盐酸介质，用火焰原子吸收分光光度法测定环境植物样品中的微量铜、铅、锌、铁、锰。该方法简单、快速、可靠。对环境植物标准样品的测定结果理想。