青岛高新区雨水利用研究

在水资源急缺以及雨水利用技术大规模应用下,对青岛高新区提出了雨水利用的开源模式,并进行雨水利用试点,可促进该区域的水资源持续利用。     

浅谈调蓄池在大定海低标排水系统改造工程中的应用

上海中心城区的合流制强排系统雨天放江,已成为上海城区水体污染的主要原因之一,设置调蓄池可以减少排入黄浦江的污染物总量,减轻对黄浦江的污染。该文介绍了调蓄池在大定海低标排水系统改造工程中的作用、设置形式、调蓄容积计算、运行模式和防沉砂设计。     

出行者特征要素对公交服务模式的影响分析

公共交通是面向大众的服务,公共交通服务模式的制定与完善需要重点考虑出行者的出行需求,才能从根本上提高公共交通的竞争力。借鉴服务经济学的理论将公共交通服务模式分为公交服务标准、出行者界面、公交服务环境和技术4个维度。基于攀枝花市居民出行调查与公交专项调查数据,应用SPSS定量分析出行者特征要素与公交服务选择的相关性,以考察研究出行者对于公交服务的需求,并提出改善策略。通过研究表明,出行目的、出行时间、职业和年龄与公交服务模式的相关性较大。     

8170型柴油机应用可变几何排气管增压系统的计算研究

为了实现8缸柴油机高低负荷兼顾,提出新的可变几何排气管增压系统,通过安装在排气管上的可控阀门来实现增压方式的转换。对可变几何排气管增压系统进行稳态和瞬态计算研究。稳态计算结果表明,与原机MPC增压系统相比,在25%、50%、75%和100%负荷时,可变几何排气管增压系统的平均扫气系数均大于MPC系统的平均扫气系数,油耗均小于MPC增压系统的油耗。瞬态计算结果表明,可控阀门关闭以后,压气机后进气压力增加的程度较大。     

水下爆炸载荷作用下舰船总体毁伤模式研究

建立舰船三维有限元模型,采用数值仿真方法计算舰船总体在水下爆炸载荷作用下的动响应,讨论船体主要构件破坏模式以及舰船鞭状运动对船体总纵强度的影响,总结舰船总体在冲击波阶段与气泡脉动阶段舰船毁伤模式及规律。     

基于出行方式链的城市轨道交通客流分析方法

传统"四阶段"法预测流程无法准确预测与轨道交通接驳的交通方式及换乘客流.借鉴基于活动的交通需求模型中利用出行链来解释人的出行行为的方法,提出了基于出行方式链的轨道交通客流分析方法.使用三层的Nested-Logit模型来模拟出行者选择轨道交通为主要出行方式接驳其他交通方式和预测各种方式的客流,建立了轨道交通出行方式链模...     

Schedule-based transit assignment model with vehicle capacity and seat availability

In this paper, we propose a new schedule-based equilibrium transit assignment model that differentiates the discomfort level experienced by sitting and standing passengers. The notion of seat allocation has not been considered explicitly and analytically in previous schedule-based frameworks. The model assumes that passengers use strategies when traveling from their origin to their destination. When loading a vehicle, standing on-board passengers continuing to the next station have priority to get available seats and waiting passengers are loaded on a First-Come-First-Serve (FCFS) principle. The stimulus of a standing passenger to sit increases with his/her remaining journey length and time already spent on-board. When a vehicle is full, passengers unable to board must wait for the next vehicle to arrive. The equilibrium conditions can be stated as a variational inequality involving a vector-valued function of expected strategy costs. To find a solution, we adopt the method of successive averages (MSA) that generates strategies during each iteration by solving a dynamic program. Numerical results are also reported to show the effects of our model on the travel strategies and departure time choices of passengers.     

Bus congestion, optimal infrastructure investment and the choice of a fare collection system in dedicated bus corridors

Microeconomic optimisation of scheduled public transport operations has traditionally focused on finding optimal values for the frequency of service, capacity of vehicles, number of lines and distance between stops. In addition, however, there exist other elements in the system that present a trade-off between the interests of users and operators that have not received attention in the literature, such as the optimal selection of a fare payment system and a designed running speed (i.e., the cruising speed that buses maintain in between two consecutive stops). Alternative fare payment methods (e.g., on-board and off-board, payment by cash, magnetic strip or smart card) have different boarding times and capital costs, with the more efficient systems such as a contactless smart card imposing higher amounts of capital investment. Based on empirical data from several Bus Rapid Transit systems around the world, we also find that there is a positive relationship between infrastructure cost per kilometre and commercial speed (including stops), achieved by the buses, which we further postulate as a linear relationship between infrastructure investment and running speed. Given this context, we develop a microeconomic model for the operation of a bus corridor that minimises total cost (users and operator) and has five decision variables: frequency, capacity of vehicles, station spacing, fare payment system and running speed, thus extending the traditional framework. Congestion, induced by bus frequency, plays an important role in the design of the system, as queues develop behind high demand bus stops when the frequency is high. We show that (i) an off-board fare payment system is the most cost effective in the majority of circumstances; (ii) bus congestion results in decreased frequency while fare and bus capacity increase, and (iii) the optimal running speed grows with the logarithm of demand.     

坚持公交优先,发展立体交通,构建市民和谐出行环境

公交优先发展战略是当前许多国家实施可持续交通发展的治本之选,公交优先体现了平民权利的优先.结合《建设部关于优先发展城市公共交通的意见》和南京市交通建设规划现状,对公交优先策略的必要性、实施公交优先的方法与有效措施等问题进行了深入分析,提出了坚持公交优先,发展立体交通,构建市民和谐出行环境的城市交通建设理念.     

基于绿色交通理念的深圳市盐田区交通规划探索与实践

绿色交通已经成为建设低碳社会的有效抓手,是当今世界城市交通发展的必然趋势。首先介绍了绿色交通的内涵与基本特征,提出了绿色交通的发展内容与模式;在借鉴国内外绿色交通发展经验的基础上,并在深圳市绿色交通体系及模式的指引下,对深圳市国家生态城区——盐田区进行了绿色交通规划的探索。结合盐田区城市土地空间不足、生态资源受约束的现实条件,采取了空间差异性交通发展模式,并着重分析了地区公共交通系统、自行车、山海步行系统的发展规划思路。