长江三角洲地区CO2浓度本底特征及来源分析

二氧化碳(CO₂)是引起全球变暖的最主要的温室气体(GHGs),直接观测大气CO₂浓度对于研究人类活动和自然活动对大气温室气体的贡献至关重要,而在多个高度上观测大气CO₂浓度则有助于明晰CO₂浓度的时空变化规律,确定其影响机制.本文利用临安区域大气本底站2018-12—2020-11不同高度(距地面21 m、53 m)处的CO₂在线观测数据,结合日变化及地面风的影响,对观测数据进行筛分,采用HYSPLIT后向轨迹模型和潜在源贡献因子法,初步探讨气象因素以及大气远距离传输对长江三角洲地区大气CO₂浓度的影响.结果表明,临安站高低层大气CO₂日变化呈夜间高于白天的特点;低层CO₂浓度大于高层,冬季高低层浓度差小于其他三季;日较差呈夏季>春季>秋季>冬季的特点;大气CO₂本底季节变化由于受到风向和气团传输的影响呈现出冬季>春季>秋季>夏季的特点;潜在源贡献分析得...     

长江中下游地区地下水中Cu元素的背景特征分析

根据国家科技攻关项目〈长江中下游重点地区地下水环境背影值调研〉的研究结果，论述了长江中下游地区地下水铜元素的背景特征及其与地下水的含水介质成分、上覆岩土性质，氧化还原环境、地下不的戏流条件、地下水及土壤的酸碱度的密切关系。结果表明，长江中下游地区地下水中Ｃｕ元素含量一般比较低；Ｃｕ元素在区域上分布，鄱阳湖区〉长江三角洲南部区〉江汉平原东部区。在人群普遍缺铜的地区，应寻找含Ｃｕ量较高的地下水作为水源     

Positive vs. false detection: A comparison of analytical methods and performance for analysis of cyclic volatile methylsiloxanes (cVMS) in environmental samples from remote regions

Contamination and analytical variation can significantly hinder trace analysis of cyclic methyl volatile siloxanes (cVMS); potentially resulting in the report of false positives at concentrations approaching detection limits. To assess detection and variation associated with trace cVMS analysis in environmental matrices, a co-operative laboratory comparison for the analysis of octametylcyclotetrasiloxane (D4), decamethylcylcopentasiloxane (D5), and dodecametylcyclohexasiloxane (D6) in sediment and biota from the Svalbard Archipelago was conducted. Two definitions of detection limits were evaluated in this study; method detection limits (MDL, matrix defined) and limits of detection (LOD, solvent defined). D5 was the only cVMS detected above both LOD (0.08–0.81 ng g⁻¹ ww) and MDL (0.47–2.36 ng g⁻¹ ww) within sediment by all laboratories where concentrations ranged from 0.55 to 3.91 ng g⁻¹ ww. The percentage of positive detects for D5 decreased by 80% when MDL was defined as the detection limit. D5 was also detected at the highest frequency among all laboratories in fish liver with concentrations ranging from 0.72 to 345 ng g⁻¹ ww. Similar to sediment, percentage of positive detects for D5 decreased by 60% across all laboratories for fish livers when using MDL (0.68–3.49 ng g⁻¹ ww). Similar observations were seen with both D4 and D6, indicating that sample matrix significantly contributes to analytical response variation. Despite differences in analytical methods used between laboratories, good agreement was obtained when using MDL to define detection limits. This study shows the importance of incorporating variation introduced by sample matrices into detection limit calculations to insure data accuracy of cVMS at low concentrations.     

Impact of the Saharan dust outbreaks on the ambient levels of total suspended particles (TSP) in the marine boundary layer (MBL) of the Subtropical Eastern North Atlantic Ocean

Six years (1998–2003) of measurements of ambient air concentrations of total suspended particulate (TSP) measured at a rural background monitoring station in Tenerife (Canary Islands), the El Río station (ER, 28°08′35″N, 16°39′20″W, 500 m a.s.l.) were studied. African dust outbreaks were objectively identified using a new quantitative tool, called the African Index. This index indicates the percentage of time that an air mass remained over an African region at one of three possible height intervals of the lower troposphere. After identifying these episodes, a study of the background TSP levels at the ER station and of direct and indirect (those which cause vertical deposition of dust) African air mass intrusion impacts was performed. Taking into account both direct and indirect episodes, a total of 322 days of African dust intrusion were objectively identified (a mean of 54 episodes per year) in the period 1998–2003, some of them caused by “transition episodes” or “return African air masses”. A subjective method confirmed that 256 of these days were caused by direct impacts of African dust on the ER station. A mean TSP value of 21.6 μg m⁻³ was found at the station during this period. All the episodes occurred when the TSP concentration was >28.5 μg m⁻³. The TSP background (14 μg m⁻³) can be assumed to be representative of the MBL of the Eastern North Atlantic subtropical region. The highest number of dust gravitational settlement (or indirect) episodes occurs in summer, but the highest contribution of these episodes to the TSP levels is in March with a monthly mean TSP contribution of up to 30.5 μg m⁻³.     

原子吸收光谱仪的背景校正

介绍了原子吸收光谱仪的５种主要的背景校正技术（邻近谱线技术，连续光源法，塞曼法，自吸法及连续光源单色器波长调节法ＣＥＷＭ）及其主要产品，分析评述了各种校正技术的原理，特点及其应用状况。     

Wilderness politics: Public participation and values

This article deals with wilderness politics in relationship to values and public participation; these terms are defined for the purpose of the study. It is argued that the survival, quantity, and quality of wilderness everywhere will basically be determined by the political and governmental processes through values. Yet there is a strong tendency in these processes to avoid value exposure and emphasis.Much of governmental approach toward wilderness affairs hinges upon economic development, technoscientific facts, and short-term considerations, in contrast to the intangible noneconomic and long-term values of wilderness. By not articulating nd involving wilderness values more in public participation and the political processes, the public often misses opportunities for influencing far-reaching wilderness decisions. In short, wilderness values need to be more explicitly and implicitly stated and implemented politically.More study and emphasis need to be given to wilderness values per se. It is necessary to develop more innovative ways of educating the public on wilderness values in terms of their lives and of ensuring that their value inputs are effectively incorporated into public participation and political processes. The last section of this article is devoted to efforts by the author and others to identify and describe wilderness tropical forest values.     

上海地区13种金属土壤背景值初探

对上海地区518组土壤金属浓度数据进行归纳和空间分析,得出了上海地区13种金属砷、铍、镉、铬、铜、铅、汞、镍、银、铊、锌、锑和硒在土壤中的背景值及空间分布图,直观地表现了上海地区13种金属的空间分布特点,为今后确定上海地区土壤污染的标准提供参考.     

企业厂界噪声监测问题的探讨

在厂界噪声测量中，由于国家标准测量方法——《工业企业厂界噪声测量方法》中介绍的不够详细，给分析人员在实际工作中带来许多不便，特别是临界状况时背景值的修正、周期性噪声测量方法的选择及厂界噪声测点的布设等问题，结合多年的工作经历针对这些问题谈谈看法。