空调供风质量与客(滚)船舱室空气品质刍议

介绍了影响客(滚)船舱室内空气质量的各种因素,阐述了客(滚)船舱室室内空气品质的定义。通过实测,对三条航线的六艘船舶上不同等级客舱内的空气质量进行了调查分析,明确了影响舱室空气品质的主要因素为空调供风质量,并提出了改善的建议与措施。     

Levels of ultrafine particles in the Taipei Rapid Transit System

Ultrafine particle number concentrations are measured at five stations and inside trains on four routes in the Taipei Rapid Transit System during October–December 2007. The results indicate that there are no additional emission sources of ultrafine particle on the platforms. Ultrafine particle levels at a ground level station were, however, adversely affected by traffic outside of the station. Moreover, particles can enter the underground stations via the subway tunnels resulting in high levels during weekdays.     

Is in-cabin exposure to carbon monoxide and fine particulate matter amplified by the vehicle’s self-pollution potential? Quantifying the rate of exhaust intrusion

In-cabin exposure has increased in recent years due to longer commute and/or prolonged times in cars. The intrusion of the vehicle’s own exhaust into the passenger’s compartment has been recognized as a process that amplifies in-cabin passenger exposure. Quantifying its contribution is hampered by uncertainties associated with its measurement method such as trace tests and the lack of data regarding certain critical physical parameters, particularly those pertaining to air exchange rate (AER) and particulate matter deposition rate (DR). In this study, we present a hybrid methodology combining field measurements with a single-zone mass balance to estimate these parameters as well as the source term that represents vehicle self-pollution. In- and out-vehicle carbon monoxide (CO) and fine particulate matter (PM_2.5) were monitored concurrently in test vehicles under idle and moving conditions using several common ventilation modes. In addition to defining a hybrid methodology to characterize the underlying physical parameters, this study found that vehicle self-pollution can account for approximately 15 and 30% of CO and PM_2.5 exposure experienced by vehicle occupants respectively. Vehicle self-exhaust intrusion may constitute a significant PM exposure route for vehicle-based occupations or commuters with prolonged time in vehicles.     

荔浦县农村客运安全管理探讨

文章针对荔浦县农村客运发展现状,分析了当前农村客运市场发展存在的安全问题,提出了加强荔浦县农村客运市场安全管理的措施,为该县构建安全、和谐的农村客运市场提供思路。     

广西汽车维修业面临的问题与解决策略

汽车维修业的技术发展和经营方式始终都是与汽车工业的发展相辅相成的。广西加入东盟经济贸易圈后,汽车工业的蓬勃发展对汽车维修业提出了更大的挑战,同时也暴露了汽车维修行业存在的种种问题。文章从广西汽车维修行业面临的问题出发,提出了加快汽车维修行业发展的途径。     

贵港市客车联合经营模式浅析

文章针对承包经营模式存在的问题和不利条件,提出客车联合经营的解决对策,并结合贵港至黎塘班线实例,介绍了联合经营模式的具体操作方法与所取得的实际效果,分析了该模式尚存在的问题与相应的处治办法。     

Commuters’ exposure to PM2.5 and CO2 in metro carriages of Shanghai metro system

Air quality inside transportation carriages has become a public concern. A comprehensive measurement campaign was conducted to examine the commuters’ exposure to PM_2.5 (d_p ⩽ 2.5 μm) and CO₂ in Shanghai metro system under different conditions. The PM_2.5 and CO₂ concentrations inside all the measured metro lines were observed at 84 ± 42 μg/m³ and 1253.1 ± 449.1 ppm, respectively. The factors that determine the in-carriage PM_2.5 and CO₂ concentrations were quantitatively investigated. The metro in-carriage PM_2.5 concentrations were significantly affected by the ventilation systems, out-carriage PM_2.5 concentrations and the passenger numbers. The largest in-carriage PM_2.5 and CO₂ concentrations were observed at 132 μg/m³ and 1855.0 ppm inside the carriages equipped with the oldest ventilation systems. The average PM_2.5 and CO₂ concentrations increased by 24.14% and 9.93% as the metro was driven from underground to overground. The average in-carriage PM_2.5 concentrations increased by 17.19% and CO₂ concentration decreased by 16.97% as the metro was driven from urban to the suburban area. It was found that PM_2.5 concentration is proportional to the on-board passenger number at a ratio of 0.4 μg/m³·passenger. A mass-balance model was developed to estimate the in-carriage PM_2.5 concentration under different driving conditions.     

靖西县农村客运发展探讨

文章阐述了农村客运发展的意义,分析了靖西县农村客运发展的现状与问题,指出了该县农村客运发展的方向,并对其农村客运发展的对策与措施进行了探讨。     

A model of bus bunching under reliability-based passenger arrival patterns

If bus service departure times are not completely unknown to the passengers, non-uniform passenger arrival patterns can be expected. We propose that passengers decide their arrival time at stops based on a continuous logit model that considers the risk of missing services. Expected passenger waiting times are derived in a bus system that allows also for overtaking between bus services. We then propose an algorithm to derive the dwell time of subsequent buses serving a stop in order to illustrate when bus bunching might occur. We show that non-uniform arrival patterns can significantly influence the bus bunching process. With case studies we find that, even without exogenous delay, bunching can arise when the boarding rate is insufficient given the level of overall demand. Further, in case of exogenous delay, non-uniform arrivals can either worsen or improve the bunching conditions, depending on the level of delay. We conclude that therefore such effects should be considered when service control measures are discussed.     

汽车零部件行业发展分析与策略研究

文章对中国汽车零部件行业发展现状进行了详细分析和研究,结合汽车零部件行业发展面临的问题进行了研究,针对我国汽车零部件企业如何应对日趋激烈的汽车零部件市场提出了一些建议。     

Using non-real-time Automatic Vehicle Location data to improve bus services

Although real-time Automatic Vehicle Location (AVL) data is being utilised successfully in the UK, little notice has been given to the benefits of historical (non-real-time) AVL data. This paper illustrates how historical AVL data can be used to identify segments of a bus route which would benefit most from bus priority measures and to improve scheduling by highlighting locations at which the greatest deviation from schedule occurs. A new methodology which uses historical AVL data and on-bus passenger counts to calculate the passenger arrival rate at stops along a bus route has been used to estimate annual patronage and the speed of buses as they move between stops. Estimating the patronage at stops using AVL data is more cost-effective than conventional methods (such as surveys at stops which require much more manpower) but retains the benefits of accuracy and stop-specific estimates of annual patronage. The passenger arrival rate can then be used to calculate how long buses spend at stops. If the time buses spend at stops is removed from the total time it takes the bus to traverse a link, the remaining amount of time can be assumed to be the time the bus spends moving and hence the moving speed of the bus can be obtained. It was found that estimation of patronage and the speed of buses as they move between stops using AVL data produced results which were comparable with those obtained by other methods. However the main point to note is that this new method of estimating patronage has the potential to provide a larger and superior data set than is otherwise available, at very low cost.     

Lead emission rates from gasoline engines—a legislative and in‐use emission rate study of U.K. and U.S. to 1990

Concern for reduction in air‐borne lead emission from passenger cars is focussed on both the legislative and practical steps in reducing lead in gasoline. The historical trends and projections to 1990 of present U.S. and U.K. policies are examined in terms of a baseline passenger car lead emission rate, g.km^‐1. It is likely that should the U.K. adopt a lead‐free petrol the decrease in lead emissions will only partially parallel the present U.S. experience from a start‐up date typically post 1990. The U.S. gasoline pool philosophy has permitted lead levels in gasoline to remain high; a pitfall which the U.K./EEC should avoid.     

Including passengers’ response to crowding in the Dutch national train passenger assignment model

Transit passengers’ response to crowded conditions has been studied empirically, yet is limitedly included in transport models currently used in the design of policy and infrastructure investments. This has consequences for the practical applicability of these models in studies on, for instance, timetabling, train capacity management strategies, project appraisal, and passenger satisfaction. Here we propose four methods to include the effect of crowding, based on existing studies on passengers’ perception and response as well as often-used crowding indicators. These four alternative methods are implemented in the train passenger assignment procedure of the Dutch national transport model, and evaluated with respect to their impacts on the model results for the Dutch railway network. The four methods relate to four different ways in which an additive trip penalty and/or time-multiplier can be incorporated in the train utility function for different travel purposes, to capture the disutility of crowding as measured by the load factor. The analyses of the test case favor the hybrid method using both a boarding penalty (capturing seat availability upon boarding) and a time-multiplier (capturing physical comfort and safety throughout the trip). This method produces consistent results, while the additional computational effort that it imposes is acceptable. Further empirical underpinning is needed to conclusively show which of these methods best captures passengers’ response behavior quantitatively (for different travel purposes and conditions).     

推动容县农村客运健康快速发展的对策思考

文章结合容县农村客运现状,分析了农村客运发展存在的问题与原因,提出了发展农村客运的对策与保障措施。