To detect something means to find it or discover that it is present somewhere by using equipment or making an investigation.
例句
...a sensitive piece of equipment used to detect radiation...一件用于探測輻射的靈敏設備Most skin cancers can be cured if detected and treated early...如果早發現早治療，大多數皮膚癌是可以治愈的。
VERB
覺察;發覺
If you detect something, you notice it or sense it, even though it is not very obvious.
例句
Arnold could detect a certain sadness in the old man's face.阿諾德能覺察到老人臉上的一絲悲傷。
英英詞典釋義
Noun
1. a police investigation to determine the perpetrator;