close pass是什么意思

用法例句

The reason was searched why the lock pins of tin bronze would break by means of macroscopic examination, chemical analysis, metallographic test, electron microscopic observation and EDS.

采用宏观检查、化学分析、金相检验、电镜观察、断口能谱法分析了锡青铜闭口销的断裂原因,结果表明,闭口销的断裂是由于材料成分差错,导致其在应力腐蚀作用下早期断裂。