kē / xué / jiā / lì / yòng / guāng / huà / xué / fǎn / yìng / yán / jiū / qiǎng / zì / yóu / jī / de / shēng / chéng / guò / chéng科学家利用光化学反应研究羟自由基的生成过程。Scientists use photochemical reactions to study the formation of hydroxyl radicals.