selfpropelled英selprəʊ'peld美selprəʊ'peldCOCA²¹¹²¹¹ 基本例句 adj.自动的自行的 In this paper, the nonlinear dynamics of Selfpropelled machines with rocked impact, taking Frog rammer which was first devised in our country as an example, is studied. 本文以我国首创的蛙式打夯机为例,对自行式摆动冲击机构的非线性动力学进行了研究。 cnki