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41.
The reduction of CO2 emissions and fuel consumption from road transportation constitutes an important pillar of the European Union strategy for implementing the Kyoto Protocol. The commitment to reduce passenger car average CO2 emissions at 140 g/km in 2008 signed by European car manufacturers and the European Commission is up to now the most important initiative towards limiting CO2 emissions from road transportation and particularly from passenger cars. Until today, annual reports show the manufacturers’ efforts in limiting CO2 emissions is within the intermediate target set by the commitment and these results are incorporated in emissions estimations and scientific studies. This paper analyses the origin of the progress achieved so far in CO2 emissions and attempts an assessment of the commitment using independent experimental emission data. Additionally, the applicability of the commitment-monitoring data into policy and decision-making tools is being examined. The results indicate that a significant part of the reductions achieved so far is due to a market shift towards diesel vehicle sales and that no reduction factors should be applied yet in CO2 emissions estimation models. 相似文献
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福州火车站智能化系统包括到发通告、旅客引导显示、客运广播、建筑设备自动控制等7个子系统和系统总集成。 相似文献
45.
The effect of the degree of crosslinking of glassy polymers on the transport mechanism of penetrants was investigated using a series of divinyl benzene (DVB)-crosslinked polystyrenes of nominal crosslinking ratio X from 0.001 38 to 0.060 mol DVB/mol styrene. The number average molecular weight between crosslinks, , was determined from equilibrium swelling experiments in cyclohexane. Dynamic swelling experiments with cyclohexane at 30°C showed that the mechanism of penetrant transport was anomalous. An overshoot in the penetrant uptake was observed, characteristic of macromolecular relaxations and of changing solubility of the cyclohexane in the continuously swelling polystyrene. Photographs of various samples during the swelling process showed that solvent crazing occurred predominantly in loosely crosslinked samples. 相似文献
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Open window buses without air-conditioning are a major mode of urban and inter-city transport in most countries. High occupancy
combined with hot and humid conditions makes travel in these buses quite uncomfortable. In this study air flow through a bus
has been studied that could be the basis for low cost and eco-friendly methods of increasing passenger comfort and possibly
reduce drag. The aerodynamics of such a road vehicle has not been studied as previous investigations have been confined to
vehicles with closed windows that present a smooth exterior to air flow. Using a 1:25 scaled Perspex model of an urban bus
in Delhi, flow visualization was performed in a water channel. The Reynolds numbers were one-tenth of a real bus moving at
10 m/s. Smoke and tuft visualizations were also performed on an urban bus at 40 km/h. Numerical simulations were performed
at the actual Reynolds number. Even though there were Reynolds number differences, the broad features were similar. Air enters
the bus from the rear windows, moves to the front (relative to the bus) and exits from the front windows. Inside air velocity
relative to the bus is about one-tenth of the free-stream velocity. The flow is highly three-dimensional and unsteady. 相似文献
50.
Hermann Knoflacher 《Sadhana》2007,32(4):293-307
Technological determinism has become a kind of religion for many people since it appears to offer solutions for societal problems
as never before in history. Transport is one of the fascinating technology branches developed during the last 200 years. Effortless
movement over long distances has become possible for car users as long as cheap fossil energy is available. However, the effect
of fast transport on urban structures and society was not taken into account when developing these technical means. Technologists
and economists have used indicators for expected benefits of these fast transport modes without taking into account the real
system effects on society and urban structures. Plausible assumptions and hopes instead of scientific understanding of the
complex system are used in practice. In contradiction to widely held beliefs of transportation planners, there is actually
no growth of mobility if counted in number of trips per person per day, no time saving by increasing speed in the system,
and no real freedom of modal choice. Modal choice is dependent on physical and other structures, the artificial environment
built by urban planners, transport experts and political decisions. The core hypothesis of traditional urban and transport
planning ‘growth of mobility’, ‘travel time saving by increasing speed’ and ‘freedom of modal choice’ are myths and do not
exist in the real urban and transport system. This is the reason why urban planning and transport planning based on traditional
non-scientific assumptions is creating continuously not only more transport problems, but also environmental and social as
well as economic problems all over the world, where these principals are applied. Urban transport planning in Europe, understanding
the transport system and the solutions are presented in this paper. 相似文献