Two concepts frequently described in green chemistry are atom economy and chemical specificity, indicating that green chemistry is the chemistry about reaction and reaction efficiency.
绿色化学中经常讨论的两个概念是原子经济性和化学专一性，这说明绿色化学是关于反应和反应效率的化学。
2
The efficiency of solid-oxide fuel cells is limited by the electrolyte's ability to transport oxygen ions, which must pass from atom to atom through the solid electrolyte.
固态氧化物燃料电池的效率受限于电解质传送氧离子的能力，而氧离子要在固态电解质的原子间传递。
3
So it is not necessary to use a broad-band laser to guarantee excitation efficiency for an atom with hyperfine split levels.