共查询到18条相似文献,搜索用时 46 毫秒
1.
我国轨道交通基础建设实现了跨越式发展,但针对轨道工程运营的安全管理与高效维护,仍存在许多复杂的难题亟待解决,突出表现为轨道结构实际服役周期难以达到设计寿命。因此,组织实施铁路轨道工程长寿命安全保障计划尤为迫切。本文首先回顾了我国铁路轨道工程领域取得的成绩,进一步介绍了国外一些发达国家在该领域的发展动态。相比发达国家,目前我国在轨道工程长寿命安全领域的研究还存在比较大的提升空间,具体表现在缺乏顶层设计,研究工作的系统性不足,深度与广度不够。最后就该计划的实施从理论研究、人才培养、智能化信息管理、性能提升与恢复等方面提出了若干建议。 相似文献
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我国已建成了规模居于世界前列的交通基础设施,但由于多种因素的影响,交通基础设施重大结构的安全保障问题面临着越来越严峻的挑战。本文分析了我国交通基础设施的发展现状,综述了国内外相关领域的研究进展,讨论了我国交通基础设施重大结构长寿命安全保障领域存在的主要问题及实现安全保障的技术途径,提出了实施安全保障计划应达到的目标以及需解决的关键问题。 相似文献
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南方钢铁公司炼钢厂600吨混铁炉,40吨转炉两座,2吹1。一台150mm*150mm断面四机四流连铸机,2004年7月新建投产至今,生产运行近7年时间,出铁水量约480万吨。没有进行大修、中修,炉衬,炉况依然良好。 相似文献
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本文从设计施工、环境侵蚀、突发自然灾害及突发事故灾害四个方面,分析了我国隧道衬砌结构安全所面临的问题;对上海地区黄浦江越江隧道和地下交通隧道等水下隧道工程进行了调查,重点分析了我国在役水下隧道衬砌结构服役的现状。并基于此,为有效保障隧道结构全寿命周期过程中的安全服役性能,及预留隧道结构长寿命有效条件,从隧道建设、结构性能退化、自然灾害、突发事故灾害等方面入手,探寻我国水下隧道结构的长寿命安全保障对策,以确保在隧道的全寿命周期内乃至长寿命要求下结构的安全服役性能。研究成果可为保障我国水下隧道等重大隧道结构的长寿命安全提供参考。 相似文献
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程婧 《中国新技术新产品》2011,(18)
随着我国经济建设的飞速发展,公路建设事业得到了迅猛发展,目前很多铺筑的公路路面在通车一、二年内就出现不同程度的损坏现象,严重的还影响到路面的正常使用和寿命。因此,为了提高长寿命沥青路面的工程质量、完善使用性能、提高使用寿命和节约投资,设计出符合我国国情的长寿命沥青路面具有重大的现实意义。本文首先介绍了长寿命沥青路面破坏模式,然后重点探讨了长寿命沥青路面的设计方法,希望对相关行业的专业人员有一定的借鉴作用。 相似文献
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英国Hymatic Engineering公司新研制成一种用于自导导弹和自导武器的冷却装置,此装置费用为原先的十分之一,可成批制造。为了达到最佳工作状态,发现和跟踪目标,红外线探测器的温度必须迅速冷却到80-100K。 相似文献
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在分析收发多功能芯片失效模式和失效机理的基础上,通过试验研究,提出包括样品筛选、抽样与组装、试验温度、试验时间、失效判据等内容的收发多功能芯片长寿命评价试验方法. 相似文献
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《中国新技术新产品》2015,(8)
近些年来,随着我国城市化进程的加快,我国城市轨道交通基础设施建设也取得了显著的发展,从当前建设的现状来看,对于传统的以政府为主导的投资融资模式已难以满足现代建设的发展需求,因此新型的基础设施融资模式就显得非常具有应用价值,也就是国际较为流行的公私合作式融资模式即"PPP模式"。本文主要对"PPP模式"在城市轨道交通基础设施建设中的选择问题进行了分析探讨。 相似文献
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近些年,国家实施稳健的财政政策、加快基础设施建设步伐的有利环境,为交通事业快速发展提供了难得的机遇。交通事业在快速、健康发展的同时,也面临着反腐败严峻形势的挑战。认真分析交通基础设施建设领域腐败现象的成因,采取积极的应对措施,是遏制腐败问题高发态势、促进交通事业又好又快发展的关键。笔者就这一问题浅谈粗浅的认识。 相似文献
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介绍了一种用于测试线形压缩机驱动的微型同轴脉冲管制冷机系统可靠性的试验系统,此试验台的建立将用来获得目前国内的同类系统的可靠性数据,为今后此种制冷系统用于军事实用打下基础。 相似文献
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Enrico Cagno Massimiliano De AmbroggiOttavio Grande Paolo Trucco 《Reliability Engineering & System Safety》2011,96(1):139-148
The paper presents an integrated approach for vulnerability and resilience analysis for underground infrastructures, i.e. a societal risk analysis of the failures of underground services for an urban area. The approach is based on the detailed study of (1) domino-effects for the components of a single infrastructure and for a given set of infrastructures interoperated and/or belonging to the same area; (2) risk and vulnerability analysis of a given area; (3) identification of a set of intervention guidelines, in order to improve the overall system resilience. The use of an integrated (interoperability and area) approach, breaking down the analysis area extent into sub-areas and assessing the dependencies among sub-areas both in terms of interoperability and damage propagation of critical infrastructures, demonstrates a useful advantage in terms of resilience analysis, more consistent with the “zoned” nature of failures of the underground infrastructures. An applied case, describing the interoperability and damage propagation analysis with the evaluation of time-dependency for the infrastructures and targets and of different kinds of interventions of the underground infrastructures of a town, is presented for this purpose. 相似文献
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The rapid evolution of computing and communication technologies and their standardizations have made the boom in e-commerce
possible. Lowering of the cost of operation, increase in the speed of transactions, and easy global reach to customers and
vendors have been the reasons for the overwhelming popularity of this new way of commerce. This article examines the issues
related to the security of the assets and transactions in the e-commerce components and activities. Since large public money
is involved in the transactions, the role of information security and privacy is not exaggerated in this kind of business.
After examining the technologies used in e-commerce, the article goes on to identify the security requirement of e-commerce
systems from perceived threats and vulnerabilities. Then e-commerce security is viewed as an engineering management problem
and a life cycle approach is put forward. How the e-commerce systems can be made secure using the life cycle approach is outlined.
The relevant standards and laws are also discussed in the perspective of e-commerce. The article closes with some future research
directions and conclusions. 相似文献
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Xiaofei Huang Kehao Tao Tianli Han Jinjin Li Huigang Zhang Chaoquan Hu Junjie Niu Jinyun Liu 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(39):2302706
Due to the relatively high capacity and lower cost, transition metal sulfides (TMS) as anode show promising potential in sodium-ion batteries (SIBs). Herein, a binary metal sulfide hybrid consisting of carbon encapsulated CoS/Cu2S nanocages (CoS/Cu2S@C-NC) is constructed. The interlocked hetero-architecture filled with conductive carbon accelerates the Na+/e− transfer, thus leading to improved electrochemical kinetics. Also the protective carbon layer can provide better volume accommondation upon charging/discharging. As a result, the battery with CoS/Cu2S@C-NC as anode displays a high capacity of 435.3 mAh g−1 after 1000 cycles at 2.0 A g−1 (≈3.4 C). Under a higher rate of 10.0 A g−1 (≈17 C), a capacity of as high as 347.2 mAh g−1 is still remained after long 2300 cycles. The capacity decay per cycle is only 0.017%. The battery also exhibits a better temperature tolerance at 50 and −5 °C. A low internal impedance analyzed by X-ray diffraction patterns and galvanostatic intermittent titration technique, narrow band gap, and high density of states obtained by first-principle calculations of the binary sulfides, ensure the rapid Na+/e− transport. The long-cycling-life SIB using binary metal sulfide hybrid nanocages as anode shows promising applications in versatile electronic devices. 相似文献
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Fu-Kwun Wang Chang-Yi Huang Tadele Mamo Xiao-Bin Cheng 《Quality and Reliability Engineering International》2021,37(1):34-46
Proton exchange membrane fuel cell (PEMFC) stacks are widely used in mobile and portable applications due to their clean and efficient model of operation. We propose an ensemble model based on a stacked long short-term memory model that combines three machine-learning models, including long short-term memory with attention mechanism, support vector regression, and random forest regression, to improve the degradation prediction of a PEMFC stack. The prediction intervals can be derived using the dropout technique. The proposed model is compared with some existing models using two PEMFC stacks. The results show that the proposed model outperforms the other models in terms of mean absolute percentage error and root mean square error. Regarding the remaining useful life prediction, the proposed model with the sliding window approach can provide better results. 相似文献
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Failures in critical infrastructures may be hazardous to population, economy, and national security. There can be strong interdependencies between various infrastructures, but these interdependencies are seldom accounted for in current risk and vulnerability analyses. To reduce probability and mitigate consequences of infrastructure failures, these interdependencies have to be assessed. The objective of this paper is to present a method for assessing interdependencies of critical infrastructures, as part of a cross-sector risk and vulnerability analysis. The method is based on a relatively simple approach applicable for practitioners, but may be extended for more detailed analyses by specialists. Examples from a case study with the Emergency Preparedness Group of the city of Oslo, Norway, are included. 相似文献
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目的 研究堆码产品的缓冲包装在连续复杂运输工况下的受到振动冲击后的疲劳损伤。方法 采用Miner准则、Dirlik法和Steinberg三区间法,并结合Workbench和ncode疲劳分析模块建立2层堆码模型进行有限元仿真,通过不同工况的振动激励来模拟缓冲包装在复杂连续工况下的振动疲劳损伤并得出对应的疲劳结果云图和疲劳寿命云图。结果 复杂工况下瓦楞外包装的疲劳寿命为9.26×109,最大节点处的损伤值为1.08×10-10,EVA内缓冲衬垫的疲劳寿命为1.882×1014,最大节点处的损伤值为5.313×10-15。堆码包装模型的易损点主要集中于内外缓冲包装的边角和楞边区域。通过Dirlik和Steinberg方法证明了缓冲件在经历16 h的复杂运输工况下的剩余寿命为2.6×104 h和9.198×105 h,利用Miner准则证明了缓冲包装结构对内部产品可以起到良好的保护作用。结论 通过该种方法可以对堆码包装在复杂工况下进行可靠的疲劳寿命分析,并对堆码... 相似文献
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