简介:采用多孔氧化铝模板,通过直流电化学沉积法成功制备出不同掺杂浓度的Cd1-xMnxS纳米线,用XRD、SEM、HRTEM对纳米线的成分、形貌、结构进行了系统分析,并用SQUID对样品进行了磁性测量,结果表明,制得的Cd1-xMnxS纳米线呈单晶CdS纤锌矿结构,而且沿002方向有择优取向性,没有发现其它含Mn的化合物生成。从ZFC/FC曲线看出样品的居里温度接近于室温,且在低温处存在奇异现象。45K和300K下测量的的M-H曲线显示磁滞现象,测得的矫顽力分别是300Oe和100Oe,说明样品具有铁磁性。样品的紫外-可见光反射谱显示Cd1-xMnxS纳米线的吸收边并不随掺杂浓度x单调变化,而是随着掺杂量的增大能隙先减小后增大。掺杂度在1%处能隙有最小值。
简介:Na5+xYAlxSi4-xO12superionicconductorsarerhombohedralR3cspacegroup.Theirstructuresarecharacterizedby(Alx/4Si1-x/4)O4tetrahedralinkedtoformpuckered(Al3xSi4-x)4O35ringsparalleltothebasalplaneofthehexagonalcell.Theserings,separatedbypartsofsodiumoxygenpolyhedron,arestackedtoformlargerigidcolumsparalleltocaxis.Thecolumnsarelinkedby[YO6]octahedratoformathree-dimensionalFrameworkwithlargechannelsbetweentherings.PartsofNaionslocatedinthecoresofthecolumnsaremovable.Intermsoftheconductionmechanism,theconcentrationofconductingNa+ionswascarriedoutandcomparedwiththeexperimentalresults.Itwasfoundthatthetheoreticalvaluesaccordwiththeexperimentalresults.
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简介:CdSe/CdS半导体量点共同敏化TiO2nanorod数组在透明的传导性的做氟的符号的听氧化物(FTO)上被制作使用热水、连续的离子的层吸附和反应(SILAR)过程的底层。样品的结构、词法的性质被X光检查描绘衍射(XRD),地排放扫描电子显微镜学(FESEM),和传播电子显微镜学(TEM)。结果显示CdSe/CdSQD在TiO2nanorods的表面上是一致地涂的。轻吸收边的移动被拿紫外可见的吸收系列监视。与TiO2nanorod数组的吸收系列相比,CdSe/CdSQD的免职转移吸收边到更高的波长。当在量点的co-sensitizers敏化太阳能电池(QDSSC),在CdSe/CdS/TiO2nanorod数组的可见光的区域的提高的轻吸收显示CdSe/CdS层能行动。由优化CdSe层免职周期,5.78mA/cm2的光电流,0.469V的开的电路photovoltage和变换,1.34%的效率在100mw/cm2的照明下面被获得。
简介:ThethermodynamicphasestabilityareadiagramsofBCl3-NH3-SiCl4-H2-ArsystemwereplottedviaFactsagesoftwaretopredictthekineticexperimentalresults.Theeffectsofparameters(ie,partialpressureofreactants,depositiontemperatureandtotalpressure)onthedistributionregionsofsolidphaseproductswereanalyzedbasedonthediagrams.Theresultsshowthat:(a)Solidphaseproductsaremainlyaffectedbydepositiontemperature.TheareaofBN+Si3N4phaseincreaseswiththetemperaturerisingfrom650to900℃,anddecreaseswiththetemperaturerisingfrom900to1200℃;(b)Whentemperatureandtotalpressureareconstants,BN+Si3N4phaseexistsatahighpartialpressureofNH3;(c)Theeffectoftotalsystempressureiscorrelatedtodepositiontemperature.Thetemperaturerangingfrom700to900℃underlowtotalpressureistheoptimumconditionforthedeposition.(d)Appropriatekineticparameterscanbedeterminedbasedontheresultsofthermodynamiccalculation.Si–B–Ncoatingisobtainedvialowpressurechemicalvapordeposition.TheanalysisbyX-rayphotoelectronspectroscopyindicatesthatB–NandSi–Narethemainchemicalbondsofthecoating.
简介:FenanowirearraywithstrongshapeanisotropywasemployedasthesoftphaseinNd-Fe-Bbasednanocomposites.TheeffectsoftheFenanowiredistributiononmagneticpropertiesofthenanocompositeswereinvestigatedbymicromagneticsimulation.TheresultsindicatethattheshapeanisotropyofFewiresaddedinthesamedirectionastheuniaxialmagnetocrystallineanisotropyofthehardphasecannotincreasethecoercivityofthenanocomposite.Whenthenanowiresaredistributedperpendiculartotheeasyaxisofthehardphase,theshapeanisotropyofsoftphasecanretardthemomentsfromrotatingtothefullreverseddirection,leadingtoenhancedcoercivity.Inaddition,withincreasingthenanowirediameter,thecoercivityofthenanocompositedecreases,butthedipolarinteractionshowsdifferentrolesinmagneticreversalofnanocompositefordifferentdistributionsofnanowires.ThecurrentresultssuggestthatthecoercivityoftheNd2Fe14B/α-Fenanocompositecanbeenhancedbyintroducingthesoftmagneticnanowirearraywiththediameterlessthantheexchangelengthandwiththelongaxisalongthedirectionotherthantheeasyaxisofhardphase.
简介:Inthepresentpaper,twomodelsbasedonartificialneuralnetworksandgeneticprogrammingforpredictingsplittensilestrengthandpercentageofwaterabsorptionofconcretescontainingZrO2nanoparticleshavebeendevelopedatdifferentagesofcuring.Forbuildingthesemodels,trainingandtestingusingexperimentalresultsfor144specimensproducedwith16differentmixtureproportionswereconducted.Thedatausedinthemultilayerfeedforwardneuralnetworksmodelsandinputvariablesofgeneticprogrammingmodelswerearrangedinaformatofeightinputparametersthatcoverthecementcontent,nanoparticlecontent,aggregatetype,watercontent,theamountofsuperplasticizer,thetypeofcuringmedium,ageofcuringandnumberoftestingtry.Accordingtotheseinputparameters,intheneuralnetworksandgeneticprogrammingmodels,thesplittensilestrengthandpercentageofwaterabsorptionvaluesofconcretescontainingZrO2nanoparticleswerepredicted.ThetrainingandtestingresultsintheneuralnetworkandgeneticprogrammingmodelshaveshownthattwomodelshavestrongpotentialforpredictingthesplittensilestrengthandpercentageofwaterabsorptionvaluesofconcretescontainingZrO2nanoparticles.Ithasbeenfoundthatneuralnetwork(NN)andgeneexpressionprogramming(GEP)modelswillbevalidwithintherangesofvariables.Inneuralnetworksmodel,asthetrainingandtestingendedwhenminimumerrornormofnetworkgained,thebestresultswereobtainedandingeneticprogrammingmodel,when4geneswereselectedtoconstructthemodel,thebestresultswereacquired.Althoughneuralnetworkhavepredictedbetterresults,geneticprogrammingisabletopredictreasonablevalueswithasimplermethodratherthanneuralnetwork.