汽油无铅化的关联问题

在实施汽油无铅化的过程中，一个值得引起重视的问题是，要防止“污染替代”发生，即在消除铅污染的同时，防止另一些对环境和健康构成严重威胁的污染物被引入。该文在调研大量中外文献的基础上，综述了目前研究较多的苯、芳烃、烯烃、甲基叔丁基醚等汽油组成和汽油蒸气压对汽车排放正、负方面的影响，提出了制定汽油燃料环保标准，汽油无铅化和安装催化转化器同步进行等建议。     

基于安全性目标的车辆维护周期数学模型研究

本研究旨在建立一个相应于不同的给定的行驶安全性的车辆最优维护周期数学模型，同时，利用汽车制动系、转向系等系统或装置的运行故障分布参数，求出了不同安全性水平下该数学模型的解。还依据原始数据，给出了同样基于行驶安全性目标的汽车维护周期允许上限。本研究结果可用于指导汽车维护工作，而且对保证或提高在用车辆的行驶安全性具有重要的作用     

Aerial photographs: their use in guiding pilgrims and pointers for developing countries

The problems faced by authorities in Saudi Arabia in managing the large numbers of pilgrims visiting Muna during a brief period each year has led to experiments with aerial photography and computer techniques. This paper describes briefly the new method initiated in 1981 emphasising the remarkably short time available for information assembly and interpretation and concludes with pointers towards the development of the techniques for Third World urbanisation studies.     

Phytosociological inference and resource management

The application of vegetation information to resource management problems is reviewed in four areas: (1) the stratification of vegetation data by classification and gradient analysis, (2) the storage and retrieval of these data, (3) the sources of vegetation information, and (4) the accuracy and resolution requirements posed by different management applications. Conclusions indicate that the successful application of inference methods to resource management problems requires an appropriate integration of these four components.     

Influence of cetane improvers on the air quality in an urban street canyon

The concentration distributions of NO_x, PM, HC and CO in an urban street canyon have been estimated using a two-dimensional air quality numerical model based on the k– turbulent model and the atmospheric convection diffusion equation when various cetane improvers were used in diesel fuels. A wind vortex can be found within the street canyon, and the pollutants emitted from the bottom of the street canyon tend to follow the course of the wind field, moving circularly. The addition of cetane improvers can improve the air quality in a street canyon, all of the pollutants were found to decrease with increasing centane number.     

汽车尾气超标原因分析与防治

通过对烟台市近几年的尾气检测与治理的经验分析,简要论述了汽车尾气超标的原因,并针对不同的超标情况提出相应的解决方案.     

济南市机动车排气污染现状与控制对策研究

机动车排气污染已经成为济南市空气污染的重要来源,NOx,CO,THC等污染物排放量分别占机动车与固定源排放总量的22%,96%和92%,机动车排气污染使得道路空气环境质量明显恶化。出租车、轿车、摩托车是机动车污染的3种主要车型。文中在阐明造成机动车污染较重的原因基础上,提出了控制机动车污染的管理、技术以及辅助对策。      

高速车辆/列车控制中无线数据传输的可靠性、可用性分析

无线通信技术快速地发展 ,使得利用无线技术传送车、地信息成为可能。该技术在车辆 /列车控制系统中应用时的关键问题是无线传输的可靠性、可用性 ,特别是在高速情况下 ,无线传输的误码率能否满足车辆 /列车控制系统的要求。笔者分析了高速环境下无线信道的特性 ;分析无线传输用于高速车辆 /列车控制系统的可靠性、可用性 ,建立信道模型 ;分析了车辆 /列车速度对无线信息传输误码率的影响 ;结合环境特点提出改进无线链路性能的具体措施。最后 ,还提出了高速环境下判断无线传输能否满足车辆 /列车控制要求的具体方法     

Fall arrest characteristics of a scissor lift

Problem

Census of Fatal Occupational Injuries (CFOI) data indicate 306 aerial lift fatalities between 1992-2003. Seventy-eight of these fatalities specifically involved scissor lifts. Members of standards committees have requested that NIOSH conduct research to determine the effects of safety-control practices related to using fall-protection systems for scissor lifts.

Method

This research examined the structural and dynamic stability of a scissor lift subjected to fall arrest forces. This was accomplished by conducting drop tests from a scissor lift. Anchorage locations evaluated included manufacturer-supplied anchorage points on the scissor lift platform as well as mid-rail and top-rail locations.

Results

Preliminary drop tests determined that a 2400 lb maximum arrest force (MAF) could be generated by dropping 169 lb through a fall height of 36” using Nystron® rope as a lanyard. The scissor lift maintained structural and dynamic stability for all drop tests when fully extended and on an incline.

Discussion

Anchoring a fall arrest system to either the mid-rail or top-rail is not a recommended practice by the scissor lift manufacturer. Anchor points are provided on the platform floor of the scissor lift for this purpose. However, our results demonstrate that the mid-rail and top-rail absorb substantial energy from an arrested fall and may have potential as appropriate anchorage points.

Impact to Industry

Employers and workers should consider implementing fall arrest systems when using scissor lifts as part of their overall risk mitigation plan for fall injury prevention.     

Hazard perception of stroke drivers in a video-based Japanese hazard perception task

Objective: Hazard perception (HP) is the ability to identify a hazardous situation while driving. Though HP has been well studied among neurologically intact populations, little is known about the HP of neurologically impaired populations (in this study, stroke patients). The purpose of this study is, first, to investigate the HP of stroke patients and, second, to verify the effect of lesion side (right or left hemisphere) on HP, from the viewpoint of hazard types.

Methods: Sixty-seven neurologically intact age-matched older drivers and 63 stroke patients with valid driver’s licenses conducted a video-based Japanese HP task. Participants were asked to indicate the hazardous events in the driving scenario. These events were classified into 3 types: (1) behavioral prediction hazards (BP), which are those where the cause is visible before it becomes a hazard; (2) environmental prediction hazards (EP), which are those where the ultimate hazard may be hidden from view; and (3) dividing and focusing attention hazards (DF), which are those where there is more than one potential hazard to monitor on approach．Participants also took part in the Trail Making Test (TMT) to evaluate visual information processing speed.

Results: The results showed that the number of responses was significantly fewer for stroke patients than for age-matched drivers for all hazard types (P < .001), and this difference was not affected by lesion side (P > .05). It was also found that stroke patients showed a slower response time than age-matched drivers only for BP (P < .001). The lesion side did not affect response latency (P > .05). Results of the TMT revealed that age-matched drivers completed the task significantly faster than stroke patients (P < .001) and that neither TMT-A nor TMT-B differentiated between patients with left hemisphere damage and patients with right hemisphere damage (P > .05).

Conclusions: Firstly, HP in stroke patients is low compared to age-matched drivers. Secondly, even if stroke patients notice hazards, their response may be delayed in a BP situation, due to a slower visual information processing speed. Thirdly, the lesion side does not appear to affect HP.