| 北京大气中BTEX的观测分析与研究 |
| 摘要点击 1304 全文点击 1380 投稿时间：2003-06-22 修订日期：2003-11-12 |
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| 中文关键词 二步深冷浓缩 气相色谱/质谱联机 苯类物质 日变化 季变化 年际变化 |
| 英文关键词 two step cryo-focuses GC/MS BTEX diurnal variation seasonal variation annual variation |
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| 中文摘要 |
| 采用二步深冷浓缩与气相色谱/质谱联机对北京大气中的苯类物质(BTEX) 进行了长期连续观测.最近4年观测数据表明:日变化有双峰和3峰变化,冬、春季呈现与交通高峰期吻合的双峰变化,即上午08:00至10:00和下午17:00前后各出现一个高值;秋季日变化中,夜间22:00出现第3峰值;夏季日变化呈3峰型,最大峰值在正午前后.2000～2002年BTEX月平均总浓度为(44.1±24.5) nmol/mol(碳单位),季变化峰值出现在夏季.年际变化趋势中,北京大气BTEX的总平均浓度从 1999 年到2002年大幅度下降.
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| 英文摘要 |
| Atmospheric trace BTEX in Beijing was observed by a gas chromatography/mass spectrometry in the latest 4 years. The diurnal, lunar and annual concentration variations of these pollutants were reported. In winter and spring, the diurnal profiles exhibited two peak values corresponding to the daily rush hours 08:00～10:00am and 17:00pm; in autumn, there was the third peak value in the night at 22:00; the highest concentration of BTEX in summer appeared in the midday and totally three daily maxima were in the sampled day. In the lunar variation of the BTEX from 2000 to 2002,the average concentration was about (44.1±24.5) nmol/mol(C unit), and the seasonal maximum value appeared in summer. The trend of BTEX was decreased greatly from 1999 to 2002. |
