简介：使用部分还原－共沉淀方法制备了平均粒径为3－11nm的球形Fe3O4纳米颗粒，以16：4：1的甲醇－乙醇－水混合溶液作为传压介质和均分散介质，利用金刚石对顶砧装置（DAC）研究了球形Fe3O4纳米颗粒的原位常温高压（0－31．8GPa)XRD谱和纳米颗粒的压致晶格结构变化。

简介：Nanostructuredγ-Al2O3withhighsurfaceareaandmesoporousstructurewassynthesizedbysol-gelmethodandemployedascatalystsupportfornickelcatalystsinmethanereformingwithcarbondioxide.ThepreparedsampleswerecharacterizedbyXRD,N2adsorption-desorption,TPR,TPO,TPH,NH3-TPDandSEMtechniques.TheBETanalysisshowedahighsurfaceareaof204m2g-1andanarrowpore-sizedistributioncenteredatadiameterof5.5nmforcatalystsupport.TheBETresultsrevealedthatadditionoflanthanumoxidetoaluminumoxidedecreasedthespecificsurfacearea.Inaddition,TPRresultsshowedthatadditionoflanthanumoxideincreasedthereducibilityofnickelcatalyst.Thecatalyticevaluationresultsshowedanincreaseinmethaneconversionwithincreasinglanthanumoxideto3mol%andfurtherincreaseinlanthanumcontentdecreasedthecatalyticactivity.TPOanalysisrevealedthatthecokedepositiondecreasedwithincreasinglanthanumoxideto3mol%.SEMandTPHanalysesconfirmedtheformationofwhiskertypecarbonoverthespentcatalysts.AdditionofsteamandO2todryreformingfeedincreasedthemethaneconversionandledtocarbonfreeoperationincombinedprocesses.

简介：Multilayerblackphosphorus（BP）nanoplateletsofdifferentthicknesseswerepreparedbytheliquidphaseexfoliationmethodanddepositedontoyttriumaluminumgarnetsubstratestoformsaturableabsorbers（SAs）.Thesewerecharacterizedwithrespecttotheirthickness-dependentsaturableabsorptionpropertiesat3μm.TheBP-SAswereemployedinapassivelyQ-switchedEr:Lu2O3laserat2.84μm.ByusingBPexfoliatedindifferentsolvents,stablepulsesasshortas359nsweregeneratedatanaverageoutputpowerofupto755mW.Therepetitionrateintheexperimentwas107kHz,correspondingtoapulseenergyof7.1μJ.TheseresultsprovethatBP-SAshaveagreatpotentialforopticalmodulationinthemid-infraredrange.

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简介：以异丙醇铝为前驱体，HNO3为胶溶剂，采用溶胶-凝胶法制备Al2O3膜。考察HNO3浓度对溶胶及薄膜的影响，通过TG-DTG，XRD，AFM，BET等表征手段对溶胶的稳定性及黏度，薄膜的热稳定性，物相组成，表面形貌，微孔结构及分布等进行综合分析。结果表明：随HNO3浓度增大，溶胶黏度增大，HNO3浓度为5mol/L时溶胶发生团聚；薄膜的热稳定性较好，高于500℃加热薄膜几乎没有质量损失；随烧结温度升高，薄膜中的γ-AlOOH逐渐向γ-Al2O3转变，薄膜因此变得更加稳定；薄膜表面较为平整，微孔分布均匀，平均孔直径为4.22nm。

简介：Erbium,Ytterbium-codopedZrO2nanoparticles(ZrO2∶Er3+,Yb3+)werepreparedbythesol-emulsion-geltechnique.Thepurposeofthepresentstudyistheapplicationofupconversionphosphorinthebiologicallabel.Inordertomakeoutthemechanismofupconversionunder980nmexcitationthe488nmpumpwasused.Theinfluenceoftemperatureonthecrystallitephasewasstudied.TheresultsconfirmtheupconvertedmechanisminZrO2∶Er3+,Yb3+nanocrystalsisduetoanenergytransferupconversion(ETU).

简介：CaF2:Ho3+/Yb3+nano-particleswithintensegreenup-conversion(UC)luminescencearesuccessfullysynthesizedviaafacilehydrothermalapproachbyusingNH4FasthefluoridesourceandNa2EDTAasachelatingreagent.PowderXraydiffraction(XRD),transmissionelectronmicroscopy(TEM),fieldemissionscanningelectronmicroscopy(FE-SEM),andUCemissionspectraareusedtocharacterizethestructures,shapes,andluminescentpropertiesofthesamples.TheeffectsfromfluoridesourcesandchelatingreagentsontheformationsofCaF2nano-particlesareinvestigated,andtheformationprocessisalsodeduced.Undertheexcitationofa980-nmlaserdiode,thesampleseachshowagreenup-conversionemissioncenteredat540nmcorrespondingtothe5S2/5F4→5I8transitionsofHo3+.Moreover,theUCmechanismsofHo3+/Yb3+co-dopedCaF2nano-particlesarealsodiscussed.

简介：Er3+/Yb3+codopedzincateBaGd2ZnO5phosphorsweresynthesizedviaatraditionalsolidstatereaction.ThecrystalstructureandphasepuritywerecheckedbymeansofX-raydiffraction(XRD),andtheresultsshowedthatpurephaseBaGd2ZnO5phosphorswithvariousEr3+,Yb3+concentrationswereobtained.TheinfluenceofEr3+andYb3+dopingconcentrationsonthegreenandredupconversionemissionswasstudied.Itwasfoundthatbothgreenandredupconversionemissionsunder980nmexcitationweretwo-photonprocessesindependentfromtherareearthdopingconcentrations.However,theupconversionluminescenceintensitiesgreatlydependedontherareearthdopingconcentration.Furthermore,thepopulationprocessesofupconversionluminescenceandthequenchingmechanismswereanalyzed.Thetemperature-dependentgreenupconversionluminescencewasstudied,andthetemperaturequenchingprocessoftwogreenupconversionemissionswasmodeled.Thethermalquenchingprocessesofthegreenupconversionemissionscouldbewellexplainedbythemodelweproposed.

简介：为确定热加工性能的最佳条件，在温度350~500°C、应变率0.0005~0.5s-1下研究Al6061/Al2O3纳米复合材料的热压缩行为。采用双曲正弦函数得到材料热压缩测试活化能为285kJ/mol。用动态材料模型和相应的加工图，确定了温度450°C、应变速率0.0005s-1和温度500°C、应变速率0.0005~0.5s-1为Al6061/Al2O3材料的热加工性能安全区，最大功率损耗率为38%。由于材料大变形，在温度400°C和应变速率0.5s-1下得到了被伸长和扭结晶粒。

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简介：随着原油的劣质化和环保法规的日益严格，传统的金属硫化物加氢精制催化剂已经不能满足人们对油品含硫、氮和芳烃的日益苛刻的要求，因此开发新型深度加氢精制催化剂成为一个非常具有挑战性的课题。本论文采用改进的溶胶-凝胶法制备的MoP/TiO2-Al2O3二元复合载体负载磷化钼，以喹啉为模型化合物，并在固定床反应器上对催化剂活性进行评价。

简介：无机化学实验中Cr2O3溶于浓硫酸的内容,其目的是试验并证明铬的氧化物的两性,接铬元素所在周期表的位置,其正常氧化物应能溶于酸和碱中,即属两性氧化物。对这一问题,我们查阅了有关资料,发现各有不同说法,计有下列三种不同叙述,一是载Cr2O3可溶于酸亦可溶于碱;二是载Cr2O3能溶于酸,但不溶于碱;三是载Cr2O3不溶

简介：Theimplantedionrange,thedepthprofileandthefilmsttuctureoftheimplantedlayerwerestudied;thecarrierconcentrationandthemobilityweremeasured;theconductivitymechanismofthefilmimplantedFeintoAl2O3ceramicwasdiscussed.TheconclusionisthattheimplantedFe2+ionsmoveintoAl2O3latticeandreplaceAl3+toformsubs-titutionimpuritiessothattheionimplantedlat-tice,ascomparedwiththeoriginalone,presentsaneffectivenegativechargewhichformsanegativechargecenter.Avacancyisboundarroundit,andanacceptorisintroducedintheforbiddenband.

简介：摘要采用溶胶-凝胶法制备了Al2O3-ZrO2复合溶胶膜，研究了化学组成和添加剂对复合溶胶的影响。结果表明，当Al2O3/ZrO2=1，DMF=40vol%时，可得到澄清透明，粘度适中，稳定性好，且凝胶干燥后几乎无开裂的溶胶膜

简介：ＥｌｅｃｔｒｏｃｒｙｓｔａｌｌｉｚａｔｉｏｎＭｅｃｈａｎｉｓｍｏｆＴｕｎｇｓｔｅｎｉｎＭｏｌｔｅｎＫＦ－Ｂ＿２Ｏ＿３－Ｋ＿２ＷＯ＿４ＷｅｎＺｈｅｎｈｕａｎａｎｄＬｉＧｕｏｘｕｎ文振环，李国勋（ＧｅｎｅｒａｌＲｅｓｅａｒｃｈＩｎｓｔｉｉｕｔｅｆｏｒＮｏ...

简介：摘要随着社会经济不断发展，我国印染行业发展迅速，无论是印染规模还是印染技术，均得到了长足的发展和提高，印染废水产生量日益增多，印染废水污染物组成也愈发复杂，相应提高了对于印染废水回用技术的实际要求。但就我国印染行业当前的印染废水回用现状来看，其废水回用技术仍以传统二级生物处理工艺为主，面对污染物更加复杂、结构更加稳定的现代印染废水，表现出较明显的不适应性和局限性。在这种环境背景下，笔者就A2/O-O3-BAF工艺在印染废水回用中的应用进行了试验探索，试验结果表明，A2/O-O3-BAF工艺可有有效处理印染废水中的复杂污染物，使其达到废水回用相关标准要求，具有较好的经济性和适用性。

简介：美国宇航局在加州帕萨迪纳的喷气推进实验室研究成功了一种制造YBa2Cu3O7-α高温超导电缆（封装在金属套管内）的新方法。据称,这种方法成本较低,过程易于控制,且对各种前体材料有很强的适应能力。该法分4个步骤:生产具有化学（配）比的前体（Precursor）粉;将前体粉包封在金属套管内;用轧制的方法使前体粉固结;在液态锂金属浴槽内进行处理,使之转变成超导组

简介：Themicrostructureandslagerosionfractaldimensionofreactioninterfaceofβ-Sialon-Al2O3brickusedin300MtironladleofBaosteelhavebeenstudiedbySEMandXRD.Theresultsindicatedthatβ-Sialon-Al2O3brickexhibitedexcellentslagresistance.Themainwearmechanismofβ-Sialon-Al2O3brickismainlyfromthespallingcausedbythermalmechanicalstressandattackedbyslagsecondly.

简介：Basedonthedifferenceofhydroxygroupconfigurationondifferentplanesofα-Fe2O3nanoparticles,usingthespecialadsorptionandcoordinationofphosphateonthe(001)planeofα-Fe2O3,well-crystallizedandwelldispersedα-Fe2O3nanodiskswithdiameterof150–200nmandthicknessof40–80nmweresynthesizedviaahydrothermalmethod.Themagneticpropertiesofsynthesizednanodiskswereinvestigated.Itwasfoundthatthenanodiskspossessedasaturationmagnetization(Ms)of0.38emu/g,aremanentmagnetization(Mr)of0.031emu/gandacoercivityof452.91Oeatroomtemperature.TheMrandcoercivityofsynthesizedα-Fe2O3nanodisksarehigherandtheMsislowerthanthoseofotherpreviouslyreportedα-Fe2O3nanostructures.