学科分类
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500 个结果
  • 简介:应用纳米SiO2胶体、含单宁酸活性单体、丙烯酸类及含氟单体合成了氟碳防锈乳液。该乳液及其涂膜具有较好的综合性能。该防锈乳液与普通苯丙乳液相比具有更优异的防锈性能和涂膜硬度。

  • 标签: 氟碳乳液 水性防锈涂料 单宁酸
  • 简介:建立了碱熔水浸的方法溶解试样,ICP-AES法同时测定钛铁矿中硅和铝的方法,对分析过程中的一些条件进行了研究,该法用于测定钛铁矿中SiO2和Al2O3,得到了满意的结果,相对标准偏差为3.00%~5.04%,回收率在96.5%~103.8%之间。

  • 标签: 碱熔水浸 ICP-AES 钛铁矿 SIO2 AL2O3
  • 简介:Thecombinationofdeepwetetchingandamagneto-rheologicalfinishing(MRF)processisinvestigatedtosimultaneouslyimprovelaserdamageresistanceofafused-silicasurfaceat355nm.ThesubsequentlydepositedSiO2coatingsareresearchedtoclarifytheimpactofsubstratefinishingtechnologyonthecoatings.Itisrevealedthatadeepremovalproceedingfromthesinglesideordoublesidehadasignificantimpactonthelaser-induceddamagethreshold(LIDT)ofthefusedsilica,especiallyfortherearsurface.Afterthedeepetching,theMRFprocessthatfolloweddoesnotactuallyincreasetheLIDT,butitdoesamelioratethesurfacequalitieswithoutadditionalLIDTdegradation.Thecombinationguaranteeboththeintegrityofthesurface’sfinishandthelaserdamageresistanceofthefusedsilicaandsubsequentSiO2coatings.

  • 标签: SiO2涂层 二氧化硅涂层 光学表面 熔融石英 激光损伤 后处理
  • 简介:据报道,中南大学以卢斌博士为核心的团队,经过10多年研究,突破并掌握了高端透明凝胶技术,研制出“新型透明凝胶材料”。这种由中南大学研制的新型超级节能凝胶玻璃近日在我国首次实现量产,填补了我国在凝胶研发应用领域的一项空白。质量仅为水的1/10、超级保温绝热、防火防爆、隔音降噪……这种由中南大学研制的新型超级节能凝胶玻璃近日在我国首次实现量产,填补了我国在凝胶研发应用领域的一项空白。

  • 标签: 气凝胶玻璃 中南大学 国内空白 填补 节能 气凝胶材料
  • 简介:Inthepresentwork,core-shellNi@SiO2catalystswereinvestigatedinordertoevaluatetherelevanceofcatalyticactivityandsurfacestatesofNicoreaswellasNinanoparticlessizetocatalyticpartialoxidationofmethane(POM).ThecatalystswerecharacterizedbyN2adsorption,H2-TPR,XRD,TEMandXPStechniques.Thecatalyticperformanceofthecore-shellcatalystswasfoundtobedependentonthesurfacestatesofcatalyst,whichinfluencedtheformationofproducts.Itwasconsideredthatcarbondioxideformedontheoxidizednickelsites(NiO)andcarbonmonoxideproducedonthereducedsites(Ni).ThesurfacestatesofactivemetalinthedynamicwereinfluencedbothbythesizeofNicoreandtheporosityofsilicashell.However,thecatalyticactivitywouldbedebasedwhenthesizeofNicorewasunderacertainextent,whichcanbeascribedtothefactthecarbondepositionincreasedwiththeincreasingcontentofNiO.TheeffectsofsurfacestatesofNi@SiO2catalystonthecatalyticperformancewerediscussedandthereactionpathwayoverNicoreencapsulatedinsidesilicashellwasproposed.

  • 标签: 催化剂性能 催化部分氧化 SIO2 表面态 甲烷 核壳
  • 简介:Newvisibletransparent,UVabsorption,andhighinfraredreflectionpropertieshavebeenrealizedbydepositingmultilayerSiO2/ZnO:Al/CeO2-TiO2/SiO2filmsontoglasssubstratesatlowtemperaturebyradiofrequencymagnetronsputtering.OptimumthicknessofSiO2,ZnO:Al(ZAO)andCeO2-TiO2(CTO)filmsweredesignedwiththeaidofthinfilmdesignsoftware.Thedegreeofantireflectioncanbecontrolledbyadjustingthethicknessandrefractiveindex.TheouterSiO2filmcandiminishtheinterferencecoloringandincreasethetransparency;theinnerSiO2filmimprovestheadhesionofthecoatingontheglasssubstrateandpreventsCa2+,Na+intheglasssubstratefromenteringtheZAOfilm.Theaveragetransmittanceinthevisiblelightrangeincreasesbynearly18%-20%,ascomparedtodoublelayerZAO/CTOfilms.Andthefilmsdisplayhighinfraredreflectionrateofabove75%inthewavelengthrangeof10-25μmandgoodUVabsorption(〉98%)properties.Thesesystemsareeasytoproduceonalargescaleatlowcostandexhibithighmechanicalandchemicaldurability.ThetriplefunctionalfilmswithhighUVabsorption,antireflectiveandhighinfraredreflectionratewilladapttoapplicationinflatpaneldisplayandarchitecturalcoatingglass,automotiveglass,withdiminishinglightpollutionaswellasdecreasingeyefatigueandincreasingcomfort.

  • 标签: SI O2/Zn O:Al /Ce O2-Ti O2/Si
  • 简介:Differentrareearth(RE)ionsdopantswereaddedintotheSrAl2SiO7:Eu2+phosphorsinordertoenhancethephosphorescenceproperties,andtheeffectoftheREionsincludingYb3+,Ce3+,Nd3+,Dy3+andTm3+,wascomparativelyinvestigated.ItwasfoundthatNd3+additionimprovedthephosphorescencepropertiesobviouslyamongallthestudiedREions.Therefore,Sr1.96–xAl2SiO7:xEu2+,yNd3+phosphorswerestudiedindetail,andtheoptimumEu2+andNd3+concentrationsweredeterminedwiththeafterglowtimeofabout20min.Thephasestructures,photoluminescence(PL)properties,long-lastingphosphorescence(LLP)properties,afterglowdecaycurvesandthermo-luminescence(TL)fortheselectedphosphorsduringthecorrespondingstudywereinvestigated.AllthephosphorsexhibitedgreenPLemissionandLLPemission.ThereweretwoTLbandslocatedatabout325and380Kforthestudiedsamples,andtherelationshipbetweenREadditionandphosphorescencepropertieswasdiscussed.

  • 标签: 稀土掺杂 光性质 荧光粉 磷光 欧盟 稀土离子
  • 简介:Afacilemethodforthesynthesisofsilver-silica(Ag-SiO2)Janusparticleswithfunctionalitiessuitablefortextileapplicationsisreported.SilicananoparticlespreparedbytheStobermethodwerefunctionalizedwithepoxy,amine,andthiolgroups,whichwereconfirmedbyFouriertransforminfraredanalysis.ThefunctionalizedsilicananoparticleswereusedtoproducePickeringemulsions,andtheexposedsurfacewasusedfortheattachmentofsilvernanoparticles(AgNPs)viathelow-temperaturechemicalreductionmethod.ThemorphologyandstructureoftheAg-SiO2Janusparticleswerecharacterizedbyscanningelectronmicroscopy,scanningtransmissionelectronmicroscopy,high-resolutiontransmissionelectronmicroscopy,energy-dispersiveX-rayanalysis,andUV-visspectroscopy.Becauseoftheirspecificfunctionalities,theseAg-SiO2Janusparticlesareproposedforapplicationsontextilesubstrates,astheycanovercomeseveraldrawbacksofdirectapplicationofAgNPsontextiles,suchasleaching,agglomeration,andinstabilityduringstorage.

  • 标签: 硅纳米颗粒 纺织应用 原位合成 环氧树脂 纺织品 二氧化硅纳米粒子
  • 简介:Inthiswork,theinfluenceofCO2onthestructuralvariationandcatalyticperformanceofNa2WO4/Mn/SiO2foroxidativecouplingofmethanetoethylenewasinvestigated.ThecatalystwaspreparedbyimpregnationmethodandcharacterizedbyXRD,RamanandXPStechniques.AppropriateamountofCO2inthereactantgasesenhancedtheformationofsurfacetetrahedralNa2WO4speciesandpromotedthemigrationofOinMOx,Na,Wfromthecatalystbulktosurface,whichwerefavorableforoxidativecouplingofmethane.WhenthemolarratioofCH4/O2/CO2was3/1/2,enrichedsurfacetetrahedralNa2WO4speciesandhighsurfaceconcentrationofOinMOx,Na,Wweredetected,andthenhighCH4conversionof33.1%andhighC2H4selectivityof56.2%wereobtained.WithfurtherincreaseofCO2inthereagentgases,thecontentofactivesurfacetetrahedralNa2WO4speciesandsurfaceconcentrationofOinMOx,Na,Wdecreased,whilethatofinactivespecies(MnWO4andMn2O3)increaseddramatically,leadingtolowCH4conversionandlowC2H4selectivity.ItcouldbespeculatedthatNa2WO4crystalwastransformedintoMnWO4crystalwithexcessiveCO2addedunderthereactionconditions.PretreatmentofNa2WO4/Mn/SiO2catalystbymoderateamountofCO2beforeOCMalsopromotedtheformationofNa2WO4species.

  • 标签: 结构变化 催化剂 甲烷氧化偶联 Na2WO4 MN2O3
  • 简介:Blueshifl国际材料公司推出了一种可以商业化的聚酰亚胺凝胶,它将塑料薄膜的物理性能和强度与凝胶绝缘性结合形成一种轻质高强柔韧清洁的绝缘薄膜。这种产品百分之百用聚酰亚胺聚合物制成,消除了粉尘以及危险处理协议。

  • 标签: 聚酰亚胺 气凝胶 商业化 材料 国际 绝缘薄膜
  • 简介:Sr1.995–1.5xGdxSiO4:0.005Eu2+phosphorserieswithx=0–0.08molfornear-ultravioletwhitelight-emittingdiodes(NUVw-LEDs)weresynthesizedviasolid-statereactionmethod.XRDprofilepatternandrefinementresultsdemonstratedthatdopingGd3+ionsresultedinthephasetransformation(β-Sr2SiO4→α’-Sr2SiO4).Thephotoluminescencespectrumofthesamplewithx=0moldisplayedtwoemissionpeakscenteredat470and525nm.Thetwo-peakspectrabecameone-peakspectrawiththeGd3+concentrationincreasing.Actually,thefittingresultsdemonstratedthattheone-peakspectrawerestillcomposedoftwosingleemissionspectra.ThephotoluminescenceintensitywasimprovedandtheCIEchromaticitycoordinateswereadjustedviadopingGd3+.

  • 标签: 过掺杂 荧光粉 Gd 发光性能 晶体结构 紫外发光二极管
  • 简介:采用溶胶凝胶法(sol-gel)合成2CaO-MgO-2SiO2∶Ce^3+,Tb^3+绿色荧光粉,研究发现在Ce^3+和Tb^3+共激活的2CaO-MgO-SiO2荧光粉中,Ce^3+能很有效地把能量传递给Tb^3+,从而使Tb^3+的发射大大加强。Ce^3+和Tb^3+之间的能量传递初步判断为以电多极子相互作用为主的共振能量传递。

  • 标签: 绿色荧光粉 溶胶凝胶法 光谱性质
  • 简介:基于炉渣结构分子和离子共存理论,建立1273-1733K下的PbO-CaO-SiO2-FeO-Fe2O3渣系氧化铅活度热力学模型,计算PbO活度并绘制等活度曲线,考察炉渣碱度Q、氧化铁比率R和温度T对活度NPbO和活度系数γPbO的影响。结果表明,活度系数γPbO的模型计算值与文献测定值吻合程度高,说明该模型能较好地反映该渣系结构本质;NPbO呈拉乌尔正偏差,且随渣中PbO含量的升高而增大,但受温度的影响不明显;γPbO随Q的升高而增大;对于Q〉0.3的碱性渣,γPbO随R的升高而出现极大值。该研究结果可用于现代炼铅工艺的热力学研究和操作优化。

  • 标签: 分子和离子共存理论 热力学模型 氧化铅 活度
  • 简介:PureAl2O3-2SiO2powderswerepreparedbysol-gelandcoprecipitationmethods,andtheiralkaliactivationreactivitieswerecompared.Thealkali-activationreactivityofthepowderpreparedbythesol-gelmethodwashigherthanthatofthepowderpreparedbythecoprecipitationmethod.Thepowderswereinvestigatedby27AIand29Simagic-anglespinningnuclearmagneticresonancespectroscopy(MASNMR)tounderstandtherelationshipbetweentheirstructureandalkali-activationreactivity.The27AlMASNMRdatashowedthatthefive-coordinateAIcontentofthepowderpreparedbythesol-gelmethodwashigherthanthatofthepowderpreparedbycoprecipitation.Thehighercontentoffive-coordinateAlcorrespondedtohigheralkali-activationreactivity.The29SiMASNMRdatashowedthatforthepowderpreparedbythesol-gelmethod,siliconwasreplacedbyaluminumatsecondarycoordinationsitesofthecentralSiatomsduringcalcination.However,forthepowderpreparedbysingle-batchcoprecipitation,themainchangewasfromalowdegreeofpolycondensationtoahighdegreeofpolycondensation.

  • 标签: 魔角旋转核磁共振 活化反应 固体碱 核磁共振光谱 粉末 化学合成
  • 简介:建立了凝胶渗透色谱-相色谱同时测定含硫蔬菜(洋葱、大蒜)中24种有机氯和拟除虫菊酯类农药残留的测定方法。采用30%磷酸处理含硫蔬菜,去除含硫化合物的干扰,再用乙腈提取,凝胶渗透色谱净化,用相色谱-电子捕获检测器检测。样品加标回收率在72%~125%之间,相对标准偏差在1.8%~13.4%之间。该方法的最低检出限为0.1~4.7μg/kg。

  • 标签: 含硫蔬菜 凝胶渗透色谱 气相色谱 有机氯农药 拟除虫菊酯类农药
  • 简介:摘要目的分析重组人干扰素a-2b凝胶治疗慢性宫颈炎的临床效果。方法选择我院2013年1月-2013年12月收治的140例慢性宫颈炎患者,随机分为观察组和对照组两组,每组70例,对照组给予凝胶基质治疗,观察组给予重组人干扰素α-2b凝胶治疗,比较两组的治疗效果,临床症状改善情况及不良反应发生率。结果观察组治疗有效率85.71%,显著优于对照组57.14%,差异有统计学意义(P<0.05);治疗前两组临床症状比较,差异无统计学意义(P>0.05);治疗后,观察组白带增多、腰酸、腰痛及接触性出血症状显著低于对照组,差异有统计学意义(P<0.05);治疗期间,两组均未发生任何明显不良反应。结论重组人干扰素α-b凝胶治疗慢性宫颈炎,疗效显著,安全性高,可以明显改善患者的临床症状,值得临床推广应用。

  • 标签: 重组人干扰素 慢性宫颈炎 疗效观察
  • 简介:本文制备了Bi2O3-Ni2O3纳米粉末,对其结构进行了表征,并研究了制备的纳米粉末对苯光催化降解的影响因素。结果表明:制备的纳米粉末由Bi2O3和Ni2O3复合而成,经750℃焙烧的光催化剂对苯光催化降解活性最高;水蒸气的加入和氧气的增加,都能促进苯的降解率增大;由Langmuir-Hinshelwood动力学模型得出苯的光催化降解反应的吸附常数和反应速率常数分别为0.1398L·μmol^-1和0.0024μmol·L-1·min^-1。

  • 标签: Bi2O3-Ni2O3 光催化 动力学
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  • 简介:建立党参中18种农药残留量的分析方法,对10种不同批次的党参样品进行农药残留测定。样品以乙腈-水(5+1)涡旋震荡萃取,提取液经Carb/NH2固相萃取柱(SPE)净化后、再经在线凝胶渗透色谱(gelpermeationchromatography,GPC)净化,利用相色谱-质谱选择离子监测模式进行分析,外标法定量。18种农药峰面积与质量浓度在10—1000μg·L^-1呈良好线性关系,相关系数为0.993~1.000;定量限(10S/N)在0.06~6.3μg·kg^-1;在20~200μg·kg^-13个浓度水平下。方法回收率为76.8%~104.4%,RSD为4.2%~9.9%。该方法简便、快速,灵敏度高、重复性好,能够准确地检测党参中18种农药残留。

  • 标签: 固相萃取 在线凝胶色谱串联气相色谱-质谱 有机氯农药 党参