含碳、氢的化合物往往都是有机化合物,而尿素的分子式为CO(NH2)2,所以尿素生产是有机化工。
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管路交叉时,一般将上面(或前面)的管路断开;也可将下方(或后方)的管路画上断裂符号断开。
YouworkasadatabaseadministratorforSupportcenter.cn.UsersintheSupportCenterPRODdatabasecomplainabouttheslowresponsewhenaccessingthedatabase.IntheActiveSessionWaiting:Configurationpageyoufindthatthemajorityofthewaittimeisfortheredologbuffer.FurtherinvestigationusingtheRunQueuegraphandoperatingsystemtoolsrevealsthattheredologfilesareonthesamedisks,andthatthediskI/Ofortheredologfilesisthereasonfortheperformancedegradation.
Whichtwoactionswouldyoutaketogainperformance?()
离心压缩机的“喘振”现象是由于进气量超过上限所引起的。