【摘要】 氧化流动反应器（OFR）可以模拟真实大气环境,且能在数分钟内达到高度氧化OFR的实验条件,因此被广泛应用于二次有机气溶胶（SOA）生成的研究中。羟基自由基暴露量(OH_exp)是量化中氧化过程的关键参数,但受到·OH较高反应活性的限制,难以被直接测定。为了快速且准确地对复杂外场条件下OFR中的OH_exp定量,本研究基于实验室标定实验和动力学模型的模拟结果,发展了一套可基于直接测量反应条件和参数（如停留时间、水汽浓度、臭氧浓度和反应物的·OH反应活性）来估算OH_exp的方程参数。结果表明,当OFR中相对湿度（RH）大于20%时,通过估算方程计算的OH_exp与基于实验室挥发性有机物及外场观测中苯的消耗计算的OH_exp一致,表明该估算方程可以实现对使用最广泛的OFR中的OH_exp快速且准确地定量,为其他研究提供参考。更多还原

【Abstract】 An oxidation flow reactor （OFR） is widely used to study secondary organic aerosol formation because it can mimic photochemistry under a real atmospheric environment and achieve a high oxidation condition within the residence time of several minutes.The OH radical exposure (OH_exp) is key to quantifying the oxidation process within OFR;however,it is difficult to measure this directly because of the chemical reactivity of OH radicals.We combined the results from laboratory calibration experiments and kinetic model simulations to develop the equation parameters for estimating the OH_exp in OFR under complex external field conditions quickly and accurately based on the direct measurement of reaction conditions and parameters （such as residence time,water vapor concentration,ozone concentration,and external OH radical reactivity）.The results indicate that that the OH_exp estimated by the equation is consistent with that calculated based on the measured decay of volatile organic compounds in the laboratory and benzene in the field observation when the relative humidity in the OFR is greater than 20%.This implies that the estimation equation can used to estimate OH_exp in the widely used OFR and act as a reference for other OFR studies.更多还原