简介：Wesynthesized(Pb,Cd)Sr2(Y,Ca)Cu2O7+x,phasesuperconductor.AftersubstitutionofPbwithBi,theBiCd1212phaseshowsnosuperconductivity.AlthoughpreviousEXAFSstudyhasshownthelocalstructureenvironmentoftheCuissimilarinbothcompounds,EXAFSresultsofBiandPbheredemonstratethatσ2ofPb-Oin-planeislargerthanthatofBi-Oinplane,whereasσ^2ofPb-OapicalissmallerthanthatofBi-O,wheraseσ^2ofPb-OapicalissmallerthanthatofBi-Oapical.TheSrshellfeaturesarealsodiffernet,itappearedthatsuperconductivityneedssomedisorder.incarrierreservoirlayer,whichisduetothesubstitutionaldefectcausedbydifferentionicradii.

简介：2008年3月17日经国防科工委批准,《铀矿地质勘查安全生产规程》等28项标准正式以核行业标准颁布,该28项核行业标准将于2008年10月1日起正式实施。

简介：ThetransientopticalpropertiesofnovelPbSnanoparticlescoatedwith2.6-O-diallyl-β-cyclodextrines(CDs)werestudiedbythefemtosecondpump-probetechnique.Theresultsshowthattheultrafasttransient-inducedabsorptionforthenovelcase.ComparedtothePbSnanoparticlesstabilizedwithpolyvinylalcohol(PVA),wefindthattheprocessforthenovelcaseisdifferentfromthePbS(PVA),WesuggestthattheCDssurfacemodificationcantrapholesonthesurfaceofPbSnanoparticles.ThiscaninduceanefficientchargeseparationbetweenthePbSnanoparticlesanditssurfaceandresultinanultrsafast-inducedabsorptionfornovelPbSnanoparticles.