排序方式: 共有89条查询结果,搜索用时 15 毫秒
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涡干涉的流动显示与数值模拟 总被引:1,自引:0,他引:1
通过流动可视化方法并结合数值计算模拟了两个不同旋转方向涡的干涉及其发展过程.结果表明:在靠近装有涡产生器(VG)壁面的截面上的涡的强度较大,远离壁面的截面上的涡的强度较小;不同旋转方向的两个涡系相互干涉时合成涡系的强度有减弱趋势,离装涡产生器表面较近的纵向切面上合成涡系的强度减弱程度较小,在离装涡产生器表面较远的纵向切面上合成涡系的强度减弱程度较大,中心切面上合成涡系的强度减弱程度居中. 相似文献
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B. M. Duan Q. N. Wang J. N. Wang X. N. Li T. Ba 《International Journal of Automotive Technology》2017,18(2):335-344
This paper presents a calibration method of a rule-based energy management strategy designed for a plug-in hybrid electric vehicle, which aims to find the optimal set of control parameters to compromise within the conflicting calibration requirements (e.g. emissions and economy). A comprehensive evaluating indicator covering emissions and economy performance is constructed by the method of radar chart. Moreover, a radial basis functions (RBFs) neural network model is proposed to establish a precise model within the control parameters and the comprehensive evaluation indicator. The best set of control parameters under offline calibration is gained by the multi-island genetic algorithm. Finally, the offline calibration results are compared with the experimental results using a chassis dynamometer. The comparison results validate the effectiveness of the proposed offline calibrating approach, which is based on the radar chart method and the RBF neural network model on vehicle performance improvement and calibrating efficiency. 相似文献
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This paper presents an innovative approach to analyzing road vehicle freight traffic that uses a dynamic panel data specification derived from a gravity model. This dynamic approach, which has recently been employed in international goods trade models in lieu of the traditional static specification, is applied to the case of Spain using data for the countrys 15 NUTS-3 regions between 1999 and 2009. Using the system general method of moments approach, we obtained significant evidence that the flow of vehicles carrying commodities by road has a strong persistence effect when controlling for unobserved heterogeneity. We also found that the quality of road transport infrastructure has a significant impact on vehicle trips. According to our findings, we suggest that this type of specification be employed in distribution models in which fixed effects and lags of the dependent variable are included to account for unobserved heterogeneity and persistence effects, respectively. 相似文献
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北京某高速公路孙村一大庄段双龙高架桥,桥面两侧设置混凝土防撞护栏,采用C35钢筋混凝土现场浇筑。文章介绍钢筋制作安装、模板作业、混凝土浇筑与养生等施工工艺,以及质量保证措施。 相似文献
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从市场数据收集、数据分析和营销计划3个阶段探讨了西方新兴的服务管理在我国交通信息企业市场规划中的应用,举例说明了采用产业经济和统计回归的方法进行交通信息产业市场分析的思路,提出了集成企业营销计划的具体行动指南. 相似文献
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在交通可持续发展理念的要求下,城市交通既要满足城市系统的交通需求,又必须符合资源环境的客观约束,因此,有必要采用一种定量方法直接度量人类交通活动对自然的具体影响程度,交通规划可持续发城市交通,做出正确的交通发展选择提供依据。定量分析城市交通活动对自然环境的影响,从而为我们进行已成为城市交通展的必然要求。本文引入国际上构建可持续发展指标体系四大主流方法之一的生态足迹法,提出了活动对自然影响的测度框架,并针对各类哈尔滨城市交通活动对自然影响的程度进行了分析。 相似文献