Short for "reduction-oxidation," referring to chemical reactions where electrons are transferred between species. One species is oxidized (loses electrons) while another is reduced (gains electrons).

氧化还原的缩写，指的是物质之间发生电子转移的化学反应。一种物质被氧化（失去电子），而另一种物质被还原（获得电子）。(Yǎng huà huán yuán de suō xiě, zhǐ de shì wù zhì zhī jiān fā shēng diàn zǐ zhuǎn yí de huà xué fǎn yìng. Yī zhǒng wù zhì bèi yǎng huà (shī qù diàn zǐ), ér lìng yī zhǒng wù zhì bèi huán yuán (huò dé diàn zǐ).)