简介:摘要本文整理了常规岛内的主要转动设备,汇总了世界上使用60Hz电网的国家和地区,分析60Hz电网对核电常规岛转动设备的影响,电网频率变化导致转动设备的转速发生变化,进而需要对转动设备重新进行设计优化和试验校核。
简介:摘要:本文针对25 Hz 相敏轨道电路的基本结构和工作原理,分析了50Hz电信号对轨道电路产生干扰的因素、机理,提出通过提高维修质量,掌握查找干扰源的基本方法,有利于高效解决50HZ牵引回流干扰隐患,减少轨道电路故障,确保铁路运输安全。
简介:TheenvironmentalconditionsaroundthefirstoffshoreHZ21-1steelwellheadplatformintheSouthChinaSeaarecharacterizedbydeepwater,frequenttyphoons,roughwaves,highwatertemperature,severelycorrosiveseawater,andthickfoulingorganismattachments.Thedesignandeffectivenessofgalvanicanodeprotectionsystemarepresented,andseveralmethodsaredescribed,whicharethecalculationmethodoftheprotectivecurrentdensityconsideringthevariationofwaterdepth,themethodofdeterminingprotectionparametersconsideringvariousfactors,thearrangementofanodesbasedonpotentialdistributionandcurrentrequirementsatdifferentwaterdepths,andthemethodofanodeinstallation.Finallytheeffectoftheaccuracyofselectedcathodicprotectionparametersontheeconomicbenefitsofoffshoreprojectsisalsodiscussed..
简介:ThepurificationprocessoftotalflavonesofginkgoleavesbyresinHZ-841fromethanolextractwasstudied.First,thetotalflavonewasextractedfromthedefattedpowderofginkgoL.bilobaleaves.Effectsofsolventsandoperationconditionswereexaminedtogetarelativehighyieldandpurityinthisstep.ThecrudeextractwasfurtherpurifiedbyresinHZ-841.Bothadsorptionandelutionprocesswerestudiedtoobtainanoptimizedconditions,i.e.,pH,flowrate,concentration.Ayellowpowderwasobtained,ofwhich37.3%wasflavones,obviouslyhigherthanthebasicinternationalstandardof24%.