简介:该文介绍了MSP430单片机性能特点,结合MC14433A/D转换器的外部特性,给出MC14433与MSP430F449的接口电路及程序设计方法。实现模拟信号转换为计算机要求的数字信号。该电路接口简单.能较好地控制模拟信号的采集和转换。
简介:Theeffectofhydrogenpassivationonmulticrystallinesilicon(mc-Si)usedforsolarcellsisdescribed,andthemechanismofhydrogendiffusionandpassivationisalsoinvestigated.Then,thehydrogenpassivationprocessesappliedinindustriesandresearchlaboratoriesareintroduced.Finallytheexistingproblemsandtheprospectsofhydrogenpassivationarereviewed.
简介:Thisstudytestedfivemethodswidelyusedinestimatingthecompletemagnitudes(MC)ofearthquakecatalogs.Usingcatalogsofobservedearthquakeproperties,wetesttheperformanceofthesefivealgorithmsunderseveralchallengingconditions,suchassmallvolumeofeventsandspatial-temporalheterogeneity,inordertoseewhetherthealgorithmsarestableandinagreementwithknowndata.Wefindthatthemaximumcurvaturemethod(MAXC)hasperfectstability,butwillsignificantlyunderestimateMCunlessheterogeneityisabsent.MCestimatedbytheb-valuestabilitymethod(MBS)requiresmanyeventstoreachastableresult.Resultsfromthegoodnessoffitmethod(GFT)wereunstablewhenheterogeneityloweredthefitnesslevel.Theentiremagnituderangemethod(EMR)isrelativelystableinmostconditions,andcanreflectthechangeinMCwhenheterogeneityexists,butwhentheincompletepartoftheearthquakecatalogisdismissed,thismethodfails.Themedian-basedanalysisofthesegmentslopemethod(MBASS)cantoleratesmallsamplesize,butisincapableofreflectingthemissingdegreeofsmalleventsinaftershocksequences.InconditionswhereMCchangesrapidly,suchasinaftershocksequences,observingthetimesequencedirectlycangiveapreciseestimationofthecompletesub-catalog,butonlywhenthenumberofeventsavailableforstudyislargeenoughcantheMAXC,GFT,andMBSmethodsgiveasimilarlyreliableestimation.
简介:TotesttheantigenicactivityofMprotein(Mcprotein)intheinnermembraneofSARS-CoV,SARS-CoVMcprotein'sbaseslocatinginsidethemembranewerecloned,theHis-fusionproteinwasexpressedinE.coliandanalyzedforitsantigenicactivity.Amongthose7clinicallydiagnosedpatients'sera,therewere5positiveand2negativeinreactionwithHis-fusionprotein.Allofthe20healthypersons'seraandrabbitanti-OC43and229EwereofnegativereactionwithHis-fusionprotein.TheanimalsimmunizedwithHis-fusionproteinhaveproducedmulti-clonalantibody.TheHis-fusionproteincouldspeciallyreactwithclinicallydiagnosedSARSpatients'seraandtheanimalsimmunizedwithHis-fusionproteincouldproducespecificallymulti-clonalantibody,butitcouldnotreactwiththeseraofhealthypersonsandtherabbitanti-OC43and229E.
简介:本文介绍了下一代移动通信系统中关键技术——正交频分复用(OFDM),它具有良好的抗多径干扰性能和高频谱利用率。然后给出多载波调制和CDMA结合的MC-CDMA系统,此系统可以支持高数据传输率和高用户容量。接着简述了可以充分利用空间资源,提高无线信道容量和信道可靠性的MIMO技术,并给出结合MIMO和MC-CDMA即MIMO-MC—CDMA系统模型,最后简要介绍了此系统中所涉及的同步及信道估计技术。