共查询到19条相似文献,搜索用时 62 毫秒
1.
Magneticpolymermicrospherecanbeseparatedquicklyundermagneticfieldandithasgotwideappli cationinmanyfields ,suchascellseparationetc .Themicrospheremustpossesshighmagneticresponsibili ty ,sothatmagneticseparationisquickandconve nient.Themagneticresponsibilit… 相似文献
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WuChao ChenWen ZhouJing TianGao ZhaoChunxia 《中国稀土学报(英文版)》2005,23(2):i002-i002
Nanosized mesoporous molecular sieve MCM-41 was synthesized with tetraethyl orthosilicate (TEOS) as the source of silica and cetyltrimethyl-ammonium bromide (CTAB) as the template. The photoluminescent functional supramolecule Eu(DBM)3phen/MCM-41 between the nanosized MCM-41 and Eu(DBM)3phen was prepared in chloroform, and characterized by XRD, HRTEM, IR and fluorescent spectroscopy. 相似文献
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Synthesis and Characterization of Gadolinium Doping M-type Hexagonal Barium Ferrite Ultrafine Powders 总被引:2,自引:1,他引:1
Becausepermanentbariumferritematerialpos sessesrelativelyhighsaturationmagnetization ,greatcoerciveforceandhighmagneticanisotropyfieldaswellasexcellentchemicalstabilityandcorrosionresis tance ,ithasbeenwidelyusedastraditionalperma nentmagnets ,high densitymagneticandmagneto op ticrecordingmedia ,microwavefilters[1,2 ] .Thusthestudyonthesynthesisofmagnetoplumbite typebariumferriteisconsiderablyimportanttotheelectronicandmagneticmaterialsindustry .Duringthelastfewdecades ,peoplehavemadegreateffo… 相似文献
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Poly(methyl methacrylate) (PMMA) was used to wrap alumina-siloxane sol through emulsion polymerization. A kind of suspensions with notable ER effect was produced by fully mixing the prepared microcapsule with silicon oil. Meanwhile a series of PMMA wrapped alumina - siloxane gel doped with rare earths was obtained and its ER effect was tested, like viscosity of different rare earth ion doped samples in different powder concentrations and at different temperatures, at the same time, leak current density and dielectric constant were measured. Resuits show that the ER effect of this suspension is remarkable, and its stability is much better. The condition of emulsion polymerization and the mechanism of effect are discussed. 相似文献
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Preparation and Characterization of Microporous Nano-Tungsten Trioxide and Its Photocatalytic Activity after Doping Rare Earth 总被引:6,自引:1,他引:5
Recently,heterogeneousphotocatalyticoxidation decompositionoforganiccontaminantshasbeenstud iedkeenlyinvariousfields.WO3isknownasamulti functionalmaterialapplicableforelectrochromicdis playdevice(ECD),semiconductorgassensor,cata lystetal.WO3,whosebandgapenergyhasbeenesti matedtobe2.5eV,hasthepotentialabilitytophoto catalyzeunderirradiationofvisiblelightofwavelength相似文献
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WangChen ZhangWenyong YanMi 《中国稀土学报(英文版)》2005,23(3):279-279
Effects of Nb and Zr substitutions on the crystal]ization behaviors and magnetic properties of melt-spun (Nd,Pr)2Fe14B/α-Fe alloys were studied.The results show that for (Nd0.4Pr0.6)8.5Fe85.5B6 ribbons, the metastable (Nd,Pr)3Fe62B14 precipitates after the initial crystallization of α-Fe and decomposes into the final mixture of (Nd,Pr)2Fe14B and α-Fe. For(Nd0.4 Pr0.6)8.5 Fe84.5 Zr0.5 Nb0.5B6 ribbons, however,(Nd, Pr)2Fe14B and α-Fe phases precipitate simultaneously. This indicates that both Nb and Zr dopingcan avoid the formation of metastable phase and! 相似文献
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YAG: Ce^3 + phosphor particles were prepared using polyacrylamide gel method. The structure evolution of powders during annealing process was followed by X-ray diffraction determination. It is found that some intermediate phases, including θ-Al2O3, YAM and YAP, are formed when calcining polyacrylamide gel, however, the pure YAG phase can be formed directly when calcining polyacrylamide gel with α-Al2O3 as seed crystal. These facts show that the existence of α- Al2O3 seed crystal can block the formation of θ-Al2O3, YAM and YAP, and accelerate its reaction with Y2O3 to form YAG phase directly at lower temperature. The emission peak of prepared YAG : Ce^3 + phosphor is wide with maximum at 550 nm and the exitation band has two peaks, the major one is around at 460 nm, which matches the blue emission of GaN LED and is suitable for the assemble of white LED. Some fluxes can enhance the photoluminescence intensity of phosphor particles, that can be attributed both to the improvement of crystallization processes of YAG and to the stabilization of trivalence cerium ion in YAG:Ce^3 +. 相似文献
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Preparation and Structure Characterization of Rare Earth Doped Alumina-Siloxane Gel and Its Modification on ER Effect 总被引:1,自引:0,他引:1
A series of samples of alumina-siloxane gel wrapped by poly (methyl methacrylate) and doped with rare earths such as lanthanum, praseodymium, yttrium, gadolinium and europium were prepared. The structure features were characterized by micrograph, X-ray fluorescence spectrum, X-ray diffraction spectrum, Fourier transform infrared spectrum and differential thermal analysis.Tests indicate that rare earths modify the electrorheological effects of the stable suspensions composed of samples stirred with silicon oil. 相似文献
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BaMgAl10O17 : Eu^2+ (BAM) was prepared in the microemulsion system and its phase behavior was studied. There exists a small region in the reverse microemulsion system where the dispersed particles are of spherical form. In this way, BAM blue phosphor with good dispersion can be synthesized. The microemulsion phase diagrams of the pseudo-ternary system (Triton X-100/cosuffactant-oil-BAM brine) were first established intuitively by the dilution method. The microstructure of microemulsions was determined through eyeballing, conductance technique, and polar optical microscopy. Its phase behavior is affected by various factors, such as temperature (room temperature, 30, 40 ℃), oil, surfactants, and cosurfactants in microemulsions. According to the phase diagrams, the microemulsion system of Triton X-100/1-hexanol-hexane-BAM brine was chosen to prepare the precursor. The BAM phosphor can be obtained via sintering the precursor at a comparatively low temperature. The phosphors were characterized by XRD and vacuum ultraviolet (VUV) spectra. 相似文献
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Preparation and Characterization of CeO2-ZrO2 Solid Solution Ultrafine Particles Using Reversed Microemulsion 总被引:3,自引:0,他引:3
The development of the TWCs (three-way cata-lysts) was dictated bythe need to si multaneously con-vert the three main pollutants inthe exhaust gases ,i .e .,hydrocarbons (HCs) ,COand NOxpresent in theautomotive exhaust to H2O, CO2and N2[1]. Highestconvers… 相似文献
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以聚乙二醇磁性胶体粒子为种子 ,运用分散聚合法 ,同时掺入稀土离子 ,制备出表面配位有稀土离子的磁性聚苯乙烯微球 ,该微球粒径为 6 0~ 180 nm,考察了稀土磁性微球的形态和结构。并用电镜、原子吸收光谱、红外光谱对其性质进行了表征。 相似文献
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纳米稀土铁氧体磁性颗粒的制备研究 总被引:4,自引:0,他引:4
采用湿化学方法研究制备纳米稀土铁氧体磁性颗粒,研究纳米稀土铁氧体颗粒制备过程中主要影响因素,如pH和RE^3+等对纳米稀土铁氧体颗粒粒径及磁性能的影响;同时对纳米Dy铁氧体颗粒的形貌、粒度分布、晶型结构及磁性能进行了分析和研究。研究发现轻稀土对Fe3O4颗粒的磁性有削弱作用,不宜掺杂;重稀土元素掺杂是提高铁氧体磁性颗粒磁性能的有效途径,改善磁性能的强弱顺序为Dy^3+〉Gd^3+〉Er^3+。制备的Dy铁氧体颗粒的平均粒径为9.6nm,比饱和磁化强度98.27A·m^2·kg^-1,具有超顺磁特性。同时讨论了Dy^3+在Fe3O4的晶体结构中取代Fe离子增强磁性能的可能形式。 相似文献
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Study on Synthesis and Polymerization of Mono (isopropylmaleate oyloxyl) Diisopropoxyl Dysprosium 总被引:2,自引:0,他引:2
Intheearly1980s,rareearthcontainingpolymerswereprepared[1].Thenewmaterialscombinedtheoptical,electronicormagneticcharacteristicsofrareearthionswiththepropertiesoforganicpolymer.Sotheymightbeusedasfluorescent,laser,magneticmaterialsoropticalplastics[2,3].Howev… 相似文献
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Zhu Dongbin Liang Jinsheng Li Fenping Ding Yan Wang Lijuan Liang Guangchuan Xu Gangke 《中国稀土学报(英文版)》2006,24(Z2)
Rare earth composite materials radiating far-infrared rays were prepared according to far infrared absorption spectrum of main component in liquefied petroleum gas (LPG). The composite materials were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier transformed infrared spectra(FTIR). The results show that after the composite materials were calcined at 873 K for 4 h, FTIR spectra of rare earth composite materials display two new peaks at 1336 and 2926 cm-1 available for activating LPG. 相似文献
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Preparation, Characterization and Photo-Catalytic Behavior of Y_2O_3/TiO_2 Composite Semiconductor Nanopowder 总被引:3,自引:0,他引:3
TiO2 photo catalysishasbeenafocusofnumerousinvestigationsinrecentyears ,par ticularlyowingtoitsapplicationforthecom pletemineralizationofundesirableorganiccon taminantstoCO2 ,H2 Oandinorganiccon stituent[1] .However,photo oxidationisalmostnotindustriallyapplie… 相似文献