简介:摘要本文从应用角度出发,对汇川MD880变频器的硬件选择、附件选择,替换西门子6SE70变频器的应用技术步骤做了详细的介绍。
简介:一台西门子6SE3620型变频器,在运行中突然跳闸停机,液晶显示屏无显示,且无法复位。经检查,发现电源模块MPS损坏。该电源模块将380V三相交流电压转换为两路不同的电源电压,一路(50V/50kHz)主要供给接口、信号转换模块及整流模块触发电路:另一路(直流±20V)主要向模块基架供电。电源模块的原理框图如图1所示。三相交流电经整流和滤波后,由直流-交流变换器转换为200V/50kHz的中频电压。该电压-路经降压变压器降为50V/50kHz的电压:另一路再通过交流-直流变换器转换为±20V直流电压。这种电源的优点是体积小,抗干扰能力及过载能力强,对电源滤波电路要求低。
简介:介绍ER70S-6X焊丝钢的生产情况。通过化学成分及残余元素控制、精炼脱氧制度优化、连铸保护浇注和铸温铸速的稳定控制等工艺措施的实施,使EK70S-6X焊丝钢的产品质量和综合性能得到了稳定提升。
简介:ThisstudywasaimedtoobservetheexpressionofP70S6kinase(P70S6K)inoralaciniccellcarcinoma.PT0S6kinaseexpressionwasexaminedbymeansofWestern-blottestandActivityas-say.Specimenswerefrom30casesoforalaciniccellcarcinomaand15casesofnormaloraltissuewereusedascontrols.StatisticalanalysissoftwareSPSS10.0wasusedforttesttodeterminetherelationshipbetweengeneexpressionandclinicalfeatures.TheexpressionlevelofP70S6Kincreasedobviouslyinoralaciniccellcarcinomatissue(P<0.01).ActivityassaywasthesameastheWestemblottest(P<0.01).P70S6Kexpressionlevelandactivityplayedanimportantroleinthedevelopmentoforalaciniccellcarcinoma.Inconclusion,P70S6Kisamplifiedandoverexpressedinoralaciniccellcarci-nomatissue,whichsuggestsapotentialoncogenicfunction.P70S6KandotherpossibletargetsofmTORcontributesignificantlytotumordevelopmentandthatinhibitionoftheseproteinsmaybethera-peuticforcancerpatients.OverexpressionofP70S6Kmaybeinvolvedinthepathogenesisoforalacin-iccellcarcinoma.