我国城市公交全面电力化的战略思考

近两年来,雾霾天气不断侵扰我国,尽管有关部门和各级政府采取了一系列措施,仍难产生立竿见影的效果。能否积极有效地改善环境质量特别是改善城市空气质量是考验我国生态环境治理体系和治理能力的重大课题。本文提出了将城市公交全面电力化作为突破口的有益思考。     

Temporal scaling behavior of human-caused fires and their connection to relative humidity of the atmosphere

It has been found that many natural systems are characterized by scaling behavior. In such systems natural factors dominate the event dynamics. But in countries with high population density such as China and Japan, more than 95% of the forest fire disasters are caused by human activities. Furthermore, with the development of society, the wildland-urban interface (WUI) area is becoming more and more populated, and the forest fire is much connected with urban fire. Therefore exploring the scaling behavior of fires dominated by human-related factors is very challenging. The present paper explores the temporal scaling behavior of forest fires and urban fires in Japan. Our findings point out that although the human factors are the main cause, both the forest fires and urban fires exhibit time-scaling behavior. Similar distribution law characterizes the relative humidity.     

沈阳地区一次颗粒物重污染天气过程的气象成因分析

为探究沈阳地区重污染天气成因,文章利用地面、高空气象观测资料、风廓线雷达资料、NECP再分析资料以及大气污染物监测资料,对2019年3月1～6日沈阳地区出现的一次持续性重污染天气过程,探讨了大气污染物质量浓度、地面气象要素变化特征、大气环流配置与外来输送等特征.结果表明,均压场、地面风场弱及辐合、高温高湿是本次重污染天...     

嘉峪关市降水偏碱性的成因初探

通过对区域近年来的降水监测数据的收集、整理和分析,探求区域降水特点及主要成因。     

菏泽市气象因子与空气质量相关性研究与应用

利用气象因子与空气中污染物之间的相互关系,建立了旨在反映两者内在关系的多元回归方程模型。利用气象参数预报值和当日污染物监测结果,对次日空气中污染浓度进行预测。     

城市空气污染预报方法研究

介绍了国内外空气污染预报所采用的几种主要方法 ,强调指出空气污染预报的特点以及在今后预报中应注意的问题。     

The influence of parental age and weather on testosterone concentration and offspring survival in broods of tawny owl Strix aluco

Previous research has suggested that parental condition may affect offspring mortality patterns by affecting offspring testosterone levels. Accordingly, we hypothesized that there is a relationship between offspring testosterone concentration and survival during the early nestling period, and that both are influenced by parent age/experience and by prey availability. We tested our hypothesis on tawny owls Strix aluco in their first and third known breeding seasons, when they bred either in adverse or mild weather conditions, in Duna-Ipoly National Park, Hungary. Plasma testosterone concentrations of the nestlings were analyzed and related to parental condition, hatching order and nestling mortality. Inexperienced parents breeding in all weather conditions and experienced parents breeding in adverse conditions were both in poor condition compared to experienced parents breeding in mild conditions. Parents in poor condition produced broods with large between-sibling differences in testosterone concentrations and their later-hatched nestlings (which had low testosterone levels) died during the early nestling period, whereas parents in good condition produced broods with lower variation in offspring testosterone concentrations and all offspring survived the early nestling period. We discuss environmental influences on the amount of testosterone deposited in eggs, and also how maternal testosterone might induce those mechanisms producing testosterone in the nestlings.Communicated by M. Webster, T. Czeschlik     

天津静稳指数建立及在环境气象预报和评估中的应用

基于2014—2015年NCEP再分析资料及天津地区PM_2.5质量浓度数据,构建天津地区静稳指数以期反映大气综合扩散能力,为天津霾、空气质量预报和大气环境气象条件评估提供支撑.研究结果表明：本文构建的静稳指数可作为评估天津地区细颗粒物大气扩散能力的重要指标参数,其建模产品与天津地区PM_2.5质量浓度相关系数为0.62,在评测期间（2016年6月1日—2018年5月31日）,基于EC模式的静稳指数24 h预报产品与天津地区PM_2.5质量浓度相关系数为0.67,1~7 d预报产品与PM_2.5质量浓度相关系数超过0.53,8~10 d预报产品随着时效增加指示能力有所下降,相关系数为0.4左右,但通过显著性检验.对比同期基于GFS资料和WRF/Chem构建的天津中长期环境气象数值模式,其相关系数接近,趋势预报效果相当.同时,由于静稳指数综合了水平风速、混合层高度、相对湿度等多项指标,可以综合反映一个地区大气扩散能力,在大气环境气象条件评估中可发挥积极作用,以同排放源不同气象条件的数值模拟为基准定义细颗粒物大气扩散条件,2013—2018年逐月大气扩散条件同比上年改善的占总样本41%,同比转差的占总样本59%,利用静稳指数对大气扩散条件月同比变化趋势进行判断,识别准确率可达80%.     

Investigating the effects of monthly weather variations on Connecticut freeway crashes from 2011 to 2015

IntroductionThe objective of this research is to investigate the effects of monthly weather conditions on traffic crash experience on freeways, considering the interactions between weather, traffic volumes, and roadway conditions. Methods: Data from the state of Connecticut from 2011to 2015 were used. Random parameters negative binomial models with first-order, autoregressive covariance were estimated for representative types of freeway crashes (front-to-rear, sideswipe-same-direction, and fixed-object), most severe crashes (i.e., fatal and injury crashes), and non-injury crashes (i.e., property-damage-only crashes). Results: Major findings are that variations in monthly traffic volumes, roadway geometry, and weather conditions explain much of the variations in monthly traffic crashes. Time effects exist in the panel monthly data for all types of crashes. Taking into account this effect improves model prediction results. When the raw weather measures are highly correlated, using dimension reduction techniques helps to extract more interpretable weather factors. By considering the interaction effects between roadway condition variables, additional findings were found. In general, lower temperature, more heavy fog days, decreased precipitation, lower wind speed, higher monthly traffic volumes, and narrower inside shoulder were found to be associated with higher monthly crashes. The effects of area type and outside shoulder width change dramatically as the number of through lanes changes. Practical applications: The findings of this research could help researchers and general readers gain a better understanding of the effects of monthly weather conditions and other roadway factors on freeway crashes and give engineers practical guidelines on improving freeway safety.