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941.
秀山隧道水文地质特征分析研究   总被引:1,自引:0,他引:1  
研究目的:玉蒙铁路秀山隧道受云南特殊地质构造影响和异常活跃的地壳运动作用,溶蚀管道与宽大裂隙发育,岩溶水、构造裂隙水相互混杂并形成复杂的地下水网络系统。通过对隧址区域工程地质与水文地质条件以及施工开挖揭示的洞身涌水特征进行系统分析研究,查清隧道涌水来源及其与杞麓湖的水力联系。研究结论:(1)通过对隧道洞身涌水量最大段落进行综合分析及水样同位素测试,表明地下水来源于隧址区接受的大气降水;(2)杞麓湖湖水与隧址区地下水在来源上存在明显差异,隧道涌水与湖水联系较弱;(3)隧道穿越曲江、杞麓湖两个水文地质单元,施工至不同洞段水文地质特征表现出较大的差异性;(4)本文研究结论可为同类地质环境隧道工程勘察设计施工提供参考借鉴。  相似文献   
942.
汽车涂装车间设备种类繁多,许多运动设备故障隐蔽,在日常巡检过程中不易发现,常由于小问题而酿成大的设备损坏及安全事故。通过引入电感式传感器检测技术,有针对性的创新改造,实时在线的对这些设备进行监控,达到设备故障提前检测、预防维修的目的。  相似文献   
943.
Container shipping and its related service sectors help accelerate globalization of the world economy. This industry has been experiencing rapid growth, prompting container terminal operators to increase their handling capacity in response. Providing container terminal services requires substantial capital investment in physical assets such as cargo handling facilities and information systems. On the other hand, operating container terminals is a long-term investment that typically spans several business cycles. Hence prudent asset management using appropriate tools is critical for container terminal operators to sustain their businesses. Generally, due to risk-adverseness, investors are unwilling to take more risk in their investment unless they can reap a higher return. Contrary to this argument, this study finds no direct influence of better firm performance as a proxy of higher return on business risk-taking by container terminal operators. Instead, scale of operations is positively associated with business risk-taking, suggesting that container terminal operators with a larger scale of operations are willing to take more business risk.  相似文献   
944.
The considerable cost of maintaining large fleets has generated interest in cost minimization strategies. With many related decisions, numerous constraints, and significant sources of uncertainty (e.g. vehicle breakdowns), fleet managers face complex dynamic optimization problems. Existing methodologies frequently make simplifying assumptions or fail to converge quickly for large problems. This paper presents an approximate dynamic programming approach for making vehicle purchase, resale, and retrofit decisions in a fleet setting with stochastic vehicle breakdowns. Value iteration is informed by dual variables from linear programs, as well as other bounds on vehicle shadow prices. Sample problems are based on a government fleet seeking to comply with emissions regulation. The model predicts the expected cost of compliance, the rules the fleet manager will use in deciding how to comply, and the regulation’s impact on the value of vehicles in the fleet. Stricter regulation lowers the value of some vehicle categories while raising the value of others. Such insights can help guide regulators, as well as the fleet managers they oversee. The methodologies developed could be applied more broadly to general multi-asset replacement problems, many of which have similar structures.  相似文献   
945.
The aim of this study was to assess proof of concept and usability of a maritime service website prototype in a full-mission ship bridge simulator through Swedish mariners’ experiences and perceptions. This test was part of the European Commission’s EfficienSea2 project for e-navigation. The prototype was intended as an aid to existing standard systems and methodologies for planning, executing and monitoring voyages. The study began with 5 days of simulator trials focused on today’s standard practices. This served as a baseline to compare to subsequent 4 days of simulator trials testing the prototype. For data collection, observations, video footage, interviews, and eye tracking were used. Data analysis included breaking apart the qualitative data to capture the perceptions of the participants, and a preliminary analysis of eye-tracking data as a complement. The results suggested that the prototype could be more suitable for a route planning stage, that the participants were familiar with similar existing solutions from other manufacturers, and that the contents of the tool would be most beneficial if integrated within the Electronic Chart Display and Information Systems (ECDIS). There is a pressing need for the novel solutions to be user needs-driven, integrated with the existing technologies, and standardized across the domain, and these processes must go hand-in-hand with accounting for all involved stakeholders, procedures, regulations, and training, as this will alter the course of shipping.  相似文献   
946.
分析了现阶段公路工程建设造价投资控制现状及存在的问题,结合国外先进投资理念,针对决策阶段、建设阶段、运营阶段造价控制提出对策。根据国家交通运输"十二五"发展规划,提出了全寿命成本理念及交通建设节约资源、有效利用土地资源的新理念。  相似文献   
947.
We use a combination of petroleum–diesel models, datasets and tools along with biodiesel-specific corrections to create a roadway-level emissions inventory capable of evaluating spatial, temporal and scale aspects of fuel distribution options for the Midwestern US. Specifically, we compare the emissions of a year-round “low-blend” biodiesel implementation scenario, already under consideration in a variety of states, with a more strategic summer-only, interstate-only “high-blend” scenario. Our results indicate that spatial and seasonal distribution decisions do affect the overall emissions impacts of any biodiesel deployment, even those at low-blend levels. However, we also finds that changes in emissions due to biodiesel are considerably smaller than those anticipated from improvements to engine and control technologies.  相似文献   
948.
简述了海上平台发电机房通风设计方案中使用噪音分析研究的流程,介绍了建立几何模型、输入数据得到噪音预报,得出分析结果,最终完成设计方案优化,为海上平台发电机房通风设计提供了参考.  相似文献   
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950.
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