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动力集中和动力分散的特点 总被引:1,自引:0,他引:1
从运用、市场和列车型式的发展趋势等方面 ,分析了动力集中和动力分散的特点。特别阐述了利用寿命周期成本 (L CC) ,来比较这 2种方式列车的优劣 相似文献
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Volker Kreibich 《Transportation》1979,8(2):153-166
The model used a Monte-Carlo algorithm to simulate modal split and trip distribution as an interconnected decision process at the individual level. Using census data, the individuals of a planning region are classified into situation groups, which represent significantly different decision situations with respect to socio-demographic position and territorial location. According to the theoretical framework, which emphasises mobility constraints instead of preferences, household structure and sex (time budget and car availability constraints) and work place characteristics (location constraints) are the key variables. For each situation group, decision profiles are empirically determined; these describe car availability, travel time constraints and work place distribution. Modal split and trip distribution are simulated as an interconnected individual decision process, which is stochastically determined by the location of the individual and the decision profile of his situation group.The algorithm is very sensitive and flexible and extremely well suited to electronic processing. An extended and modified version is currently being used in the preparation of regional transporation plans for several German city regions. 相似文献
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In late summer 2002 and 2003, exceptionally warm inflow events of saline water were observed in the Baltic. These warm saline waters were embedded in the halocline of the Bornholm Basin and caused a strong anomaly of the seasonal temperature cycle. The temperature in October 2002 was the highest ever observed in the halocline of the Bornholm Basin.Although the oxygen content of the inflowing water was only about 1.5 ml l− 1 at the Darss Sill, it caused a moderate ventilation of the halocline in the Bornholm Basin. On the way through the Arkona Basin, the entrainment of ambient water increased the oxygen content of the inflowing saline water masses.Warm summer inflows were rare events in the last 50 years, but their frequency has increased since 1990. This is likely caused by climate change. The analysis of a 50-year time series of hydrographic parameters reveals significant changes of the thermal regime around the year 1988. The winter surface and intermediate water temperatures of the Bornholm Basin increased by about 1 °C. Also, the duration of warm water in the surface layer was prolonged after 1988. A high correlation between the minimum intermediate winter water temperatures and the NAO winter index was found.Since temperature is a key parameter for many biological processes various responses of the ecosystem to the change in hydrographic conditions could be expected. Possible biological implications of the warm inflow events for the ecosystem are discussed. 相似文献
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Volker Bertram 《船舶工程》2009,31(3)
2009年5月10日-12日,第八届"计算机和信息技术在海事行业中的应用(COMPIT)"国际会议在匈牙利首都布达佩斯举行.自2000年举办首届会议以来,COMPIT已成为海事行业信息技术领域的重要会议,汇聚了众多软件开发商和用户.会议内容涵盖了船舶的生命周期,以及海上设施与设备,从设计到营运. 相似文献
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A 3-d seakeeping code uses first-order Rankine panels with special numerical integration on the ship's hull and Rankine point
source clusters above the free surface. The code computes the motions of the ship in regular waves of small height (linearized).
The steady flow is captured without simplification by solving the fully nonlinear wave-resistance problem first. A special
treatment of the surge motion considers the influence of periodic quantities on thrust and resistance, and improves surge
motion predictions. Radiation and open-boundary conditions are enforced by staggered grids. Results for the ITTC standard
test case S-175 containership agree well with experiments except for very long waves. The importance of capturing the three-dimensional
steady flow contributions is also demonstrated. 相似文献
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Dave Hancock Volker Korte 《汽车与配件》2008,(35)
降低二氧化碳排放物,以及越来越严厉的其他排放法规,是开发未来内燃机最重要的挑战。马勒具有众多系统开发专项技术,并且有80多年成功开发和研制内燃机部件和系统的经验。现在马勒在开发具有创新意义的小型化发动机,来证明其在最新发动机技术领域的能力。 相似文献
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During a hydrographic survey in January 2006 the spreading of inflowing saline water was observed in the Arkona Basin (Western Baltic Sea). Two bottom mounted ‘pulse coherent’ acoustic Doppler profilers (PC-ADP) were used to measure the near-bottom current field of the dense plume with a high temporal (1 s) and spatial resolution (5 cm). In order to estimate the dissipation rate of turbulent kinetic energy () a structure function approach was applied to the beam velocity data. Simultaneous measurements with a microstructure shear profiler (MSS) and an acoustic Doppler velocimeter (ADV) supplied independent data for the verification of the structure function method. Additional measurements with standard CTD, near-bottom towed and vessel mounted acoustic Doppler current profilers (ADCP) completed the data set.The estimated dissipation rates from the structure function approach fit well with the values derived from the ADV and the MSS probe. It is shown that the structure function approach is a reliable and easily applicable method to derive estimates of TKE dissipation rates from PC-ADP beam velocities. The observed dissipation rates ranged between 5 · 10− 6 and 1 · 10− 8 W kg− 1 depending on the hydrographic conditions. Inside the plume the dissipation rates exceeded that of the overlaying brackish water by two orders of magnitude. Since the noise level of velocity data in pulse coherent mode is considerably lower than in the Doppler mode the PC-ADP can also be used for estimates in marine environments with low turbulence level. Reynolds stresses estimated from the PC-ADP and the ADV agreed well at the same depth level. TKE production derived from PC-ADP measurements compared reasonably well with the dissipation rate of TKE in a varying environment. 相似文献
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