【1】Improved nondestructive evaluation procedures have enabled defects to be found that would have gone unnoticed earlier.

参考译文：先进的无损检测方法将从前被忽视的缺陷检测出来.

解答：以上为“分隔定语从句”用法，即that would have gone unnoticed earlier为定语从句，修饰前面名词“defects”。定语从句与被修饰名词，被作宾补的不定式to be found分隔开。引导定语从句关系代词that代替先行词defects并在定语从句作主语成分。

【2】Contrary to the descriptions on record, no systematic evidence was found that levels of productivity were related to changes in lighting.

参考译文：与所记录的描述相反，没有发现系统的证据来说明照明的变化和效率水平有关。

解答：that levels of productivity were related to changes in lighting为that引导的同位语从句，先行词为“evidence”。