反挤压

摘要复杂盒形零件的反挤压是一个极其不均匀的流动过程，坯料的相对形状及尺寸是影响金属流动的关键因素。

backward integration

backward elimination

backward conditional probabilities

bend forward and backward

backward round-the-world echo【物】

backward read【计】;backward reading【计】;read backward【计】

backward linkage

backward movement