简介:【内容摘要】真空断路器具有维护工作量小、断流容量大、重量轻、噪声低、易安装、适宜频繁操作等许多优点,在电力系统10kV-35 kV电压等级中逐渐取代了其它类型断路器,得到了广泛的应用。真空断路器是一种以气体分子极为稀少,分子间的平均自由行程很大,电子与分子相碰撞的机会极少,绝缘强度很高的真空空间为熄弧介质的新型断路器。
简介:PhasesandmicrostructuresofthreehighZncontainingAl–Zn–Mg–Cualloyswereinvestigatedbymeansofthermodynamiccalculationmethod,opticamicroscopy(OM),scanningelectronmicroscopy(SEM)energydispersivespectroscopy(EDS),X-raydiffraction(XRD),anddifferentialscanningcalorimetry(DSC)analysis.TheresultsindicatethatsimilardendriticnetworkmorphologiesarefoundinthesethreeAl–Zn–Mg–Cualloys.Theas-cast7056aluminumalloyconsistsofaluminumsolidsolution,coarseAl/Mg(Cu,Zn,Al)2eutecticphases,andfineintermetalliccompoundsg(MgZn2).Bothofas-cast7095and7136aluminumalloysinvolvea(Al)eutecticAl/Mg(Cu,Zn,Al)2,intermetallicg(MgZn2),andh(Al2Cu).Duringhomogenizationat450°C,fineg(MgZn2)candissolveintomatrixabsolutely.Afterhomogenizationat450°Cfor24h,Mg(Cu,Zn,Al)2phasein7136alloytransformsintoS(Al2CuMg)whilenochangeisfoundin7056and7095alloys.ThethermodynamiccalculationcanbeusedtopredictthephasesinhighZncontainingAl–Zn–Mg–Cualloys.
简介:Inapreviousgreenhouseexperiment,weshowedthattherewasaninteractionbetweencuandZn,whichaffectedgrowthandmetaluptakebyyoungbarleyplantsgrownonsoiltowhichCd,Cu,Pb,andZnhadbeenadded.Wesuggestedthattheunderlyingmechanismwasthecontroloftheamountofplant-availableZnbycompetitiveadsorptionbetweenCuandZn,Inordertotestthishypothesis,theadsorptionofZnalone,andinthepresenceofaddedCd,CuandPb,hasbeenmeasuredusingthesamesoil.Followingadsorption,theextractabilityoftheZninCaCl2solutionwasmeasured.TheadsorptionisothermsshowedthatoftheaddedmetalsonlyCuhadalargeeffectonZnadsorption.TheeffectofCuwastoreduceZnadsoptionandtoincreasetheamountofCaCl2-extractable(i.e.plant-available)Zn,inagreementwiththeconclusionsfromthegreenhouseexperiment.ThemagnitudeoftheeffectofCuonplant-avalilableZnwassimilarinbothexperiments.
简介:摘要就日常巡视过程中发现10千伏ZN63A-12型真空断路器出现的异常声响进行分析,通过试验和解体检查方法,查找出ZN63A-12型真空断路器异常原因,并提出了处理措施。
简介:StudyontheavoidanceresponseofPenaeuschinensistoheavymetals(Pb,Cr,Zn)andheavymetalmixtures(Pb-Cr,Pb-Zn)iscarredoutusingaY-modelavoidanceapparatus.Theconcentrationscalculatedtoinduce50%avoidanceratebyPenaeuschinensisare11.4,33.2and238.1mg/LforPb,CrandZn,respectively.MixturesofPb-CrandPb-ZnproduceadditiveeffectintheavoidancetestusingPenaeuschinesis.ButwhenthemixedPb-Znsolutionhas0.5toxicunitPband0.5toxicunitZn,themixtureseemstohavesynergisticeffect.
简介:喷洒的Zn和Zn15Al涂层被选择保护对的高张力水泥(PHC)的结束输送的金属的弧在东北中国在北瓷器和中立草地土壤对盐咸滩土壤的腐蚀堆。在二个模仿的土壤答案的涂的Q235钢样品的腐蚀行为被potentiodynamic极化和电气化学的阻抗光谱学(EIS)调查方法。试验性的结果证明在两个都模仿的答案的矩阵Q235钢的腐蚀被Zn和Zn15Al涂层显著地禁止。Zn和Zn15Al上的腐蚀产品厚、紧缩、坚挺、保护。Zn和Zn15Al涂的样品的腐蚀水流密度icorr与腐蚀时间,和费用转移电阻Rct显然被减少极大地被增加。在模仿的中立草地土壤答案的Zn和Zn15Al的腐蚀电阻索引是比在盐咸滩土壤的那些更突出的。在盐咸滩土壤的Zn15Al的腐蚀电阻比Zn的稍微优异。当喷洒的涂层与环氧基树脂树脂被封上时,涂层的腐蚀电阻进一步显著地被提高。
简介:Three-dimensional(3D)flowerlikehierarchicalZn2GeO4andMn2+-dopedZn2GeO4microstructureshavebeenpreparedbyafacilehydrothermalapproach.X-Raydiffraction(XRD),fieldemissionscanningelectronmicro-scopy(FESEM),transmissionelectronmicroscopy(TEM)andphotoluminescence(PL)spectrometrywereemployedtocharacterizethesamples.SuchflowerlikehierarchicalZn2GeO4microstructureswithanaveragediameterof3―4μmwerefoundtobeconstructedbyabundantsinglecrystallinenanorodsofabout90nmindiameter.TheluminescentpropertiesofZn2GeO4:xMnphosphorswithdifferentcontentsofMn2+asanactivatorwereinvestigated.TheMn2+-dopedsamplesshowedgreenluminescencecorrespondingtothed-dtransitionofMn2+undertheirradiationofUVlight.Theredshift(from531nmto538nm)inλemwithincreasingMn2+contentwasobservedintheluminescentspectra,whichshouldbeattributedtoaweakcrystalfieldbecauseofthesubstitutionofZn2+byMn2+atadistortedtetrahedrallatticesite.
简介:Soilswerecollectedfrom2-year(2-y)and3-year(3-y)oldred-pineseedlingplotsintwotreenurseries,HaywardinthenorthandWilsoninthesouthwesternpartofWisconsinStaterespectively,andequilibratedwith0.01MCa(NO3)2)forsoilsolutionZnandMn(solu-ZnandMn),andwith0.01MCa(NO3)2+0.005MEDTAforsoilabsorbedZnandMn(ad-ZnandMn).BufferingcapacityofsoilZnandMn(b-ZnandMn)wasobtainedfromtheratioofad-ZnandMntothesolu-ZnandMn.Theconcernedtracesinpineseedlingneedles(ndls),stems(sts)androots(rts)weresimultaneouslymeasured.Theresultsobtainedshowthat:About60%ofsolu-andad-Znrangedfrom0.2to0.4andfrom1to2μg/gsoilrespectively.About70%ofb-Znwaswithin3-10.Thehighestcontentofsolu-Zncomparedwiththelowestshowedadiscrepanceofmorethan10-fold.ThetwoformsofsoilZnwerecommonlyhigherinWilsonthaninHaywarkNursery.About80%ofsolu-,ad-andb-Mnwerewithin3-10,5-5.8μg/gsoiland1-2respectively.Influenceoflowbufferingcapacityonsolu-ZnandMnwasabout20timesstrongerthanthatofthehigh.TheE-value,aratioofaccumulatedZnandMninneedlestothoseinthesoilsolution,isprovedtobe:E-Zn>E-Mn;E-sts>E-ndlsorE-rts;andE-2y>E-3y.Curvilinearand/orlinearcorrelationsbetweensoilsolu-,ad-andb-ZnandMnandndls-,sts-,rts-ZnandMnwereatverysignificantorsignificantlevels.Forpredictingndls-ZnandMn,tworealizableandsimplemodelsfromtworegressionequationswereestablishedthroughtheselectionofrelatedparametersanddependentvariables.BinaryregressionanalysisbasicallyeliminatedtheinfluenceofsoilpHonthepredictionofZnandMninneedles.SoilpHwasthusthoughttobeexcludedfromthemodel.