简介:TheanalysisofavailableNdisotopedatafromtheTanzaniaCratonplacesimportantconstraintsonthecrest-mantleseparationages,andeventsmarkingjuvenilecrustaladditionandcrustalrecycling.Ndmodelagesdatetheoldestcrustextractionto3.16GaintheTanzaniaCraton,althougharockrecordofsuchantiquityisyettobefoundthere.Themostsignificantperiodofjuvenilecrustaladditionaswellascrustalrecyclingis2.7-2.6Ga.TheNdisotopesofmariesamplesshowthatchemicalheterogeneityexistedinthemantlebeneaththeTanzaniaCraton,withsomesamplesoriginatingfromsignificantlydepletedmantle,andmostsamplesoriginatingfromthemixtureofprimitivemantleanddepletedmantle.TheNdisotopesectionrevealssignificantdifferencesinNdisotopesbetweenthenortheratonandcentralcraton;comparedtothenorthcraton,thecentralcratonyieldsaNdmodelagethatisapproximately100Maolder,anditsεNd(t)valuesaremorenegative,indicatingthatthetwopartsofthecratonhavedifferentmantlesourceregions.DifferenttypesofgranitoidsaredistributedintheTanzaniaCraton,suchashigh-Kandlow-Algranite,ealc-alkalinegranite,peraluminousgraniteandtransitionaltypesoftonalite-trondhjemite-granodiorites(TTGs).Mostofthegranitoidsformedlaterthanthemarierocksinsyn-collisionandpostcollisionevents.
简介:摘要目的对比分析区域折射多焦点人工晶体与衍射多焦人工晶体植入术后视觉质量。方法选取我院白内障超声乳化吸除联合多焦人工晶体植入的患者385只眼,根据晶体设计原理不同分为对照组(A组,衍射多焦型)和研究组(B组,区域折射多焦型)。A组共192只眼,B组共193只眼。随访1年,对比观察两组远、中、近裸眼视力及最佳矫正视力。结果对照组和研究组裸眼远、中距离与最佳矫正远视力无明显差异(P>0.05);研究组裸眼近视力优于对照组(P<0.05);研究组最佳矫正近视力与对照组无明显差异(P>0.05);研究组与对照组患者满意度无明显差异(P>0.05)。结论衍射多焦型人工晶体植入的裸眼远视力和最佳矫正视力、裸眼中距离视力和最佳矫正中距离视力与区域折射多焦型人工晶体无明显差异;在裸眼近视力方面,区域折射多焦型人工晶体优于衍射多焦型人工晶体。
简介:摘要目的探究在根管内充填材料的清除方面掺钕钇铝石榴石(NdYAG)激光的效果。方法选取2017年1月—2018年1月我院口腔科拔除的尚未进行根管治疗的上颌中切牙30颗,将之随机均分为研究组和对照组,两组各15颗,研究组通过NdYAG激光清除充填材料,对照组则通过ProtaperD3进行。结果研究组在充填材料清除情况以及温度升高情况方面均显著高于对照组,两组数据差异显著(P<0.05)。结论NdYAG激光能够对根管内的充填材料进行良好的清除,在进行清除时会出现根管壁温度升高的情况,但出于牙周的忍受范围之内,具有理想的清除效果,可以在临床上进行广泛的推广和应用。
简介:OnMarch13th,ReutersreportedthatthelongrunversionofTeslaModel3willusepermanentmagnetmotors.Oneofthematerialsforthistypeofmotorisrareearthmetalneodymium,whichwillfurtherincreasethesupplypressureofneodymium.Governmentsaroundtheworldarecommittedtoreducingtheharmfulemissionsproducedbyfossilfuelcars,pushingupdemandforelectricvehiclesand
简介:摘要目的观察后房型人工晶体睫状沟缝合悬吊的手术疗效,分析人工晶体悬吊术在后囊膜破损或无后囊膜的无晶体眼对矫正屈光不正的效果。方法将本院2015年3月—2017年5月收治的26例不能常规植入后房型人工晶体的患者作为研究对象,根据患者实际病情采用一期或者二期人工晶体悬吊术,术后观察6~12月。结果通过对患者实施人工晶体悬吊术后发现,所选患者手术均顺利实施,且术后未出现手术并发症,术后视力恢复良好,在对患者进行随访过程中,仅有3例出现人工晶体位置偏移的情况。结论对于无法常规进行植入后房型人工晶体的患者实施人工晶体悬吊术,有助于提升治疗效果,保证手术质量,降低术后并发症,对矫正屈光不正效果明显。
简介:EnvironmentalfriendlyrecyclingprocessforNd-Fe-Bsinteredmagnetsludgesgeneratedinthemanufacturingprocess,whichcontainlargeamountofrareearth,includingNd,PrandDy,isbadlyneededsofar.Inpresentstudy,wehavedevelopedaneffectiveroutetoobtainrecycledsinteredmagnetsfromNd-Fe-Bsinteredmagnetsludgesbycalciumreduction-diffusion(RD)process.Comparedtoconventionalrecyclingprocess,ourresearchisfocusedonrecoveringmostoftheusefulelements,includingNd,Pr,Dy,Co,andFetogetherinsteadofjustrareearthelements.Toimprovetherecyclingefficiencyandreducepollution,theco-precipitatingparametersweresimulatedandcalculatedusingMATLABsoftware.Mostofusefulelementswererecoveredbyaco-precipitationmethod,andtheobtainedcompositepowderswerethendirectlyfabricatedasrecycledNd-Fe-Bpowdersbyacalciumreduction-diffusion(RD)method.Therecoveryratesare98%,99%,99%,93%,and99%,forNd,Pr,Dy,Co,andFe,respectively.Theamountofusefulelementscontainedintherecoveredcompositepowdersisgreaterthan99.71wt%.TheprocessofRDforsynthesizingNd2Fe14BandsubsequentlyremovingCaOwasthoroughlyinvestigated.Furthermore,therecycledNd-Fe-Bmagnetexhibitsaremanenceof1.1T,acoercivityof1053kA/m,andanenergyproductof235.6kJ/m3,respectively,indicatingthatrecycledNd-Fe-Bsinteredmagnetwassuccessfullyrecoveredfromtheseverelycontaminatedsludgesviaaneffectiverecyclingroute.
简介:FenanowirearraywithstrongshapeanisotropywasemployedasthesoftphaseinNd-Fe-Bbasednanocomposites.TheeffectsoftheFenanowiredistributiononmagneticpropertiesofthenanocompositeswereinvestigatedbymicromagneticsimulation.TheresultsindicatethattheshapeanisotropyofFewiresaddedinthesamedirectionastheuniaxialmagnetocrystallineanisotropyofthehardphasecannotincreasethecoercivityofthenanocomposite.Whenthenanowiresaredistributedperpendiculartotheeasyaxisofthehardphase,theshapeanisotropyofsoftphasecanretardthemomentsfromrotatingtothefullreverseddirection,leadingtoenhancedcoercivity.Inaddition,withincreasingthenanowirediameter,thecoercivityofthenanocompositedecreases,butthedipolarinteractionshowsdifferentrolesinmagneticreversalofnanocompositefordifferentdistributionsofnanowires.ThecurrentresultssuggestthatthecoercivityoftheNd2Fe14B/α-Fenanocompositecanbeenhancedbyintroducingthesoftmagneticnanowirearraywiththediameterlessthantheexchangelengthandwiththelongaxisalongthedirectionotherthantheeasyaxisofhardphase.
简介:摘要观察超声乳化与人工晶体植入术联合治疗老年性白内障的疗效及并发症。研究对象为我院眼科收治的120例老年性白内障患者,以住院号奇偶随机均分为两组,奇数为对照组,给予小切口非超声乳化囊外摘除术治疗,偶数为观察组,给予超声乳化与人工晶体植入术联合治疗,对比两组的视力、眼压、术后并发症及生存质量的差异。术后,观察组的视力改善效果显著优于对照组,眼压及并发症发生率显著低于对照组,生存质量显著高于对照组(P<0.05),有统计学意义。老年性白内障患者采用超声乳化与人工晶体植入术联合治疗效果确切,对于改善患者视力、提升患者生存质量有重要意义,值得推广使用。