ITS与病体系统诊治

由于交通系统是一个复杂的巨系统,本文遵照钱学森院士原始的综合集成方法对城市交通系统进行研究, 结合集对分析、可拓学等新理论,提出病体交通系统及其诊治系统模型,并提出若干解决方法,最后介绍了一个具体的应用实例。     

Modeling and control strategy development for fuel cell hybrid vehicles

Using MATLAB/Simulink, we constructed a comprehensive simulation model for the fuel cell hybrid vehicle (FCHV) power train in parallel with a power control strategy that uses a logic threshold approach implemented with a hybrid control unit (HCU). The simulation implements power flow and power distribution under different vehicle operating modes using the accelerator and decelerator pedal positions deduced from the driving schedule as primary inputs. The HCU control strategy also incorporates regenerative braking and recharging for recovery of battery capacity. Using the D-optimality method for selection of the optimal experiment values, three control threshold variables for the HCU are selected to maximize the hydrogen fuel economy under certain driving cycles. The proposed method provides the optimal configuration of the FCHV model, which has the capability of achieving the requested drive power while also meeting the vehicle driving schedule and recovery needs of the state of charge (SOC) battery, with lower fuel consumption levels.     

Asian product trade

The 'Asian 'flu' has caused uncertainty about the future of product shipping in Asia. Product shipping is a difficult business, subject to the vagaries of such factors as local and regional supply/demand imbalances, refinery inputs, outputs and utilization rates, storage and terminalling considerations, product quality differences, price differentials, seasonal variations, and port traffic. This paper covers the Asia-Pacific product demand and trade by type in four major submarkets: Australasia, Southeast Asia, South Asia and East Asia. Forecasts are created of product demand by type and country, assessing likely additions to refinery capacities, and conducting computer-modelling exercises that simulate refinery output and product blending. The difference between product output and product demand in any given country is assumed to equate to trade. The analysis suggests that Asian economies will recover during the 2000-2005 period, and that there will be an increase in the petroleum product trade.     

Effect of fuel choice on nanoparticle emission factors in LPG-gasoline bi-fuel vehicles

Nanoparticle and gas-phase emission factors are presented for a liquefied petroleum gas (LPG) passenger vehicle and are compared to gasoline operation. A bi-fuel LPG-gasoline vehicle certified for use on either fuel was used as the test vehicle so that a direct comparison of the emissions could be made based on fuel choice. These values were considered along with previous studies to determine the relative change in particulate emissions due to fuel choice over a wide range of vehicles and operating conditions. The vehicle examined in this study was tested on a chassis dynamometer for both steadystate and transient conditions. Transient test cycles included the US FTP72 driving cycle, Japanese driving cycle and modified Indian driving cycle while steady-state tests were done at vehicle speeds ranging from 10–90 km/hr in various transmission gears. Exhaust particle size distributions were measured in real-time using a differential mobility spectrometer (DMS50), and particle number and particle mass emission factors were calculated. For both fuels, the majority of the particles ranged from 5 to 160 nm in terms of particle diameter, with typically more than 85% of the particles in the nucleation mode (between 5–50 nm). In most cases, the vehicle produced a greater fraction of larger (accumulation mode) particles when fuelled on LPG. Using the data in the literature as well as the data in the current study, gasoline fuel produces 4.6 times more particles in terms of number and 2.1 times more particles in terms of mass.     

基于ERP的高速公路机电设备维修策略分析

在对高速公路机电设备故障及其规律,以及现有高速公路机电设备维修方式进行分析的基础上,提出基于ERP的高速公路机电设备维修策略。阐述将ERP应用于高速公路机电设备维修必须注意系统建设、管理创新、ERP与现有维修方式相结合。现有的维修方式与ERP平台中其他资源均可动态共享,解决当前信息管理和过程控制的主要问题,除提供全套的物流解决方案、监控和优化企业整个生产流程外,也为企业成本管理领域提供强大的核算、分析和控制功能。     

电力机车自动过分相功能检测系统研制

电力机车自动过分相功能检测系统是保证电力机车自动过分相的功能正常可靠，保证电力机车安全自动通过分相点的有效手段。     

水泥混凝土路面破坏的成因分析

水泥混凝土路面发生破坏的原因是多方面的，不仅与设计、施工等路面形成前的环节有关．而且与路面形成后的使用、养护等也联系紧密。因此，需要有关各方各负其责，严格把关，减少水泥混凝土路面的破坏，延长水泥混凝土路面的使用周期，提高投资效益。     

排水板堆载预压加固软基中固结度和沉降的计算

软基监测作为信息化施工的一部分,在施工组织中起着重要的作用。结合某堆载预压工程现场监测数据,采用目前常用的几种方法推算软基的固结度和最终沉降量,并进一步分析了各种计算方法间的差别及各自的适用性和局限性,为今后相关的监测工作提供参考。     

有关道路照明的几个问题

介绍了公路照明的评价指标、灯具选择与布置方法 ,以及节省投资的措施等     

Large-scale physical controls on phytoplankton growth in the Irminger Sea Part I: Hydrographic zones, mixing and stratification

Hydrographic surveys in three consecutive seasons in the Irminger Sea in 2001/2002 have revealed six physical regimes (zones) in which different surface mixing and spring re-stratification processes dominate. They are the South Irminger Current, the North Irminger Current, the Central Irminger Sea, the Polar-origin East Greenland Current, the Atlantic-origin East Greenland Current and the Reykjanes Ridge. The variations in restratification processes in particular have significant implications for the timing of shallow spring mixed layer development and therefore the timing and strength of the spring bloom. The relative roles of heat and freshwater in controlling re-stratification are examined for each hydrographic zone, and it is shown that the simplest concept of solar warming generating spring stratification is appropriate for the Irminger Current and the central Irminger Sea. However in the East Greenland Current and the Reykjanes Ridge zones, the springtime arrival of fresh or saline water at the surface dominates re-stratification and generates the earliest and strongest spring blooms of the region. In the cool fresh centre of the Irminger Sea the relatively low chlorophyll-a throughout the year cannot be wholly explained by stratification or nutrient concentrations. Details of the annual cycle in temperature, salinity, chlorophyll-a and nutrients are presented for each hydrographic zone.