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介绍炼油装置中高温高压临氢管道产生腐蚀的形态,并对腐蚀产生的基理、影响因素及材料的回火脆性作了概要的分析和讨论。提出材料选用时应考虑的问题和相应的对策。 相似文献
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随着国内炼制俄罗斯原油企业数量的增加,常减压装置的腐蚀逐渐加重,由此带来的不利影响越来越明显,因此急需开展俄罗斯原油加工过程中的腐蚀特征及防护技术研究。以某炼油厂常减压塔顶冷凝冷却系统为研究对象,对该系统炼制俄罗斯原油前后过程进行腐蚀分析。利用RBI技术进行有针对性的计算和分析,找到最有可能发生腐蚀的位置,即原油-常顶油气换热器油气出口管段,并应用该技术开展工艺防腐的可行性分析,提出了控制腐蚀的措施和方法。通过应用RBI技术、在役检验技术与腐蚀在线监测技术,能够及时有效地筛选出准确的腐蚀部位和腐蚀发展趋势,保证装置的长周期安稳运行。 相似文献
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湛茂线是华南地区运营30多年的原油管线。针对湛茂线运营期间遇到的各类管线腐蚀问题,通过收集原油长输管线内检测腐蚀缺陷资料,深入剖析管线内腐蚀与外腐蚀产生机理,运用异常阴保电位排查、清理杂散电流、修复补强外防腐层等技术手段,对各腐蚀缺陷管段进行有针对性的防护补强和修复,有效防止管线出现异常腐蚀现象,并形成一套成熟的区域原油管线维护保养经验。 相似文献
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Pedestrians as compared to vehicular traffic enjoy a high degree freedom of movement even in heavily congested areas. Consequently, there are more alternative links available to pedestrians between a given origin‐destination (O‐D) pair. This paper describes a study done by the University of Calgary to evaluate the factors affecting the choice of route on intra‐CBD trips or trips within the Central Business District (CBD). An origin destination survey conducted in downtown Calgary, Alberta enabled the identification of the most significant factors influencing the choice. These factors were analyzed in relation to the physical characteristics of the location, personal characteristics of the trip maker and the type of the trip. It appears that most people chose the shortest link and factors such as the level of congestion, safety or visual attractions were only secondary. This suggests that the length should be made a major consideration when planning and designing pedestrian links. 相似文献
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《Transportation Research Part A: General》1991,25(6):407-418
The main deficiency of most current modeling approaches to transportation can be identified as neglect of the integration of existing geographical knowledge in regard to the ex ante transport/land use modeling approaches, with its focus on territorial dynamics and theory development. This paper addresses this aspect of the problem by introducing a theoretical and methodological framework for the analysis of the interrelationship between land uses. The analysis attempts to determine to what extent the functional land use in a city can be considered an ordered pattern. The order sought does not rely on purely spatial configurations, but on the correlation of transportation and land use. The first section of this paper focuses on theoretical considerations. It stresses the fact that conventional approaches do not apply in the present context. It then suggests an alternative based on areas of influence and measured in terms of level of attractance of land uses. The second describes a procedure based on this alternative following the remarkable contribution of Hanjoul, Beguin and Thill. An application of this procedure to the analysis of Shanghai is then examined. Finally, an evaluation of the strategies for optimizing the interrelationship between land uses is presented. The paper concludes with a possible research agenda. 相似文献
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明确埋地管道防腐保温层的技术评价标准,对埋地钢质管道的安全运行,延长管道使用寿命具有重要意义。为了对埋地管道防腐保温层做出有效评价,从间接检测与开挖检测2个方面,结合现场检测数据,提出了基于防腐保温层的电流衰减率、绝缘电阻率、质量状况与厚度的分级评价标准及基于4种评价指标的综合评判方法。工程实践表明,该评价标准对防腐保温层是否存在失效能做出有效判断。 相似文献
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介绍了城市轨道交通工程中杂散电流不同的监测系统的构成,分析了集中式、分散式和智能型等监测系统的配置和功能,以及智能型实时在线监测系统的重要意义,为轨道交通工程杂散电流监测系统的选择与应用提供参考。 相似文献
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天然气自动计量系统有多种组态软件,由于软件的不相通性,造成了计量系统数据采集的通用性差、数据传输与入库的时效性差、数据利用的可靠性低.结合各组态软件的实际情况,从设计上充分利用Oracle大数据处理能力以及Partition(分区表)的特性,实现历史数据的存储,应用WebService与COM+数据访问组件提供多层数据访问架构,采用OPC与DDE工业数据交换协议,实现了各站场计量数据的实时上传,为连续数据采集和实时监控提供了可能,节约了改造成本. 相似文献
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Joseph N. Prashker 《Transportation》1979,8(4):329-346
Reliability of travel modes was found to be the most important characteristic of transportation systems in several attitudinal investigations of individual travel behavior. This paper represents the first part of a research effort aimed at gaining a better understanding of the characteristics of reliability of transportation modes in urban travel. In this research, reliability characteristics are identified; their importance relative to each other is assessed, and an insight into possible structure of an objective reliability index is discussed. The research is based on perceived values of reliability, which were identified through a large attitudinal survey conducted in the Chicago metropolitan area. 相似文献
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