共查询到20条相似文献,搜索用时 46 毫秒
1.
2.
3.
4.
5.
6.
依据长输管道长时间实际运行过程中的运行状况,可以改变长输管道进站压力设定值。依据公式:P_实=P_进+P_损,对长输管道上不同输油量对应的进站压力数据进行计算,得出所需要的符合实际运行的系列数据,然后综合分析,确定适合长输管道长时期运行的经济实用的进站压力值。 相似文献
7.
8.
高温大直径薄壁管道由于受到径向膨胀的影响,管道易发生塑性变形、泄漏等管道破坏情况。小直径管道的常规应力计算,则对径向膨胀忽略不计。为了解决径向膨胀引起高温大直径管道塑性变形等问题,通过对催化烟气管道的应力模拟与分析,探讨在节点和补偿器建模因素影响下,高温大直径管道应力的变化。结果表明:对于高温大直径薄壁管道,当采用管壁节点时径向膨胀对管道应力的影响较大;当采用复杂补偿器模型时管道节点的位移和约束力改变较大。最后通过数据分析得出采用管壁节点约束可模拟管道径向膨胀和复杂补偿器模型可优化管道应力分析,为高温大直径管道的应力模拟提供参考。 相似文献
9.
简单介绍了我国管道企业站(库)内埋地管道阴极保护技术现状,对站(库)内管道阴极保护实施过程中的绝缘、阳极分布、调试、安全等问题提出了解决、处理措施。 相似文献
10.
11.
开展水土流失监测是水土保持监管的重要手段。文章以广西沿海高速公路改扩建工程一期工程水土保持监测实践为例,分析了工程建设水土流失特点,介绍了水土保持监测技术和方法,并通过对工程实例监测结果的分析评价,提出了水土保持监测工作中易出现的问题及相应的解决方案。 相似文献
12.
Caspar G. Chorus 《Transportation Research Part A: Policy and Practice》2012,46(7):1003-1012
This paper studies to what extent the Logsum-measure of user benefits relates to travelers’ perceptions of choice set-desirability and choice-satisfaction. Knowing these relations is important since researchers have recently started to analyze and interpret user benefits in general – and Logsums in specific – in terms of these more behaviorally oriented notions, rather than in terms of expected utility. Participants to a stated route choice experiment were asked to indicate, after each choice made, to what extent they considered the choice set to be desirable, or to what extent they were satisfied with the chosen alternative. These measurements were correlated with Logsums that were computed for each choice situation. In addition, the paper derives a regret-based Logsum (which gives the expected regret of a choice situation) and presents a comparison with its utilitarian counterpart. Also for this regret-based Logsum, correlations with desirability- and satisfaction-ratings are computed. As a general finding, it appears that all computed correlations are rather weak. This suggests that, at least in the context of our data, the utility-based Logsum and its regret-based counterpart appear to have only a fairly weak connection with the behavioral notions of choice set-desirability and choice-satisfaction. 相似文献
13.
14.
通过研究汽车与船舶的油耗特点,结合燃油种类与CO_2排放量的关系,建立了计算公路运输与水路运输单位耗油量与单位CO_2排放量的数学模型。通过敏感性分析,研究车速或航速与载货率对车辆或船舶单位CO_2排放量的影响。以从厦门港到盐田港的干散货运输为例,做了节能减排计算分析,并将结果与用其他方法获得的结果对比。在此基础上,对公路运输与水路运输节能减排做了敏感性分析研究,可以计算出能够体现水路运输节能减排优势的临界货运量。结果表明本文中介绍的方法能够为核算、比较公路运输与水路运输的节能减排效果提供更科学的量化参考。 相似文献
15.
Recent years have shown a rising popularity of the concept of resilience—both theoretically and empirically—in complex systems analysis. There is also a rising literature on resilience in the transport and spatial-economic field. The pluriform interpretation of resilience (e.g., engineering vs. ecological resilience) is related to methodological differences (e.g., stability in dynamics vs. evolutionary adaptivity). But in all cases the fundamental question is whether a complex system that is subjected to an external shock is able to recover, and if so, to which extent. The present paper [Based on presentation from cluster 6 (Accessibility) of the Nectar 2015 conference in Ann Arbour, USA.] aims to add a new dimension to resilience analysis in spatial systems, by addressing in particular the relationship between spatial accessibility at a municipality level and the resilience outcomes of the spatial system concerned. It does so by investigating to which extent accessibility of Swedish and Dutch municipalities has mitigated the local shock absorption from the recent economic recession. In our study the shock absorption capacity of municipal accessibility is estimated by analysing the relevant resilience indicators for the period concerned. In this context, conventional resilience indicators based on either multivariate complex data (in particular, the Foster Resilience Capacity Index) or employment data (in particular, the Martin Resilience-Employment Index) are confronted with spatial connectivity data based on local accessibility measures, so that geographical mobility may be regarded as one of the shock-mitigating factors. The empirical analysis is carried out for two countries which have both proven to be rather shock-resistant during the recent economic crisis, viz. Sweden and The Netherlands. Clearly, the geographical structure of these countries forms a sharp mutual contrast, viz. a spatially dispersed economy with a few distinct urban concentrations versus a spatially dense economy with one major metropolitan centre (the Randstad), respectively. Our experiments are carried out for the 290 municipalities in Sweden and 40 COROPs in The Netherlands. Our research findings show relevant and new insights into differences in the local recovery potential in Sweden and The Netherlands. 相似文献
16.
隧道及地下工程结构防排水技术的发展和应用 总被引:4,自引:0,他引:4
文章总结了大瑶山隧道修建以来其复合式衬砌结构防排水试验研究和应用情况,介绍了塑料防水隔离层的防水机理及各种防水型式的优缺点,提出了改进建议. 相似文献
17.
18.
19.