1996年亚特兰大奥林匹克运动会的遗产--亚特兰大的尝试、失误与成功

1996年亚特兰大奥林匹克运动会已经过去38年．这次奥林匹克运动会的遗产、记忆与成功对经济和社会的影响一直在伴随着我们．作为一个奥林匹克运动会的组办城市，亚特兰大不得不面对奥林匹克运动会后的挑战，这些挑战并不比组办奥林匹克运动会来得轻松．本文报导了我们的尝试、失误与成功的经历，它描述了该地区正在前进的方向和相关的交通规划和土地使用策略．     

脐血红细胞免疫功能的观察

对７７例脐血红细胞免疫功能及其调节因子活性进行了测定，以６５例正常人静脉血作为对照。结果发现：脐血ＲＢＣ·Ｃ３ｂＲ及ＲＢＣ·ＩＣＲ均增高，差异显著（Ｐ＜０．０１）；ＲＦＥＲ高于正常人静脉血（Ｐ＜０．０１），ＲＦＩＲ无差异（Ｐ＞０．０５），故二者比值Ｅ／Ｉ升高，差异显著（Ｐ＜０．０１）。结果表明脐血红细胞免疫功能高于正常人静脉血。     

对道路交通标志牌设置的对比研究

根据我国现有道路交通标志使用方面存在的问题,基于国外相关方面的研究思路、设置方法以及理论方面的相关分析而提出的一些建议和相关的改善措施,可为我国道路交通标志牌的合理设置提供参考.     

Living with aircraft noise: Airport proximity,aviation noise and subjective wellbeing in England

Airport expansion is an issue of intense public debate due to the potential impacts on climate change and the quality of life of affected local communities. This paper is the first study to analyse the relationships between airports and multiple subjective wellbeing measures, by merging national-level population statistics with noise measurement maps for seventeen English airports. The presence of daytime aviation noise was found to consistently negatively impact on five subjective wellbeing measures. We found a marginal negative association with every additional decibel of aircraft noise. We found no significant association between wellbeing and living within night-time noise contours or living in close airport proximity. We conclude that living under air traffic flight paths has a negative effect on peoples’ overall and momentary wellbeing, equivalent to around half the effect of being a smoker for some wellbeing measures. The subjective wellbeing method findings support wider revealed preference literature showing lower market demand in areas affected by aviation noise.     

Introducing specific power to bicycles and motorcycles: Application to electric mobility

Electric bicycles and motorcycles have emerged as a possible way of improving the transportation system sustainability. This work’s aim was to quantify the energy consumption, the trip travel and the driving dynamics on specific routes in Lisbon, Portugal. Six electric and conventional bicycles and motorcycles were monitored, and a methodology to quantify the power required in each driving second was developed: Motorcycle and Bicycle Specific Power (MSP and BSP respectively). MSP and BSP allows characterizing energy consumption rates based on on-road data and to define real-world operation patterns (driving power distribution), as well as to benchmark the different propulsion technologies under the same baseline of specific power. For negative MSP and BSP modes, the conventional and the electric motorcycles and bicycles demonstrated a similar pattern. However, their behavior was different for positive modes, since electric technologies allow reaching higher power conditions. The methodology developed estimates accurately the energy consumption (average deviation of −0.19 ± 6.76% for motorcycles and of 1.41 ± 8.91% for bicycles). The MSP and BSP methodologies were tested in 2 Lisbon routes. For the electric motorcycle an increase in trip time (+36%) was observed when compared to the conventional one, while for the electric bicycle a 9.5% decrease was verified when compared to the conventional one. The Tank-to-Wheel (TTW) energy consumption for motorcycles was reduced by 61% when shifting to electric mobility, while a 30% Well-to-Wheel (WTW) reduction is obtained. For the electric bicycles, an additional energy use is quantified due to the battery electricity consumption.     

The socio-economics of travel behavior and environmental burdens: A Detroit,Michigan regional context

The transportation industry—particularly light-duty vehicles—is a significant contributor of greenhouse gasses, accounting for about one-third of overall emissions in the U.S. Research to date has studied various factors that impact travel behavior of residents with varying socio-economic characteristics. However, research on the socio-economic characteristics of residents and their impact on environmental burdens within a single urban region, as measured by fuel consumption and vehicular emissions, is recognized as under-represented in the U.S. planning and transportation literature. This study focuses on the Detroit region, Michigan, a unique case study due to the scale of suburbanization and urban decline, yet representative of many mid-western cities. The article explores how socio-economic characteristics impact travel patterns and environmental burdens within six Detroit region neighborhoods. Data on individual travel behavior and personal vehicle characteristics gathered from a mail survey enabled an analysis into how associated environmental burdens varied with socio-economic composition. The analysis explores contributions to environmental burdens between poorer urban and wealthier suburban populations.     

How much can public private partnership really do for urban transport in developing countries?

A few cities in some of the larger developing countries in Latin America and Asia have made increasing use of multi-year concessions or franchises, competitively awarded to private companies, for construction and operation of urban transport infrastructure and for provision of public transport services. In view of the strong prospective growth of developing-country cities with large transport needs, and the rise in the emerging economies of potential new sources of private capital, it is important to see how effective PPP has so far been in this area. The experience is analyzed principally by thorough comparative review of what has actually happened for some of the main users to date: Bogotá, Santiago, São Paulo, Seoul, and several cities in both China and India. Despite delays and mistakes that have been made in development of most of the projects, the overall results, already delivered and in prospect, are very positive and urban public transport is benefiting substantially, with significant side effects on poorer people's access to work and to services, air pollution levels and road accident rates. The widest and most important advantage of the PPP arrangements, as compared with more conventional short-term contracting, is found to be the innovations, technical and managerial, developed, and, in particular, the mutual capacity building of the countries' private and public sectors and their more effective interaction. The experience in the six countries covered suggests that other developing-country cities may be best assisted to develop sound urban transport PPPs more rapidly through provision of help on chosen items among 7 elements that have proved particularly crucial but sometimes weak in the projects reviewed: Civic consultation systems, Land-use/Transport strategic planning, Land/property market management, Monitoring systems, Progressive policies, Economic regulation, and Public institutional framework for PPPs.     

Effects of Human Activities on the World's Most Vulnerable Coral Reefs: Comoros Case Study

Effective management of highly biodiverse and threatened reefs requires the identification of human activities driving declines on the particular reef to be managed. The island nation of the Comoros is a model setting to investigate effects of human activities on diverse and threatened coral reefs, with abundant and diverse marine life, local dependence on reef resources, and a variety of anthropogenic pressures on reefs rendering the nation vulnerable to coral reef degradation. Using data from 21 sites throughout the Comoros, we evaluated the relative influence of human activities and other natural and anthropogenic factors on benthic cover and fish richness, abundance, and biomass with the goal of providing prioritized management targets. Human activities including fishing, beach sand extraction, and beachfront housing and development had the strongest relationship with degraded reefs but with some seasonal fluctuation, while geographic patterns most consistently predicted reef degradation across seasons. Comparing analyses conducted with and without human activities as predictors, the inclusion of human activities greatly improved explanatory power. Baseline data on reef biotic composition and localized anthropogenic impacts, monitoring over time, and controlled experiments can facilitate an adaptive management approach for protecting fragile reef ecosystems in the Comoros and elsewhere.     

On Impact mechanics in ship collisions

The purpose of this paper is to present analytical, closed-form expressions for the energy released for crushing and the impact impulse during ship collisions. Ship–ship collisions, ship collisions with rigid walls and ship collisions with flexible offshore structures are considered. The derived mathematical models include friction at the contact point so that situation where the collision results in a sliding motion is included. Results obtained by application of the present procedure are compared with results obtained by time simulations and good agreement has been achieved. In addition, a number of illustrative examples are presented. The procedure presented in the paper is well suited for inclusion in a probabilistic calculation model for damage of ship structures due to collisions.     

Numerical prediction of the dilution process and its biological impacts in CO2 ocean sequestration

 In order to investigate the biological impacts of the ocean sequestration of CO₂ (carbon dioxide), the dilution processes of CO₂ were investigated near injection points in the deep ocean. From a combined fluid-dynamics, chemical, and biological approach, a two-phase computational fluid dynamics (CFD) method with mass transfer was developed to predict droplet plume flow, the dissolution of CO₂ from droplets into seawater, and the advection–diffusion of dissolved CO₂ (DCO₂) in the deep ocean. Changes in pH due to the concentration of DCO₂ were also calculated. In addition, the isomortality concept of Auerbach et al. was incorporated to predict the lethal damage to marine organisms caused by DCO₂. The simulation results suggested that the biological impacts of CO₂ sequestration were insignificant in terms of mortality in both small-scale field experiments and the real-life cases we propose. Received: October 3, 2001 / Accepted: December 14, 2001