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室内空气中甲醛测定比对试验的探讨   总被引:1,自引:0,他引:1  
为了检验化学酚试剂比色法与便携式甲醛测定仪测定室内空气中甲醛方法间有无显著性差异,用2种方法做了比对试验,并对2种方法的相关性、精密性进行了分析。结果表明,2种分析方法无显著性差异。便携式甲醛分析仪具有操作简单、携带方便、直观性强等优点,有利于民用建筑室内环境中甲醛的测定。  相似文献
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环境空气质量不同监测方法的对比   总被引:1,自引:0,他引:1       下载免费PDF全文
在对环境空气质量的监测中,有些城市存在着人工采样实验室测定和连续自动监测系统监测并行的情况。为考察这两种方法监测结果的异同,于夏季连续20d和冬季连续15d进行了对比监测。监测项目为SO2,NO2和PM10。在对比监测中采取了质量控制措施。对人工采样实验室测定进行了综合采样器流量校正,现场空白样和全程序平行样测定;在自动监测系统中,对SO2,NO2监测仪器作零点,标点校正,PM10监测仪作K0校正。对所测得的209个日均值进行了统计分析,结果表明:SO2,PM10两方面测定结果方差相同,NO2两种方法在冬夏两季方差间均有显著性差异;夏季SO2,PM10,冬季NO2两种方法监测结果一致;冬季SO2,PM10,夏季NO2两种方法监测结果有显著性差异;样品浓度水平及天气状况对两种方法测定结果的差异亦产生较大的影响。  相似文献
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Lake V?nern, the largest lake in Sweden, has been seriously contaminated with mercury during the 20th century. In the 1970's and 80's the direct load, mainly from a chlor-alkali industry in the area, of mercury was drastically reduced as a response to new legislation, from three to five tons down to between five and ten kg yr(-1). Large amounts of the disposed pollutant have accumulated in the sediments. The question posed in this work is now, is the effect of the drastic load reduction after more than two decades visible in the sediments? The question is relevant as large areas still are blacklisted for fishing, but also as a follow-up of a major remedy action. The lake also serves as a freshwater reservoir for even Sweden's second largest city. This work synthesises and compares data of mercury in the sediments from three major field programs, in 1974, 1984 and 1998. The interest is focused on both spatial heterogeneity and temporal trends. In 1974, the surface concentrations are significantly higher than in subsequent surveys. Significant differences are also found between 1984 and 1998. Significant spatial differences within the lake are found for respective year. The most contaminated area is located in the north, close to the major point source (a former chlor-alkali industry). This is also the area with the largest improvement, as a direct response to the reduction in load. Further from the outlet, the recovery is more affected by burial and transport processes out into the deeper basins.  相似文献
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