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简介：Recently,bismuthsulfide(Bi2S3)hasattractedmuchattentioninthethermoelectriccommunityowingtoitsabundance,lowcost,andadvancedproperties.However,itspoorelectricaltransportpropertieshavepreventedBi2S3devicesfromrealizinghighthermoelectricperformance.Inthiswork,ourmotivationistodecreasethelargeelectricalresistivity,whichisrecognizedastheoriginofthelowZTvalueinundopedBi2S3.Wecombinedmeltingandsparkplasmasintering(SPS)inacontinuousfabricationprocesstoproduceBi2S3–xSex(x=0,0.09,0.15,0.21)andBi2S2.85–ySe0.15Cly(y=0.0015,0.0045,0.0075,0.015,0.03)samples.OurresultsshowthatSealloyingatSsitescannarrowthebandgapandactivateintrinsicelectronconduction,leadingtoahighpowerfactorof~2.0μW·cm–1·K–2atroomtemperatureinBi2S2.85S0.15,about100timeshigherthanthatofundopedBi2S3.Moreover,ourfurtherintroductionofClatomsintotheSsitesresultedinasecond-stageoptimizationofcarrierconcentrationandsimultaneouslyreducedthelatticethermalconductivity,whichcontributedtoahighZTvalueof~0.6at723KforBi2S2.835Se0.15Cl0.015.OurresultsindicatethathighthermoelectricperformancecouldberealizedinBi2S3withearth-abundantandlow-costelements.

简介：Rapidgrowthofmannedspaceflightresultsinmoreconcernabouthealthriskandanurgentneedofhealthassessmentinspacetravel.Sincetheimportanceofbrainfunctionstoastronauts,weexploredthelong-termeffectsandpotentialmechanismsof56Feionradiationonmicebrain.

简介：Wehavestudiedthetwo-andthree-photonabsorption(2PAand3PA)propertiesofMn-dopedCsPbCl3twodimensionalnanoplatelets(2DNPs)andcubicnanocrystals.Comparedwiththeircubiccounterparts,theMn-doped2DNPsexhibitstrongerquantumconfinementeffectsthatcanmoreefficientlyenhancetheirdopantcarrierexchangeinteractionsandmultiphotonabsorption.Morespecifically,themaximumvolume-normalized2PAand3PAcrosssectionsofthe2DNPswere6.8and7.2timesgreaterthanthoseoftheircubiccounterparts,respectively,reachingupto1237GM∕nm3inthevisiblelightbandand2.24×10-78cm6·s2·photon-2∕nm3inthesecondbiologicalwindow,respectively.

简介：在模拟球面元件曲率半径的仿面形夹具上镀制了AlF3单层薄膜，并对不同口径位置上的薄膜进行了比较，以表征球面元件表面镀制薄膜的光学特性和微观结构。首先，采用紫外可见光分光光度计测量了不同口径位置上薄膜样品的透射和反射光谱，反演得出AlF3的折射率和消光系数。然后，使用原子力显微镜观察了样品的表面形貌和表面粗糙度。最后，使用X射线衍射仪对薄膜的内部结构进行了表征。实验结果表明：在球面不同位置镀制的AlF3单层薄膜样品的光学损耗随着所在位置口径的增大而增大。口径为280mm处的消光系数是中心位置处消光系数的1.8倍，表面粗糙度是中心位置的17.7倍。因此，球面元件需要考虑由蒸汽入射角不同带来的光学损耗的差异。

简介：以呋咱环为基本结构单元可以构建多系列性能优异的新型呋咱含能衍生物，它们一般具有能量密度高，标准生成焓大，氮含量高以及分子热力学稳定性较好等优点。3-叠氮-4-氨基呋咱（AAF）作为合成三唑联呋咱、多叠氮基呋咱、呋咱醚、腈基呋咱等多类含能化合物的重要中间体，而且本身也是一个高能量密度化合物，因此探讨其合成方法具有一定的意义。3-叠氮-4-氨基呋咱的合成路线如图1所示，合成分为3步：第一步是乙二醛与盐酸羟胺在氢氧化钠溶液中发生加成缩合反应得N-氨基乙二肟（DAG）。该反应具有强放热性，实验操作应小心。

简介：Synthesis,structureandmagneticpropertiesofRudopedperovskitestructuredmanganiteLa0.5Sr0.5MnO3wereinvestigatedexperimentally.Ahydrothermalmethodwasusedforthepreparationofthesamples.Ahigh-temperatureannealingprocesswasalsoemployedtomakeacomparison.AslightlyenhancementoftheunitcellvolumewasobservedwiththeincreaseofRuconcentration.Scanningelectronmicroscopyshowsthatthematerialsaremadeupofcube-shapedparticleswithdimensionofseveralmicrometers.Importantly,itisfoundthatboththeCurietemperatureTCandsaturationmomentcanbereducedbyRudoping.ThevalueofcoercivefieldisnotaffectedbytheintroductionofRu.

简介：用浸渍法制备了一系列镍基催化剂并以苯加氢反应及二硫化碳中毒为手段考查了ＭｏＯ３对Ｎｉ基催化剂的改性机制。结果表明，钼的加入能增加Ｎｉ催化剂的催化活性和抗二硫化碳毒性，原因是钼的加入增加了催化剂的活性中心数量和镍的分散度，改变了催化剂与反应物所形成中间体的活化焓及熵。根据过渡态理论，钼对Ｎｉ基催化剂的影响即有电子效应又有几何效应，但以电子效应为主。更多还原

简介：本文对JM-2/JM-3转动惯量仪进行了改进,减小了实验误差.

简介：AnapplicatiopnoftheopticalpyrometerisstudiedformeasuringmonochromaticemissivitiesofcementclinkerwithvariousFe2O3contnet.Theidsaofusing“brightnesstemperature”isintroducedintotheeimssivitymeasurement.Inthismethod,thereisnoneedformeasuringanactualtemperatureofsamplesurfaces,onlywithdeterminingbothbrightnesstemperaturesofasampleandablackbodycantherequiredemissivitybeevaluatedaccordingtoWien'sradiationlaw.Inpractice,thecementclinkerisregardedasagreybody,themonochromaticemissivityisapproximatelyequaltothetotalemissivity,soasingle-colouropticalpyrometerisappliedforthispurpose,Testmeasurementsarecarriedouton10kindsofcementclinkers,Experimentaldataaretreatedbytheleastsquaremethod.Asaresult,theemissivityvariationwithtemperatureatacertainFe2O3contentisquitewellrepresentedbyεn=a+bT.Furthermore,thisworkfirstreportedthattheeimissivitiesofcementclinkerchangeconsierablywithFe2O3contents.Inmultiplecementproductionthisconclusionisveryimportant.

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简介：WepresentseveralcomparisonsofGEANT4simulationswithtestbeamdataandGEANT3simulationsfordifferentliquidargon(LAr)calorimetersoftheATLASdetector,Allrelevantpartsofthetestbeamsetup(scintilators,multiwireproportionalchambers,cryostatetc.)aredescribedinGEANT4aswellasinGEANT3.MuonandelectrondataatdifferentenergieshavebeencomparedwithMonteCarloprediction.

简介：针对DC/DC的质子位移效应,选取具有抗TID能力的DC/DC器件作为试验样品,在3MeV质子辐照条件下获取了器件的失效位移损伤剂量.结果表明,DC/DC功能失效是PWM控制器输出异常导致的.通过等效^60Coγ辐照及退火试验,排除了TID效应的影响,确定器件功能失效是由位移损伤引起的.高温退火后器件功能恢复,并立即对该器件进行了测试.结果表明,输出电压、电压调整度、负载调整度、交叉调整度、纹波及负载跃变时的输出电压均大幅衰退.利用这些敏感参数,获取了位移损伤导致的电源性能衰退模式.根据位移损伤缺陷类型及退火温度,分析了DC/DC的退火规律,可为DC/DC质子辐射损伤模拟试验方法的建立及其空间应用提供依据.

简介：Thegreenlong-after-glowluminescencefromTb3+-dopedSr2SiO4phosphors,whicharesynthesizedbythehightemperaturesolidstatereactioninareductiveatmosphere,isobservedinthispaper.Theresultsshowthatunderultravioletexcitation,theobtainedphosphorsproduceanintensegreen-lighting-emissionfromtheTb3+,andthegreen-lightinglongafter-glowluminescencerelatedtoTb3+canlasthalfanhouraftertheirradiationsourcehasbeenremoved.Moreover,theeffectsofco-dopingLi+,Dy3+,Er3+,Gd3+,andYb3+withTb3+onthedecaypropertiesandthermoluminescencepropertiesareinvestigatedtoconfirmthelong-after-glowmechanism.

简介：PlanarringresonatorwaveguidesarefabricatedinthinfilmsofAs2S3chalcogenideglass,depositedonsilicaon-siliconsubstrates.WaveguidecoresaredirectlywrittenbyscanningthefocusedilluminationofafemtosecondTi:sapphirelaseratacentralwavelengthof810nm,throughatwo-photonphoto-darkeningprocess.Alargephotoinducedindexchangeof0.3–0.4refractiveindexunitsisobtained.Theradiusoftheringresonatoris1.9mm,correspondingtoatransmissionfreespectralrangeof9.1GHz.Ahighloaded（intrinsic）Qvalueof110,000（180,000）isachieved.Thethermaldependenceoftheresonatortransferfunctionischaracterized.Theresultsprovidethefirstreport,tothebestofourknowledge,ofdirectlywrittenhigh-Qringresonatorsinchalcogenideglassfilms,anddemonstratethepotentialofthissimpletechniquetowardsthefabricationofplanarlightguidecircuitsinthesematerials.

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简介：ThetemperaturedependenceofresistivityρofYSZdopingcompositeof(1-x)La0.67Ca0.33MnO3+xYSZandY2O3dopingcompositeof(1-y)La0.67MnO3+yY2O3isinvestigated,respectively,inatemperaturerange77-300K,wheretheYSZrepresentsyttria-stabilizedzirconia(8mol%Y2O3+92mol%ZrO2).ExperimentalresultsshowthattheYSZdopinglevelhasimportanteffectsonboththemetal-insulator(M-I)transitiontemperaturesandzerofieldresistivityofthecompositesof(1-x)La0.67Ca0.33MnO3+xYSZ.However,theY2O3dopinglevelhaslittleeffectontheM-Itransitiontemperaturesandthezerofieldresistivityof(1-y)La0.67Ca0.33MnO3+yY2O3onlyincreasesslightly.Thedifferencebetweenthetwotypesofcompositesmaymainlyresultsfromthedifferentdistributionofhighresistancephasesatthegrainboundariesand/orsurfacesofLa0.67Ca0.33MnO3grainsratherthanthesubstitutionofLa^3+ionswithY^3+ions.