大型自航绞吸挖泥船的发展与新的技术要求

论文介绍了国内外自航绞吸挖泥船的发展现状,对比了国内外大型自航绞吸挖泥船技术特点,提出了大型自航绞吸挖泥船新的技术要求;探讨了自航绞吸挖泥船装机功率科学合理增加的可行性;文中表述了绞吸式挖泥船关键技术的研究和应用。     

农用车辆配套简易播种机设计

文章介绍的旋耕播种机主要由六个部分组成,即:悬挂装置、动力传输装置、旋耕装置、播种装置、镇压装置和链条传动装置。农用车辆拖拉机前进后镇压装置也向前运行带动链条传动装置,与之另一端连接的播种箱的播种轴也随之转动,使种子从排种孔中流出顺着播种管与播种开沟器流出最后流入垄沟,从而实现播种机的播种作业。播种机播种后的农作物生长均匀分布排列整齐,这样可以便于人们实现播种过后对田地的管理作业,也是人们实现农业机械现代化的重要技术手段之一。     

高速公路隧道突发事件应急管理研究

高速公路隧道应急管理研究目的在于完善隧道应急管理体制,在应急救援过程中提高应急救援效率,尽可能的减少人民群众生命财产损失。文章分析了应急管理体系、应急预案、应急演练以及应急新闻发布方面存在的问题,并提出灵活组合使用四种应急处置机制、加强应急救援演练等建议。     

纯电动卡车总装混线生产的工艺研究

纯电动卡车的产品特点与传统燃油卡车既有共性又存在差异,对比两种车型的底盘装配和调试工艺后,在传统燃油车总装配线的基础上设计了一套新能源的装配工艺流程,不仅提高总装配车间柔性化生产,还实现了纯电动卡车和燃油卡车的混线生产。     

市政给中水管道设计优化分析

市政给排水管道结构设计是一项关乎管道安全的重要设计,设计人员往往根据以往经验和常规做法进行管道设计,忽略了管道安全计算,这将直接影响城市市政道路给排水管道工程的质量。结合实际项目,对给水、中水管道的常规管材球墨铸铁管进行结构计算分析,并根据计算结果选择相应的措施,进一步完善市政管道设计,在满足设计规划、规范和要求的基础上,提高设计质量,确保城市道路市政给排水管道正常、高效地运行。     

综合交通枢纽车道边交通组织方式研究

针对现代综合交通枢纽车道边的交通组织方式进行研究,结合车站的整体建筑布局、周边路网、交通量等提出了简单、实用和高效的交通组织方式。     

On a link-based day-to-day traffic assignment model

In this paper, we perform a rigorous analysis on a link-based day-to-day traffic assignment model recently proposed in He et al. (2010). Several properties, including the invariance set and the constrained stability, of this dynamical process are established. An extension of the model to the asymmetric case is investigated and the stability result is also established under slightly more restrictive assumptions. Numerical experiments are conducted to demonstrate the findings.     

广西高速公路生态环境保护对策研究

文章针对广西高速公路生态环境现状,分析当前高速公路环境保护工作中存在的问题,从生态学角度提出了高速公路沿线生态环境建设和保护对策。     

Activity involvement and time spent on computers for leisure: an econometric analysis on the American Time Use Survey dataset

Internet is capturing more and more of our time each day, and the increasing levels of engagement are mainly due to the use of social media. Time spent on social media is observed in the American Time Use Survey and recorded as leisure time on Personal Computer (PC). In this paper, we extend the traditional analysis of leisure activity participation by including leisure activities that require the use of a PC. We study the substitution effects with both in-home and out-of-home leisure activities and the time budget allocated to each of them. The modeling framework that includes both discrete alternatives and continuous decision variables allow for full correlation across the utility of the alternatives that are all of leisure type and the regressions that model the time allocated to each activity. Results show that there is little substitution effect between leisure with PC and the relative time spent on it, with in-home and out-of-home leisure episodes. Households with more children and full-time workers are more likely to engage in in-home and PC related leisure activities (especially during weekends). Increments in the travel time of social trips result in significant reductions in leisure time during weekdays.