简介：π-/π+ratiowasfoundtobeasensitiveprobetothehigh-densitybehaviorofthesymmetryenergybyusingseveraltransportmodels.However,asshowninFig.1,atbeamenergiesbelowthepionproductionthreshold,theeffectsofin-mediumnucleon-nucleonscatteringcrosssection(whichisstillcontroversial)stronglyaffectthevalueofπ??/π+ratio[1].Itisthusnecessarytodoacomparativestudyoftheeffectsofthein-mediumNNcrosssectionandtheeffectsofthesymmetryenergyonpionproductioninheavy-ioncollisionsatlowerbeamenergies.

简介：采用拉曼光谱原位分析、扫描探针显微镜、扫描电镜和X射线能谱研究了Ce-5％（质量分数）La合金在空气中的氧化过程。

简介：

简介：ThecokedepositiononHZSM-5/SAPO-34compositecatalystshasbeenstudiedintheconversionofethanoltopropylene.TheHZSM-5/SAPO-34compositecatalystsweresynthesizedbyhydrothermalmethod（ZS-HS）andfullyblending（ZS-MM）.TheusedcatalystswerecharacterizedbyXRD,N2adsorption–desorption,TGA,TPO,elementalanalysis,FTIRandXPS.ThecokingkineticsonbothZS-HSandZS-MMhasbeeninvestigatedandtheircokingrateequationswereobtained.TheusedZS-MMcatalysthadhigheramountofcokeandlowernC:nHthantheusedZS-HS.90%ofthecokewasdepositedinthemicroporesofZS-HS,whilealmost45%ofthecokelocatedinthemicroporesofZS-MM.ThecokedepositedonZS-HScatalystwasmainlygraphite-likecarbonspecies,whereasdehydrogenatedcokespecieswasthemajoronZS-MM.ThecokingactivationenergyofZS-MMwaslowerthanthatofZS-HS,andthecokingrateonZS-MMwasfasterthanonZS-HS.Inaddition,theregenerationofZS-MMcatalystshowedthatithadagoodhydrothermalstability.Thedifferencesoncokingbehaviorsonthetwocatalystswereduetotheirdifferentacidicpropertiesandtextures.

简介：

简介：Zn/ZSM-5（NZ2）andZn/Ni/ZSM-5（NZ3）asthecatalystsformethanoltoaromatics（MTA）weresynthesizedbyasimpleultrasonicimpregnation.ThetexturalandacidpropertiesofallcatalystswerecharacterizedusingXRD,HRTEM,NH3-TPD,Py-IR,XPS,XRFandTGtechniques.TheXRDandHRTEMresultsshowedthatthebasiczeolitestructureswerenotaffectedmuchwiththeincorporationofZnandNispecies.However,greatchangeshavetakenplaceinacidproperties.ThePy-IRandXPSresultsindicatedthattheZn-Lewisacidsites（ZnOH+species）,whichhavestrongerinteractionwiththezeoliteframeworkcomparedwithZnOspecies,weregeneratedattheexpenseofBacidsiteswiththeincorporationofzincspecies.Moreover,theproductanalysisresultsshowedthattheincorporationofzincspeciespromotedtheprimaryaromatizationbyenhancingthedehydroaromatizationandsuppressingthecrackingandsubsequentH-transferreaction.Furthermore,theadditionofNispecieswellinhibitedthelossofzincspeciesbyconvertingpartialZnOspeciestoZnOH+species,andthusimprovedthearomatizationactivityandcatalyststability.ThecatalyticperformanceresultsshowedthattheNZ3possesshigherconversionofmethanolinalongertimeandloweraveragerateofcokeformationcomparedwithNZ2.Inaddition,theNZ3alsoexhibitedthehighestyieldofBTXasthereactionproceeds.

简介：

简介：CarbondepositionduringmethanoltohydrocarbonsleadstothequickdeactivationofZSM-5catalystanditisoneofthemajorproblemsforthistechnology.DecreasingthecrystalsizeorintroducingmesoporesintoZSM-5zeolitescanimproveitsdiffusionpropertyanddecreasethecokeformation.Inthispaper,nano-sizedZSM-5zeolitewithintercrystallinemesoporescombiningthemesoporousandnanosizedstructurewasfabricated.Forcomparison,themesoporousZSM-5andnano-sizedZSM-5werealsoprepared.ThesecatalystsampleswerecharacterizedbyXRD,BET,NH3-TPD,TEM,Py-IRandTGtechniquesandusedontheconversionofmethanoltogasolineinafixed-bedreactoratT=405°C,WHSV=4.74h-1andP=1.0MPa.Itwasfoundthattheexternalsurfaceareaofthenano-sizedZSM-5zeolitewithintercrystallinemesoporesreached104m2/g,largerthanthatofmesoporousZSM-5(66m2/g)andnanosizedZSM-5(76m2/g).Catalyticlifetimeofthenano-sizedZSM-5zeolitewithintercrystallinemesoporeswas93h,whichwasonlylongerthanthatofmesoporousZSM-5(86h),butshorterthanthatofnanosizedZSM-5(104h).Strongaciditypromotedthecokeformationandthusdecreasedthecatalyticlifetimeofthenano-sizedZSM-5zeolitewithintercrystallinemesoporesthoughitpresentedlargeexternalsurfacethatcouldimprovethediffusionproperty.Thespecialzeolitecatalystwasfurtherdealuminatedtodecreasethestrongacidity.Afterthis,itscokeformationratewasslowedandcatalyticlifetimewasprolongedto106hbecauseofthelargeexternalsurfaceareaanddecreasedweakacidity.Thisspecialstructuralzeoliteisapotentialcatalystformethanoltogasolinereaction.

简介：

简介：Veryrecently,BelleannouncedtheirobservationofΥ(5S)!bJ!(J=0;1;2),indicatingthattheΥ(5S)!bJ!decaysalsohavelargedecaywidths,i.e.,themeasuredbranchratiosofΥ(5S)!bJ!are<3:410??3,(1:640:23+0:30??0:22)10??3,and(0:570:220:07)10??3withJ=0;1;2,respectively[1].ItshouldbenoticedthateventhoughthetreelevelcontributionstoΥ(5S)!bJ!(J=0;1;2)shouldbestronglysuppressedduetotheOkubo-Zweig-Iizuka(OZI)rule,suchlargedecaywidthsareobserved,whichagaininspiresourinterestinunderstandingsuchquantities.Inthiswork,weproposethatthecontributionfromthehadronicloopshouldbeconsideredinstudyingΥ(5S)!bJ!.

简介：Nuclearmassmeasurementsprovidevaluableinformationonthenuclearbindingenergywhichreflectsthesummedresultofallinteractionsamongitsconstituentprotonsandneutrons.Thesystematicandaccurateknowledgeofnuclearmasseshavewideapplicationinmanyareasofsubatomicphysicsrangingfromnuclearstructureandastrophysicstothefundamentalinteractionsandsymmetriesdependingontheachievedmassprecision[1].

简介：IntheinterlayerexpansionofthelayeredzeoliteprecursorCOK-5,aSn,salt,bis(2,4-pentanedionate)-dichlorotin[Sn(acac)2Cl2],insteadofasilylatingagentwasusedtolinkthelayersat180°C.Theobtainedmaterial,whichisdesignedasSn-COE-5,showsashiftofthefirstXRDreflection,whichisverysimilartothatofCOK-5interlayerexpandedwithdichlorodimethylsilane(DCDMS),indicatinganincreaseininterlayerdistance.X-raydiffraction(XRD),N2sorptionisotherms,inductivelycoupledplasma(ICP),andX-rayphotoelectronspectroscopy(XPS)supporttheincorporationofisolatedSnsitesinthesample.Intheconversionofglucosetolevulinicacid,Sn-COE-5exhibitsmuchhigheractivitythanCOK-5,whichisduetothepresenceofLewisacidicsitesintheSn-COE-5.

简介：Unlikeorganic–inorganichybridperovskites,all-inorganiccesiumleadhalideperovskitesholdgreatpromisefordevelopinghigh-performanceoptoelectronicdevices,owingtotheirimprovedstability.Herein,weinvestigatetheperovskite-relatedCsPb2Br5nanoplatelets（NPLs）withtunableemissionwavelengthsviachangingthereactiontemperaturesto100°C,120°C,and140°C.ReactiontemperatureplaysakeyroleindeterminingtheshapesandthicknessesoftheresultingCsPb2Br5NPLs.AhighertemperatureisinfavoroftheformationofsmallerandthickerNPLs.Todeveloptheirpotentialapplicationsinoptoelectronicdevices,greenlightemittingdiodes（LEDs）andphotodetectorsbasedonCsPb2Br5NPLsarefabricated.ThegreenLEDsbasedonCsPb2Br5NPLssynthesizedat140°Cexhibitanexcellentpuregreenemission（fullwidthathalf-maximumof<20nm）anddisplayaluminousefficiencyof34.49lm∕Wunderanoperationcurrentof10mA.Moreover,thephotodetectorbasedonCsPb2Br5NPLssynthesizedat100°Chasbetterperformancewitharisetimeof0.426s,adecaytimeof0.422s,andaratioofthecurrent（withandwithoutirradiation）of364%.

简介：Micro-mesoporouscompositemolecularsievesH-ZSM-5/MCM-41werepreparedbythehydrothermaltechniquewithalkali-treatedH-ZSM-5zeoliteasthesourceandcharacterizedbyscanningelectronmicroscopy,transmissionelectronmicroscopy,energydispersivespectroscopy,X-raydiffraction,N2adsorption-desorptionmeasurementandNH3temperature-programmeddesorption.ThecatalyticperformancesforthemethanoldehydrationtodimethyletheroverH-ZSM-5/MCM-41wereevaluated.Amongthesecatalysts,H-ZSM-5/MCM-41preparedwithNaOHdosage(nNa/nSi)varyingfrom0.4to0.47presentedexcellentcatalyticactivitywithmorethan80%methanolconversionand100%dimethyletherselectivityinawidetemperaturerangeof170—300℃,andH-ZSM-5/MCM-41preparedwithnNa/nSi=0.47showedconstantmethanolconversionofabout88.7%,100%dimethyletherselectivityandexcellentlifetimeat220℃.Theexcellentcatalyticperformanceswereduetothehighlyactiveanduniformacidicsitesandthehierarchicalporosityinthemicro-mesoporouscompositemolecularsieves.ThecatalyticmechanismofH-ZSM-5/MCM-41forthemethanoldehydrationtodimethyletherprocesswasalsodiscussed.

简介：Two-dimensionalatomic-layeredmaterialisarecentresearchfocus,andsinglelayerTa2O5usedasgatedielectricinfield-effecttransistorsisobtainedviaassembliesofTa2O5nanosheets.However,theelectricalperformanceisseriouslyaffectedbyelectronicdefectsexistinginTa2O5.Therefore,spectroscopicellipsometryisusedtocalculatethetransitionenergiesandcorrespondingprobabilitiesfortwodifferentchargedoxygenvacancies,whoseexistenceisrevealedbyx-rayphotoelectronspectroscopyanalysis.SpectroscopicellipsometryfittingalsocalculatesthethicknessofsinglelayerTa2O5,exhibitinggoodagreementwithatomicforcemicroscopymeasurement.NondestructiveandnoncontactspectroscopicellipsometryisappropriatefordetectingtheelectricaldefectslevelofsinglelayerTa2O5.

简介：Ta2O5电影被常规电子横梁蒸发方法在熔化硅石底层上扔。由在不同温度退火，非结晶、六角形、斜方晶的阶段的Ta2O5电影被获得并且由X光证实衍射计(XRD)结果。X光检查光电子光谱学(XPS)分析证明所有这些电影的化学作文是stoichiometry。非结晶的Ta2O5电影完成最高的激光，这被发现在355或1064nm的导致的损坏阀值(LIDT)任何一个，由六角形的阶段和最后斜方晶的阶段列在后面。当前者显示出一个一致熔化区域，当后者在至少一个缺点点上被集中时，在355和1064nm的损坏形态学是不同的，它被不同损坏机制导致。在1064nm的LIDT的减少被归因于增加结构的缺点，当时在355nm由于增加的联合效果结构的缺点和减少的乐队差距精力。[从作者抽象]

简介：为实现2×5GW级双路输出超宽谱高功率微波驱动源的小型化,研制了一种初级脉冲功率源——与双筒脉冲形成线(Blumlein线)相配一体化的带有开路磁芯的Tesla变压器.通过对Tesla变压器的理论分析,并根据简化的磁路模型得出了Tesla变压器初、次级线圈电感等电参数的估算方法,给出了Tesla变压器磁芯截面的估算和磁芯制作方法.实验结果表明,Tesla变压器最大输出电压为880kV,充电时间约为20μts,耦合系数约为0.95,与理论值吻合较好.

简介：AseriesofRbxCs1-xAg4I5(x=0-1)thinfilmsweregrownbyvacuumevaporationonNaCIcrystalsubstratesat350K.Theabsorptionspectraofthesefilmsweremeasuredat80Kinthewavelengthrangefrom240nmto400nm.ItisshownthatsuperionicconductorthinfilmsofquaternarycompoundRb0.5Cs0.5Ag4I5andternarycompoundRbAg415canbeobtainedatx=0.5-0.6andx=0.7-1,respectively.Atx=0.65,thecombinedcompoundfilmofthemixtureof30mol%RbAg4I5and70mol%Rb0.5Cs0.5Ag4I5ispresented.Then,basedonthespectralpositionsoftheA1andA2peaks,wedeterminedthattheRb0.5Cs0.5Ag4I5excitoncouplingenergyRexis0.21eV,theforbiddenzonewidthEgis3.82eVandtheexcitonradiusaexis0.70hm.Furthermore,theionicconductivitiesofsuperionicconductorthinfilmsofRbAg4I5andRb0.5Cs0.5Ag4I5andtheirmixturefilmareinvestigated,respectively,inthetemperaturerange303K-393K.

简介：Aserialofprotonatedandlayeredtransitionmetaloxides,includinglayeredHTaWO6,HNbMoO6aswellasHNbWO6,weresynthesizedbysolid-statereactionandion-exchange.ThelayeredHTaWO6hasbeensystematicallystudiedasasolidacidtorealizethedehydrationoffructoseto5-hydroxymethylfurfural（HMF）.ThetransitionmetaloxidesampleswerecharacterizedwithICP-OES,EDS,XRD,XPS,SEM,TGA,FT-IR,N2adsorption–desorptionandNH3-TPD.Theinfluentialfactorssuchasreactiontemperature,reactiontime,solvent,catalystamountandsubstrateconcentrationweredeeplyinvestigated.Theoptimizedfructoseconversionrateof99%withHMFyieldof67%wereachievedafter30minat140°Cindimethylsulfoxide.

简介：利用基于密度泛函的第一性原理对Zr5Te3化合物晶格常数、形成焓、弹性常数、以及电子态密度等性质进行了计算。在该研究中,为了获得Zr5Te3化合物的结构稳定性,考虑了Cr5B3、W5Si3以及Mn5Si3等三种结构类型,计算的形成焓表明：具有Cr5B3结构类型的Zr5Te3最稳定,其次是Mn5Si3型,最后才是W5Si3型。也对该化合物的电子态密度和电荷密度差进行了计算,利用徳拜模型计算了其在高温高压下的体积、体积模量、热熔以及热膨胀等的热物理性质。