Riffault Véronique, Gierczak Tomasz, Burkholder James B, Ravishankara A R
National Oceanic and Atmospheric Administration, Earth System Research Laboratory, 325 Broadway, Boulder, CO 80305-3328, USA.
Phys Chem Chem Phys. 2006 Mar 7;8(9):1079-85. doi: 10.1039/b513760h. Epub 2006 Jan 31.
The quantum yields for OH formation from the photolysis of HNO(3) were measured to be (0.88 +/- 0.09) at 248 and (1.05 +/- 0.29) at 308 nm and of H(2)O(2) to be (1.93 +/- 0.39) at 308 and (1.96 +/- 0.50) at 320 nm. The quoted uncertainties are at the 95% confidence level and include estimated systematic uncertainties. OH radicals were produced using pulsed laser photolysis and monitored using pulsed laser-induced fluorescence. Quantum yields were measured relative to the OH quantum yields from a reference system. The measured quantum yields at 248 nm are in agreement with previous direct determinations. The quantum yield values at 308 and 320 nm are the first direct quantum yield measurements at these wavelengths and confirm the values currently recommended for atmospheric model calculations. Rate coefficients (at 298 K) for the OH + H(2)O(2) and OH + HNO(3) + M (in 100 Torr of N(2)) reactions were measured during this study to be (1.99 +/- 0.16) x 10(-12) cm(3) molecule(-1) s(-1) and (1.44 +/- 0.12) x 10(-13) cm(3) molecule(-1) s(-1), respectively.
通过对硝酸（HNO₃）光解生成羟基（OH）的量子产率在248纳米处测得为（0.88±0.09），在308纳米处为（1.05±0.29）；而过氧化氢（H₂O₂）光解生成OH的量子产率在308纳米处为（1.93±0.39），在320纳米处为（1.96±0.50）。所引用的不确定度为95%置信水平，且包括估计的系统不确定度。OH自由基通过脉冲激光光解产生，并使用脉冲激光诱导荧光进行监测。量子产率相对于参考体系中OH的量子产率进行测量。在248纳米处测得的量子产率与先前的直接测定结果一致。在308和320纳米处的量子产率值是这些波长下的首次直接量子产率测量，并证实了目前推荐用于大气模型计算的值。在本研究中，测量了OH与H₂O₂以及OH与HNO₃ + M（在100托氮气中）反应在298 K时的速率系数，分别为（1.99±0.16）×10⁻¹²立方厘米·分子⁻¹·秒⁻¹和（1.44±0.12）×10⁻¹³立方厘米·分子⁻¹·秒⁻¹。
