汽车空气悬架的结构型式及导向机构研究

对空气悬架的结构型式及特点予以介绍，并对几种典型的导向机构进行了较为详细的分析。阐明了导向机构与整车操纵稳定性的关系。     

萎缩性胃炎胃泌酸储备功能的研究

采用五肽胃泌素刺激试验对47例慢性萎缩性胃炎（CAG）进行胃液分析，并和49例慢性浅表性胃炎（CSG）进行对照，以测定CAG患者胃酸分泌的储备功能。结果：①CAG患者BAO、MAO和PAO均明显降低，平均壁细胞数4．9亿个。非分泌状态的储备壁细胞3．7亿个。CSG平均壁细胞数8．1亿个，6．5亿个是非分泌状态的储备壁细胞，大约是CAG的1．7倍，表明CAG胃泌酸储备功能降低。②CGG患者胃液分泌量明显减少，但空腹胃液及五肽胃泌素刺激后胃液［H+］和CSG相同，说明CAG现存壁细胞的功能正常。③五肽胃泌素刺激后［H+］及胃液分泌量在CAG和CSG均明显增加，说明H+分泌速率代偿性增强，因此胃泌酸储备功能包括二个方面即壁细胞的数量和壁细胞对H+的分泌速率。     

Assessing the CO2 impact of current and future rail track in the UK

This paper investigates the CO₂ impact of current and future UK rail track and estimates the material, process and transport emissions associated with construction, maintenance and end-of-life activities for designs at high and low traffic loads. Analysis shows that for current track configurations, track with concrete sleepers has the lowest CO₂ impact, followed by steel, hardwood and softwood. Several potential future rail track designs have been analysed including embedded rail and double and quadruple-headed rail. All future track designs have a lower impact than current designs, but this improvement is more marked at high traffic loads. Up to a 40% reduction in CO₂ impact could be achieved if the UK rail network was to move from conventional track design to a double-headed embedded rail design. Key levers for reducing the CO₂ impact of track are identified as service life extension, traffic load reduction and the selection of low impact track designs.     

An integrated model system and policy evaluation tool for maximizing mobility under environmental capacity constraints: A case study in Dalian City,China

This paper presents an integrated model system for mobility maximization based on a quantified specification of environmental capacity, and evaluates policy interaction and effectiveness by simulating a number of policy scenarios. The system is designed to specify the maximum level of car ownership and number of trips by private and public modes subject to an environmental capacity constraint defined as the frontier emission under maximum system efficiency. Four types of hypothetical policies (population change, urban sprawl, land-use pattern and network improvement) are designed and the effects of 13 policy scenarios are simulated using data of Dalian City, China. Results reveal that the integrated model system reacts sensitively to policy interventions. The urban sprawl reflected in a changing residential distribution from central to suburban areas is most instrumental from the perspective of pollution alleviation. If the goal is to simultaneously reduce emissions while accommodating mobility, two combinational policy scenarios outperform all others.     

Economic analysis of Japanese air pollution regulation: An optimal retirement problem under the vehicle type regulation in the NOx–particulate matter law

This paper examines the vehicle type regulation that was introduced under the Automobile Nitrogen Oxides–Particulate Matter Law to mitigate air pollution in Japanese metropolitan areas. The vehicle type regulation effectively sets the timing for vehicle retirement by initial registration year and type. However, there was no consideration of cost or efficiency in choosing the timing of retirement. We solve an optimal problem to maximize the social net benefit under the current framework of the vehicle type regulation. The analysis finds that the net benefit can more than double if the optimal retirement timing is chosen. Further, we find that even a simple alteration of the retirement timing can increase the social net benefit by 13%.     

Evaluation of factors for carrier selection in the China Pearl River delta

The efficient integration of logistics modes is critical for international cargo shipping. The local transportation connecting to the export port then plays a vital role in such integration. This paper investigates the problems of carrier selection in the China Pearl River delta area, with respect to international shipping. The analytical hierarchy process (AHP) model is constructed based on a comprehensive industrial interviews and statistical analysis. Rather than simply ranking the given alternatives, we use AHP is used to analyse the weakness and strength of impacting factors in carrier selection. The model is implemented under different types of shipper. Seven criteria are statistically summarized from the questionnaire for evaluating eight different modes. The results are useful to those liner companies serving the PRD region in relationship to port selection and fleet deployment.     

Sampling of alternatives for route choice modeling

This paper presents a new paradigm for choice set generation in the context of route choice model estimation. We assume that the choice sets contain all paths connecting each origin–destination pair. Although this is behaviorally questionable, we make this assumption in order to avoid bias in the econometric model. These sets are in general impossible to generate explicitly. Therefore, we propose an importance sampling approach to generate subsets of paths suitable for model estimation. Using only a subset of alternatives requires the path utilities to be corrected according to the sampling protocol in order to obtain unbiased parameter estimates. We derive such a sampling correction for the proposed algorithm.Estimating models based on samples of alternatives is straightforward for some types of models, in particular the multinomial logit (MNL) model. In order to apply MNL for route choice, the utilities should also be corrected to account for the correlation using, for instance, a path size (PS) formulation. We argue that the PS attribute should be computed based on the full choice set. Again, this is not feasible in general, and we propose a new version of the PS attribute derived from the sampling protocol, called Expanded PS.Numerical results based on synthetic data show that models including a sampling correction are remarkably better than the ones that do not. Moreover, the Expanded PS shows good results and outperforms models with the original PS formulation.     

地铁暗挖工程对既有结构影响的控制——大北窑桥DB134、DB135、DB142桥桩加固技术

为减小暗挖施工对既有桥梁短桩的环境影响,北京地铁10号线国贸站通过采用复合锚杆桩对既有桥梁短桩进行加固隔离围护,以达到减小桥桩沉降的目的,介绍复合锚杆桩的施工工艺。