简介:Chemical-loopingcombustion(CLC)isanovelcombustiontechniquewithinherentCO2separation.Magnetite(Fe3O4)wasselectedastheoxygencarrier.Shenhuacoal(InnerMongolia,China),strawcokeandnaturalcokewereusedasfuelsforthisstudy.Influencesofoperationtemperatures,coaltoFe3O4massratios,anddifferentkindsoffuelsonthereductioncharacteristicsoftheoxygencarrierwereinvestigatedusinganatmospherethermogravimetricanalyzer(TGA).Scanningelectronmicroscopy(SEM)wasusedtoanalysethecharacteristicofthesolidresidues.Experimentalresultsshownthatthereactionbetweenthecoalandtheoxygencarrierbecomestrongatatemperatureofhigherthan800℃.Astheoperationtemperaturerises,thereductionconversionrateincreases.Atthetemperaturesof850oС,900℃,and950℃,thereductionconversionrateswere37.1%,46.5%,and54.1%respectively.However,SEMimagesshowthatatthetemperatureofhigherthan950℃,theironoxidesbecomemeltedandsintered.Thepossibleoperationtemperatureshouldbekeptaround900℃.WhenthemassratiosofcoaltoFe3O4were5/95,10/90,15/85,and20/80,thereductionconversionrateswere29.5%,40.8%,46.5%,and46.6%respectively.Withtheincreaseofcoal,theconversionrategoesup.Butthereexistanoptimalratioaround15/85.Comparisonsbasedondifferentkindsoffuelsshowthatthesolidfuelwithahighervolatileandamoredevelopedporestructureisconducivetothereductionreactivityoftheoxygencarrier.
简介:Wemeasurethecurrent–voltage(I–V)characteristicsforthesinglecrystalofTl0.4K0.41Fe1.71Se2withthesuperconductingtransitiontemperature(TC)around30.5K,undera10Tmagneticfieldappliedperpendicularandparalleltotheabplane.WefindthattheshapesoftheI–Visothermsareverydifferentfromthedescriptionbythevortex-glass(VG)model.CombiningtheoreticalcalculationsandanalysisoftheρH⊥ab–TandρHab–Tdata,wegiveanexplicitdiscussionoverthesuitabilityoftheVGmodelfortheA0.8Fe2Se2superconductors,andpointoutthepossibilityofthematerialactingasaconvenientplatformforre-examinationandfurtherstudyofthecomplexvortexbehaviorsinthelayeredsuperconductors.
简介:建立了电感耦合等离子体发射光谱法测定镍铬合金中Si,Mn,Fe,Ti,A1,Cu元素含量的分析方法。确定了溶样方法和分析谱线,采用基体匹配消除干扰。对方法精密度和准确度进行实验,实验结果表明,各元素的相对标准偏差均小于3%,加标回收率在86.8%~106.9%,镍铬合金标准物质的各元素测定结果均与标准值一致。所建立的方法快速、准确,适用于镍铬合金中多元素同时测定。
简介:HeteroatomM-ZSM-12zeolites(M=B,Al,Ge,Ga,Fe)arehydrothermallysynthesizedanditisprovedthattheheteroatomMisinvolvedintheframeworkofsynthesizedmolecularsievesbymeansofXRD,IRspectra.TheresultsofadsorptionanddiffusionexperimentsindicatethattheheteroatomMmodifiestheporevolume,specificsurfacearea,andthechannelofZSM-12molecularsieves.
简介:在微波辐射条件下,以2-氨基-5-苯并呋喃基-1,3,4-噻二唑和N.取代三氯乙酰苯胺为原料,在固体氢氧化钠作用下,“一锅法”高产率合成了10种N-(5-苯并呋喃基-1,3,4-噻二唑-2-基)-NL芳基脲,并通过IR、^1HNMR和元素分析表征了目标产物的结构.
简介:Fe_(3–x)O_4raspberryshapednanostructures/graphenenanocompositesweresynthesizedbyaone-steppolyol-solvothermalmethodtobetestedaselectrodematerialsforLi-ionbattery(LIB).Indeed,Fe_(3–x)O_4raspberryshapednanostructuresconsistoforiginalorientedaggregatesofFe_(3–x)O_4magnetitenanocrystals,ensuringalowoxidationstateofmagnetiteandahollowandporousstructure,whichhasbeeneasilycombinedwithgraphenesheets.TheresultingnanocompositepowderdisplaysaveryhomogeneousspatialdistributionofFe_(3–x)O_4nanostructuresatthesurfaceofthegraphenesheets.TheseoriginalnanostructuresandtheirstronginteractionwiththegraphenesheetsresultedinverysmallcapacityfadinguponLi+ionintercalation.Reversiblecapacity,ashighas660mAh/g,makesthismaterialpromisingforanodeinLi-ionbatteriesapplication.
简介:与黄金和氧化铁nanoparticles并且与silibinin装载的PEGylated-PLGA随机的nanofibrous膜被electrospinning免职准备。nanofibrous膜能遥远地被控制并且由一盏激光灯或磁场激活在需求上释放生物代理人。nanosystems用扫描电子显微镜学被描绘,红外线的光谱学,原子磁性的回声光谱学,和thermogravimetric分析的Fourier变换。装载效率和药内容百分比的药被紫外力的光吸收光谱学决定。nanofibrous膜由相对低紧张的激光照耀或由一个磁场刺激了为至少60h显示出持续silibinin版本,没有爆炸效果。建议便宜electrospinning过程能够集合,经由一个一步舞过程,有外部地为控制的药交货要激活的金属性的nanoparticles的刺激应答的装载药的nanosystem。
简介:用Co2(CO)8与CH3CSNH2反应制得产物Ⅰ,又用Na2Fe(CO)4与Ⅰ反应制得产物Ⅱ(Ⅰ:Co3(μ3-S)(CO)7(CH3CSNH),Ⅱ:Co2Fe(μ3-S)(CO)7(CH3CSNH).通过元素分析。IR、UV、1HNMR、MS表征并用X射线衍射法测得Ⅱ的单晶结构.该簇合物属三斜晶系、PT空间群,晶胞参数:a=0.9203(1),b=1.1296(2),c=1.1425(2)nm;α=116.40°(2),β=101.92°(2),γ=92.58°(1);z=2,V=1.2162nm3,Dc=1.698cm3,μ=21.89cm-1.结构分析表明,Co2FeS构三角锥分子骨架,所有CO均为端基配体,S1为面桥基配体,CH3CSNH为双齿配体,与Co、Fe形成五元环结构.
简介:Toimprovetheinitialcoulombicefficiencyandbulkdensityoforderedmesoporouscarbons,activeFe2O3nanoparticleswereintroducedintotubularmesoporechannelsofCMK-5carbon,whichpossesseshighspecificsurfacearea(>1700m2g-1)andlargeporevolume(>1.8cm3g-1).FineFe2O3nanoparticleswithsizesintherangeof57nmwerehighlyandhomogenouslyencapsulatedintoCMK-5matrixthroughammonia-treatmentandsubsequentpyrolysismethod.TheFe2O3loadingwascarefullytailoredanddesignedtowarrantahighFe2O3contentandadequatebufferspaceforimprovingtheelectrochemicalperformance.Inparticular,suchFe2O3andmesoporouscarboncompositewith47wt%loadingexhibitsaconsiderablystablecycleperformance(683mAhg-1after100cycles,99%capacityretentionagainstthatofthesecondcycle)aswellasgoodratecapability.Thefabricationstrategycaneffectivelysolvethedrawbackofsinglematerial,andachieveahigh-performancelithiumelectrodematerial.
简介:WhileFe-basedoxygencarriers(OC)areregardedtobepromisingforchemicalloopingcombustion(CLC),thedecreaseofCO2selectivityduringdeepreductionprocessandthesevereagglomerationofFe2O3oftenoccuraftermultipleredoxcyclesduetothelowoxygenmobility.Herein,Fe-substitutedBahexaaluminates(BaFexAl12–xO19,denotedasBFxA-H,x=1and2)preparedbyamodifiedtwo-stepmethodexhibitednotonlyhigheramountofconvertedoxygen(Ot)andCH4conversion(77%and81%vs.17%and75%)thanthosepreparedbythetraditionalco-precipitationmethod(BFxA-C,x=1and2)butalsohighCO2selectivityabove92%duringthenearlywholereductionfromFe3+toFe2+.Furthermore,theBFxA-Hexhibitedtheexcellentrecyclabilityduring50cycles.ThebetterperformancewasascribedtothemarkedlyenhancedoxygenmobilitywhichresultedfromdominantoccupancyofFecationsinAl(5)sites(Fe5:71%and70%vs.49%and41%)inmirrorplanesofhexaaluminateleadingtolargeramountoflatticeoxygencoordinatedwithFe5(O–Fe5)(0.45and0.85mmol/gvs.0.31and0.50mmol/g).TheimprovementofoxygenmobilityalsofavoredthepreservationofchemicalstateofFecationsinhexaaluminatestructureinthere-oxidationstep,resultingintheexcellentrecyclabilityofBFxA-H.
简介:当我听到您于2015年10月24日因病逝世的噩耗时,一瞬间心中充满了悲伤。禁不住的眼泪随着西雅图的秋雨模糊了眼前的一切。几天后我放下手上所有的工作飞回了上海,和您做最后的告别。11月6日参加完您的追悼会,我的脑子里很长一段时间都是空荡荡的,您那亲切而富有感染力的笑容不停地展现在我眼前。当我不得不相信您正在远离这么多爱戴您的学生、亲人和朋友时,点点滴滴的往事汇集在一起、越来越清晰地浮现,所有的一切犹如发生在昨天。我看到了那个在黑板上为我梳理有限元方法计算结构的无限耐心的学者;看到了那个在我第一次出国前,和李大潜先生一同带我到西餐厅,教我使用刀叉的亲切的老人;看到了那个在中山公园的石凳
简介:本文通过使用变量重排的方法,改变了多项式环中理想的Groebner基的计算过程,得到不同的过程的计算效率也不同,因此通过这种方法应该能够找出减少计算Groebner基时间的方法.