Part change and structure change were two factors causing PFA evolution.Part change leading to PFA evolution was discussed in particular. 產品族結構進化的因素包括零件變化和結構變化，重點研究了由於零件的變化而引起的產品族結構進化問題。
Strictly speaking, the classical definition of thixotropy pertains only to those fluids that exhibit reversible structural changes. 嚴格說來，對觸變性所下定義只限於那些表現可逆性結構變化的流體。
The microstructures change of super-high strength of austenite stainless still silk in multi-ply drawing were analysed. 分析了超高強度奧氏體不鏽鋼絲在多道次拉拔過程中的組織變化。
