1)extrinsic reinforcer,外加强化物2)reinforcement,加强，强化加强物3)intensify,加强强化4)fortification,加强,强化5)v. intensify; to become more intense,强化，加强6)exterior strengthen,外加强
用法和例句
Based on GB 150—1998,a mathematical optimum design model of wall thickness and exterior strengthen structure for rectangular pressure vessel was established.