noun · a metallurgical process where the physical properties of a metal or alloy change over time, often used to increase strength

通过人工时效处理，这种铝合金的硬度得到了大幅提升。

noun · a legal time limit or period after which a claim, right, or liability becomes invalid or unenforceable

超过了法定诉讼时效，原告将丧失胜诉权。

noun · the quality of being timely or the specific period during which something remains valid or effective

这些新闻信息过了几个小时就会失去时效。