简介：本文介绍航海－ⅢＧ型陀螺罗经用大功率三相正弦波脉宽调制中频静止电源，它由Ｅ－ＰＲＯＭ构成的可编程正弦波脉宽调制信号发生器、Ａ／Ｄ转换器组成的幅度调节器以及场效应管功率放大器等电路组成，输出频率、幅度、相位稳定的纯三相正弦波，具有效率高、负载能力强等优点，该电源还设置了多种故障检测、报警和多重过载保护电路，整机性能稳定，工作可靠。它不仅适用于航海型陀螺罗经的供电，对于其他功率较大的中频供电场合也是适宜的

简介：Liquid-solid(L-S)masstransfercoefficients(Ks)werecharacterizedinagas-liquid-solid(G-L-S)three-phasecountercurrentmagneticallystabilizedbed(MSB)usingamorphousalloySRNA-4asthesolidphase.Effectsofsuperficialliquidvelocity,superficialgasvelocity,magneticfieldstrength,liquidviscosityandsurfacetensionwereinvestigated.ExperimentalresultsindicatedthattheexternalmagneticfieldincreasedKsinthree-phaseMSB,ascomparedtothoseinconventionalG-L-Sfluidizedbeds;thatKsincreasedwithmagneticfieldstrength,superficialgasandliquidvelocitiesanddecreasedwithliquidviscosityandsurfacetension;andthatKsshoweduniformaxialandradialdistributionsexceptforsmallincreasesclosetothewall.DimensionlesscorrelationswereestablishedtoestimateKsoftheG-L-ScountercurrentMSBusingSRNA-4catalyst,withanaverageerrorof3.6%.

简介：