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461.
A wide range of transport‐related decisions involve the linking of discrete choices (e.g. of vehicle choice) and continuous choices (e.g. of vehicle use). In recent years econometricians have developed procedures for integrating such choices into a framework that is both economically and statistically sound. The literature is however somewhat technical. The objective of this paper is to provide a general overview of the basic elements of discrete/continuous econometric modelling with an emphasis on transport applications. It is hoped that such an introduction will demonstrate that the essence of the approach for the practitioner is quite straightforward and can be implemented with widely available computer software. 相似文献
462.
T. L. Beagley 《运输评论》2013,33(4):389-395
A conference organized in December 1993 by ESTI and CER discussed the major challenges facing the European railway industry. There are great opportunities in prospect for such an environmentally friendly industry, but there are many structural, financial and operational problems to overcome. The 1991 European Union Policy laid down the separation of the management of operation and infrastructure from the provision of railway transport services: measures for improving the financial structure of undertakings; and the introduction of international competition. The conference discussed the progress in restructuring, technical harmonization and interoperability and the practical issues involved in introducing competition. 相似文献
463.
David A. Hensher Anne Yvrande‐Billon Rosário Macário John Preston Peter White Bill Tyson 《运输评论》2013,33(4):411-448
Abstract This paper documents some thoughts on the reform agenda in public transit that is occurring throughout the world. The specific focus is on a growing commitment to competitive regulation through competitive tendering, and the efforts by a few governments (notably in Australia) to take control of the tangible assets used by private operators as a mechanism to exercise the opportunity, if so taken, to put services out to competitive tender. The paper reviews the theoretical arguments and empirical evidence on contracting regimes and asset ownership, and the role that government and the operator might play in a setting in which building trusting and collaborative partnerships has merit in delivering services that are in the main funded from the public purse. 相似文献
464.
In Hong Kong the high cost of land reclamation servicing has made it necessary to plan land use through zoning commercial and industrial activity and by adopting very high densities for residential accommodation. Traffic has concentrated along particular corridors where its volume now exceeds road capacity. The imperative development of an urban rail system has affected the economic stability of most public transport. Simultaneously, private motoring has increased so rapidly that fiscal restraints have been imposed, generating a serious proposal for electronic road pricing. The future growth of links with China will end Hong Kong's relative isolation and present new transport planning challenges. 相似文献
465.
The great majority of analyses made in transport economics use, explicitly or, more often, implicitly, the common assumption of perfect competition. This is the case, for instance, when infrastructure projects are evaluated using the mere sum of the surpluses of transport users and providers. Even when putting aside the question of externalities such as noise, safety or environmental quality, the real chain of economic interactions that takes place in transport provision or downstream of transport provision is not taken into account. Surely enough, describing and simulating this chain could be quite complex. Nevertheless, it is not uninteresting to try to estimate if it does make a big difference or not to make this approximation. The paper makes such an attempt for two broad kinds of applications of transport economics: 相似文献
466.
S. Hellman M. Uddin P. T. Tkacik S. D. Kelly 《International Journal of Automotive Technology》2016,17(2):281-288
The performance and safety of the rear wing and spoiler employed on the National Association of Stock Car Auto Racing (NASCAR) COT (car of tomorrow) racecar are experimentally studied using 10 % scale models in a water channel. Particle image velocimetry is used to qualitatively examine the differences in flow structures between the two downforce-generating devices under 0 and 180-degree yaw cases. The latter is important due to an issue with the COT flipping into the air when at extreme yaw (i.e. during a crash). At zero yaw, it is observed that smaller length scales of the flow structures in the wake of the wing compared to those in the wake of the spoiler, provide more predictable handling for racecars in close proximity and may allow more safe and competitive racing. At 180-degree yaw, it is observed that wake-structure interactions may not allow proper operation of anti-flipping devices (roof flaps) on the winged car. In the extreme yaw case, local flow scales are examined and show much stronger Reynolds number (Re) dependence for the wing than the spoiler. 相似文献
467.
J. M. Hills D. Alcock T. Higham H. Kirkman M. Le Tissier C. Pagdilao 《Coastal management》2013,41(3):323-337
Development of awareness and capacity is a central component to the delivery of ICM and spans from local communities to national-level politicians. Education and training activities associated with ICM must be extremely varied to match both the existing capacity and role that the stakeholders play within the process of ICM. Consequently, there cannot be considered any effective “generic” ICM training; training must be tailored to match the requirements of target groups. The transfer and uptake of good-practice thus becomes an important aspect of quality enhancement in ICM capacity development. Six case studies from the Asia-Pacific region are presented that show diverse and innovative examples of good practice. A comparative analysis of these case studies is carried out in terms of institutional level of impact. In addition a generic systems-based evaluation framework is used to determine the extent to which the training impacts upon ICM implementation indicators. It is concluded that the exchange, transfer, and translation to local conditions of appropriate good practice in ICM capacity development can be an important element in enhancing the impact of ICM programs on the coastal environments and societies. Furthermore, there appears to be a positive link between the involvement of national/state/regional stakeholders in capacity-building initiatives and impacting a wider variety of indicators of ICM delivery. 相似文献
468.
469.
Zheng Li John M. Rose David A. Hensher 《Transportation Research Part A: Policy and Practice》2010,44(1):16-38
Transport fuel consumption and its determinants have received a great deal of attention since the early 1970s. In the literature, different types of modelling methods have been used to estimate petrol demand, each having methodological strengths and weaknesses. This paper is motivated by an ongoing need to review the effectiveness of empirical fuel demand forecasting models, with a focus on theoretical as well as practical considerations in the model-building processes of different model forms. We consider a linear trend model, a quadratic trend model, an exponential trend model, a single exponential smoothing model, Holt’s linear model, Holt–Winters’ model, a partial adjustment model (PAM), and an autoregressive integrated moving average (ARIMA) model. More importantly, the study identifies the difference between forecasts and actual observations of petrol demand in order to identify forecasting accuracy. Given the identified best-forecasting model, Australia’s automobile petrol demand from 2007 through to 2020 is presented under the “business-as-usual” scenario. 相似文献
470.
David G. Blair 《Journal of Marine Science and Technology》2006,11(2):123-130
In underwater acoustic imaging, which is used to produce high-quality images in turbid waters, a specular reflector can produce
a “pseudoimage” of the receiving array at the reflecting surface. Based on the “geometrical approximation” (which is similar
to geometrical acoustics), formulae are derived for the size and shape of the pseudoimage for both flat and curved reflectors.
For curved reflectors, described by two principal radii of curvature, the formulae also assume the “large-range approximation.”
The formulae allow radii of curvature to be determined from an image. Also discussed briefly are some possible extensions
and the role of nongeometrical effects. 相似文献