金川二矿区14行风井返修支护效果分析

针对金川二矿区14行风井的返修支护方案,本文根据金川矿区高应力破碎岩体的条件,从锚杆、喷射混凝土、钢筋网三方面,分析了该方案中喷锚网支护的作用机理,并通过数值方法分析了该返修支护方案的效果。研究结果表明:14行风井的返修支护措施对竖井围岩移动、变形有一定的限制作用,但效果不是很好;随着开采深度和规模的扩大,井筒围岩还将产生较大的位移,并有可能重新发生破坏。     

Somatom Plus全身CT机架冷却系统驱动电路维修和改进

本文描述了Ｓｏｍａｔｏｍ Ｐｌｕｓ全身ＣＴ机架冷却系统的工作原理及维修方法。另外,为了提高冷却系统的可靠性,本文还提出了一套行之有效的对冷却系统驱动电路进行改进的方法。     

A probabilistic framework for correlated seismic downtime and repair cost estimation of geo‐structures

An important component of probabilistic risk assessment methods is the development of models to quantify the direct consequences of damage to geo‐structural components for a given intensity of the hazard. This paper presents a general probabilistic framework for correlated repair cost and downtime estimation of geo‐structures exposed to seismic hazards. The framework uses as input the results of nonlinear time‐history analysis of geo‐structures for the set of earthquake records that are representative of the seismic hazard models for the region of interest. The repair cost and downtime are estimated for individual earthquakes probabilistically considering the uncertainties associated with damage states. In addition, the formulation of the repair cost and downtime accounts for the reduction in the repair requirements as the number of damaged components in the given damage state increases. An analytical linear and two bilinear regression models are proposed for conditional correlated seismic repair cost and downtime estimation of geo‐structures given the intensity measure. The proposed framework is demonstrated by developing seismic repair models of a typical pile‐supported wharf structure on the west coast of the United States. The presented framework is general and can be applied to other types of geo‐structures and hazards and can include other decision variables such as loss of life as well. Copyright © 2013 John Wiley & Sons, Ltd.     

柯达M7B型洗片机的故障分析与检修

为保证自动睛机能够正常运转,给ＣＴ机,Ｘ光机提供最佳质量的图象,已成为放射维修人员工作的重要内容之一。本文以柯在Ｍ７Ｂ型洗片机为例,从维修角度上谈一谈怎样能够快速准确地寻找出机器的故障点,并及时维修,使洗片机能够正常运转。     

北京采矿废弃地植物修复重金属去除率研究

结合北京市采矿废弃地土壤地质环境情况,选取密云区西坨古金矿尾矿土、密云区冯家峪铁矿尾矿土和门头沟区桑峪煤矸石堆为研究对象,进行植物修复研究。共开展4种类型的修复试验,即选用高羊茅、紫花苜蓿和三叶草3种修复植物分别进行修复,同时与板蓝根、桔梗、波斯菊和薄荷等中草药进行混合种植修复,在植物生命周期的不同阶段采集样品分析测试。结果表明:在4种修复类型中,高羊茅对金矿尾矿土中Pb、Zn、Cr、Cd去除效果最好,最大去除率达到18.10%、14.57%、13.81%、18.12%;混合种植对铁矿尾矿土中Cr、Ni、As、Hg去除率达到4种修复类型的最大值,分别为14.81%、9.80%、37.25%、50%。三叶草对煤矸石修复效果最好,对Cr、Pb、Zn、Cd的去除率分别为5.65%、37.15%、15.15%、20%,是4种修复模式去除率的最大值。在生命周期的不同阶段,对比4种修复模式对采矿废弃地土壤中8种重金属的去除效果,均发现有去除率先升后降的现象,因此可对修复植物的进行定期收割,为提高植物吸附土壤重金属的效率,提供一定科学依据。     

Seismic response of natural gas and water pipelines in the Ji-Ji earthquake

In order to study the damage patterns of natural gas and water pipelines in the Ji-Ji earthquake, a GIS database and analysis procedures were established. Repair statistics was obtained from major natural gas companies and the Taiwan Water Supply Corporation (TWSC), and entered into the system. Then, repair rates (RR) were calculated. Previously, damage was analyzed without considering the corresponding pipeline material and diameters. In this study, new attempts were made to collect more data including those related to the composition of pipelines to provide a more detailed analysis of the relationship between earthquake forces and the resulting damage. Statistical analysis was also conducted to understand the correlation between RR and seismic parameters such as the peak ground acceleration, peak ground velocity, and spectrum intensity.     

Automatic correction and simplification of geological maps and cross-sections for numerical simulations

Incorporating prior geological knowledge in geophysical process models often meets practical meshing challenges and raises the question of how much detail is to be included in the geometric model. We introduce a strategy to automatically repair and simplify geological maps, geological cross-sections and the associated meshes while preserving elementary consistency rules. To identify features breaking validity and/or the thin features potentially problematic when generating a mesh, we associate an exclusion zone with each model feature (horizon, fault). When these zones overlap, both the connectivity and the geometry of the geological layers are automatically modified. The output model enforces specific practical quality criteria on the model topology and geometry that facilitates the generation of a mesh with lower bounds on minimum angles and minimum local entity sizes. Our strategy is demonstrated on an invalid geological cross-section from a real-case study in the Lorraine coal basin. We further explore the impacts of the model modifications on wave propagation simulation. We show that the differences on the seismograms due to model simplifications are relatively small if the magnitude of simplifications is adapted to the physical problem parameters.     

Best of two worlds? Towards ethical electronics repair,reuse, repurposing and recycling

International trade of discarded electronics (e-waste) has become a matter of concern over the last decade because of the actual and potential harms associated with their hazardous materials. An initiative under the aegis of the UN called the Best-of-Two-Worlds (Bo2W) philosophy is one solution to the e-waste problem that has gained some traction. Our dual purpose is to examine the ethical grounds of Bo2W and to propose an alternative program for action. We call this alternative ethical electronics repair, reuse, repurposing, and recycling (EER4). To explore the ethical grounds of Bo2W and to articulate EER4 as an alternative, we draw on notions of ethics, technology, and organization developed in science and technology studies (STS) and diverse economies literatures while empirically we explore a mixed methods case study of a small recycling firm in northern Mexico. Conceptually and empirically, our analysis points to a need for a richer imagination of the possibilities for economic action oriented toward managing discarded electronics. More broadly, our findings may act as a reminder that the space between use and discard proliferates the literal and figurative resources for enriching the imagination and enactment of diverse economic possibilities via the action of repair, reuse, repurposing, and recycling.