PEG-PVP组合表面活性剂-(NH4)2SO4-H2O双水相体系萃取Eu3+的研究

研究了聚乙二醇1500—聚乙烯吡咯烷酮(PVP,K30)组合表面活性剂水溶液在(NH4)2SO4存在下形成双水相体系的条件;讨论了以偶氮氯磷 作萃取剂,在该萃取体系中Eu3+、Pb2+、Cu2+的萃取行为。在一定pH条件下实现了Eu3+-Pb2+、Eu3+-Cu2+的定量萃取分离与测定。初步探讨了组合表面活性剂相的萃取机理。     

CaO-La2O3-B2O3-Eu2O3转光玻璃的合成及荧光性质

X射线衍射研究表明CaO-La2O3-B2O3-Eu2O3体系的玻璃化温度在1025℃附近.荧光光谱和ESR谱研究表明,在CaO-La2O3-B2O3-Eu2O3玻璃体系中存在着Eu2+和Eu3+两种价态离子. 316, 360, 379, 394, 413, 462和532nm锐线激发峰和592,616和650红区发射峰分别对应Eu3+的f-f激发跃迁和5D0-7FJ (J=1,2,3)跃迁发射;351nm和427nm宽带激发峰和蓝区发射分别对应Eu2+的5d-4f激发跃迁和发射.     

Eu3+激活的Li2Gd4（MoO4）7钼酸盐红色荧光体及其发光性质

由高温固相反应首次合成Li2(Gd1-xEux)4(MoO4)7(0相似文献   

稳定性油基纳米Fe3O4磁性流体的制备与性能研究

采用化学共沉淀法制备纳米Fe3O4磁性颗粒,在强超声振荡下将其分散在煤油中。采用正交试验设计技术,研究不同用量表面活性剂对Fe3O4磁性颗粒分散的状况以及对饱和磁化强度的影响,通过X射线衍射、红外光谱、VSM振动磁强计对纳米磁流体颗粒的分散稳定性、饱和磁化强度、纯度等进行表征。结果表明:在Fe3+与Fe2+摩尔比约为3∶2、最佳反应温度40～45℃,表面活性剂油酸用量为0.6～0.9ml/g(Fe3O4)的条件下合成的油基磁流体分散均匀、性能稳定;测得的Fe3O4比饱和磁化强度为83.33 A.m2.kg-1,矫顽力为3.40 kA.m-1,具有超顺磁性。     

SrY2O4:Eu3+超细荧光粉的制备及光致发光性能研究

采用OP-10(表面活性剂)/异戊醇(助表面活性剂)/水/环已烷(油)W/O微乳液为反应器,以草酸盐沉淀为前驱物制备了SrY2O4:Eu3 超细荧光粉.通过热重及差热分析(TG-ETA)、X射线衍射(XRD)、扫描电镜(SEM)和荧光光谱观测,研究了SrY2O4:Eu3 超细荧光粉的制备条件、形貌以及光致发光性能.XRD结果表明,1000℃烧结2h可得到SrY2O4纯相.扫描电镜照片显示颗粒基本为橄榄球形,粒径约为70nm～100nm.分别以250nm和260nm的近紫外光激发样品,SrY2(1-x)O4:Eu2x3 超细荧光粉发出明亮的红光,对应于Eu3 的4f-4f跃迁,当Eu3 的掺杂浓度为9%(摩尔分数,下同)时,在610nm和615nm处的发光强度最大,而5D0→7F0和5D0→7F1跃迁的分裂表明Eu3 在SrY2O4晶格中占据了Y3 的两种不同格位.     

SiO2@ZnWO4∶Eu3+红色荧光粉的制备及其发光性质研究

以正硅酸乙酯为硅源,用水热法制备了SiO2@ZnWO4∶Eu3+荧光粉,对样品分别进行了X射线衍射(XRD)、透射电镜(TEM)、荧光光谱(PL)等表征。XRD结果表明,当水热反应温度为180℃,反应时间12小时,可以得到ZnWO4的纯相。TEM和EDS结果表明,样品中含有Si、Eu、O、Zn、W元素。荧光光谱结果表明,SiO2@Zn-WO4∶Eu3+荧光粉能够被393 nm的紫外光激发,在615 nm处发出红色荧光,且SiO2@ZnWO4∶Eu3+荧光粉的发射光谱中电偶极跃迁5D0→7F2强度大于磁偶极跃迁5D0→7F1的强度,表明Eu3+在其中处于没有对称中心的格位。     

离子液体[Bmim]BF4-NaH2PO4-偶氮胂Ⅲ体系中La（Ⅲ）的存在形态及测定

建立了室温离子液体四氟硼酸1-丁基-3-甲基咪唑([Bmim]BF4)和NaH2PO4组成的双水相体系, 并用于对偶氮胂Ⅲ和La(Ⅲ)配合物萃取测定研究.考察了离子液体用量、溶液酸度、偶氮胂Ⅲ加入量、盐的浓度和加入其他物质对La(Ⅲ)配合物测定的影响.结果表明, 离子液在4.0 ml, 磷酸二氢钠加入量在2.0～3.0 g, 偶氮胂Ⅲ溶液1.0 ml, 溶液酸度在pH值为2～6范围, 偶氮胂Ⅲ和La(Ⅲ)配合物在离子液相中有较大的吸光度.除阳离子表面活性剂外, 其他离子表面活性剂和大多数无机离子不影响La(Ⅲ)的测定.吸收光谱、摩尔比、连续浓度变换、加入表面活性剂等实验表明, 在萃取相La(Ⅲ)与偶氮胂Ⅲ是以1∶3络阴离子形式存在的.利用离子液体双水相体系, 测定了样品中La(Ⅲ)的含量.     

碳酸盐前驱体和CS_2硫化制备SrY_2S_4∶Eu~(2+)红色荧光粉及其表征

以Sr2+,Y3+和Eu3+的混合硝酸盐溶液为阳离子溶液,以(NH4)2CO3为沉淀剂,共沉淀法制备了碳酸盐前驱体,TG-DSC分析结果表明,随着(NH4)2CO3浓度的升高,前驱体组成由碱式碳酸盐向正盐转变。以CS2为硫化剂,高温煅烧前驱体合成了SrY2S4∶Eu2+红色荧光粉。XRD表明前驱体经800℃处理得到纯相SrY2S4。荧光光谱和SEM研究表明在[Sr(NO3)2+Eu(NO3)3]∶[Y(NO3)3]∶[(NH4)2CO3]=0.25∶0.50∶2.00(摩尔比)条件下制备前驱体,然后1050℃煅烧4 h所得荧光粉的发光强度最大,粒径小于1μm,粒子形貌呈椭球。Eu2+在SrY2S4基质中的最佳掺杂摩尔分数是0.6%。     

Ti/SnO2-Sb:Eu3+电极制备及性能表征

以SnCl4·5H2O、Sb2O3和Eu2O3为原料,以钛片为基体,采用涂层热解法制备了Eu3+掺杂Ti/SnO2-Sb电极.研究了电极的电化学性能,对所制备的电极作LSV和Tafel曲线,以对硝基苯酚为目标降解有机物,考察了电极的电催化活性.分析Eu3+掺杂量对电极性能的影响,采用X-射线衍射(XRD)、扫描电镜(SEM)和能谱仪(EDS)等检测方法对Eu3+掺杂Ti/SnO2-Sb电极表面涂层的晶体结构、形貌和元素组成进行了研究;,发现掺杂量为1％的电极的性能最佳,此条件下得到的电极有高的析氧电位和电催化活性,以及较好的电极涂层结构和覆盖度.     

稀土固体超强酸Ce4+-SO42-/SnO2-Nd2O3微乳法制备及表征

采用OP-10/正丁醇/环己烷微乳体系制备出新型固体超强酸Ce4+-SO42-/SnO2-Nd2O3.以乙酸正丁酯合成为探针反应.得出Ce4+ -SO42-/SnO2-Nd2O3的优化制备条件:R=65:100(表面活性剂:水溶液),Ce( SO4)2·4H2O占8％,Nd2 O3加入量为8％,陈化时间12 h,浸渍浓度3 mol/L,焙烧温度550℃,焙烧时间3h.并采用XRD、FTIR、TG-DTA和SEM表征技术对该催化剂的结构进行研究.     

Water and solute activities of the solution systems of H2So4-Cuso4-H2O and Hci-Cuci2-H2O

The activities of water, α(H₂O), in the solution system of H₂SO₄-CuSO₄-H₂O were determined by an isopiestic method and those in the solution system of HCl-CuCl₂-H₂O by a transpiration method, both at 298 K. The activities of H₂SO₄ and H⁺ in the solution system of H₂SO₄-CuSO₄-H₂O were also determined at 298 K by the emf method. The water activities in both systems obeyed the Zdanovskii rule relatively well. The α(H₂O) experimentally determined in the sulfate system showed a satisfactory agreement with those calculated from the Robinson-Bower equation, assuming the complete dissociations of H₂SO₄ and CuSO₄, whereas a good agreement between the calculated and experimentally determined α(H₂O) for the chloride system was obtained when the formation of Cu(II) chloro-complexes was taken into consideration. The mean activity coefficients, γ_±, of solutes, including H₂SO₄, HC1, and CuCl₂ in these solution systems, were calculated at 298 K by the McKay-Perring method using the activity data. The γ_±(H₂SO₄) values in the solution system of H₂SO₄-CuSO₄-H₂O were in good agreement with those determined by the emf method. On the other hand, the γ_±(CuSO₄) were calculated at the same temperature based upon the Gibbs-Duhem equation using both measured α(H₂O) and calculated γ_±(H₂SO₄) values, because of solubility limitations.     

小颗粒氧化铈制备过程中的团聚控制

本文主要探讨在草酸沉淀法制备氧化铈的过程中,通过调节pH、采用不同的沉淀剂和添加分散剂使中间产物草酸铵铈充分分散,最后经焙烧得到分散良好的小颗粒氧化铈。     

Superconducting Transition Temperature in YBa2Cu4O8/La2/3 Ca1/3 MnO3 / YBa2 Cu4O8 Heterostructure

YBa2Cu4O8/La2/3 Ca1/3 MnO3/YBa2Cu4O8 （ Y-124/LCMO/Y- 124） heterostructure was prepared by facing-target sputtering technique. The oscillatory superconducting transition temperature was observed when the thickness of LCMO d L is larger than critical thickness d L^CR. The metal-insulator transition temperature can only be detected at d L 〉 d L^CR. The dependence on the spacer layer in LCMO/Y-124 systems suggests strongly the interplay of ferromagnetic and superconducting couplings.     

Morphology of dispersed nickel electrochemically deposited in solutions of the system NiSO4(NiCl2)-(NH4)2SO4-NH3·H2O

Morphology of dispersed nickel obtained by electrolysis in electrolytes (0.1–0.5 M) NiSO₄(NiCl₂)-0.5 M (NH₄)₂SO₄-NH₃·H₂O (to pH 8.0–8.5), which model the leaching solutions of secondary metal, is investigated. It is noted that the sediment of three structural levels is formed on the cathode at the current density 20–100 A/dm². These are (i) spherical particles, (ii) spherical agglomerates, and (iii) conglomerates of the particles of the second structural level. The shape of first-level elemental particles is governed by adsorption of the surface-active NH₃ molecules on the surface of crystalline nuclei. The second and the third levels of structuring emerge due to high surface energies of elemental particles. Spherical agglomerates are mechanically stable and determine the main characteristics of the nickel powder. The sizes of these agglomerates decrease as the cathode current density increases and the nickel concentration in electrolytes decreases, and lie in the limits 2–10 μm. Original Russian Text ? O.I. Kuntyi, 2007, published in Izvestiya VUZ. Tsvetnaya Metallurgiya, 2007, No. 1, pp. 20–23.     

Li4SiO4-Y2O3的溶胶-凝胶法合成及离子导电性研究

用溶胶-凝胶法制备了Li4SiO4-xY2O3(x=0～0.5)离子导体材料,并用DTA-TG、XRD及交流阻抗等技术对样品进行了测试,结果发现用溶胶-凝胶法可降低Li4SiO4的合成温度并可提高离子的导电性,适量Y2O3的掺入可增强基质的致密性,并可提高材料的导电性能.     

Catalytic combustion of diesel soot over K2NiF4-type oxides La2-xKxCuO4

Nanostructure K2NiF4 type oxides La2-xKxCuO4 complex oxides were prepared using the Sol-Gel method, characterized by X-Ray Diffraction （XRD）, Fourier Transform Infrared （FT-IR）, and Scanning Electron Microscopy （SEM）. The catalytic activity for soot combustion was evaluated by the Temperature-Programmed Reaction （TPO） technique. The results demonstrated that the substitution quality of K^＋ for La^3＋ at the A-site would increase the catalytic activities of La2-xKxCuO4 for soot combustion greatly; the substitution quality affected the structure and catalytic activity obviously. The La1.8K0.2CuO4 complex oxides with tetrahedral structures had the best catalytic activity for soot combustion, and the ignition temperature of soot combustion was lowered from 490 to 320 ℃.     

Leaching of a sphalerite concentrate with H2SO4–HNO3 solutions in the presence of C2Cl4

The enhanced leaching of sphalerite concentrates in H₂SO₄–HNO₃ solutions and the extraction of sulfur with tetrachloroethylene were studied. Variables of the process were investigated including leaching temperature, reaction time, liquid / solid ratio, and tetrachloroethylene concentration. The number of cycles that tetrachloroethylene could be recycled did not have a significant effect on zinc extraction. The results indicated that 99.6% zinc extraction was obtained after three hours of leaching at 85 °C and 0.1 MPa O₂, when 20 g of sphalerite concentrate were leached in a 200 ml solution containing 2.0 mol/L H₂SO₄ and 0.2 mol/L HNO₃, in the presence of 10 ml C₂Cl₄. Leaching rates were significantly improved under these conditions.     

LiF-CaF2-BaF2-ZrO2熔盐中Zr4+在钨电极上的电化学还原机理

以LiF-CaF₂-BaF₂为熔盐体系, ZrO₂为原料, 1 373 K条件温度下利用循环伏安法, 计时电位法, 计时电流法, 研究锆离子在钨电极上的电化学过程,对不同ZrO₂含量0.5 %,0.7 %,0.9 %的熔盐体系进行电化学分析,研究结果表明:Zr4+在钨电极上还原是通过两步得电子反应, 即Zr4++2e→Zr2+,Zr2++2e→Zr,相对参比电极铂还原峰分别为0.9 V和1.2 V,析出过程是受扩散控制的准可逆反应. 1 373 K时Zr4+在LiF-CaF₂-BaF₂-ZrO₂熔盐中的扩散系数D为6.7×10-6 cm2/s.      

Na3PO4—Na2B4O7体系中钛合金微等离子体氧化陶瓷膜研究

在钛合金上用微等离子体氧化法制备氧化膜,用扫描电镜（SEM）、X-射线（XRD）测其表面形貌、相组成,并对现象及测试结果进行分析,。从而推理其成膜机理。