简介:老师在课堂上用实验演示了弹簧振子做简谐运动的周期T与振幅A无关,而取决于振子质量m和劲度系数k.为了便于记忆,老师给出了它的周期公式T=2πm/k~(1/2).这个公式是教材中没有的,老师也没有加以证明.我想,能否利用我所学的知识证明它呢?我头脑一下子兴奋起来了,课后就开始着手去证明了.在简谐运动过程中,弹簧的弹力是变化的,要
简介:ThecharacteristicsofsuspendedsedimentimagecanbereflectedbythecoefficientsofbiorthogonalwavelettransformofCDF(2,2).Basedonthepowerdistributionindifferentscales,anadaptivealgorithmisproposedinthispaper,wherebythecoefficientsareadjustednon-linearly.Theparticleinformationcanbewellretainedwhiletheuselessbackgroundisremoved.Inthisway,satisfactorybinaryimagecanbeobtainedforfurtheranalysisofthesedimentparticle.
简介:Throughmeasuringthecoefficientoflinearexpansion,thestructureandpropertiesoftheLi2O-Al2O3-SiO2lowexpansionglassceramicscontainingB2O3arestudiedbyJRandXRD.ItisshoutnthattheIRmethodisefficientinthestudyoftheglass-ceramicsstructure.Thereisa"Boronabnormality"inthesystemwhichhasanimportantinfluenceonthepropertiesoftheglass-ceramics.
简介:摘要目的探究GATA3和bcl-11b在外周T细胞淋巴瘤(peripheral T-cell lymphoma,PTCL)中的表达情况及其与临床病理特征之间的关系。方法利用Oncomine数据库和GEO数据库分析GATA3和bcl-11b mRNA在PTCL中的表达水平;收集山西省肿瘤医院2010年1月至2020年6月间诊断为PTCL的127例患者病例资料及石蜡标本,制作组织芯片,采用免疫组织化学染色(IHC)方法检测GATA3和bcl-11b蛋白在127例PTCL患者组织标本及40例反应性增生淋巴结中的表达情况。结果Oncomine数据库和GEO数据库中的数据显示,GATA3和bcl-11b mRNA在PTCL组织中表达低于正常组织(P<0.05)。IHC结果显示,GATA3在PTCL和淋巴结反应增生性淋巴组织表达率分别为60.6%(77/127)和85.0%(34/40;P<0.05),bcl-11b在PTCL和淋巴结反应增生性淋巴组织表达率分别为55.1%(70/127)和75.0%(30/40;P<0.05)。GATA3的表达与PTCL患者病理分型有关,与患者Ann Arbor分期呈负相关;bcl-11b的表达与患者国际预后指数评分呈负相关(P<0.05),二者表达与患者年龄、性别、乳酸脱氢酶水平、B症状等临床病理特征均无关(P>0.05);Spearman相关分析显示,PTCL组织中GATA3蛋白与bcl-11b蛋白的表达呈正相关。结论GATA3和bcl-11b与PTCL的预后密切相关,可能是PTCL发生发展的重要参与因子。
简介:Twooxo-vanadium(IV)complexes,[VO(C2O4)(2,2′-bipy)(H2O)]·C2H5OH(1)andVO(C2O4)(phen)(H2O)(2),where2,2′-bipy=2,2′-bipyridyl,phen=1,10-phenanthroline,weresynthesizedaspotentialfunctionalmodelsofvanadiumhaloperoxidases(VHPOs)inmixedsolventofethanolandwateratroomtemperature.Thecomplexeswerecharacterizedbyelementalanalysis,infrared(IR),UV-VisandX-raycrystallography.Structuralanalysesshowedthatvanadiumatomwascoordinatedbyaterminaloxygen,oneoxygenatomfromcoordinatedwater,twooxygenatomsfromthecarboxylategroupofoxalicacid,andtwonitrogenatoms(N1andN2)from2,2′-bipy/phen.Centralvanadiumatomsincomplexes1and2werebothinadistorted-octahedralenvironment,andsomeintermolecularhydrogenbondinglinkageswerealsoobservedineachcomplex.BrominationreactionactivityofthetwocomplexeswasevaluatedwithphenolredasorganicsubstrateinthepresenceofH2O2,Br-andphosphatebuffer,indicatingthattheycanbeconsideredasapotentialfunctionalmodelofVHPO.Inaddition,thermalanalysiswasalsoperformedanddiscussedindetail.
简介:Thecombinationofboth4,4′-bipyridine(4,4′-bipy)anddihydrogenphosphateanionligandswithcopper(Ⅱ)resultsintheformationofanovellayeredcompoundCu(4,4′-bipy)2(H2PO4)2(H2O)2.ThecrystalstructurecomprisesdiscreteneutralCu(4,4′-bipy)2(H2PO4)2(H2O)2units.Thecopperatom,locatedonthecrystallographictwofoldaxis,iscoordinatedwithtwonitrogenatomsofterminal4,4′-bipyligandsandtwowatermoleculesattheequatorialpositions,andtwodihydrogenphosphateoxygenatomsattheaxialpositions,forminganelongatedoctahedron.Thecomplexisatwo-dimensionaldistortedrhomboidalnetworkpossessingtwokindsofrhomboidswithdimensionsofca.1.6792nm×0.3203nmand1.2778nm×0.3198nm,respectively.Thetwo-dimensionalnetworksarestackedparallellyoneachotheralongc-axistogiveanextendedthree-dimensionalchannelnetworkwithaninterlayerdistanceofca.0.5030nm.Crystaldata:triclinic,spacegroupP-1,a=1.0253(2)nm,b=1.4501(3)nm,c=0.79715(16)nm,α=97.91(3)°,β=90.99(3)°,γ=85.54(3)°,V=1.1703(4)nm3,Z=2,R=0.0892,wR=0.2451.
简介:TheelectronicstructuresofCuS2,CuSe2andCuTe2withpyritestructures,withintheframeworkthedensity-functionaltheoryhavebeeninvestigated.ThecalculatedresultsexplainedtherecentexperimentalresultswhichshowthatthereisnoclearindicationofstrongelectroncorrelationsintheelectronicpropertiesofCupyrites,duetothedominantchalcogenpcharacterratherthandcharacteristicofCuattheFermilevel.
简介:Linearcomplexityandk-errorlinearcomplexityofthestreamcipheraretwoimportantstandardstoscaletherandomicityofkeystreams.Forthe2n-periodicperiodicbinarysequencewithlinearcomplexity2n1andk=2,3,thenumberofsequenceswithgivenk-errorlinearcomplexityandtheexpectedk-errorlinearcomplexityareprovided.Moreover,theproportionofthesequenceswhosek-errorlinearcomplexityisbiggerthantheexpectedvalueisanalyzed.
简介:Loadedonthecordierite,therareearthdopedcompositecatalystwaspreparedbysol-gelmethodcombinedwithdippingtechnique.TakingOrthodichlorobenzeneasmodel,thecatalystwasusedtoremovethedioxinsofthewastegas.Theresultsshowedthatat280℃andgasspacevelocitybeing8000h-1,theorthodichlorobenzenecouldberemovedeffectivilybythepreparedCeO2-TiO2-V2O5compositecatalystwhoseactivitywasremarkablyenhancedbythedopingofCe,whiletheindustrialside-streamtestofdioxinsfromrefuseincinerationsmokeindicatedthatthedecompositionratecouldreachabove93%underthesameconditions.
简介:BackgroundTaxifolin(Tax)isanessentialnaturalantioxidant.MultiplestudieshaveshownthatTaxcanprotectcardiomyocytesfromischemia-reperfusioninjury.However,theunderlyingmechanismisstillunclear.MethodsH9C2cellswererandomlydividedintocontrol,H_2O_2group,Taxpretreatmentgroup(Tax+H_2O_2);Taxeffectgroup.CellactivitywasdetectedbyCCK-8andtheintracellularstructurewasobservedbytransmissionelectronmicroscopy.AutophagywasdeterminebyWesternblottinganalysisofBeclin-1,Bcl-2andPKC.ResultsTaxpretreatmentsignificantlyincreasedanti-apoptoticproteinBcl-2andautophagyproteinBeclin-1.ExpressionofPKCwasinhibitedbyTax.ConclusionsTaxpretreatmentcouldprotectH9C2cellsagainstH_2O_2-induceddamagethroughtheBcl-2andautophagypathways.
简介:摘要目的朗迈2(LabUmat2+Urised2)全自动尿液分析仪是LabUmat2尿液干化学分析仪和Urised2尿液有型成分分析仪通过同一标本运输轨道联机检测尿常规的全自动仪器。检测项目多、速度快、精密度高,尿液有形成分分析结合人工显微镜检查准确度高。方法LabUmat2全自动尿液干化学分析仪反射光度计法,折射仪法。Urised2全自动尿液有型成分分析仪自动离心镜检,影像式神经网络智能识别系统检测。结果LabUmat2分析仪,配用专用的尿液分析试纸条,检测尿液化学成分;Urised2分析仪检测尿液有形成分。结论朗迈2(LabUmat2+UriSed2)全自动尿液分析仪应用全过程严格按照检测前、检测中、检测后的质量保证体系做好全程质量控制,可及时、准确获得尿常规报告,为临床诊断、疗效监测、预后判断提供可靠依据。同时也是临床实验室尿常规检测技术的提高。
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