形容词术零值的; 等于零的; （协议） 无法律效力; 失效的

1. 空的：压缩的时候,有一定的 bitrate,如果前面的画面太难压缩,用掉太多 bit,到了这个画面时 bit 用光了,无法分配 bit 给这个画面使用,这时这个Frame 无法压缩,只好 drop 掉, 产生一个空的(Null) Frame.

2. 无效：由于本文采用间接法计算应力场,因此模型建立与网格剖分必须与温度场的计算模型相同,将空气与感应线圈单元设为无效(NULL)单元,温度场所用单元PLANE55转换为结构单元PLANE42,保持单元数与结点数不变.

3. null：nul; 空行;空值

1. (协议、宣言或选举结果)无法律效力的，无效的
If an agreement, a declaration, or the result of an election is null and void, it is not legally valid.

e.g. A spokeswoman said the agreement had been declared null and void...
女发言人称该协议已宣布无效。
e.g. The declaration was null and void as it was proclaimed in completely illegal circumstances.
该声明无效，因为它是在完全非法的情况下宣布的。

1. 七彩网.英语单词

noun

1. a quantity of no importance

e.g. it looked like nothing I had ever seen before
reduced to nil all the work we had done
we racked up a pathetic goose egg
it was all for naught
I didn't hear zilch about it

Synonym: nothingnilnixnadaaughtciphercyphergoose eggnaughtzerozilchzipzippo