全文获取类型
收费全文 | 844篇 |
免费 | 4篇 |
专业分类
公路运输 | 240篇 |
综合类 | 21篇 |
水路运输 | 276篇 |
铁路运输 | 22篇 |
综合运输 | 289篇 |
出版年
2022年 | 16篇 |
2021年 | 4篇 |
2020年 | 4篇 |
2019年 | 6篇 |
2018年 | 20篇 |
2017年 | 22篇 |
2016年 | 28篇 |
2015年 | 11篇 |
2014年 | 30篇 |
2013年 | 116篇 |
2012年 | 30篇 |
2011年 | 37篇 |
2010年 | 41篇 |
2009年 | 34篇 |
2008年 | 41篇 |
2007年 | 15篇 |
2006年 | 22篇 |
2005年 | 22篇 |
2004年 | 12篇 |
2003年 | 24篇 |
2002年 | 18篇 |
2001年 | 12篇 |
2000年 | 13篇 |
1999年 | 18篇 |
1998年 | 29篇 |
1997年 | 20篇 |
1996年 | 16篇 |
1995年 | 8篇 |
1994年 | 4篇 |
1993年 | 13篇 |
1992年 | 13篇 |
1991年 | 12篇 |
1990年 | 7篇 |
1989年 | 12篇 |
1988年 | 7篇 |
1987年 | 7篇 |
1986年 | 4篇 |
1985年 | 13篇 |
1984年 | 8篇 |
1983年 | 6篇 |
1982年 | 8篇 |
1981年 | 8篇 |
1980年 | 8篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1977年 | 7篇 |
1976年 | 5篇 |
1975年 | 6篇 |
1974年 | 10篇 |
1972年 | 5篇 |
排序方式: 共有848条查询结果,搜索用时 187 毫秒
351.
Donald G. Kasten 《Maritime Policy and Management》1980,7(3):197-203
The oceans of the world, which comprise 71% of the earth's surface, provide a vast resource of renewable energy which has only been used in limited quantities. The feasibility of the extraction of energy from the ocean has been discussed and deemed possible, but with very few successful applications. However, as the world energy and economic situation changes, many countries are initiating R&D programmes to use the ocean waves, tides, currents, and temperature differentials to produce electricity. The transmission and utilization of this oceanderived electricity requires the integration of an ocean facility into an existing land-based electric power transmission grid. Extensive use of this energy source is still years in the future; however, prototype systems have been and are being developed so that this limitless supply can be successfully tapped. 相似文献
352.
353.
Yorgos J. Stephanedes Panos G. Michalopoulos Tassos Bountis 《Transportation Research Part B: Methodological》1985,19(2):95-111
The problem of dynamic transit scheduling is addressed, and a method for transient and steady-state solutions is developed. The dynamic demand-supply formulation employed is based on previously calibrated disaggregate demand specifications. The existence and feasibility of solutions are examined, and stability conditions are derived. Numerical examples for both urban and rural conditions are given. The new methodology does not require time-series endogenous data but only initial conditions to provide long- or short-term scheduling plans. Futhermore, it takes into account passenger demand fluctuations and explicitly deals with management responsiveness and time lags in implementing scheduling decisions. Owing to its dynamic nature the methodology can be used as a design tool in transit scheduling and for assessing the effects of time-varying exogenous events such as gasoline price fluctuations, transport budget restrictions and other contingencies. 相似文献
354.
The extreme wave and current response of a typical North Sea jack-up drilling platform has been calculated using nonlinear, stochastic, time-domain analysis techniques. A statistical treatment of the response-time histories has been performed. Appropriate probability distributions have been fitted to simulated response amplitudes and extrapolated to determine extreme values in storms of 3 or 6 h duration. Nonlinear geometric effects and dynamic effects are also addressed.
The results of the nonlinear time-domain analyses are compared to the results of more simplified methods used in jack-up designs. 相似文献
355.
356.
This paper proposes a theoretical methodology and practical data collection approach for modeling enroute driver behavioral choice under Advanced Traveler Information Systems (ATIS). The theoretical framework is based on conflict assessment and resolution theories popularized in psychology and applied to models of individual consumer behavior. It is posed that enroute assessment and adjustment is a reactionary process influenced by increased conflict arousal and motivation to change. When conflict rises to a level at which conflict exceeds a personal threshold of tolerance, drivers are likely to alter enroute behavior to alleviate conflict through either route diversion of goal revision. Assessment and response to conflict arousal directly relate to the driver's abilities to perceive and predict network conditions in conjunction with familiarity of network configurations and accessible alternate routes.Data collection is accomplished through FASTCARS (Freeway andArterialStreetTrafficConflictArousal andResolutionSimulator), in interactive microcomputer-based driving simulator. Limited real-world implementation of ATIS has made it difficult to study or predict individual driver reaction to these technologies. It is contended here that in-laboratory experimentation with interactive route choice simulators can substitute for the lack of real-world applications and provide an alternate approach to data collection and driver behavior analysis. This paper will explain how FASTCARS is useful for collecting data and testing theories of driver behavior. 相似文献
357.
A. G. Corbet 《Maritime Policy and Management》1989,16(4):277-292
Legislative measures, rather than further technological advances, are needed if there is to be any extensive development of Vessel Traffic Services. Reasons are given why this conclusion differs from that of the COST 301 Study with respect to legal liability of Vessel Traffic Services. 相似文献
358.
Three alternative definitions of traffic equilibrium are compared in terms of the mechanisms of route-choice inherent in them. These definitions are the usual Wardrop equilibrium and user-optimised ones and a new one. Conditions on the cost function are established under which the Wardrop definition is equivalent to each of the other two. Some circumstances are identified in which these conditions are satisfied. A detailed discussion is given of an example in which these conditions are not satisfied and the three definitions are not equivalent. 相似文献
359.
M.G. Fodor Graduate Research Assistant R. Redfield 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1993,22(1):1-20
This paper introduces the concept of regenerative damping in vibration control, die storage of energy normally dissipated by a passive viscous damper. A device, the Variable Linear Transmission, is proposed to accomplish this task. Analysis of die proposed device as a damper in a typical passenger vehicle is conducted for die cases in which the device's active component operates ideally and with activation dynamics included. Results indicate that regenerative vibration control is feasible and can provide damping nearly identical to that of a passive viscous damper while storing the damped energy. 相似文献
360.
This paper discusses structural response to blast loading and temperature changes in fires. Both extreme events can be modelled using a range of analytical techniques from simple methodologies to the very complicated finite element analysis. The relatively simple techniques are appropriate for this type of problem and degree of accuracy required given the level of uncertainty in the loading. Given specific boundary conditions and physical properties, the methodologies proposed in the paper provide as good estimates of the dynamic response to blast loading and temperature increases in fires as the more sophisticated finite element method. Experimental data compares well with the analytical results. 相似文献