Atmospheric Change and Biodiversity: Co-Networks and Networking

Canada responded to the Global Biodiversity Convention by completing the Canadian Biodiversity Strategy in 1995. At the same time, Environment Canada also completed a national Science Assessment on Biodiversity. During this period, the Smithsonian Institution, in partnership with Parks and Environment Canada, initiated the implementation of a global biodiversity monitoring program in Canada. Under the auspices of the United Nations Man and the Biosphere Program, the SI/MAB monitoring protocols and plots have spread across Canada at an unprecedented rate. National champions in the science and educational sectors, working within an inter-disciplinary ecological framework, have guided the development, education, quality control and sharing of atmosphere-biodiversity observations electronically.Atmospheric-Biodiversity Networks and Networking have traditionally operated within separate mandates with little degree of integration. Air-Bio Networks were designed within an integrated framework to better understand the atmospheric stress on biodiversity and the adaptation actions, nationally and regionally. Detailed examples of the cumulative effects of climate change, stratospheric ozone depletion, acid deposition, ground-level ozone, suspended particulate matter and hazardous air pollutants on biodiversity will be discussed using a Southern Ontario case study. In addition, recommendations will be presented for future paired SI/MAB plots, linked networks and networking for adaptation within the context of climate, chemical and ecological gradients.     

On the Performance and Applicability of Nonlinear Two-Equation Turbulence Models for Urban Air Quality Modelling

It is well known that the commonly used k- turbulence models yield inaccurate predictions for complex flow fields. One reason for this inaccuracy is the misrepresentation of Reynolds stress differences. Nonlinear turbulence models are capable to overcome this weakness while being not considerably more complex. However no comprehensive studies are known which analyze the performance of nonlinear turbulence models for three-dimensional flows around building-shaped structures. In the present study the predictions of the flow around a surface-mounted cube using three nonlinear two-equation turbulence models are discussed. The results are compared with predictions of the standard k- turbulence model and wind tunnel measurements. It is shown that the use of nonlinear turbulence models can be beneficial in predicting wind flows around buildings.     

A New All Season Passive Sampling System for Monitoring Ozone in Air

A new all season passive sampling system for monitoring O₃ in the atmosphere has been developed in the laboratory and validated in the field. The unique features for this system include a newly designed passive sampler and a rain shelter, which allow the passive sampler to be installed in the field facing downwards. An equation associated with meteorological parameters is used to calculate the passive sampling rates. This system has been extensively tested in the lab (temperature from –18 to 20°C, relative humidity from 13 to 81%, and wind speed from 0.5 to 150 cm/s) and validated in the field in climates of all seasons. The accuracy of the ozone concentrations in the atmosphere obtained with the use of the new passive sampling system was higher than 85% compared to those obtained with continuous ozone analyzers. The new ozone passive sampling system can be used to measure ambient O₃ concentrations ranging from 3 ppb to 1000 ppb based on one-day exposure and 0.1 ppb to 140 ppb for a monthly exposure period. It is also reasonable to conclude that the new passive sampling system can be used for eight-hour exposure study because of the low field blanks and high sampling rates.     

鞍山市城区采暖期大气PM_(2.5)中PAHs的污染特征研究

通过对鞍山市(1个工业区、2个工业区周边、3个居住区、1个对照点)2015年1月采暖期大气PM_(2.5)中多环芳烃(PAHs)的监测,采用BaP当量致毒系数TEF,分析了鞍山市大气PM_(2.5)中典型PAHs毒性当量分布特征。研究表明,鞍山市大气PM2.5中工业区及工业区周边Ba P毒性当量浓度要远高于居住区和对照点,污染物主要由4~6环的PAHs组成,很强致癌BaP当量浓度为9.351~38.59 ng/m3。     

Optimized determination of airborne tetracycline resistance genes in laboratory atmosphere

• Sampling parameters with high efficiency was determined. • Operational process to detect airborne ARGs was optimized. • Providing research basis to control airborne ARGs of a laboratory atmosphere Antibiotic resistance genes (ARGs) have been detected in various atmospheric environments. Airborne ARGs transmission presents the public health threat. However, it is very difficult to quantify airborne ARGs because of the limited availability of collectable airborne particulate matter and the low biological content of samples. In this study, an optimized protocol for collecting and detecting airborne ARGs was presented. Experimental results showed that recovery efficiency tended to increase initially and then declined over time, and a range of 550–780 copies/mm² of capture loading was recommended to ensure that the recovery efficiency is greater than 75%. As the cell walls were mechanically disrupted and nucleic acids were released, the buffer wash protects ARGs dissolution. Three ratios of buffer volume to membrane area in buffer wash were compared. The highest concentrations of airborne ARGs were detected with 1.4 µL/mm² buffer wash. Furthermore, the majority of the cells were disrupted by an ultrasonication pretreatment (5 min), allowing the efficiency ARGs detection of airborne samples. While, extending the ultrasonication can disrupt cell structures and gene sequence was broken down into fragments. Therefore, this study could provide a theoretical basis for the efficient filter collection of airborne ARGs in different environments. An optimized sampling method was proposed that the buffer wash was 1.4 µL/mm² and the ultrasonication duration was 5 min. The indoor airborne ARGs were examined in accordance with the improved protocol in two laboratories. The result demonstrated that airborne ARGs in an indoor laboratory atmosphere could pose the considerable health risk to inhabitants and we should pay attention to some complicated indoor air environment.     

海洋大气腐蚀性分类分级

本文介绍了国内外大气腐蚀性分类分级的主要方法和发展状况，论述了在我国沿海开展大气腐蚀性研究的重要性，并提出了开展该项研究着重需要考虑的几个问题。     

O2/CO2气氛下石灰石煅烧分解的动力学和热力学研究

富氧燃烧是一种能够综合控制燃煤污染物排放的新型洁净燃烧技术。针对O2／CO2气氛下石灰石煅烧分解特性进行了热力学分析和热重试验结果的动力学分析，将热力学分析结果与热重试验结果进行了对比，得出石灰石的起始分解温度随CO2分压比的增大而增高。     

大气汞氧化还原过程与机制的计算化学研究进展

大气中汞的氧化还原反应对于其全球生物地球化学循环起着极其重要的作用,它促进了汞在全球范围内的扩散.汞主要以气态元素汞的形态释放到大气中,并经历复杂的均相和非均相化学反应,被氧化为活性气态汞和颗粒态汞;同时,活性气态汞也可经过光致还原反应光解生成气态元素汞.计算化学是一种基于理论方法利用计算软件来对化学现象和本质进行解释...     

嵊州、新昌地震与低空大气增温异常

从嵊州、新昌地震 (1998 0 8 17T 1∶4 6ML4 5)的地震地质构造环境、卫星热红外异常与近地表大气增温异常等三个方面 ,进行了研究。认为地震前几日 ,震区及周围大面积的突发性低空大气增温异常与卫星红外异常是一种临震前兆 ,并总结了增温异常的时空演变规律与地震活动的关系。     

土壤,沉积物中微量金属形态分配预测初步研究

本文讨论了土壤、沉积物中微量金属的形态分配预测问题。对已有的一些工作进行了总结,并以我国东部平原为例,建立了土壤微量金属多元回归相分配预测摸型。