当树木长大枝叶茂盛时,它们可以起到隔声的作用.Trees also serve as sound Barriers when full grown and leafed out.实施减轻环境影响的措施,包括建造隔声屏障和广泛植树.Environmental impact abatement measures including noise barriers and extensive planting.本文介绍一种新型电动机隔声罩.Th...
Purification of 2,6 dichlorotoluene by the recrystallization method without solvent was studied.研究了用无溶剂重结晶法提纯2,6二氯甲苯.Taking p chlorotoluene as raw material , 2,4 Dichlorotoluene was synthesized via catalytic chlorination...
Cholelithiasis may be associated with present or past episodes of either acute or chronic cholecystitis.胆石症可能与现在和过去的急性或慢性的胆囊炎发作有关.Aim To explore the clinical characters of senile cholelithiasis and cholecystitis.目的探讨老年型胆...