Sentence:  In the gas <WSD>phase</WSD> , with * * f of * * f and * * f of * * f , quantum yields of the order of * * f have been observed at 85 ` . 
Meaning of the word marked with <WSD> tags:  (physical chemistry) a distinct state of matter in a system; matter that is identical in chemical composition and physical state and separated from other material by the phase boundary