生态—水力学法在山区小型引水电站最小下泄流量计算中的应用

以川西某山区小型引水式电站为例,选择水深和流速为生境参数,以华鲮为生态保护目标,计算河道的最小生态需水量和对应的电站最小下泄流量,并与Tennant法、代表年法的计算结果对比。结果表明,生态水深0.12m对应的最小生态流量和Ten nant法的结果差异度为8.63%,较合理;生境参数标准值对计算结果影响显著;在选择合适的参数和参数标准值的前提下,生态—水力学法适用于山区小型河流。     

Noise annoyance from industrial and road traffic combined noises: A survey and a total annoyance model comparison

The literature on noise annoyance emphasizes that acoustical factors cannot totally explain the annoyance felt by a population exposed to community noises, and that some non-acoustical factors have an effect on annoyance. This research paper deals with the annoyance caused by combined noises coming from road traffic and an industrial site. This type of combination has been very little studied to date. An in situ study was conducted in an area of a French town exposed to these two noise sources. To investigate the annoyance caused by these combined noises, the work involved both a mapping of the industrial and road traffic noises present in the survey area and a questionnaire designed to evaluate the noise annoyance experienced by residents and to identify the factors that probably influence noise annoyance. The results highlight the link between the noise levels measured and the annoyance felt by the respondents. They also show that certain non-acoustical factors have an impact on annoyance felt. Indeed, the results highlight a positive correlation between fear of industrial sites and the annoyance expressed. They also show correlations between some items to evaluate noise sensitivity and the annoyance expressed. No significant correlation has been found between annoyance and the other non-acoustical factors such as age, sex and length of residence. Finally, several total annoyance models were tested for this noise combination. Two of them, namely the strongest component model and a proposed perceptual version of the mixed model, were able to better predict total annoyance than the other tested models.     

Biochemical study of retired pentachlorophenol workers with and without following dietary exposure to PCDD/Fs

Objectives

This is the first research study to compare among female, non-smoker workers: (a) the exposure to benzene, toluene and xylenes (BTXs) in urban air during work in the street (traffic policewomen, TP) vs. work in vehicles (police drivers, PD); (b) the exposure to BTXs in urban environments (in street and in car) vs. rural environments (roadwomen, RW); (c) the values of blood benzene, urinary trans, trans muconic acid (t,t-MA) and urinary S-phenylmercapturic acid (S-PMA) in urban areas (in street and in car) vs. rural areas.

Methods

Passive personal samplings and data acquired using fixed monitoring stations located in different areas of the city were used to measure environmental and occupational exposure to BTXs during the work shift in 48 TP, 21 PD and 22 RW. In the same study subjects, blood benzene, t,t-MA and S-PMA were measured at the end of each work shift.

Results

Personal exposure of urban workers to benzene seemed to be higher than the exposure measured by the fixed monitoring stations. Personal exposure to benzene and toluene was (a) similar among TP and PD and (b) higher among urban workers compared to rural workers. Personal exposure to xylenes was (a) higher in TP than in PD and (b) higher among urban workers compared to rural workers. Blood benzene, t,t-MA and S-PMA levels were similar among TP and PD, although the blood benzene level was significantly higher in urban workers compared to rural workers. In urban workers, airborne benzene and blood benzene levels were significantly correlated.

Conclusions

Benzene is a human carcinogen, and BTXs are potential reproductive toxins at low dose exposures. Biological and environmental monitoring to assess exposure to BTXs represents a preliminary and necessary tool for the implementation of preventive measures for female subjects working in outdoor environments.     

超大城市昼夜交通事故严重程度致因对比分析——以深圳市为例

为研究夜间交通事故严重程度致因,基于深圳市3年3 244起交通事故数据,获取昼夜交通事故分布的时空特征;进一步选取交通事故集聚的南山区、福田区、罗湖区的1 798起交通事故,以交通事故严重程度为因变量,以事故原因、日期、事故形态等10个因素为候选自变量,构建广义有序Logit回归模型,对比分析昼夜不同严重程度交通事故的影响因素。结果表明:路口路段类型、疲劳驾驶、事故日期在夜间模型参数估计值分别为0.493,-0.363,-0.309,而在日间模型表现为不显著,道路路面材料在日间模型参数估计值为-0.232,而在夜间表现为不显著;事故原因、道路横断面渠化方式等因素在日间和夜间所引起交通事故的严重等级均存在较大差异。     

考虑街区尺寸的应急救援路径选择仿真研究

为分析街区尺寸对应急救援车辆行程时间的影响,基于小（120 m）、中（264 m）、大（440 m）3种典型街区尺寸,将救援车辆行程时间分为街区内、外2部分,以总行程时间最小为目标,构建基于背景流量水平的救援车辆路径选择仿真模型。设置4种救援场景,分别求解各救援场景在不同街区尺寸下的最短路径时间、冗余度及复杂度。结果表明:街区尺寸对街区内、外部救援时间均有影响,而前者在救援路径距离较短、街区尺寸较大的路网中占据较大比例（可达50%以上）;救援路径包含路段的流量较小时,中、大街区尺寸路网表现类似,而高流量下大尺寸具备更优的救援时间;街区尺寸越小,救援路径冗余度与复杂度均越大。     

基于文本挖掘的管制运行风险主题分析*

为充分挖掘管制运行风险信息和隐藏规律,实现数据驱动的风险管理。以某管制单位2004—2019年共269条管制原因不安全事件数据为挖掘语料,在考虑上下文语义的基础上,运用潜在狄利克雷分配（LDA）主题模型挖掘管制运行风险主题及关键词,使用Word2Vec挖掘主题之间、关键词之间的关联关系,运用社会网络分析软件UCINET、可视化工具NETDRAW构建语义网络将关联关系进行可视化并进行网络分析。结果表明:LDA主题模型可以通过运行数据实现对管制运行风险的高效提取和深层挖掘,挖掘到管制人为因素、特情处置、地空配合、班组资源管理、组织管理、运行环境、管制指挥共7个主题,其中管制人为因素主题是核心主题,与其他主题都具有较强的相互关联;Word2Vec和语义网络相结合能够更准确地挖掘风险之间的关系,确定主题的重要度排序,识别关键风险。     

公路突发交通事件应急资源配置效率研究*

为合理有效配置公路突发事件下的应急资源,从资源投入与产出角度建立3级评价指标体系,在此基础上将应急资源投入与产出比作为目标函数,引入数据包络分析法构建应急资源配置效率模型,采用TOPSIS法对应急资源配置方案效率进行排序。以新疆10个公路局应急资源配置效率为例,分析其资源投入与产出的冗余度,并对有效决策单元进行排序。结果表明:该模型能获得应急资源配置冗余度,并对其进行资源配置效率分析,从而为公路局进行有效资源配置提供参考。     

空管安全风险管理信息系统分析与设计

针对空中交通服务管理系统(简称为"空管",下同)中存在的安全管理不规范、安全信息不畅通和信息化程度低等安全管理问题,根据空管安全风险管理信息系统(SRMIS)的工作原理,提出SRMIS的业务流程和组织结构,设计了SRMIS的总体结构、风险管控和指标预警等主要功能,研究实现过程中的指标评价、部门评价和模糊综合评价等信息评价方法以及指标预警、因素预警和综合预警等预警预控方法和关键技术。该系统能进行持续的风险识别和综合预警,定期自检、自查、自审,不断改进安全管理工作,并在武汉空管中心实证有较好的应用效果,为空管中心的安全风险管理提供了信息化管理的工具和途径。     

基于分类交通冲突与微观仿真分析的城市交叉口安全诊断及改善

鉴于传统的城市交叉口交通冲突整体评价方法不能深入地分析和解决交叉口内部的交通安全问题,依据流量和相位时长关系确定分类交通冲突评价系数,计算出不同相位阶段中不同交通冲突类型(机-机、机-非、机-人)的交通冲突率和分类综合交通冲突率,从而比较和诊断交叉口内部危险性高的交通冲突类型及所在相位,并应用VISSIM仿真软件评估相应交通安全改善措施对路口交通效率的影响。以北京市光彩北路路口为对象进行实验分析,其结果表明,分类交通冲突技术与微观交通仿真分析的充分结合,可提高城市交叉口安全诊断的准确性及相应改善措施的有效性。     

我国公路交通事故的现状及特征分析

根据2000—2006年全国公路交通事故统计数据,以2006年为重点,分析当前我国公路交通事故的发展形势、地区差异和事故特征。研究表明:我国的公路交通事故自2003年开始总体由快速上升转为持续下降,但高速公路和西部地区的公路交通事故仍有增长可能;与经济欠发达地区相比,经济发达地区的事故总量较大,但事故死亡率较低;国道、省道和高等级公路的事故死亡率均大幅高于其他公路;约80%的死亡事故是发生在平直、一般弯和一般坡等良好路段上的车辆互碰、碰撞行人和翻车,76%的特大事故属于坠车和正面碰撞;雾、雪等恶劣天气更易在高等级公路上引发交通事故。