全新世以来浙江余姚河姆渡—田螺山遗址的古环境演变及人类活动*

通过对浙江余姚河姆渡—田螺山遗址附近的HMD1501和HMD1502两个钻孔的微体古生物学研究,揭示了该地区全新世以来的植被演变、气候变化、海平面变迁及人类活动。孢粉、海相沟鞭藻、淡水藻类及有孔虫内衬的记录表明: (1)在早全新世(对应于镇海组下部),植被群落属于常绿阔叶和针叶混交林,气候温暖潮湿,研究区属于海侵阶段。(2)在中全新世(对应于镇海组中部),植被群落虽仍为针阔叶混交林,但气候转为温和湿润,研究区仍属于海侵阶段。(3)由于人类活动的进一步加剧,在晚全新世(对应于镇海组上部)的植被群落中草地的面积也随之扩大,并在滨海地区开始有一些以莎草科为主的沼泽地形成,植被群落属于针阔叶混交林—草地,气候更加凉爽干燥,研究区转为海退阶段。(4)在~7235—3327 cal. yr B.P.期间,草本花粉的含量激增,特别是一些粒径不小于35,μm 的禾本科栽培作物花粉的含量增加,说明此时人类活动开始增强,河姆渡—田螺山遗址附近出现较多的水稻种植区。     

汶川8.0级地震陕西省数字强震动记录分析

本文对2008年5月12日四川汶川8.0级地震陕西数字强震动台网27个台的地震加速度记录进行了处理和分析,包括对加速度波形数据的基线调整、滤波、加速度反应谱计算,以及速度和位移计算。结果表明：除局部场地条件的影响外,大地震的能量辐射方向和传播路径中介质的横向不均匀对PGAH衰减的离散性可能有一些影响; 对于同一烈度值,PGA/PGV较小,PGA在数值上平均只有PGV的5倍左右,反映了地震动的低频成分比较丰富; 绝大部分强震台所处地区的烈度为Ⅴ—Ⅶ度; PGAH与水平单分向加速度峰值PGA（E-W）和PGA（N-S）中较大值之间的相对偏差绝大部分小于10%; 波形的性质为面波,盆地中覆盖土层较厚的场地长周期的面波更为发育,波列持续时间较长; 局部场地的介质特性对地震动特征有相当大的影响,盆地中较厚的覆盖土层对较长周期的地震波有明显的放大作用。     

RSM仪与场地剪切波波速测试技术

介绍了采用检层法进行场地剪切波波速测试的技术和应用以及这种方法的原理、发展历史、测试技术和计算方法。本文还简要介绍了ＲＳＭ的设备和软件以及作者的现场实测经验     

天津某项目长大桩检测实例分析与探讨

基桩承载力与完整性检测是隐蔽工程验收的关键环节,通常于桩基设计阶段即规划好检测方法,在施工阶段安放好检测设施或解决好地基处理问题,以利于后续检测工作的顺利开展。大直径超长桩因设计承载力大、桩身情况复杂,对检测工作要求较高,更应遵循检测与设计同步的原则。本文所述天津某项目恰恰忽视了基桩检测的事前设计,致使长大桩检测遇到棘手问题。作者在有限条件下通过专业技术分析,利用多年实践经验,因地制宜制定检测方法措施,采取分步加载法解决了大吨位堆载试验对长大桩承载力的验证性试验问题,综合利用低应变法与高应变法解决了长大桩的完整性检测问题,为类似工程提供了宝贵经验。     

铜镍矿床地球化学模式的应用——在贵州西部寻找隐伏铜镍矿床(含矿岩体)的探讨

根据已建立的铜镍矿床地球化学模式,通过对区域化探地球化学数据(Cu、N i、Co、Cr、Ag、B、Ba、As等元素)处理、分析、综合研究,认为在贵州威宁黑石镇—哲觉镇地区有可能找到隐伏铜镍矿床(含矿岩体)。     

隔震铅芯橡胶支座变形发热及其强度退化研究综述

铅芯橡胶支座（lead-rubber bearing,LRB）是目前应用最为广泛的减隔震装置,普遍应用于建筑、桥梁、储罐和核电站等结构,其抗震性能已在屡次地震中得以验证。当LRB承受大幅值的往复变形时,其力学性能受内部铅芯发热的影响而发生显著变化,主要表现在滞回耗能、特征强度和刚度的降低等方面。首先,总结了铅芯橡胶支座及其结构在以往地震中的震害情况,介绍了预测LRB内部铅芯变形发热和温度升高的理论及近似求解方法,以及基于试验和有限元的验证方法及注意事项;其次,概述了LRB因内部铅芯变形发热导致其强度退化的分析模型和强度退化对结构地震反应的影响;最后,归纳了隔震结构在进行模型试验时,铅芯橡胶支座的相似理论和缩尺问题。     

空间数据质量控制与评价方法及实现技术

针对空间数据质量控制探讨较少的状况,提出了空间数据质量模型,阐述了各质量指标的检验与评价方法,重点探讨了自动检查与评价方法。开发的空间数据质量控制与评价系统软件的应用结果表明,本文所述方法正确,检验与评价结果可靠。     

Fractional flow dimensions and hydraulic properties of a fracture-zone aquifer, Leppävirta, Finland

 In order to characterize the hydraulic properties of an aquifer in Finland comprising two subvertical fracture zones, observation-well responses were matched with generalized radial flow (GRF) type curves. The responses in six wells out of seven are consistent with the GRF model. The fractional flow dimensions (1–1.2 and 1.5) were determined by regression analysis of straight-line slopes and type-curve matching. In each test, the flow dimensions in the neighboring fracture zone range from 2–2.25. Comparisons of the late-time responses with the asymptotic GRF solution and the flow dimensions obtained by reversing the pumping and observation points suggest homogeneous hydraulic properties. Deviations in responses can be explained by flow-path tortuosity. After assessments of the extent of the flow and radial distances along the fracture system, hydraulic conductivities and storativities were determined from the results of the type-curve matching procedure. The obtained hydraulic conductivities are 1.3×10^–5 to 7.9×10^–5 m/s and 5.0×10^–6 to 2.5×10^–5 m/s for the western and the eastern fracture zones, respectively. The results were verified by applying them to analytical solutions for pumping wells. The calculated pumping-well responses are consistent with the observations. The analysis of flow dimension also enhances qualitative interpretations on the hydrogeology of fracture zones. Received, April 1997 · Revised, September 1997 · Accepted, May 1998     

Performance-based landfill design: development of a design component selection matrix using GIS and system simulation models

Designing environmentally safe and economically feasible landfills can be a challenging task due to complex interactions that need to be taken into account between landfill size, waste and site characteristics. The main focus of this study is, by interfacing the geographic information systems (GIS) with system simulation models (SSM), to develop a methodology and a landfill design component selection matrix that can enable the determination of landfill design components providing the desired performance with minimal design details. In this paper, the conceptual framework and applications of the developed methodology demonstrating the selection of landfill design components that are suitable for the existing site conditions are presented. The conceptual model defines design variables, performance criteria and design components of a landfill. GIS and SSM are used to handle the site-specific data and to evaluate the landfill performance, respectively. Results indicate that the landfills having the same design characteristics show different performance under different site conditions; therefore, a landfill design that is technically and economically feasible should be selected on the basis of performance.     

砂质土壤组分检测能力验证结果分析

对中国实验室国家认可委员会（CNAL）编号为CNAL T0242的砂质土壤中Cu、Pb、Zn、Mo、V五组分测试结果进行统计,采用稳健统计法,根据z比分数评判各实验室的测试结果。通过对CNAL T0242能力验证结果分析,客观反映参加实验室的测试能力和测试水平。