A general simple method for calculating consolidation settlements of layered clayey soils with vertical drains under staged loadings

Acta Geotechnica - It is well known that the calculation of consolidation settlements of clayey soils shall consider creep compression in both “primary” consolidation and so-called...     

粤东中生代火山岩基底涌流相岩相岩石学特征及其判别标志

蒸气爆发、蒸发岩浆爆发起因于岩浆与外部水的相互作用所形成的基底涌流堆积物。近代火山学资料表明都是一些尚未固结的松散物，而在古火山岩区则是一套成层性极大的火山碎屑岩。着重论述粤东中生代火山岩区基底涌流相地层学、岩石学特征，指出该相岩石具有沉积碎屑岩和火山碎屑岩的双重特点，但其岩石命名应与火山碎屑流相相对应。该相岩石所具多种组分特征、结构构造和岩石类型，可作为在古火山岩区识别这类岩石的重要依据。     

造岩矿物性质对岩体可破坏性的影响

工程地基的选址依据,本世纪中叶以前是地基范围内没有断裂,即避免断裂原则。６０年代以后,工程选址的条件由避免断裂转变为考察断裂是否活动。美国率先制定了工程地基范围内活动断裂指标规范,认为具有非活动性断裂的岩体上可以构筑大型工程。花岗岩体规模大,整体性好...     

藏北查桑上三叠统复理石沉积大地构造背景的初步探讨

藏北羌塘地块的构造性质和构造局是中国地学界长期争论的重要问题。这里人迹罕至,研究程度很低,基础地质资料缺乏。这是有关地质问题得不到解决的根本原因之一。本项研究的首要目的也是为该地区的地质研究提供一份基础资料,羌塘地块腹地查桑地区的上三叠统肖茶上涨且,下部为细碧岩、中基性火山岩、玄武质角砾岩来灰岩和大理岩,上部主要为碎屑岩（复理石）和灰岩,我们在肖茶卡组上部的复理石中采集砂岩、粉砂岩样品,进行主量元     

Rhenium–Osmium Isotope Measurements in Marine Shale Reference Material SBC‐1: Implications for Method Validation and Quality Control

In this study, the USGS black shale reference material SBC‐1 was investigated as a matrix‐matched reference material for both intra‐laboratory calibration and inter‐laboratory comparison of high‐precision Re‐Os dating for organic‐rich sedimentary rocks. This reference material was analysed for Re‐Os isotopic composition by three digestion protocols – inverse aqua regia, CrO₃‐H₂SO₄ and H₂O₂‐HNO₃. The results for SBC‐1 obtained by inverse aqua regia digestion yielded similar Re mass fractions but slightly (~ 5%) higher Os mass fractions and lower ¹⁸⁷Os/¹⁸⁸Os values than the CrO₃‐H₂SO₄ and H₂O₂‐HNO₃ digestions. The data set of inverse aqua regia digestion exhibited strong correlations in plots of ¹⁸⁷Os/¹⁸⁸Os vs. 1/¹⁹²Os and ¹⁸⁷Os/¹⁸⁸Os vs. ¹⁸⁷Re/¹⁸⁸Os, which may signify the incorporation of detrital Re and Os into organic matter in the Re‐Os system. Similar correlations were also observed for the CrO₃‐H₂SO₄ digestion data set, but not for that of H₂O₂‐HNO₃. The data indicate that there is an amount of non‐hydrogenous Os in SBC‐1 and that CrO₃‐H₂SO₄ and H₂O₂‐HNO₃ digestions would minimise liberation of the non‐hydrogenous Os component. We propose that SBC‐1 may be a more suitable reference material to monitor the influence of detrital Re and Os on Re‐Os isochron age data, especially for samples with less organic matter and more siliceous detritus.     

Extraction and Analysis of Land Cover Heterogeneity over China

Spatial heterogeneity exists in land surface at every scale, and it is one of key factors to bring uncertainty to land parameter retrieval from remote-sensed data. This paper proposed a methodology to use the boundary length among different land cover types to characterize and quantify land surface heterogeneity based on high-resolution land cover images. Then the heterogeneity feature at 1 kilometer scale in China was extracted from “GlobalLand30” land cover datasets with the spatial resolution of 30 m. The mixed structure, degree of fragmentation and intra-heterogeneity of eight main vegetation biomes from MODIS land cover product over heterogeneous surface in china were analyzed. Mountain area and ecotone are more heterogeneous than other regions. Savanna biome (average boundary length is 7 426 meters) is the most heterogeneous zone followed by forest, grass/crop and shrub biome with average boundary length of 4 323, 3 160, 1 779 meters, respectively.     

Influence of transboundary air pollution on air quality in southwestern China

Air pollution is a grand challenge of our time due to its multitude of adverse impacts on environment and society,with the scale of impacts more severe in developing countries,including China.Thus,China has initiated and implemented strict air pollution control measures over last several years to reduce impacts of air pollution.Monitoring data from Jan 2015 to Dec 2019 on six criteria air pollutants(SO2,NO2,CO,O3,PM2.5,and PM1o)at eight sites in southwestern China were investigated to understand the situation and analyze the impacts of transboundary air pollutants in this region.In terms of seasonal variation,the maximum concentrations of air pollutants at these sites were observed in winter or spring season depending on individual site.For diurnal variation,surface ozone peaked in the afternoon while the other pollutants had a bimodal pattern with peaks in the morning and late afternoon.There was limited trans-port of domestic emissions of air pollutants in China to these sites.Local emissions enhanced the concen-trations of air pollutants during some pollution events.Mostly,the transboundary transport of air pollution from South Asia and Southeast Asia was associated with high concentrations of most air pollu-tants observed in southwestern China.Since air pollutants can be transported to southwestern China over long distances from the source regions,it is necessary to conduct more research to properly attribute and quantify transboundary transport of air pollutants,which will provide more solid scientific guidance for air pollution management in southwestern China.     

巴基斯坦胡兹达尔- 拉斯贝拉铅锌成矿带遥感地质特征与找矿模型

巴基斯坦胡兹达尔- 拉斯贝拉铅锌成矿带是特提斯成矿域铅锌成矿带的重要组成部分,该成矿带的矿床类型主要为喷流- 沉积型(SEDEX)和密西西比河谷型(MVT)。目前针对胡兹达尔- 拉斯贝拉铅锌成矿带及典型矿床的研究程度较低,制约了对该成矿带的认识及找矿勘查研究。本研究以胡兹达尔- 拉斯贝拉成矿带为研究区,通过合理选择遥感数据源和图像处理方法,对典型矿床(杜达、贡尕铅锌矿床)及部分矿点的样品光谱特征、影像特征综合分析,结合关键控矿要素研究,建立了胡兹达尔- 拉斯贝拉地区与沉积岩有关铅锌矿遥感找矿标志并开展成矿预测,为该成矿带找矿提供可行性方法。基于本研究建立的找矿标志,利用增强型专题制图仪(Enhanced thematic mapper, ETM)和先进星载热辐射与反射辐射计(Advanced spaceborne thermal emission and reflection radiometer, ASTER)影像圈定主要预测含矿地层分布区30处,结果与已知矿床、矿点吻合较好,圈定的含矿地层分布区主要集中在研究区中部和北部,均位于侏罗纪地层内且矿化带与地层走向一致,矿化主要位于安吉拉组、劳瑞莱组地层内部;根据含矿地层像元光谱,利用资源一号02D高光谱影像提取了中部地区含矿地层的空间分布,提取结果与找矿标志分析结果吻合较好,证实了在该区利用国产高光谱影像开展含铅锌矿地层自动提取与找矿的可行性。     

轻微的机械作用对断裂源形态的影响

俄罗斯科学院约费技术物理研究所提出了固体断裂的两阶段模型,该模型不随断裂尺度变化。第一阶段为裂隙的积累,其大小受限于构造单元的特征尺度,当达到其阈值密度时,就形成局部的断裂源,此时过程进展加速,并完成宏观断裂。当过程进展缓慢时,研究轻微的作用下断裂源的状态就具有意义。     

冬季黄渤海大风天气与渔船风损统计分析

选用1987-2006年NECP 500hPa高度场及海平面气压场日平均再分析资料及沿海岸基、石油平台、海岛及船舶实时观测资料,统计分析了冬季造成黄渤海海域8级和10级以上大风天气过程;选用中国渔船安全分析报告1999-2005年风灾船损事故资料,分析了大风和船损灾害的关系.结果显示:(1)冬季影响黄渤海的冷空气过程主要是来自西北路径,占全部冷空气过程的50.4%.(2)造成海上8级以上大风的冷空气过程的天气类型主要是小槽发展型112次,占全部冷空气过程的50.0%;其次是横槽转竖型61次,占全部冷空气过程的27.2%.(3)近20年冬季冷空气大风过程次数呈下降趋势;(4)风灾事故占渔船全损事故的51.85%,冬半年突发性的冷空气大风是导致木质渔船出现风灾事故的主要原因.