derivet除铆钉derivev.获取；得自；起源derived set operation导集运算derived working limit导出工作极限:由最大容许剂量推得的工作极限, 推定作业限值derived secondary word派生次位词derived subject theory派生主语理论derived type structure导出式结构derived centre channel导出中心通道derived center channel[电] 导出中心波道derived transformation导出变换derived demand deposit派生性活期存款derived phrase-marker派生的短语标记