Late summer stratification, internal waves, and turbulence in the Yellow Sea

Microstructure profiling measurements at two locations in the Yellow Sea (a deeper central basin and a local shelf break) were analyzed focusing on tidal and internal-wave induced turbulence near the bottom and in the pycnocline. A classical three-layer density structure consisting of weakly stratified surface and bottom boundary layers and a narrow sharp pycnocline is developed by the end of warm season. Turbulence in the surface layer was not influenced by the tidal forcing but by the diurnal cycle of buoyancy flux and wind forcing at the sea surface. The enhanced dissipation and diffusivity generated by the shear stress at the seafloor was found in the water interior at heights 10–15 m above the bottom with a phase shift of ~ 5–6 m/h. No internal waves, turbulence, or mixing were detected in the pycnocline in the central basin, in contrast to the pycnocline near the local shelf break wherein internal waves of various frequencies were observed all the time. The thickness of the surface layer near the local shelf break slightly exceeded that of the bottom layer (20 vs. 18 m). A 5–6 m high vertical displacement of the pycnocline, which emerged during the low tide, was arguably caused by the passage of an internal soliton of elevation. During this episode, the gradient Richardson number decreased below 0.25 due to enhanced vertical shear, leading to local generation of turbulence with dissipation rates exceeding the background level by an order of magnitude.     

用地性质与线路区位对社区公交的影响研究

社区公交的开通可有效缓解乘客出行的"最后一公里"问题,合理的站点布局可提高社区公交的客流量、促进公共交通发展。基于交通实地调查、SP调查和RP调查,对郑州市社区公交现状进行分析,分别对出行者的性别、年龄、家庭人口数、月收入、职业、出行目的进行特征分析。考虑用地性质和线路的区位影响,分别对社区公交的客流量和乘坐社区公交前使用的交通方式进行研究,分析其对社区公交的站点布设、两站点间的距离、发车间隔和发车频率等的影响,为社区公交的布设提供依据,增加社区公交的竞争力,更好地满足社区居民的出行需求。     

Evaluation of energy consumption of vehicles in EU Trans-European Transport Network

The paper presents the results of field tests evaluating energy consumption in the vehicles of Trans-European Transport Network (TEN-T) of selected EU countries: Poland, Germany and France. The energy consumption of vehicles in a highway system was assessed based on the telemetry analysis systems for traction parameters, tachograph record of digital speed waveform and their statistical analysis. The empirical cumulative distribution functions of speed transitions (acceleration, deceleration) were used to determine the kinetic energy losses of the vehicle (fuel consumption). To assess the statistical significance of differences between cumulative distribution functions the Smirnov–Kolmogorov test was used.     

Using the sustainable modified TAM and TPB to analyze the effects of perceived green value on loyalty to a public bike system

This article explores the effects of perceived green value, perceived green usefulness, perceived pleasure to use, subjective norms and perceived behavioral control on green loyalty to a public bike system. The mediators between perceived green value and green loyalty and a moderator of general attitude toward protecting the natural environment are also discussed. The aim of this research was to understand how to establish green loyalty via the other dimensions based on the sustainable modified technology acceptance model (modified TAM), the theory of planned behavior (TPB), and a moderator. The findings reveal that perceived pleasure to use and subjective norms have the strongest power to influence loyalty for both users and non-users. The implications of this finding are that fun in people’s lives has a strong influence on sustainable continuous use of public bikes, and that subjective norms are more effective for non-users. In addition, environmental attitude has stronger moderating effects for non-users than for users on perceived green usefulness, perceived pleasure and subjective norms. Therefore, governmental policies should promote the attitude of protecting the natural environment, perceptions of pleasure, and subjective norms so as to increase green loyalty to public bike-sharing.     

An aircraft boarding model with the group behavior and the quantity of luggage

A reasonable boarding model can effectively improve the boarding efficiency. Therefore, developing boarding models/strategies to improve the boarding efficiency has been an interesting topic in the air transportation. In this paper, we incorporate the group behavior and the quantity of luggage into the boarding process, and then develop an extended boarding model to investigate the effects of the two factors on the delay time and boarding time. The numerical results show that the quantity of luggage may make each passenger’s boarding behavior more complex, while the group behavior can shorten some passengers’ delay time and the total boarding time. The results can help administrators organize the boarding process and enhance the boarding efficiency.     

厦漳跨海大桥南汊主桥高低腿龙门吊设计与研究

钢-砼组合梁以其自重小,能充分发挥钢材的抗拉性能和砼的抗压性能,以达到增加桥梁的抗弯性能和强度等特点,在斜拉桥主梁中应用越来越广泛.组合梁的钢梁部分在工厂制作成一个个构件,运送到现场拼装,砼部分可以现浇也可以预制安装,因此组合梁吊装施工中构件的起吊是关键一环.针对用于厦漳跨海大桥南汉主桥组合梁构件起吊的高低腿龙门吊的研究设计做了介绍.     

基于广义3S的公路安全评价数据采集方法探讨

本文以当前测绘行业比较热门的广义3S技术为基础,针对公路运营安全这一热点问题展开研究。内容涉及基于广义3S技术交通运营安全空间数据库的建立、基于广义3S技术的动态信息获取技术以及基于广义3S技术的动态交通运营安全后评价体系的建立等创新研究工作。     

浅谈公共交通公众出行信息服务系统的应用

本文阐述了公众出行信息服务系统在公共交通领域中的应用,目标是建设个性化的公交实时位置信息接入平台,用户可以通过自己的手机,随时随地查询本市各公交车辆的实时位置、上下行方向等信息,方便市民适时安排自己的乘车计划,达到方便出行的目的.     

大型国际活动交通组织规划方法综述

探讨夏季奥运会采用的交通组织规划方法,同时总结世界上最大规模的特殊活动——沙特阿拉伯麦加朝觐/副朝交通组织规划经验。每年一度的麦加朝觐已经延续几个世纪,在最近几十年人数持续增长,朝圣者已增至600万人,包括朝觐一周内300万人和斋月期间100万人。目前,这项活动是历史上规模最大且定期举行的特殊活动,其规模预计还将大幅增长。奥运会是世界上第二大特殊活动,每4年举办一次,在主办城市持续2周。通常奥运会主办城市自身的交通压力已经非常巨大,在奥运会期间同时还要额外满足4万名奥运官员和运动员以及800万名观众的出行需求。因此,奥运会交通组织规划对于保障赛事顺利开展至关重要。通过描述这两项活动的背景和交通供需特征,概述已有交通组织规划方法,旨在分析和总结大型活动交通组织规划的经验教训,探讨可供选择的规划策略。     

基于模拟直齿轮啮合模型的齿根强度分析

齿轮啮合是一个比较复杂的过程,由于渐开线齿廓的固有特性使得齿轮在啮合过程中会产生许多非线性的影响,这些非线性影响对于齿轮啮合特性的分析和优化有着举足轻重的意义。文章首先基于先进的有限元理论,提出一种能够准确计算齿轮啮合刚度,并可模拟齿轮啮合动态过程的有限元模型。其次将应用此模型考虑摩擦的影响对直齿轮齿根应力进行分析,并对直齿轮轮齿的齿根应力在啮合过程中的变化趋势以及相应的摩擦影响进行讨论和总结。