生活在更新世南美洲的大型贫齿类哺乳动物,现已灭绝。
Large bear sized extinct edentate mammal of the Pleistocene in South America.
生活在更新世南美洲的大型贫齿类哺乳动物,现已灭绝。
Large bear sized extinct edentate mammal of the in South America.
分析了因模具结构造成钻齿类合金压坯分层的原因,提出了改进模具结构设计的措施。
Analysis is made of the reasons of layering in compact of drill tooth alloys due to the die structures. Measures are taken to improve the die structures.
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