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611.
Recently, telematics services and in-vehicle display devices such as the CNS (Car Navigation System) have become new causes of traffic accidents. These accidents are caused by ‘Inattention’ from the increase of the driver’s mental workload while he/she is driving. The driver of a vehicle (except for emergency or police vehicles) must not use a hand-held mobile phone while the vehicle is moving. To address this problem, Australia, England, Italy, Brazil and some states in the US have banned the use of hand-held mobile devices during driving. However, there are no restrictions on the use of in-vehicle displays or on the display’s positions. The position of a navigation system in a vehicle should be assessed objectively, and the effect of the position on the driver’s attention should be studied. Some existing research reports that in-vehicle distraction not only leads to reduced speeds and more frequent lane switching, but also more gazing by the driver to the centre of the road. In this study, to develop an assessment method and to propose the proper position of a CNS, an experiment is carried out in a driving simulator environment. Different methods to track the gaze and physical parameters of the driver are used for HMI (Human-Machine Interface) assessment. The experiment is carried out in a driving simulator to observe the glancing distribution during driving according to the position of the navigation system. Fourteen subjects participated in this experiment. Changes in subjects’ physiological signals and glancing distribution rates were collected.  相似文献   
612.
This paper reviews theoretical issues surrounding transport safety modeling and the implications for road safety policy. The behavioral mechanisms that affect transport safety are typically not considered in safety modeling. These issues are discussed in the context of trade-offs between risk-taking, as perceived by travelers, and other mobility objectives and the attributes associated with them. This is an extension of other theoretical frameworks, such as risk compensation, and attempts to integrate some of the previous frameworks developed over the years. Various examples of behavioral adaptation to specific policies are discussed and linked to the framework. These issues are then discussed in the context of improvements to empirical work in this area and the linkage of theoretical frameworks to crash modeling, in particular the estimation and use of Crash Modification Factors. Conclusions suggest that there are many deficiencies in practice, from estimation of models to choice of effective policies. Progress is being made on the former, while the publication of practical guidance seems to have substantial lags in knowledge.  相似文献   
613.
By high particulate matter(PM) reduction performance, diesel particulate filter(DPF) is applied to almost all of modern HSDI diesel engine. PM emitted from diesel engine is consist of carbon based and non-carbon based material. Representative carbon based PM is soot. Non-carbon based PM is produced by wear of engine and exhaust component, combustion of lubrication oil and sulphur in fuel. Accumulation of non-carbon based PM affects pressure difference of DPF and thus accuracy of soot mass estimation in DPF can be lowered during normal and regeneration condition when the pressure difference caused by non-carbon based PM is not recognized correctly. Also unevenly accumulated PM inside of DPF can produce locally different exhaust gas temperature and thus it can lower accuracy of soot mass estimation during regeneration. This study focuses on estimation of soot oxidation rate not by conventional pressure difference but by exhaust gas analysis at up and downstream of DPF. Results, strong correlations between CO2 -fuel mass ratio and soot oxidation was observed.  相似文献   
614.
615.
Abstract

Carpooling, the process by which individuals share a private vehicle for a particular journey or journeys, has been undertaken both formally and informally for a great number of years. A variety of computational methods for undertaking the ‘ride-matching’ element for the formation of carpools have been developed and subsequently made into integrated tools to allow the formation of multiple carpools. Such tools are commonly used by both Local Authorities and employers who are looking to establish and operate their own formal carpool scheme, increasingly using a web-based interface.

The aim of this paper is to understand how users enrolled with employer-led carpool schemes perceive the importance of several different factors in their decision to participate. It is a further aim to determine the importance they attach to employer provided priority parking spaces. A survey-based approach investigates the perceptions of users from six different employer operated carpool schemes in the UK.

The paper suggests that saving money was perceived as the most important reason for an individual's decision to use a formal employer-led carpool scheme – even amongst carpool schemes where the employer provides significant incentives to participate. No regular access to their own vehicle and ‘more sociable travel’ were generally perceived as less important reasons to participate. For employers who offer priority parking to carpoolers, this was generally valued as important by participants, even when the employment location did not have significant parking pressures.  相似文献   
616.
Using a data-set collected among paratransit users in Bandung, Indonesia, this paper explores the impacts of paratransit users' negative experiences and dissatisfactions with their paratransit usage pattern. Segmentation and ordered probit analyses are used to examine the impacts of users' opinions on service quality on their trip-making behaviour. The results indicate that users are divided into six segments – namely, the unlucky, the young user, the experienced, the adapter, the infrequent user and the captive. The results further indicate that paratransit users, especially women, perceive negative experiences related to on-time performance (departure and arrival time) and security issues related to vehicles. Despite these dissatisfactions and negative experiences, they are still likely to use paratransit as part of their daily life. Two paratransit market segments (the adapter and the captive) are also likely to result in more trips using paratransit. The study offers several strategies and recommendations that can improve the current paratransit system so that it can better serve local needs.  相似文献   
617.
The maritime industry operates in a dynamic global environment subject to a great number of variables. In this context, the investment challenge facing shipowners is correctly to value alternate mutually exclusive investment strategies before proceeding with confidence to commit to a project which will add the greatest value to the firm. To survive in the competitive market environment shipping companies must be flexible. Companies that rely solely on traditional discounted cash flow analysis may be underestimating the true value of their investment by not valuing any embedded real options specifically. To avoid misallocation of resources, the true value of these embedded options (strategies) should be recognised and quantified where possible for inclusion in the capital budgeting process. Using real options analysis, (ROA), as a development of the financial pricing advances of the 1970s, flexibility is valued like a financial option using non-arbitrage and added to the present value of the original strategy to derive the present value of the flexible strategy. The more uncertainty (risk) present, the greater will be the value of the real options. Similarly, the larger the shipowner's portfolio of options (strategies) from which to choose, the greater will be the valuation of the project. Real options give the shipowner the flexibility to exchange one risky income stream associated with one strategy for that of another. The analysis shows that if managers have the flexibility of more than one embedded option (in this paper, a European put associated with a replacement investment and an option on the maximum of two operating strategies, trading or chartering out) then the project will have greater value than if the there was no choice or if it was limited to one or the other strategy. Sensitivity analysis extends the analysis to demonstrate that if the volatilities of the risky income streams are highly correlated then the additional value of this flexibility will diminish.  相似文献   
618.
The demand for continually improving the transient performance of diesel engines requires higher rail pressure and more efficient turbocharger. Before the test, a two-stage turbocharger with a turbine by-pass valve (TBV) had been matched reasonably with the base engine. In order to reduce smoke emission under the typical 5-second transient process of constant speed and increasing torque, the influence of rail pressure on combustion, emissions and performance characteristics was experimentally investigated. The results showed that the two-stage turbocharger was helpful in improving transient performance. Moreover, the full-stage rail pressure (FSRP) strategies (increasing rail pressure during the whole transient process) could reduce smoke emission when the TBV was closed. However, smoke deteriorated once TBV opening got larger. Then the sectional-stage rail pressure (SSRP) strategies (increasing rail pressure from a pre-set load to 100 % load) were presented under small TBV opening to improve in-cylinder thermal condition. Hence, the air-fuel mixing process was improved at medium and large loads. Then the maximum decline of smoke opacity peak was 56.3 %, which happened under 10 % TBV opening. In addition, fuel consumption of FSRP strategies got worse under larger TBV opening. However, this deterioration situation could be effectively restrained by the utilization of SSRP strategies.  相似文献   
619.
The marine environmental condition, especially NaCl, has been identified as one of the major sources of contamination on the performance of open cathode Proton Exchange Membrane Fuel Cells (PEMFC) system, when the power source is based on fuel cells for marine applications like submarines, navy ships etc., In the present paper, we have studied the performance of PEMFCs under the marine environment for a longer duration and also the recovery mechanism of the PEMFC power pack after contamination. It has been observed that the NaCl is a major contaminant for PEMFC, compared to NO x and SO x , which are major contaminants for fuel cells operating in the land regions. We have observed a performance loss of 60 % in PEMFC, when operated for 48 h, due to poisoning of PEMFC by NaCl vapours. The recovery of the stack is attempted by repeated water washing on the cathode side of the fuel cell, presuming that the salts get deposited only on the surface of the electrodes and the performance is easily recoverable. The recovery mechanisms are analysed by constant-current discharging operation and by modified experimental methods and are reported here. The performance vagaries in fuel cells due to sea water contamination is also analysed by linear fit and it is found that the rate of power increment after water wash is higher than the rate of power increment, around 11.5 W/10?h compared to normal environmental conditions, which is 4.1 W/10?h.  相似文献   
620.
The image of the shipping industry plays a vital role in developing maritime transport as a major future, sustainable transport alternative. In particular, it is crucial to understand the image the shipping industry has among young people and the anatomy of the concept in order to be able to effectively promote careers in shipping, to cultivate shipping as an attractive labour market and to develop attractive educational programmes. The focus of this paper is the image of the shipping industry. This study reports on the findings of a large-scale survey of the image of shipping- and image-related concepts among upper secondary school pupils in Sweden, Norway and Greece. We define and analyse empirically by means of multivariate statistical analysis the anatomy of the image concept. We identify various image dimensions, estimate how young people rate the shipping industry along these dimensions and estimate their relative importance to young people who are planning their future careers. The results from this study can be used as a base for describing and explaining the images that young people have of the shipping industry. Such knowledge is fundamental for deriving and developing constructive strategies to promote careers in shipping, to adapt shipping to the expectations of young people and to develop creative and relevant educational programmes. Finally, understanding the image of shipping among young people is important not only for the shipping industry, but for other stakeholders as well, such as ship-owners associations, trade associations, labour unions, transport authorities and administrations and policy makers at the national and supra-national level.  相似文献   
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