Sedimentary characteristics and depositional model of a Paleocene-Eocene salt lake in the Jiangling Depression,China

We studied the sedimentary characteristics of a Paleocene-Eocene salt lake in the Jiangling Depression through field core observation,thin section identification,scanning electron microscopy,and X-ray diffraction analysis.On the basis of sedimentary characteristics we have summarized the petrological and mineralogical characteristics of the salt lake and proposed 9 types of grade IV salt rhythms.The deposition shows a desalting to salting order of halite-argillaceous-mudstone-mud dolostonemud anhydrock-glauberite-halite.The relationship among grade IV rhythms,water salinity and climate fluctuations was analyzed.Based on the analysis of the relationship between boron content and mudstone color and by combining the mineralogy and sedimentary environment characteristics,we propose that the early and late Paleocene Shashi Formation in the Jiangling Depression was a paleolacustrine depositional environment with a high salt content,which is a representation of the shallow water salt lake depositional model.The middle Paleocene Shashi Formation and the early Eocene Xingouzui Formation were salt and brackish sedimentary environments with low salt content in a deep paleolake,which represents a deep salt lake depositional model.     

Chemical characteristics of wet precipitation at an urban site of Guangzhou, South China

The pH variation and chemical characteristics of rainwater were investigated from January 2006 to December 2006 at an urban site of Guangzhou, South China. The rainwater was typically acidic with a volume-weighted mean pH value of 4.49, which ranged from 3.52 to 6.28. The volume-weighted mean equivalent concentration of components followed the order: SO₄²⁻ > Ca²⁺ > Cl⁻ > NH₄⁺ > Na⁺ > NO₃⁻ > K⁺ > Mg²⁺ > F⁻, indicating that SO₄²⁻, Cl⁻ and NO₃⁻ were the main anions, while Ca²⁺ and NH₄⁺, were the main cations. Ca²⁺ and NH₄⁺ were major neutralization constituents of the precipitation. Furthermore, correlation analysis and principal component analysis method were performed to identify possible common sources of major ions. Sources of the major ions were assessed based on enrichment factor method.     

我国渔港沉积物的重金属污染及潜在生态风险评价

分析了青岛、宁波、舟山、厦门、深圳、珠海、澳门、茂名和三亚共9个渔港（包括综合港口区）表层沉积物中的Cd、Cu、Pb、Zn、Co和Ni等典型重金属元素的含量,探讨了其可能的来源。采用沉积物质量基准法和Hakanson潜在生态风险指数法,评价了各渔港重金属的污染状况和潜在生态风险。结果表明：（1）渔港沉积物中重金属Cu、Zn、Pb和Cd的富集较为严重,位于珠江三角洲的渔港重金属含量显著高于其他渔港,尤其是Cu和Zn,最高含量分别达到1249mg／kg和664mg／kg,而Cd和Pb的污染也不容忽视;（2）珠三角渔港具“高”或“中等”潜在重金属生态风险,其中Cu和Cd具有高的潜在生态风险,其他渔港均属低生态风险,渔港总的潜在生态风险由高至低顺序为：澳门〉深圳〉珠海〉茂名〉三亚〉厦门〉青岛〉宁波〉舟山;（3）渔港沉积物中重金属主要来自工业废水、生活污水、污灌土壤以及大气沉降的污染和渔船防护漆的使用。而船体防护漆中Cu／氧化亚铜的大量使用是渔港中Cu污染的主要来源。     

Minerals mapping of the lunar surface with Clementine UVVIS/NIR data based on spectra unmixing method and Hapke model

The distribution of minerals on the lunar surface is information which could contribute to studying lunar origin and evolution. In this paper, the distribution of clinopyroxene, orthopyroxene, olivine, ilmenite, and plagioclase on the lunar surface has been mapped based on Hapke radiative transfer model and linear unmixing of spectra with Clementine UVVIS/NIR data. The results have been validated on the basis of minerals modal abundance data of the Apollo samples, and problems in the minerals abundance mapping have been analyzed. The validation based on analysis data of Apollo samples indicates that plagioclase mapped in this paper represents the total abundance of plagioclase and agglutinitic glass. The minerals mapping results show that the lunar surface is mainly composed of pyroxene, plagioclase, agglutinitic glass, and ilmenite. Basalt in the lunar mare is mainly composed of clinopyroxene and ilmenite, and lunar highland is mainly composed of plagioclase and agglutinitic glass. Orthopyroxene is mainly distributed on the north of Mare Imbrium, on the south of Maria and Aitken Basin. According to our results, there is probably no large area of olivine distribution on the lunar surface which is different from earlier published results. Therefore, emphasis should be put on the olivine distribution in the minerals mapping using hyperspectral data such as M³ of Chandrayaan-1 and IIM of ChangE-1.     

越南金瓯化肥项目真空预压监测成果分析

越南金瓯化肥项目软基采用真空预压法处理,在预压过程中采用了膜下真空度、地面沉降、分层沉降、地下水位、孔隙水压力、深层水平位移等多种监测方法。对监测目的、方法做了介绍,根据监测的数据预测了最终沉降,计算了固结度,为卸载提供了依据。     

三峡水库蓄水后巴东地区波速比( Vp/ Vs)研究

采用固定台站法计算了三峡水库蓄水后湖北省巴东地区 ML2.0以上地震的波速比值,并给出了各自的相关系数.结果显示,巴东地区地震波速比值变化与水库地震的震源浅,裂隙发育,水的渗入作用等有关,并存在扩容期间波速比降低,震前波速比回升的现象.     

从地壳运动角度分析大陆强震机理的一种物理方法

为了从地壳运动角度利用重复大地测量数据分析大陆强震机理,提出了利用反映地壳内部密度变化或时变的物理量来分析强震发生的密度变化机理的一种物理方法(1)介绍了地球内部密度时变的一般理论和单层密度时变理论,提出了分步迭代算法;(2)简要分析了断层位错引起的单层密度变化效应;(3)分析了1996年丽江7级地震前震区南部地壳密度时变(变化)的特征;(4)初步探讨了强震孕育过程中可能的地壳内部密度时变(变化)前兆模式或发震机制.     

电解二氧化锰制备条件与晶体结构及电气性能的关系Ⅱ．不同电解液体系的影响

在MnSO4-H2SO4和MnCl2-HCl电解液体系中分别制备出电解二氧化锰（EMD），并在该二电解液中制备出掺杂MnO2样品，而后用X射线衍射确定其晶型为MnO2-γ，用扫描电镜观察其表面形貌，用XPS研究掺钛EMD表层物种，用模拟电池在实验室中快速检测掺杂样品的电性能，进而探讨了不同电解液体系中制备所得MnO2与其晶体结构及电气性能的关系。     

耀斑中正负电子湮灭线

本文简要回顾了耀斑中正负电子湮灭线的形成过程,着重研究了一个强γ射线耀斑０ ．５１１ ＭｅＶ 线随时间的演化。结果表明,为解释观测数据,加速质子谱必须随时间变化, 从而间接地提出了一种基于０ ．５１１ ＭｅＶ 线获取加速质子谱演化信息的新途径。