雾对SO_2烟羽清除作用的研究

在雾稳定的条件下,研究了雾滴穿过SO_2烟羽沉降到地面的过程中吸收、析解以及酸化等过程。结果表明,雾对烟羽中SO_2的清除具有某些奇特的现象。即仅在离源较远的区域才表现出有限的清除作用:而在近源区,主要以析解为主,使源附近地面SO_2浓度增加,高架源成了低架源。雾滴在地面附近的这种析解作用,是造成雾天污染物浓度高的重要原因之一。     

闽南地区酸性雾水特征初探

1993年3～4月,在闽南地区进行了一次综合性酸雨集中观测,探讨其雾水特征如下:闽南地区雾水已严重酸化,其最低pH值达到2.91,是该地区酸性湿沉降的重要组成部分;雾水中有机酸根的贡献占总阴离子量9%;雾水含较多四价硫,并与甲醛反应形成络合物;雾水受到周围海洋的影响,Cl-有严重的亏损      

LY12CZ铝合金腐蚀损伤的概率分布及其变化规律

采用铜加速乙酸盐雾试验方法对LY12CZ铝合金腐蚀行为进行了研究。结果表明：腐蚀深度服从Gumbel分布、正态分布、威布尔分布和对数正态4种分布。选用正态分布描述了LY12CZ铝合金在盐雾环境下的腐蚀损伤的分布特性,并得出了不同置信度和可靠度下腐蚀深度随时间变化的规律。     

Sampling and physico-chemical analysis of precipitation: a review

Wet deposition is one of two processes governing the transfer of beneficial and toxic chemicals from the atmosphere on to surfaces. Since the early 1970s, numerous investigators have sampled and analyzed precipitation for their chemical constituents, in the context of "acidic rain" and related atmospheric processes. Since then, significant advances have been made in our understanding of how to sample rain, cloud and fog water to preserve their physico-chemical integrity prior to analyses. Since the 1970s large-scale precipitation sampling networks have been in operation to broadly address regional and multi-regional issues. However, in examining the results from such efforts at a site-specific level, concerns have been raised about the accuracy and precision of the information gathered. There is mounting evidence to demonstrate the instability of precipitation samples (e.g. with N species) that have been subjected to prolonged ambient or field conditions. At the present time precipitation sampling procedures allow unrefrigerated or refrigerated collection of wet deposition from individual events, sequential fractions within events, in situ continuous chemical analyses in the field and even sampling of single or individual rain, cloud and fog droplets. Similarly analytical procedures of precipitation composition have advanced from time-consuming methods to rapid and simultaneous analyses of major anions and cations, from bulk samples to single droplets. For example, analytical techniques have evolved from colorimetry to ion chromatography to capillary electrophoresis. Overall, these advances allow a better understanding of heterogeneous reactions and atmospheric pollutant scavenging processes by precipitation. In addition, from an environmental perspective, these advances allow better quantification of semi-labile (e.g. NH4+, frequently its deposition values are underestimated) or labile species [e.g. S (IV)] in precipitation and measurements of toxic chemicals such as Hg and PCBs (polychlorinated biphenyls). Similarly, methods now exist for source-receptor studies, using for example, the characterization of reduced elemental states and/or the use of stable isotopes in precipitation as tracers. Future studies on the relationship between atmospheric deposition and environmental impacts must exploit these advances. This review provides a comprehensive and comparative treatment of the state of the art sampling methods of precipitation and its physico-chemical analysis.     

Fog as a Fresh-Water Resource: Overview and Perspectives

The collection of fog water is a simple and sustainable technology to obtain fresh water for afforestation, gardening, and as a drinking water source for human and animal consumption. In regions where fresh water is sparse and fog frequently occurs, it is feasible to set up a passive mesh system for fog water collection. The mesh is directly exposed to the atmosphere, and the foggy air is pushed through the mesh by the wind. Fog droplets are deposited on the mesh, combine to form larger droplets, and run down passing into a storage tank. Fog water collection rates vary dramatically from site to site but yearly averages from 3 to 10 l m⁻² of mesh per day are typical of operational projects. The scope of this article is to review fog collection projects worldwide, to analyze factors of success, and to evaluate the prospects of this technology.     

Urban climate in the Tokyo metropolitan area in Japan

Long-term climate changes related with urbanization in Tokyo, Japan, and recent temperature and heavy rainfall distribution in the Tokyo metropolitan area are reviewed. A relatively high temperature increase in annual mean temperature at the rate of 3.0°C/century was detected in Tokyo for the period 1901–2015. Some observational evidence showed the existence of both thermal and mechanical effects of urbanization on recent heavy rainfall occurrences, and modeling studies also support precipitation enhancement. Urban influences were recognized in other climatological elements, such as number of fog days, relative humidity, and wind circulation.     

成都市郊区雾水中阴离子变化的研究

本文用冷凝法采集雾水样品,用离子色谱法测定雾水样品中阴离子(氟离子、氯离子、亚硝酸根离子、硝酸根离子、硫酸根离子)的浓度,研究表明雾水中阴离子浓度与雾的浓密有关,雾水中硫酸根离子含量最高;雾水中阴离子浓度随大雾的消失而降低;雾水中阴离子浓度大于雨水。所得结果对在大雾天气情况下保护人体健康有一定参考意义。     

Fog composition along the Yangtze River basin: Detecting emission sources of pollutants in fog water

To investigate the fog chemistry along the Yangtze River basin, a field observation experiment was performed from Shanghai to Wuhan during November 2015. Fifteen fog water samples were collected by using a three-stage Caltech Active Strand Cloud water Collector(CASCC). The three-stage CASCC was mounted on the board of a ship. PH, electrical conductivity(EC), H_2O_2,HCHO, S(IV), ten inorganic ions, seven organicacids and sixteen trace metal elements were measured in this study. The p H of fog water samples ranged from weakly acidic(pH 4.3) to weakly alkaline(pH 7.05) and the EC ranged from 32.4 to 436.3 μS/cm. The main cations in fog water were NH+4 and Ca~(2+), accounting for 12.35% and 29.07% of those inorganic ions,respectively. In addition, SO_4~(2-) and NO_(-3) contributed to 25.52% and 12.93% to total anion concentrations respectively. Moreover, the dominant kinds of organicacids were formate and oxalate, occupying 45.28% and 28.03% of the total organicacids, respectively. For trace metal elements in fog samples, Al, Fe, Zn, and Ba revealed 34.6%, 16.4%, 19.3%, and 20.9%contributions to these sixteen trace element concentrations, respectively. The results indicated that pollutants were mainly from human activities, including fossil fuel combustion,biomass burning, steel-making, stone quarrying and sand digging. Besides, natural sources including natural background levels and long-range transport of sea salt particles also aggravated the pollution levels in the fog events along the Yangtze River.     

重庆雾的酸化机理及物态的特征

本文对重庆雾滴谱及含水量进行了对比分析.重庆大气污染严重,使雾的物化性质有雾滴平均直径下降、数密度增加、含水量偏低的特点.文中用主成分分析、相关分析及相图等方法对雾水酸度来源、形成机理进行了探讨.     

氮氧化物在闽南地区酸雨中的贡献

通过对闽南地区降水?雾水和空气质量等数据的分析,说明闽南地区酸雨是燃煤和光化学烟雾混合型污染;闽南地区降水的SO2-₄/NO-₃比值是我国主要酸雨区中最低的,NO_x是闽南地区酸沉降形成的重要致酸前体物之一;闽南地区酸沉降中的NO-₃主要来源于当地的源排放。