ASTUDY OF VALENCE OF YTTRIUM IN Y_2O_3 Mo CATHODE

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添加0.1 mass%Y的K38G高温合金1000℃恒温氧化行为

研究了添加0.1mass%稀土Y的铸造K38G高温合金在1000℃的恒温氧化行为.结果表明,较之不含Y的合金,含Y铸态K38G合金的氧化速率显著降低; 氧化时形成双层的外氧化膜,表层为以Cr2O3和TiO.2为主的混合氧化物层,内层为连续的Al2O3层;没有内氧化和内氮化,没有氧化膜的剥落,加入稀土Y有效地提高了氧化膜的粘附性能.     

高硼/钇合金化提高FeAl基金属间化合物多孔材料的抗氧化性能（英文）

利用反应合成法制备高铬(Cr)、硼(B)、钇(Y)复合合金化的B2结构FeAl基金属间化合物多孔材料,通过研究FeAl基多孔材料氧化后的孔结构演变、氧化动力学和氧化膜构型,探讨其高温氧化行为。结果显示,添加高含量合金元素Cr、B和Y后,FeAl多孔材料在600～800℃下氧化增质显著降低。富集在氧化膜表面的B和偏聚在氧化膜与基体界面处的Y共同促进多孔材料表面形成薄且具有优异防护性的结节状α-Al₂O₃氧化膜。研究表明,引入较高含量的活性元素如B和Y有利于FeAl金属间化合物在较低氧化温度和无预处理的情况下选择性生长单一的α-Al₂O₃氧化膜。     

Synthesis and characterization of Y_2O_2S:Eu~(3+),Mg~(2+),Ti~(4+) nanorods via a solvothermal routine

Y2O2S:Eu3+,Mg2+,Ti4+ nanorods were prepared by a solvothermal procedure.Rod-like Y(OH)3 was firstly synthesized by hydrothermal method to serve as the precursor.Y2O2S:Eu3+,Mg2+,Ti4+ powders were obtained by calcinating the precursor at CS2 atmosphere.The Y2O2S:Eu3+,Mg2+,Ti4+ phosphor with diameters of 30-50 nm and lengths up to 200-400 nm inherited the rod-like shape from the precursor after calcined at CS2 atmosphere.The Y2O2S:Eu3+,Mg2+,Ti4+ nanorods showed hexagonal pure phase,good dispersion and exhibite...     

聚锑酸离子交换剂的制备及分离锶和钇

以三氧化二锑为原料,双氧水为氧化剂,经氧化回流法制备聚锑酸无机离子交换剂.该聚锑酸离子交换剂对锶-钇混合溶液中的锶具有较好的选择性吸附能力.通过正交实验设计法对反应影响因素进行了优化,结果表明,在60 ℃时加入40 mL水和12 mL H_2O_2氧化10 g Sb_2O_3固体,反应120 min可制得对Sr~(2+)和Y~(3+)具有较高分离系数的聚锑酸离子交换剂.理化性能研究表明,产物是一种阳离子交换剂,对溶液中的Sr~(2+)和Y~(3+)的动态吸附分离具有较高的选择性.     

掺钕钇铝石榴石透明陶瓷 (Nd:YAG)体视学研究

采用低温燃烧法合成出掺钕钇铝石榴石(Nd：YAG)粉末,经模压300MPa成型,于1700℃真空烧结5h,制备出尺寸φ9mm×1mmNd：YAG透明陶瓷片．对Nd：YAG透明陶瓷片进行光透过率、场发射-环境扫描电镜测量．采用体视学原理与方法定量地研究了Nd：YAG透明陶瓷的微观结构参数和光透过率之间的关系．研究结果表明：尺寸φ9mm×1mmNd：YAG透明陶瓷片在可见光波段光透过率约为45％,在近红外光波段约为55％；随着入射光波长的增加,光透过率增加；随着晶粒三维球当径(D_(3S))的增加,光透过率增加,当D_(3S)约为20μm时,Nd：YAG透明陶瓷光透过率接近单晶理论值；随着晶粒以及单个晶粒平均比表面积的增加,光透过率降低；随着晶粒三维平均自由距离的增加,光透过率降低．     

Preparation and Characterization of Porous Yttrium Oxide Powders with High Specific Surface Area

Y2O3isoftenusedinthemanufactureofphos phorsandceramics[1～3].However,itisalsousedas selectivecatalysts[1,4,5],suchasforthedehydrationof2alkanols,thedimerizationofmethane,1butene isomerization,hydrogenationof1,3butadieneandac etonealdoladdition,andsupport[6,7]formetalsthat catalyzetheformationofmethanolfromCO2andH2.It iswidelyacceptedthatthecatalysispropertiesofox idesdependstronglyontheirphysicalcharacteristics,especiallyontheirspecificsurfaceareaandporous structure.Agreatdealofattentionhasb…     

Effects of Host Doping on Spectral and Long-Lasting Properties of Sm^3＋ -Doped Y2O2S

Gd- or Lu-doped long afterglow red phosphor Y2O2S：Sm^3＋ was synthesized using the high temperature flux fusion method. The obtained phosphors were analyzed using X-ray diffraction to determine the crystal structure, and the phase analyses show that the product is in single phase. The luminescence spectra and decay curve were measured on a Hitachi F-4500 fluorescence spectrophotometer. The decay time was determined on an ST-900PM weak light photometer. The analyses show that host doping of Lu improves both luminescence and decay time of the materials. The concentration of doped Lu and Sm was varied in order to determine the optimal condition and to synthesize the product with the best properties. The mechanism of the long afterglow was also briefly discussed.     

Microstructure and electrical properties of Y2O3-doped ZnO-based varistor ceramics prepared by high-energy ball milling

Y2O3-doped ZnO-based varistor ceramics were prepared using high-energy ball milling （HEBM） and low-temperature sin- tering technique, with voltage-gradient of 1934-2197 V/mm, non-linear coefficients of 20.8-21.8, leakage currents of 0.59-1.04 μA, and densities of 5.46-5.57 g/cm3. With increasing Y2O3 content, the voltage-gradient increases because of the decrease of ZnO grain size; the non-linear coefficient and the leakage current improve but the density decreases because of more porosity; the donor con- centration and density of interface states decrease, whereas the barrier height and width increase because of the acceptor effect of Y2O3 in varistor ceramics.