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871.
872.
An increasing number of legislative efforts have been undertaken to prohibit the use of hand-held wireless devices while driving. As of July 2012, ten states and the District of Columbia enforce laws banning the use of hand-held cell phones while driving. Thirty-nine states and the District of Columbia have banned text messaging while driving. Recent studies of driver behavior suggest that hand-held wireless device usage negatively impacts driver performance. However few studies at the aggregate level address the plausible link between the use of hand-held wireless devices while driving, increased risk of automobile accidents, and government legislative efforts to reduce such risk. This paper analyzes data at the aggregate level and builds a regression model to estimate the long term accident rate reduction due to a hand-held ban. This model differs from previous studies, which consider short term accident rate reduction, by considering time trends in the accident rate due to the ban. Additionally, counties considered in this analysis are placed into groups based on driver density, defined by the number of licensed drivers per centerline mile of roadway, and a separate analysis is performed within these groups. This approach allows one to better quantify the effect of hand-held bans in counties of different driver densities. Results from this paper suggest that bans on hand-held wireless device use while driving reduce the rate of personal injury accidents in counties with high levels of driver density, but may increase accident rates in counties with low driver density levels. These results can inform transportation policymakers interested in reducing automobile-accident-risk attributable to the use of hand-held wireless devices while driving.  相似文献   
873.
874.
The primary focus of this research is to develop an approach to capture the effect of travel time information on travelers’ route switching behavior in real-time, based on on-line traffic surveillance data. It also presents a freeway Origin–Destination demand prediction algorithm using an adaptive Kalman Filtering technique, where the effect of travel time information on users’ route diversion behavior has been explicitly modeled using a dynamic, aggregate, route diversion model. The inherent dynamic nature of the traffic flow characteristics is captured using a Kalman Filter modeling framework. Changes in drivers’ perceptions, as well as other randomness in the route diversion behavior, have been modeled using an adaptive, aggregate, dynamic linear model where the model parameters are updated on-line using a Bayesian updating approach. The impact of route diversion on freeway Origin–Destination demands has been integrated in the estimation framework. The proposed methodology is evaluated using data obtained from a microscopic traffic simulator, INTEGRATION. Experimental results on a freeway corridor in northwest Indiana establish that significant improvement in Origin–Destination demand prediction can be achieved by explicitly accounting for route diversion behavior.  相似文献   
875.
Road freight transport in New Zealand has operated under government regulations since 1936, primarily to protect the freight revenue of the New Zealand Railways. In 1983 an Act was passed to deregulate the freight transport industry and to switch over to a qualitative licensing system. This is expected to have some impact on competition within the road freight industry as well as between road and rail. This paper analyses the institutional structure of the road freight industry at the pre‐deregulation phase. The trend over the last few years, shows that the number of single vehicle owners (mostly owner‐drivers) and their share in the industry is growing at a faster rate than others. The vehicle authority distribution varies widely from one region to another in the country. Economic factors like employment, population, urbanization etc. could not explain this variation. The segregation of demand by existing government regulations appears to be the main reason for such diversity in vehicle authority distribution. Apparently there is no monopoly trend in the aggregate nor in the regional distribution. However, many owner drivers work closely with large firms, which may change the concentration observed in the distribution of vehicle authorities.

Productivity is relatively high for one person operations, i.e., mainly owner drivers. It then goes down and then rises to a certain limit. This gives an indication of the possibility of economies of scale, the single vehicle firms being an exception.  相似文献   
876.
C. A. Nash 《运输评论》2013,33(4):289-300
This paper presents a brief review of rail policy and the performance of the rail system in Australia, and draws some comparisons with the rail systems of Western Europe. Australian railways present a somewhat paradoxical mixture of booming traffic with severe financial problems, poor productivity and — in some cases — outdated equipment. The competitive environment they face varies from state to state both in the freedom accorded to road competition and the degree to which the railways themselves are permitted to take decisions on a commercial basis. Whilst some railways in Australia — notably Westrail — have virtually completed the transition from a government department to a commercial enterprise, others have only just begun.  相似文献   
877.

Most airlines across Asia are struggling to cope with an unprecedented economic crisis which they have very little control over, and the survival of some remains in doubt. The continuing uncertainty generated by the crisis has accelerated the process of change in the aviation industry and has highlighted the need for adaptability, and its effects have been deeper and longer lasting than previously anticipated. After a year-long slump in the Asian travel market, airlines are now considering a range of options and rehabilitation programmes including a series of cost-cutting measures. There appears to be a trend towards the extension and consolidation of strategic alliances, structural and operational reorganization, and the application of new technologies. The success of these measures will become apparent over time, but action is necessary to minimize the adverse consequences of the crisis which has dominated the region since 1997.  相似文献   
878.
Air quality modelling plays an important role in formulating air pollution control and management strategies by providing guidelines for better and more efficient air quality planning. Several line source models, mostly Gaussian‐based, have been suggested to predict pollutant concentrations near highways/roads. These models, despite several assumptions and limitations, are used throughout the world, including in India, to carry out air pollution prediction analysis due to vehicular traffic near roads/highways. These models are being continuously upgraded and modified based on field experiments, and numerical and physical modelling results. An effort has been made in the present paper to review briefly the philosophy and basic features of most of the commonly used highway dispersion models. The paper also discusses various theories and techniques that led to the development and modification of these models along with the statistical analysis tools to evaluate the performance of these models. An attempt has also been made to summarize briefly the various line source models currently used in India and to highlight the difficulties being faced while using them in an Indian context.  相似文献   
879.
880.

The use of third-party logistics services by large US manufacturers continues to grow. Increasingly, those services are used to support international sourcing and sales activities. Use of these services is often triggered by specific events such as a corporate restructuring, a top management change or a benchmarking effort. Nearly two-thirds of users report they experienced significant impediments in implementing third-party agreements. After starting conservatively, the typical user buys a wide variety of logistics services. Users generally report that buying logistics services has had a positive impact on their organizations, particularly with respect to logistics costs and customer service. However, many also report negative impact on employee morale linked to downsizing the logistics workforce. More than two-thirds of users report cancelling at least one-third-party logistics contract. Nevertheless, if given complete responsibility to make the decision, >70% of users would increase their companies' use of such services.  相似文献   
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