clearance

noun

1. permission to proceed

e.g. the plane was given clearance to land

2. the distance by which one thing clears another
the space between them

3. vertical space available to allow easy passage under something

Synonym: headroomheadway

1. 清除;清理
Clearance is the removal of old buildings, trees, or other things that are not wanted from an area.

e.g. ...a slum clearance operation in Nairobi...
内罗毕拆除贫民窟的行动
e.g. The UN pledged to help supervise the clearance of mines.
联合国承诺协助监督扫雷工作。

2. (官方的)批准，许可
If you get clearance to do or have something, you get official approval or permission to do or have it.

clearance

e.g. Thai Airways said the plane had been given clearance to land...
泰国航空公司说，该飞机已经得到降落许可。
e.g. He has a security clearance that allows him access to classified information.
他持有安全许可，可以接触机密信息。

3. (路面、河面与上方桥梁之间的)净空，间隙，间距
The clearance of a bridge is the distance between the lowest point of the bridge and the road or the water under the bridge.

clearance的解释

e.g. The lowest fixed bridge has 12.8m clearance.
最低的固定桥下方通行高度为12.8米。

1. 间隙：看下土,处于中间位置的式快cam,最大因为升程间隙(clearance)最大. 处于右边的是中速cam,形状中等. 在左边的是慢cam,升程最小,形状最小. 好了,看看下面两张图就能明白了. 是不是现在觉得活瓣正时技术(VVT)已经没有之前那么神秘而高不可攀了呢?

2. 净空：由於打线接合受导线末端成球大小、接合工具形状、接垫之几何排列与构装基板结构净空(Clearance)等条件的限制(2),因此仅适用於低密度连线(低於300个集积数,Input/Output Counts)之构装.

3. 清除：目前存在着Hp清除(clearance)和Hp根除(eradication)两个概念,前者系指治疗结束时复查Hp阴性,后者是指停止治疗1个月这后复查Hp阴性. 清除只是Hp暂时的抑制,停药之后Hp感染很快复发;而根除是指85%以病人1a之内不复发,起到了治疗的作用.

4. 廓清率：於一般的情况下,肌酸酐的廓清率(clearance)应与肾丝球过滤率(GFR)成正比,但肾丝球过滤率会受体内水量多寡的影响,且大约14%的肌酸酐经由肾小管的主动分泌排除,因此肌酸酐的廓清率并不能代表肾丝球过滤率.