The extraction mechanism of palladium in chloride system by di ( 1 - methyl heptyl ) acetamide ( N _ ( 503 )) has been studied.本文研究了N, N二 甲庚基乙酰胺 ( N_ ( s03 ) )从氯化物体系中萃取钯的机理....
It is usually found in metaxylem tracheids and vessels.经常在木质部管胞和导管中发现.Exarch Denoting a stele in which the metaxylem develops to the inside of the protoxylem.外始式:指后生木质部在原生木质部之内的中柱类型....