应用瑞雷波等方法对公路质量进行无损检测

针对水泥混凝土公路质量检测的内容和目前常规检验方法的不足,本文叙述了采用瑞雷波法、超声波法和音频共振法的结合,测试路基路面强度和路面厚度的基本原理,并对几个工程测试实例进行了分析。     

MapInfo中的坐标系与地图数据的转换

本文就MapInfo系统中地图投影坐标系和有关GIS数据的转换作了一些有益的探讨，并就目前比较多的各种地图数据转换成经纬度投影坐标(例如：WGS84投影坐标)进行了尝试和研究，以供各位读者参考，也希望相关方面的专业人士能给予纠正及补充。     

Holocene Yellow Silt Layers and the Paleoclimate Event of 8200 a B.P. in Lop Nur, Xinjiang, NW China

Many yellow silt layers have been identified in the Holocene sediments in the last lake of Lop Nur (playa), Xinjiang, northwestern China. Statistics of drill-hole cores have revealed more than one hundred layers, which exhibit regularity in time sequence. Study has further verified that these yellow silt layers were deposited through eolian processes. The time-frequency distribution diagram shows an obvious peak occurring at about 8200 a B.P., which is consistent with the dry, windy and cold climate event occurring at 8200 a in other places around the world. Therefore, this event is regarded as a response to the global climate change.     

地质矿产部区域重力调查成果与展望

区域重力调查是一项基础地球物理调查工作。它的成果可用于研究地质构造、资源勘探、环境调查，地震灾害、地球形状、地球物理理论等方面。它象征着一个国家科学技术发展水平，特别是地学方面的水平。地矿部研究了国内外重力勘查情况，于１９７８年提出并组织、实施了全国范围的区域重力调查。通过十多年的工作，取得了丰硕成果。本文就地矿部区域重力调查成果与展望，予以论述。     

高压合成的Mg-Fe-Mn-Al榴石系列的研究

对高压下合成的12个Mg-Fe-Mn-Al榴石系列矿物样品进行X射线衍射和红外光谱研究,获得了该系列矿物晶胞参数、红外吸收带频率与化学成分关系的系统资料。并根据人工合成石榴子石的压力和天然石榴子石的产状,讨论了当研究具有复杂成分的天然石榴子石时,应将Al离子优先与Mg、Fe离子组成端元组分,而Cr离子优先与Mn、Ca离子结合。     

Multiple Dolomitization and Fluid Flow Events in the Precambrian Dengying Formation of Sichuan Basin,Southwestern China

The Precambrian Dengying Formation is a set of large-scale, extensively dolomitized, carbonate reservoirs occurring within the Sichuan Basin. Petrographic and geochemical studies reveal dolomitization was a direct result of precipitation by chemically distinct fluids occurring at different times and at different intensities. Based on this evidence, dolomitization and multiple fluid flow events are analyzed, and three types of fluid evolution models are proposed. Results of analysis show that Precambrian Dengying Formation carbonates were deposited in a restricted peritidal environment(630–542 Ma). A high temperature and high Mg~(2+) concentration seawater was a direct result of dolomitization for the micrite matrix, and for fibrous aragonite in primary pores. Geochemical evidence shows low δ~(18)O values of micritic dolomite varying from-1.29‰ to-4.52‰ PDB, abundant light rare earth elements(REEs), and low dolomite order degrees. Microbes and meteoric water significantly altered dolomite original chemical signatures, resulting in algal micritic dolomite and the fine-grained, granular, dolosparite dolomite having very negative δ~(18)O values. Finely crystalline cement dolomite(536.3–280 Ma) and coarsely crystalline cement dolomite have a higher crystallization degree and higher order degree. The diagenetic sequence and fluid inclusion evidence imply a linear correlation between their burial depth and homogenization temperatures, which closely resemble the temperature of generated hydrocarbon. Compared with finely crystalline dolomite, precipitation of coarsely crystalline dolomite was more affected by restricted basinal fluids. In addition, there is a trend toward a more negative δ~(18)O value, higher salinity, higher Fe and Mn concentrations, REE-rich. Two periods of hydrothermal fluids are identified, as the exceptionally high temperatures as opposed to the temperatures of burial history, in addition to the presence of high salinity fluid inclusions. The early hydrothermal fluid flow event was characterized by hot magnesium-and silicon-rich fluids, as demonstrated by the recrystallized matrix dolomite that is intimately associated with flint, opal, and microcrystalline quartz in intergranular or intercrystalline pores. This event was likely the result of a seafloor hydrothermal chimney eruption during Episode I of the Tongwan Movement(536.3±5.5 Ma). In contrast, later hydrothermal fluids, which caused precipitation of saddle dolomite, were characterized by high salinity(15–16.05 wt% NaCl equivalent) and homogenization temperatures(250 to 265°C), δ~(18)O values that were more enriched, and REE signatures. Geochemical data and the paragenetic sequence indicate that this hydrothermal fluid was related to extensive Permian large igneous province activity(360–280 Ma). This study demonstrates the presence of complicated dolomitization processes occurring during various paleoclimates, tectonic cycles, and basinal fluids flow; results are a useful reference for these dolomitized Precambrian carbonates reservoirs.     

新疆三塘湖盆地马朗凹陷石炭系原油形成过程及勘探意义

新疆三塘湖盆地马朗凹陷牛圈湖构造带马25井石炭系火山岩储层中发现了原油和固体沥青共存,通过储层多级分离抽提和原油地球化学分析,并对这些原油(或固体沥青)的形成过程与其勘探意义进行了研究,结果表明这些原油和沥青可能主要来自下石炭统烃源岩,具有较低姥植比和伽玛蜡烷含量、高丰度三环萜、高Ts/Tm比值和重族组分碳同位素(δ13C-28.0‰)特征;现今油藏原油富含生物降解标志物(25-降藿烷),同时却无明显其它生物降解特征(正构烷烃、甾藿烷等保存完整),反映多期充注特征,即二叠纪中晚期成藏后遭受生物降解,白垩纪后期又再次充注形成;下石炭系有效烃源岩的存在预示着本区具有深部下石炭统源岩贡献的油气藏勘探前景。     

Analysis of influencing factors of clay particle diffusion in electric double layer北大核心CSCD

双电层结构对研究黏土力学特性、冻土水分迁移等具有重要意义。为了探究不同影响因素对黏土颗粒扩散双电层电势分布的影响,借鉴Gouy-Chapman-Stern双电层理论,基于Nernst-Planck方程和Poisson-Boltzmann方程,利用数值软件COMSOL定量分析了温度、浓度、颗粒尺寸、颗粒形状以及溶液相对介电常数对扩散双电层电势分布的影响规律。研究表明：温度对电势分布的影响不明显,但随着温度以及Stern层厚度增加,黏土颗粒表面电势和Stern电势均增加;而随着溶液浓度以及相对介电常数减小,表面电势值增加;在矿物成分、表面电荷密度以及颗粒形状确定的情况下,尺寸对于扩散双电层电势分布的影响不显著;但颗粒的不规则形状对电势分布的影响较为明显,当颗粒形状存在夹角时,夹角处的表面电势远大于其他位置,且夹角越小,夹角处表面电势值越大。     

罗布泊第四纪湖盆物源与盆地构造演化特征：来自LDK01孔碎屑锆石U-Pb年龄证据

为揭示罗布泊盐湖第四系潜在物源区及凹陷阶段性演化过程,本文对罗布泊第一口钾盐科探深钻LDK01孔更新统不同深度样品进行碎屑锆石U-Pb微区定年分析。Th/U比值显示,钻孔碎屑锆石类型主要为岩浆锆石,少量为变质成因锆石。锆石年龄主要集中在209~240Ma、265~304Ma、320~385Ma、406~446Ma、705~880Ma及2376~2405Ma几个区间。综合分析潜在物源区的岩石属性和年龄构成,初步认为罗布泊地区前寒武纪年龄来自北部山前库鲁克塔格地区,加里东期碎屑锆石可能来源于阿尔金造山带和(或)南天山构造带。276Ma的峰值记录了塔里木盆地二叠纪大火成岩省事件,南天山最有可能为主导物源区。印支期和新生代碎屑锆石年龄暗示了北山地块和东天山,甚至较远的帕米尔-西昆仑山等地可能也提供了物源。凹陷周缘富钾岩体广泛出露,经风化、淋滤搬运至罗布泊,为凹陷第四纪成钾提供了有利的物质来源。塔里木盆地内部流域带来的碎屑组分是主要的物质来源,近源地区造山带岩体提供的物源有限。碎屑锆石年龄纵向变化特征显示,罗布泊北部地区在中更新世发生一次明显的构造抬升,可能是导致罗北凹地形成的重要原因。     

高速铁路对中国区域经济格局均衡性的影响

交通运输是影响区域经济格局均衡性的一个重要因素。构建的基于交通线路影响的区域经济格局演变模型证明,交通线路对不同区域经济增长的影响存在差异,从而引起区域经济格局均衡性发生相应的改变。分析表明,2020年高速铁路网建成后,受其影响,全国及东部、中部、西部地区的区域经济格局将向非均衡状态发展;大长三角和泛珠三角地区的区域经济格局均衡性将增强;东北及环渤海地区的区域经济格局均衡性基本保持不变。因此,国家可考虑对高速铁路网空间布局规划进行适当的调整,减小其对全国及东部、中部和西部地区的区域经济协调发展的不利影响,增强其对东北、环渤海地区经济协调发展的积极作用。同时,还可考虑规划建设以高速铁路为空间组织架构的经济区,在目前四大区域发展战略基础上形成区域经济协调发展的新格局。