protraction 

英汉解释

n. 伸长，延长；制图

同义词

n. continuation，lengthening，lengthiness，perpetuation

参考例句

1. In addition, the most practical representation and protraction methods will be studied.
同时，探索出最适合箱包设计的表现与绘制方法。
2. Classical wrapped V-belts feature high strength, low protraction, small matching tolerance and a fatigue endurance limit of over 107times.
普通V带具有高强力，低伸长，配组公差小，耐疲劳度达107次以上等优点。
3. Objective To appraise the effects of the maxillary protraction and rapid palatal expansion by analyzing the effects of two groups of children of different ages.
目的分析骨性Ⅲ类错牙合矫治前、后头影测量变化，评价前牵引联合快速扩弓治疗的疗效。

英英解释

n.
  1. the consequence of being lengthened in duration
  2. the act of prolonging something

网络释义

protraction
伸长; 前伸; 延长; 伸展;
dose protraction
剂量迁延; 释义：长时间低照射量,剂量延长分割; 连续弱剂量; 剂量延伸;
Front Protraction
前伸;
protraction exposure
释义：低量长时间照射;
Rear Protraction
后伸;