Establishing the time of initial human occupation of Liang Bua, western Flores, Indonesia     

K.E. Westaway  M.J. Morwood  R.G. Roberts  J.-x. Zhao  T. Sutikna  E.W. Saptomo  W.J. Rink 《Quaternary Geochronology》2007,2(1-4):337-343

Liang Bua, a limestone cave in western Flores, has an archaeological and faunal sequence known to span the last 95 ka and is the type-site for a small-bodied hominid species, Homo floresiensis. This paper describes the geomorphic history of this significant site, and presents numerical ages for key events as determined by thermoluminescence dating of sediments (using a dual-aliquot regenerative-dose protocol) and uranium-series dating of flowstones. Our age estimates indicate that Liang Bua existed as a subterranean chamber by 400 ka ago. It was subsequently exposed by the incision of the Wae Racang River, which invaded the cave around 190 ka and deposited an upward-fining sequence of water-rolled boulders and cobbles. The latter conglomerate was partially reworked around 130 ka ago and was capped by flowstones at 100 ka. The conglomerate also contains stone artefacts, which implies that the occupation of the surrounding area is at least as old as the time of emplacement of the conglomerate. After 190 ka, a complex sequence of erosion and deposition led to the accumulation of at least 11 m of sediment in the front chamber of the cave, which proved suitable for hominid occupation. Such geochronological and geomorphological information is extremely valuable for interpreting the archaeological record at Liang Bua and its wider significance.  相似文献   

1970～1976年四川地震群测群防实践     

江在雄 《四川地震》2007,(1):27-31

记述了1970-1976年四川地震群测群防的兴起和发展,介绍了四川群测群防、专群结合预测预报地震的典型事例,特别对松潘—平武7.2级地震预测预报群测群防的作用作了反映。在此基础上,就这一时间四川群测群防、专线结合地震工作实践作了评析和认识。  相似文献   

试论如何依法管理地震科技档案     

贺建平 《山西地震》2007,(2):47-48

对地震科技档案目前在收集、接收等常规管理中存在的问题和如何解决这些问题进行了详细论述。认为,只有实现了档案材料形成积累和收集整理过程的一体化,才可保障档案材料的齐全完整,实现依法管理。  相似文献   

新疆渭干河灌区水文地质条件变化及排水措施探讨     

王春得  赵忠贤 《地下水》2006,28(6):87-89

渭干河灌区的水土环境及水文地质条件在克孜尔水库建成后发生了一定的变化,本文结合灌区12年来的水盐监测资料,对灌区地下水的埋深变化规律、水质演变趋势、灌区的排水效果及目前存在的问题进行了分析与探讨,并为今后灌区排水措施和保持水土环境的良性发展提出了建议.  相似文献   

温度、湿度对地磁Z基线值的影响及分析     

叶富华  林建  胡俊明  陈运能 《四川地震》2006,(1):14-18

仪器墩体受潮湿影响所产生的局部形变而引起的ZB磁变仪倾斜,是引起成都台CB3ZB变化幅度大,形成N字型年变化及其它类似形态变化的主要原因。实践证明,水泥墩湿引起的形变大,防潮效果差。而质地单纯均匀的石头墩受潮湿后引起的形变小,防潮效果好。  相似文献   

房产测量中椭圆和样条曲线的多段线逼近     

李家  张烜  周丽丽  刘颖 《现代测绘》2007,30(1):13-15

本文介绍了在AutoCAD环境中,对椭圆和样条曲线以面积为逼近指标调整偏移距离,用B样条函数处理偏移后样条曲线的控制数据,生成多段线逼近原椭圆或样条曲线的方法.解决了房产测量和建筑设计中将椭圆和椭圆弧精确地转化为多段线的问题.  相似文献   

基于支持向量机的遥感大雾判识   总被引：1，自引：0，他引：1  

刘年庆  蒋建莹  吴晓京 《气象》2007,33(10):73-79

提出了一种基于支持向量机的卫星遥感数据大雾判识方法:首先通过对风云1D卫星大雾区域的各通道辐射值出现频次进行概率统计,利用其阈值来粗判识大雾;然后在粗判识的基础上通过支持向量机的方法进行大雾细判识;最后利用腐蚀和膨胀的图像处理技术对判识后的图像进行优化处理。在对我国2006年9-12月的65条监测到大雾的风云1D轨道的探测数据进行分析之后,发现大雾判识结果与专家标记吻合。检验结果表明,利用1、2、4、6、7、10通道组合进行粗判识的结果最好,5交叉正确率为89.9849%,TS评分为74.04%。利用上述方法对个例的分析检验表明,基于支持向量机的遥感大雾判识方法是切实可行的。  相似文献   

采用掏土纠偏及袖阀管加固技术整治铁路桥涵不均匀沉降     

蒋丹阳 《探矿工程》2007,34(11):15-17,19

某钢筋混凝土箱形铁路桥发生不均匀沉降,经方案优化对比,采用了沉井射水掏土纠偏和塑料袖阀管注浆加固进行综合治理。介绍了其施工工艺和治理效果。  相似文献   

中国大陆科学钻探钻探子工程钻进实时记录网页的开发     

邵春  张晓西  杨凯华  张培丰 《探矿工程》2003,30(2):56-59

以中国大陆科学钻探实时记录网页的开发为例，介绍了在开发网络数据库时，利用Excel组件作输入界面，实现查询界面上表格的表头和表尾不动、而中间行可以滚动，实现回次滚动查询和界面实时刷新。  相似文献   

Neuzeitlicher Schadstofftrend: Polycylische aromatische Kohlenwasserstoffe (PAK) in aquatischen und terrestrischen Sedimenten     

Hubert Hellmann 《洁净——土壤、空气、水》2003,31(2):85-96

A Recent Contamination Trend: Polycylic Aromatic Hydrocarbons (PAHs) in Aquatic and Terrestrial Sediments Concentrations of polycylic aromatic hydrocarbons (PAHs) measured in aquatic sediments of small, medium‐sized or very large inland lakes, of estuaries as well as in terrestrial sediments from Germany, the UK, Finland, and the USA were plotted in 10 trend curves over the period from 1800 to 1990. The segments of the bore cores were dated for their deposition age. For comparability of the results, the trend is preferentially shown by the guide parameter fluoranthene. Until the 19th century, a constant background value of C_Fluo = 10…50 μg/kg was observed in all regions. Then a steep increase in concentration followed, reaching in the aquatic sediments a maximum in the period 1940 to 1965, while the individual fluoranthene values ranged widely from 90 to 2400 μg/kg. In several regions, a more or less distinct decrease superseded this maximum, although this development did not appear in terrestrial sediments, in one estuary, and in remote forest lakes in Finland. The trend curves reflect the atmospheric deposition of PAHs in airborne dust and in some cases the import through runoff via rivers. Thus, the sediment profiles depict the development of air pollution by pyrogenic contaminants over more than a century. Sediment profiles from rivers can be used only with a high degree of reservation, because of the irregularity and low representativity of the sedimentation.  相似文献