Silver - coated carbonyl iron powder was prepared by using electroless plating method.用化学镀法,甲醛为还原剂,制备镀银羰基铁粉.The p - chlorophenyl isocyanate is synthesised by carbonyl chloride and p - chloroaniline . The yield is 90 %.采用...
年代较近的针叶树林场还比不上年代久远的林场。The more recent conifer plantations cannot yet compare with the old woodlands.两艘驳船中较近的那艘可能有一英里远.The nearer of the two barges was perhaps a mile away.这些汽车听到愈来愈近的警笛声便停了下来.The cars had stopped at the s...