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861.
This study provided an examination of the alternative means used by Metropolitan Planning Organizations (MPOs) to carry out transportation planning activities in different areas of the U.S.A. This has been done by first developing a general profile of the nature and functions of the MPOs in the 100 largest regions in the U.S. and by an in‐depth analysis of seven regions. The purpose of these activities was to examine similarities and differences between MPOs and to identify factors that appear to lead to the effectiveness or non‐effectiveness of MPOs in different areas. From the analysis, it is evident that there are wide differences between MPOs in their organization, function, and degree of effectiveness in carrying out transportation planning. These differences do not appear to be related to any structural characteristics of MPOs, but rather are the result of past history and the attitudes of people involved. 相似文献
862.
Desiderius C. P. Masalu 《Coastal management》2013,41(4):347-359
Coastal erosion is one of the major coastal problems currently facing Tanzania. Several factors, including sea level rise, geology, and rapid coastal population growth accompanied by rapid increase of human activities that interfere with natural processes, have been linked to the problem. One of the human activities that have been well linked to the problem of coastal erosion is illegal sand mining along beaches, coastal streams/rivers, and other restricted areas. This causes localized accelerated/ severe coastal erosion and enormous environmental degradation and threat to coastal properties. Illegal sand mining is presently a big industry in Tanzania, employing many youths, and has become a social, economical, and environmental problem. Thus, it is a sensitive issue. The problem of illegal sand mining in Tanzania is revisited, and possible measures to control it are proposed. Measures that can help to reduce/eliminate illegal sand mining are: governments to address effectively the problem of unemployment and poverty in the society by formulation of effective policies, including the total liberalization of the labor market and reduction of the tax burden and regulations on potential employers; identifying alternative sources of sand that are environmentally safe to mine, of good quality, and easily accessible; launching well-focused mass education on the problem of coastal erosion; encouraging formation of legally registered associations of sand-miners that will work closely with relevant authorities to curb illegal sand mining; and strengthening of governance and improving research funding in the country. 相似文献
863.
This paper explores the relative influence of factors affecting light rail ridership on 57 light rail routes in Australia,
Europe and North America through an empirical examination of route level data. Previous research suggests a wide range of
possible ridership drivers but is mixed in clarifying major influences. A multiple-regression analysis of route level ridership
(boardings per route km) and catchment residential and employment density, car ownership, service level, speed, stop spacing,
share of accessible stops, share of segregated right of away and integrated fares was undertaken. This established a statistically
significant model (99% level, R2 = 0.76) with five significant variables including service level, routes being in Europe, speed, integrated ticketing and
employment density. In general these findings support selected results from previous research. A secondary analysis of service
effectiveness measures (boardings/vehicle km, i.e. the relative ridership performance for a given level of service), established
a statistically significant model (99% level, R2 = 0.67) with 6 significant explanatory variables including being in Europe, speed, employment density, integrated ticketing,
track segregation and service level. The latter implies that a higher frequency results in higher service effectiveness. Overall
the research findings stress the importance of providing a high level of service as a major driver of light rail ridership.
The ‘European Factor’ is also an important though intriguing influence but its cause remains unclear and requires further
research to elaborate its nature. 相似文献
864.
The role of autonomous underwater vehicles (AUVs) is more important in the quest to reach the deep seas today than ever before. The hull shape of the AUV can differ depending on the special mission considered for the vehicle. Therefore, different types of algorithms for the body shape design of these kinds of vehicles are being developed every day. In the current work, a new procedure has been proposed for designing the body shape of an AUV. Using this method which is based on a desired pressure distribution, it is possible to obtain the desired hull shape design. Artificial neural network algorithm has been used for this purpose. Preliminary data for training and testing of the network have been obtained from CFD simulation of the flow around the body of Hydrolab500 AUV. In this regard, pressure distribution has been evaluated around each body by changing the nose and tail profile of AUV. The results obtained from this research indicate that a body correlated to the desired pressure can be designed properly. 相似文献
865.
It is the aim of the European Union to develop a transport policy that supports its economic and sustainable growth and where the concept of sustainable mobility is a driver in the development of such policy. To achieve this goal, the European Union (EU) is promoting the shift of goods to unused existing capacity in rail and sea modes. As such, it is the objective of this paper to carry out a review of the European shipping policy at a time when the EU Member-States are suffering from high levels of congestion, noise and pollution that not only affect the environment but also the quality of life of all citizens. This paper considers the development of EU shipping policy in three stages. 相似文献
866.
Transportation - City events are getting popular and are attracting a large number of people. This increase needs for methods and tools to provide stakeholders with crowd size information for crowd... 相似文献
867.
K. J. Button 《运输规划与技术》2013,36(4):285-299
Internationally, recent years have seen a spread of deregulatory policies with respect to transport. Equally, transport movements across national boundaries have expanded as trade has grown. Despite these two quite noticeable trends comparatively little has been written on the problems that are created for cross‐border traffic as the result of differential changes in national regulatory policies. This paper is concerned with looking specifically at what has happened in the context of road freight transport movements across the U.S.‐Canadian border and the wider (especially for the formulation of a Common Transport Policy for the EEC) lessons which can be learned from it. 相似文献
868.
Shiyong Liu Konstantinos P. Triantis Sudipta Sarangi 《Transportation Research Part A: Policy and Practice》2010,44(8):596-608
This paper provides a modeling framework based on the system dynamics approach by which policy makers can understand the dynamic and complex nature of traffic congestion within a transportation socioeconomic system representation of a metropolitan area. This framework offers policy makers an assessment platform that focuses on the short- and long-term system behaviors arising from an area-wide congestion pricing policy along with other congestion mitigation policies. Since only a few cities in the world have implemented congestion pricing and several are about to do so, a framework that helps policy makers to understand the impacts of congestion pricing is currently quite relevant. Within this framework, improved bus and metro capacities contribute to the supply dynamics which in turn affect the travel demand of individuals and their choice of different transportation modes. Work travel and social networking activities are assumed to generate additional travel demand dynamics that are affected by travelers’ perception of the level of service of the different transportation modes, their perception of the congestion level, and the associated traveling costs. It is assumed that the, population, tourism and employment growth are exogenous factors that affect demand. Furthermore, this paper builds on a previously formulated approach where fuzzy logic concepts are used to represent linguistic variables assumed to describe consumer perceptions about transportation conditions. 相似文献
869.
This article presents the results of a study exploring travellers’ preferences for middle-distance travel using Q-methodology.
Respondents rank-ordered 42 opinion statements regarding travel choice and motivations for travel in general and for car and
public transport as alternative travel modes. By-person factor analysis revealed four distinct preference segments for middle-distance
travel: (1) choice travellers with a preference for public transport, (2) deliberate-choice travellers, (3) choice travellers
with car as dominant alternative, and (4) car-dependent travellers. These preference segments differ in terms of the levels
of involvement and cognitive effort in travel decision making, the travel consideration-set and underlying motivations. The
study showed that for most people there is more to travel than getting from point A to point B, and that there is considerable
heterogeneity in middle-distance travel preferences. Policy implications for reducing the need for travel and promoting a
modal shift from car to other travel modes are discussed. 相似文献
870.
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