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1.
1 Introduction Highpowerfactorinductionmotorwithfloatingwindinginparallelconnectionwithcapacitorsisamotorofspecialstructureandwithspecialconnection.Itsstatorcircuitconfiguration[1]isshowninFig.1.Fig1showstwosetsofstatorwindings,thepowerwindingsconn…  相似文献   

2.
1IntroductionUptonow,althepapersbutRef.[1]ontheinverseaerodynamicproblemaresolelyconfinedtosteadyflow.InRef.[1]theauthorcarie...  相似文献   

3.
1 Introduction  Considerthemodelx ¨+x(1-x)(x-a)=0,(1)whereaisaconstant.Asa=-1,Eq.(1)reducestotheDuffingequationforthesystemofsoftspringwithoutdampingx ¨+x-x3=0.(2) TheDuffingsystemhasbroadengineeringbackground.Therearepapers[1~4]relatedtothedynamic…  相似文献   

4.
1 Introduction H.P.Yuenintroducedtheconceptoftwophotoncoherentstatein1976[1].Sincethattime,thesqueezedstateshavebeenoneofthemainsubjectsinquantumoptics.Usualsqueezingreferstothesecondordersqueezing.C.K.HongandL.Mandelgeneratedthesqueezingtohighe…  相似文献   

5.
1 Introduction Stochasticglobaloptimizationalgorithmisconcernedwithusingrandomlygeneratedpointstoapproximateoptimalsolutionofmathematicalprogramming(seeRefs.1~3forasurveyofthefield).Forsomestochasticglobaloptimizationalgorithms,thenextpointsintheseq…  相似文献   

6.
1 Introduction Theproblemonthestabilityofinviscidincompressibleswirlingflowhasbeenstudiedbymanyauthors.Rayleigh[1]investigatedtheflowwithconstantaxialvelocity,i.e.U′=dUdr=0andfirstgotasufficientandnecessaryconditionofstabilityforaxisymmetricdistur…  相似文献   

7.
1 Introduction Inimagecompressioncodingschemes,variousimagecodingtechniquessuchastransformcodinghavebeendeveloped.Whilethesetechniqueshaveledtorelativelyhighqualityreconstructedimagesatbitratesaround1.0b/pixelormore,theysometimesproducespecifictypeof…  相似文献   

8.
1IntroductionThelogicalstructureofaconverterfedmachine(CFM)systemissimplysketchedinFig.1.Tostudyorevaluatesuchasystemobviousl...  相似文献   

9.
1 Introduction Tindioxidefilmshavebeenwidelyusedasconductiveelectrodes,transparentcoatings,andheterojunctionsolarcells.SnO2filmswithdifferentstructurescanbeconstructedbychemicalvapordepositiononsubstratesofdifferenttemperatures.AboafandMarcotte[1]pr…  相似文献   

10.
1 Introduction Inthelasttwodecadeseverincreasinginterestofscientistsandengineershasbeenattractedtoinverseandoptimizationproblemsofaerodynamics,butuptonowintheliteratureallpapersoninverse/hybridproblemsarestillconfinedtosteadyflow[1-3]. InRef.[5],th…  相似文献   

11.
ZnFe2O4 and ZnFe2O4-based materials were tested to obtain the electrical conductivity and corrosion resistance in melting bath for aluminum electrolysis. The results proved that adequate additives, such as Ni2O3 CuO, Cu, ZnO and CeO2 would increase the electrical conductivity, and the ZnFe2O4-based anodes with these additives were of good corrosion resistance. The current density on anode, the mole ratio of NaF/AlF3 (MR) and the content of alumina in the bath effect the anode corrosion rate in different way. Project supported by the Science Foundation of Liaoning Province, P. R. China (95 – 156)  相似文献   

12.
INTRODUCTION The solid oxide fuel cell (SOFC) has attracted much attention as a promising source of electrical power generation because of its high efficiency in converting chemical energy to electrical power. De- velopment of SOFC with operating temperature of less than 800 °C has been extensively studied. SOFC has the potential to have the cost of its materials, cell fabrication, and corrosion of its stack components dramatically reduced. Gadolinia-doped ceria with the chemical fo…  相似文献   

13.
成功制备了氧缺陷型Sb2O3-x/rGO复合材料.与纯Sb2O3材料相比,Sb2O3-x/rGO复合材料颗粒尺寸大大减小,导电性能得到提高,作为锂离子电池的负极材料,具有更高的可逆能力、更好的循环稳定性和良好的倍率性能.在电流密度为100 mAh·g^-1的情况下,Sb2O3-x/rGO复合材料的初始放电容量可达1336.6 mAh·g^-1.即使经过50次充放电循环后,其充放电容量依然可以保持在405.8 mAh·g^-1.  相似文献   

14.
导电珠光颜料是在片状云母或云母钛的表面包覆一层或几层半导体金属氧化物,如掺锑二氧化锡SnO2-Sb2O3(antimony—doped tinoxide,简称ATO),而制得的浅色导电颜料。导电珠光颜料具有稳定性高,耐腐蚀性好,产品颜色浅,导电性能好等优点,展现出了不同于传统珠光颜料的特殊的抗静电性和屏蔽电磁辐射与干扰的性能,是一种新型无机纳米功能材料,有较广阔的应用前景。本文探讨了导电珠光颜料的导电机理和ATO与基质的复合机理,介绍了导电珠光颜料的几种制备方法,如共沉淀法、均相沉淀法、微乳液法、金属醇盐水解法等。  相似文献   

15.
Fe-Cr-Ni heat resistant steels with different contents of Al and Si were cast in intermediate frequency induction furnace with non-oxidation method. With oxidation weight gain method, the oxidation resistance of test alloys was examined at 1 200℃ for 500 h. The effects of Al and Si on oxidation resistance were studied through analyses of X-ray diffraction (XRD) and scanning electron microscope (SEM). It is shown that the composition of oxide scales is a decisive factor for the oxidation resistance of heat resistant steels. The compounded scale composed of Cr2O3, ar-Al2O3, SiO2 and Fe(Ni)Cr2O4, with flat and compact structure, fine and even grains, exhibits complete oxidation resistance at 1 200℃ Its oxidation weight gain rate is only 0.081 g/(m2·h). By the criterion of standard Gibbs formation free energy, a model of nucleation and growth of the compounded scale was established. The formation of the compounded scale was the result of the competition of being oxidated and reduction among Al, Si, and the matrix metal elements of Fe, Cr and Ni. The protection of the compounded scale was analyzed from the perspectives of electrical conductivity and strength properties.  相似文献   

16.
采用失重法研究了环丙沙星在0.5 mol/L H2SO4溶液中对低碳钢的缓蚀性能以及温度对缓蚀效果的影响,通过量子化学计算和动电位极化曲线测试研究了缓蚀机理.结果表明:环丙沙星具有较好的缓蚀性能,在有效浓度为4mmol/L时对低碳钢的缓蚀效率可达到91.19%;它是以阳极抑制为主的混合抑制型缓蚀剂,通过苯环及O、N、F三种杂原子在碳钢表面形成的单分子层吸附达到缓蚀目的,并且随着温度的升高缓蚀效率降低.  相似文献   

17.
采用陶瓷薄膜技术及溶胶一凝胶法制备了氧离子传导YSZ(Y2O3稳定的ZrO2)电解膜与电极催化剂,构建了膜电极组装(MEA)及结构为H2S、(复合MoS2阳极)/YSZ传导膜/(复合NiO阴极)、空气燃料电池系统;通过在MoS2中掺杂NiS、电解质、Ag粉和淀粉制备了双金属复合MoS2阳极催化剂,在NiO中添加电解质、Ag粉和淀粉制备了复合NiO阴极催化剂:考察了不同操作温度对电池性能的影响,比较了几种不同电极催化剂的性能,研究了H2S/air固体氧化物燃料电池的电化学性能。实验结果表明,在H2S环境中,复合MoS2阳极催化剂比MoS2和Pt具有更好的性能,复合Nio阴极Pt阴极的极化小;在电极催化剂中加入Ag可显著提高电极的导电性.添加电解质和淀粉可以提高电极的离子传导性和多孔性:操作温度增加.传导膜的电传导率和电化学反应速率增加,电池的输出电流与功率密度增加,电化学性能变好。电池连续运行1~4d几乎不降级。在850℃和101.13kPa时.燃料电池最大输出功率密度为155mW·cm^-2,对应的电流密度为240mA·cm^-2。  相似文献   

18.
室温下,以Ti(S04)22-6g/L,H2021-2g/L,NaF3-5g/L,EDTA2-6g/L为转化液的主要成分,加入1-2g/LCe(N03)3 .6H20促进转化膜的致密性和均匀性,控制转化液pH4.0-4.5,转化处理10min,在样品表面制备一层化学转化膜.通过中性盐雾测试和电化学测试表征转化膜的耐蚀性,采用冷场发射扫描电镜(SEM)观察转化膜的微观形貌,X射线能谱仪(EDS)分析转化膜的化学成分.结果表明:该转化膜耐蚀性优艮,EDS能谱分析得出这层颗粒状物质主要由Na,A1,F元素和少量的Mg,Ti,O元素组成,推断转化膜的主要成分为Na3AIF6,铈盐起到促进转化膜致密性和均匀性的作用.  相似文献   

19.
研究了一种新的、简便的、环保的铝及铝合金化学镀镍新工艺,探讨了前处理、光亮剂添加量对镀层质量的影响。结果表明,铝及铝合金经过自制浸锌剂二次浸锌后,每升镀液中添加15mL光亮剂所获得的样品镀层均匀、结合力最佳。  相似文献   

20.
基于电阻探针腐蚀监测的原理,研制了适合气田环境的ER400电阻探针腐蚀监测仪,其仪器电阻分辨率可达到0.5(腐蚀速率灵敏度达到了0.1m/a)。用其所研制的电阻探针腐蚀监测设备与实验室的电化学极化测试和靖边气田现场磁阻探针、挂杆失重试验相比,发现其测量的腐蚀速率与室内和现场测试结果十分接近。说明ER400电阻探针腐蚀监测仪器的可靠性,达到了国内外同等仪器的先进水平。  相似文献   

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