基于腔衰荡光谱技术测量夜间大气中五氧化二氮

发布时间：2018-06-06 00:31

  本文选题：大气光学 + 腔衰荡光谱技术　； 参考：《光学学报》2017年09期

【摘要】：采用高温热解五氧化二氮(N_2O_5)的方法,利用N_2O_5与NO_3自由基之间的热平衡关系,通过腔衰荡光谱技术测量N_2O_5及NO_3自由基的浓度。基于二氧化氮(NO_2)与N_2O_5之间平衡可逆,探讨加热温度及NO_2浓度变化对N_2O_5分解率的影响;考虑N_2O_5在测量系统中的损耗,经初步的量化分析得到进气效率为88%。通过Allan方差选取最佳积分时间,在外场测量条件下,优化系统的体积分数探测限为8.6×10-12;通过分析进气效率、吸收截面及N_2O_5不完全热解等不确定性因素,估算得到整体测量误差约为±10%。在合肥郊区进行夜间大气实际监测,测量期间N_2O_5的浓度变化范围在(0.035~1)×10-9之间,平均浓度为4.52×10-10。该技术为实现大气中N_2O_5及NO_3自由基的高灵敏度在线监测提供了有效途径。
[Abstract]:By using the method of high temperature pyrolysis of N _ 2O _ 5) and using the thermal equilibrium relationship between the Ns _ 2O _ 5 and the no _ 3 free radicals, the concentration of the N _ 2O _ 5 and no _ 3 free radicals was measured by cavity decay spectroscopy. Based on the reversibility of the equilibrium between NSCN _ 2O _ 2) and NSP _ 2O _ 5, the effect of the change of heating temperature and no _ 2 concentration on the decomposition rate of N _ 2O _ 5 is discussed, considering the loss of N _ 2O _ 5 in the measuring system, the intake air efficiency is 88% by preliminary quantitative analysis. The detection limit of volume fraction of the optimized system is 8.6 脳 10 ~ (-12) under the condition of external field measurement by selecting the best integral time through Allan variance. The uncertainty factors such as intake efficiency, absorption section and incomplete pyrolysis of NSP _ 2O _ 5 are analyzed. The whole measurement error is estimated to be 卤10. During the measurement period, the concentration of N2O5 varies from 0.035 to 1) 脳 10 ~ (-9), with an average concentration of 4.52 脳 10 ~ (-10). This technique provides an effective way to realize the high sensitivity on-line monitoring of NSCT _ 5 and no _ 3 free radicals in the atmosphere.
【作者单位】： 中国科学院安徽光学精密机械研究所中国科学院环境光学与技术重点实验室;安徽工业大学数理科学与工程学院;安徽医科大学药学院;
【基金】：国家自然科学基金(61570206,61675006,11474003) 中国科学院环境光学与技术重点实验室开放基金(2015DP173065-2016-03) 安徽省自然科学基金(1608085MF133,1408085MA19) 安徽省高校优秀青年人才支持计划(gxyqZD2016065)
【分类号】：O433;P412
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本文编号：1984148