江苏体应变数字台网地震尾波的衰减关系与震级

体积式应变仪能记录全球大震,根据江苏体应变数字台网记录的全球大震波形,给出了测定地震尾波衰减系数、台网震级公式、震级标准差以及单台校正值的方法。由衰减经验关系lgA=G-klgτ导出的地震尾波应变双振幅A随尾波推移时间τ的衰减系数k=1.415,并取得以M(PEK)震级为基准的地震尾波应变台网震级公式MDC=4.02+1.04lgτ+0.74lgA±0.02,给出了江苏5个体应变台站的震级校正值,计算了近年内全球发生的35个地震震级值,平均震级标准差为0.11。尾波多点测量改善了7.6级以上大震MDC的精度,用该方法测量全球大震不存在震级"饱和"问题。     

Rebuilding and strengthening health systems and providing basic health services in fragile states

The international community has compelling humanitarian, political, security and economic reasons to engage in rebuilding and strengthening health systems in fragile states. Improvements in health services and systems help to strengthen civil society and to restore legitimacy to governments. Effective engagement with fragile states to inform the design of health programmes and selection of interventions depends on donor coordination and an understanding of health system challenges. Planning requires consideration of allocation (services to be delivered), production (organisation of services), distribution (beneficiaries of services) and financing. The criteria for selecting interventions are: their impact on major health problems; effectiveness; the possibility of scale-up; equity; and sustainability. There are various options for financing and models of engagement, but support should always combine short-term relief with longer-term development. Stakeholders should aim not only to save lives and protect health but also to bolster nations' ability to deliver good-quality services in the long run.     

紫下大桥安全检测与评价方法研究

钢桥因具有跨径大、承载能力强、施工工期短等特点,被世界各国广泛采用,但在使用过程中,由于重载甚至超载车辆的反复作用、自然灾害的侵袭及交通事故等人为因素的作用,经常造成桥梁损伤和局部破坏,导致桥梁承载能力和耐久性的降低,甚至影响到运营的安全。本文建立了钢拱桥的健康检测和安全评价方法,采用防腐涂层厚度测定、结合强度测定、无损探伤和动静载荷试验等手段对紫下大桥健康状况进行了检测,采用不确定层次分析法对大桥进行了安全评价,提出了处理意见和措施,为既有钢拱桥的健康检测、评价和维护积累了有益的资料。     

地震动差动作用下大跨度空间网壳结构的反应分析

选取100 m跨度的双层柱面网壳结构为研究对象,采用时程分析法,分别进行了结构在单向和三向地震行波输入作用下的反应分析,并针对多种视波速情况进行了研究,考查了地震动不同输入情况下结构杆件内力的分布特点,对其进行了对比分析,为大跨网壳结构的抗震设计提供了理论依据。研究表明,考虑行波效应会使结构部分构件内力有一定程度的提高,多维地震作用比单维地震作用下结构的杆件内力大。由此得出结论:对于大跨度空间网壳结构,应该进行多维非一致输入下的地震反应分析;为保证抗震安全,应对可能出现的地面视波速进行全面分析。     

Environmental Vulnerability Indicators for Environmental Planning and Decision-Making: Guidelines and Applications

Environmental decision-making and policy-making at all levels refers necessarily to synthetic, approximate quantification of environmental properties such as vulnerability, conservation status, and ability to recover after perturbation. Knowledge of such properties is essential to informed decision-making, but their definition is controversial and their precise characterization requires investments in research, modeling, and data collection that are only possible in the most developed countries. Environmental agencies and governments worldwide have increasingly requested numerical quantification or semiquantitative ranking of such attributes at the ecosystem, landscape, and country level. We do not have a theory to guide their calculation, in general or specific contexts, particularly with the amount of resources usually available in such cases. As a result, these measures are often calculated with little scientific justification and high subjectivity, and such doubtful approximations are used for critical decision-making. This problem applies particularly to countries with weak economies, such as small island states, where the most precious environmental resources are often concentrated. This paper discusses frameworks for a “least disappointing,” approximate quantification of environmental vulnerability. After a review of recent research and recent attempts to quantify environmental vulnerability, we discuss models and theoretical frameworks for obtaining an approximate, standardizable vulnerability indicator of minimal subjectivity and maximum generality. We also discuss issues of empirical testing and comparability between indicators developed for different environments. To assess the state of the art, we describe an independent ongoing project developed in the South Pacific area and aimed to the comparative evaluation of the vulnerability of arbitrary countries.     

气相色谱法测定土壤中六六六残留量

采用气相色谱法毛细管色谱柱分离、电子捕获检测器检测土壤中残留的六六六含量。索氏提取和超声波提取2种方法的研究结果表明，索氏提取法加标回收率在86．93％～98．54％之间，相对标准差为1．78％～9．59％；超声波提取法加标回收率在90．23％～103．29％之间，相对标准差为2．32％～9．33％。两种方法均准确、灵敏，超声波提取法时间短、效率高。     

蒙特卡洛法计算750kV输电线路绕击跳闸率的研究

利用GDS多功能三轴仪,通过控制土样应变增量比开展了饱和砂土部分排水三轴试验;利用超静孔隙水压力、有效应力路径和应力应变关系三方面的实验结果,研究了饱和砂土的渐近状态特性。研究表明,控制应变增量比为常数进行常规三轴加载时,饱和砂土的有效应力比也趋于某一常数,形成渐近状态,且渐近状态应力比随应变增量比的增大而减小。基于土的剪胀特性给出了渐近状态形成的物理机制,并给出了北京某砂土在部分排水条件下渐近状态应力比的试验结果。     

基于地震波法的底板破坏区域探测技术及应用

针对煤矿煤层底板采空区域不明确的问题,为了确定采空区的精确范围以及内部状态,采用物探的矿井反射地震波探测技术,首先利用地质探测仪对地震波波形进行数据采集,并进行数据分析以及波形的反演计算,最终根据波形的形状和频率确定底板破坏情况;其次将底板破坏区域分为上位层破碎带和下位层破碎带;最后在现场采用底板钻探的方法对地震波探测技术进行了验证。结果表明反射地震波探测技术得到的结果接近于钻探结果,采用反射地震波探测技术可以较精确判断底板采空区破坏范围。     

高速列车隧道会车流场的CFD分离涡数值模拟

目的研究高速列车隧道会车压力波及列车尾流特性。方法建立某型高速列车三节车模型,采用脱体涡方法数值模拟两列车以350km/h在隧道内等速会车的流场。数值模拟的空间离散化压力项、密度项及修正的湍流黏度项使用二阶迎风格式,动量项使用有界中心差分格式,时间离散采用预处理二阶精度差分格式,用壁面函数处理隧道壁,使用雷诺时均法作方法对比。计算列车车头、侧墙及尾车等部位的压力时间历程,然后使用傅里叶变换对尾车测点进行频谱分析,最后对尾流中不同位置的湍流强度进行分析。结果头车所受压力波动最为剧烈,中间车次之,尾车最小。列车侧墙同一垂向位置不同高度压力变化相差不大。列车尾涡主频在3.85Hz附近,其可能对列车横向振动有一定的影响。结论尾涡是两个不断向后发展的中等强度涡旋,在充分发展段,其湍流强度会有一个较为明显的抬升,之后逐渐减弱。会车侧涡流由于横向发展较为迅速,导致其强度较小且减弱速度较快。     

饥饿期间增加曝气量好氧颗粒污泥的形成特点

高有机负荷率8.0kgCOD(/m3·d)条件下,通过两种不同的曝气方式研究好氧颗粒污泥的形成特点,即在反应器R1中采用恒定的曝气流量,而在反应器R2中,30min曝气后,进行沉淀和排水,然后采用较大的曝气流量进行曝气。研究发现:(1)外部基质在前30min被快速降解,其溶解性有机碳DOC基本被消耗到最低水平;(2)在中途排水后的饥饿状态下增加曝气量的反应器R2相对于曝气量一直不变且中途未排水的R1而言,颗粒变的大而疏松,即:在R2中颗粒尺寸>0.9mm占有93%,而颗粒密度均<1.016g/mL。(3)反应器R2在饥饿状态下增加曝气量可以使胞外多聚物(EPS)糖类被当作基质被消耗。