lower derived function 下導(dǎo)函數(shù)lower density lower deck lower cutoff frequency [電子、通信與自動(dòng)控制技術(shù)]截止頻率下限lower cut lower culmination [天文學(xué)]下中天[測繪科學(xué)技術(shù)]下中天lower crust 下地殼；下部地殼lower crown height 下層樹冠高lower court lower course 下遊，下層lower cost lower corner fitting [交通運(yùn)輸工程]下角件lower core support barrel [土木建築工程]堆芯下部圍筒lower confidence limit [統(tǒng)計(jì)] 下置信限 置信下限lower color reproduction [機(jī)械工程]色彩還原不足lower class limit 組下限lower class 下層堦級；下層社會(huì)lower chord panel points [土木建築工程]桁架的下弦桿節(jié)點(diǎn)[機(jī)械工程]桁架的下弦桿節(jié)點(diǎn)lower chord 下弦；下弦桿；下楔材料lower case 小寫字母磐