Ride sharing with flexible participants: a metaheuristic approach for large‐scale problems

Severe traffic congestion and growing ecological consciousness have led to the rise of alternative transportation systems. Ride sharing is one such alternative in which drivers and passengers with similar time schedules and travel plans are matched. For this service to be effective, a large number of users are required to increase the probability of finding suitable travel partners. The present paper proposes a late acceptance metaheuristic to decide which users act as drivers and to construct their routes. The underlying optimization model allows passengers to walk to/from alternative pickup/drop‐off locations so as to further exploit user flexibility. A computational study quantifies the impact of different types of participant flexibility on CO₂ emissions. These insights can inform and support policymakers in organizing effective ride‐sharing systems.     

掩埋小目标声探测技术研究

探测和识别沉底、掩埋水雷等小目标在军事上显得愈来愈迫切。在介绍掩埋小目标探测声纳现状的基础上,剖析了掩埋小目标声探测的技术难点,总结了小目标声探测技术的发展趋势,主要包括探测频率向低频发展,重点发展合成孔径探测技术,积极探索时反探测和MIMO探测方法,小目标识别技术向联合利用图像特征和散射特征的方向发展等,对沉底/掩埋小目标声探测技术研究及其声纳设计有借鉴指导意义。     

某公路隧道洞门段冒顶处置方案及效果

公路隧道出洞开挖时地层覆盖较薄,受地质、天气状况和施工方法不当的影响,容易发生隧道冒顶事件,冒顶处理既影响工程进度又增加了工程投资成本。本文结合某公路隧道右线出口冒顶事件,剖析浅埋大跨隧道冒顶事件发生原因和处理方案,为同类工程设计、施工提供参考与借鉴。     

LTE通信基站市电引入设计中应该考虑的问题

LTE通信基站市电引入的设计是基站建设的首要环节,直接关系到基站供电的可靠性和安全性,对通信网络的安全运行起到关键的作用。基站市电引入的设计多数由施工单位自行设计施工,造成基站市电引入方式出现较混乱的局面,不合理的设计施工会造成巨大的经济损失。做好基站市电引入设计,使市电引入方式合理化、简单化,在加大可靠性和安全性的基础上,降低投资成本,减少维护量能保障通信畅通,提高经济效益。     

Effects of different loads on structure deformation of “L”‐type large‐diameter buried pipe network based on flow–heat–solid coupling

Large‐diameter buried pipelines are widely used because of their energy‐saving advantages and high efficiency. In this paper, an “L”‐type heat pipe network was taken as the research object and was studied using the flow–heat–solid coupling method. The ANSYS Workbench platform was used to simulate heat transfer and the flow of the medium in the pipe network. The pressure and temperature of the flow field and the temperature and deformation of the solid structure under different conditions were calculated. Additionally, the deformation characteristics of the pipe network under coupled and noncoupled loads were compared. Results show that the maximum deformation was located at the corner of the elbow near the long‐arm region. The deformation of the inner wall was larger than that of the outer wall at the same position. The deformation of the pipe network was mainly affected by the pressure of the fluid. The deformation of the pipe network was influenced by the temperature and pressure loads coupled, and the coupling effect was stronger with the higher pressure and temperature of the medium. However, the coupling effect had limits.     

Variation in the volatile terpenoids of two industrially important basil (Ocimum basilicum L.) cultivars during plant ontogeny in two different cropping seasons from India

BACKGROUND: Two Ocimum basilicum cultivars, ‘Vikarsudha’ and ‘CIM‐Saumya’, grown in the Kumaon region of western Himalaya were evaluated for their essential oil yield and composition at different stages of plant growth during two distinct cropping seasons (spring–summer and rain–autumn). RESULTS: The highest yield of essential oil was obtained at full bloom stage in both cultivars in both cropping seasons. The essential oils obtained from different stages in two cropping seasons were analysed by capillary gas chromatography with flame ionisation detection, and gas chromatography–mass spectrometry. The major component of cultivar ‘Vikarsudha’ was methyl chavicol (84.3–94.3%), while for cultivar ‘CIM‐Saumya’ the main components were methyl chavicol (62.5–77.6%) and linalool (14.4–34.1%). CONCLUSION: This study clearly indicated that cultivar, cropping season, plant ontogeny and plant part had significant effects on the yield and quality of the essential oil of O. basilicum. Further, the amount of methyl chavicol in the cultivars grown in this region was higher than in cultivars from other parts of India. Copyright © 2011 Society of Chemical Industry     

地铁浅埋暗挖隧道管棚预支护数值模拟

浅埋暗挖隧道的开挖及支护方式对其周围地层的影响是三维空间问题,文中通过采用拉格朗日有限差分软件数值模拟管棚预支护对地层沉降的影响,对不同施工阶段下的地层位移、地表变形及管棚、初期支护的受力进行分析。结果表明,使用管棚预支护有效减少了地层在施工过程中的变形,将沉降值控制在允许范围。     

人工堆山工程对周边环境影响数值模拟研究

对软土地基上的拟建堆土工程进行了有限元计算,探讨了当堆土高度较高时引起周边土体的沉降和水平位移,并通过超孔隙水压力消散时间分析堆土引起的沉降固结达到稳定所需的时间,得出了一些有参考价值的结论。     

谈供热直埋热水管道摩擦力的计算

通过对新旧规程中供热直埋热水管道摩擦力的计算分析,得出同条件下新规程单长摩擦力减小了很多,且考虑了地下水位对管道摩擦力的影响,指出摩擦力的变化直接影响到管道过渡段长度、自由端热伸长以及补偿器的选择等,其计算数据关系到管网的安全运行,具有重要的实用价值。     

远程监控地埋式箱变

本文分析了地埋式箱变内部配置设备及远程监控的实现方法和功能。