AgYb(MoO4)2:Er3+/Tm3+/Ho3+稀土发光材料的水热合成及其温度传感性能

为了提高Ln³⁺离子的发射强度,Yb³⁺离子在上转换(up conversion, UC)系统中通常用作敏化剂,在980 nm处有着广泛且强的吸收带.作为含有Yb³⁺的基体材料,AgYb(MoO₄)₂中的离子浓度更高,因此掺杂离子的发射强度更强,期待可以获得更好的温度敏感性.采用Er³⁺掺杂后获得的材料的温度敏感性在473 K时达到0.013 3 K^-1,对比于相同条件下合成的NaY(MoO₄)₂材料,其温度敏感性更高.并且Ho³⁺和Tm³⁺的共同掺杂还可以用来进行合成白光发射,即通过共掺杂Tm³⁺后获得蓝光部分(¹G₄-³H₆),再通过Ho³⁺的掺杂获得红光(⁵F₅-     

甲醇在纳米铂修饰的铂电极上的电化学氧化

利用循环伏安和交流阻抗技术,首次报道了甲醇在电沉积铂颗粒修饰的铂电极上的电化学氧化.结果显示,修饰铂纳米颗粒后,甲醇的氧化电流明显增加,在电极上的反应电阻明显减小.对谱图的进一步分析表明,甲醇氧化峰电流的增加并不只是由铂电极面积的增加造成的,铂纳米颗粒对甲醇的氧化有明显的催化作用.     

Nd3+修饰纳米TiO2-CNTs-PtNi复合催化剂的制备及电化学性能

采用电合成前驱体Ti(OEt)4直接水解法和电化学扫描电沉积法及物理吸附的方法制备了稀土金属离子Nd3+修饰的NanoTiO2-CNTs-PtNi复合纳米催化剂,通过计时电流和CV研究,结果表明Nd3+修饰的NanoTiO2一CNTs-PtNi的电极对甲醇电氧化的峰电位进一步负移约30mV,氧化峰电流增大,表明Nd3+的加入对甲醇的电催化氧化有一定的协同催化作用,这种作用导致CO在复合催化剂上的弱吸附,从而避免了催化剂的中毒.同时提出其可能的形成机理.     

ZnB2O4 ∶Eu3+,Yb3+的发光性质及能量传递

采用高温固相法制备ZnB₂O₄ ∶Eu³⁺,Yb³⁺近红外发光材料, 通过X射线衍射(XRD)和荧光光谱研究其制备条件及Eu³⁺和Yb³⁺掺杂对材料发光性能的影响, 并考察了反应时间及Eu³⁺和Yb³⁺掺杂摩尔分数对发光强度的影响. 实验结果表明, ZnB₂O⁴ ∶]Eu³⁺,Yb3+材料中的近红外发光是通过Eu³⁺和Yb³⁺间的能量传递实现的.     

基于金属超氧物种MnO2+-(HCO3-)n氧化的Mn~Ⅱ-BAP体系降解苯胺(英文)

为有效处理广泛存在于地下水中的苯胺污染物,采用Mn~Ⅱ-BAP体系氧化苯胺,并对氧化效果、影响因素以及氧化过程中的主要活性物种做了系统探究.在氧化苯胺过程中,通过动力学实验以及掩蔽实验探究了Mn~Ⅱ-BAP体系氧化苯胺的最佳条件以及氧化机制.实验结果显示,Mn~Ⅱ-BAP体系可以在10 min内氧化99.5%的苯胺,反应速率常数为5.30×10^-1min^-1.Mn²⁺与HCO₃^-之间存在的协同作用会导致反应体系中的HCO₃^-以及Mn²⁺的浓度对k_obs有着重要的影响,金属超氧物种Mn O₂⁺-(HCO₃^-)_n是Mn~Ⅱ-BAP体系氧化苯胺的主要活性物质.     

关于Diophantine方程X2+Y2=Zr的素数解

设r是大于1的奇数,给出了方程X²+Y²=Zr的正整数解(X,Y,Z)中Y为奇素数方幂的必要条件.     

NaY9(SiO4)6O2: Bi3+,Eu3+荧光材料的合成及温敏特性

为寻找高性能荧光温敏探针材料,用荧光强度比率法,对NaY_9-x-y(SiO₄)₆O₂:xBi³⁺,yEu³⁺荧光粉体的温敏特性进行了研究.结果表明:该材料中存在Bi³⁺→ Eu³⁺的高效能量传递,单一波段激发Bi³⁺发光离子,可获得Bi³⁺和Eu³⁺的双发射荧光光谱;温度升高时,Eu³⁺发射光谱的猝灭速率比Bi³⁺缓慢;根据不同温度下2种发光光谱强度的比值,获得了NaY_6.192(SiO₄)₆O₂:0.108Bi³⁺,2.7Eu³⁺在300~450 K最高相对灵敏度为1.51 %·K^-1,大大优于可实用温敏材料的相对灵敏度数值(0.3 %·K^-1),该材料具有较大的实际应用前景.     

BaCe1-x Yx O3-δ质子导体的制备与性能

采用高温固相合成法制备出掺杂Y³⁺的BaCeO₃电解质BaCe_1-xY_xO_3-δ（x=0.10~0.30). XRD谱分析结果表明,样品均为正交钙钛矿结构;氧空位、 缺陷缔合和固深度均对样品的质子电导率与掺杂浓度有一定影响.     

Tb3+和Gd3+掺杂的纳米TiO2薄膜的制备及发光性能与发光机

以钛酸正丁酯［Ti(OBu)₄］为前驱体, 采用溶胶 凝胶法制备Tb³⁺和Gd³⁺共掺杂的纳米TiO₂发光薄膜, 并探讨了Gd³⁺对Tb³⁺的增敏作用机理. 通过X射线衍射(XRD)、 TG/DTA综合热分析仪、 傅里叶变换红外仪(FTIR)、 透射电子显微镜（TEM）和光致发光(PL)光谱分别对不同制备条件下的TiO₂薄膜进行了表征. 结果表明, TiO₂薄膜具有一定的择优取向, 晶相为锐钛矿相, 形成了良好有序的晶体结构, 且样品粒径分布均匀, 颗粒大小约为15 nm; 以230 nm作为激发光, Gd³⁺的共掺对纳米TiO₂发光薄膜中Tb³⁺的发光有显著增强作用.     

Cu2+、Zn2+、Al3+对泥鳅的单一和联合毒性研究

 本文研究了Cu²⁺、Zn²⁺、Al³⁺3种离子对泥鳅的单一和联合毒性。结果表明：Zn²⁺和Al³⁺对泥鳅24 h的半致死浓度（LC₅₀）分别为3.24和1.50 mg/L;Cu²⁺、Zn²⁺和Al³⁺对泥鳅48 h的LC₅₀分别为1.05、3.02和1.43 mg/L,对泥鳅72 h的LC₅₀则为0.67、3.02和1.39 mg/L,对泥鳅96 h的LC₅₀分别为0.56、2.87和1.35 mg/L;而Cu²⁺、Zn²⁺、Al³⁺ 3种离子对泥鳅96 h的安全浓度分别为0.0056、0.029和0.014 mg/L。采用Marking相加指数评价法进一步分析结果显示,Cu²⁺-Zn²⁺-Al³⁺混合溶液对泥鳅表现出拮抗作用（48和72 h）和协同作用（96 h）。     

Y2O2S:Eu3+,Zn2+,Ti4+荧光体的缺陷及红色长余辉发光性质

采用高温固相法合成了红色长余辉材料Y2O2S:Eu3+,Zn2+,Ti4+,实现了余辉发光中心和缺陷中心之间的能量传递。通过XRD、荧光发射和激发光谱、余辉发射光谱与衰减曲线、色坐标和热释光谱测试手段对Y2O2S:Eu3+,Zn2+、Y2O2S:Eu3+,Ti4+、Y2O2S:Eu3+,Zn2+,Ti4+和Y2O2S:Eu3+,Mg2+,Ti4+进行了结构与性能的表征,发现其荧光发射与余辉发射基本一致,红色余辉发光主峰位于625 nm附近,来源于Eu3+的5D0→7F2跃迁发射。相比而言,Y2O2S:Eu3+,Zn2+,Ti4+余辉发光性能最好,可持续1.5 h左右。     

Synthesis and luminescence properties of Eu3+, Sm3+ doped (YxGd1-x)2O3:Si4+, Mg2+ long-lasting phosphor

A novel red long-lasting phosphor, (Y_1−x Gd _x )₂O₃:Eu³⁺, Sm³⁺, Si⁴⁺, Mg²⁺, was synthesized by the co-precipitation method using oxalate precipitation as the precursor. X-ray diffraction (XRD), scanning electronic microscopy (SEM), integrated thermal analyzer (TG), and photoluminescence spectra (PL) as well as the ST-900PM weak light photometer were used to study the synthesis conditions, morphology, luminescence properties, and the decay time of the phosphor. The XRD results show that the products synthesized at 1400°C for 4 h have good crystallization without any detectable impurity phases. Based on the PL spectra, the optimal conditions are as the following. The molar ratios of Y³⁺ to Gd³⁺ and Eu³⁺ to Sm³⁺ are 2:8 and 3:1, respectively, and the contents of Mg²⁺ and SiO₂ are 5mol% and 3mol%, respectively. The decay time monitored by the ST-900PM weak light photometer is 7200 s, increasing 44% and 100%, respectively, compared with the Eu³⁺ and Sm³⁺ single-doped phosphors. The results indicate that the energy transfer is from Sm³⁺ to Eu³⁺ ion, and Sm³⁺ is a good sensitizer to Eu³⁺.     

PbxNayYzF2x+y+3z+3m∶Erm3+上转换发光粉的低温燃烧合成及表征

采用低温燃烧合成（LCS）法一步合成了Pb_xNa_yY_zF_2x+y+3z+3m:Er_m3+氟化物体系1 550 nm响应的红外上转换发光材料. 通过正交实验研究了4种阳离子影响发光性能的主次关系及最佳配比,研究了燃料用量对晶相形成及上转换发光性能的影响. 采用X射线粉末衍射仪、透射电镜、荧光分光光度计（耦合1 550 nm激光器）等手段对样品的物相、形貌及发光性能进行了测试与表征. 结果表明:阳离子含量对红光发射强度影响的主次关系为Y3+,Pb2+,Na+,Er3+,最佳配比为Pb_0.004Na_0.003 Y_0.003 F_0.032:Er3+_0.004. 燃料取2.5倍理论用量时样品的结晶度和发光强度最高.      

Effects of lanthanide ions on hydrolysis of phosphatidylinositol in human erythrocyte membranes

The effects of lanthanides on the hydrolysis of phosphatidylinositol in human erythrocyte membranes were studied. ³H-inositol labeling chromatography and HPLC were used to determine inositol 1, 4, 5-triphosphate and diacylglycerol separately, the hydrolytic products of phosphatidylinositol due to the reaction of lanthanide ions with human erythrocyte membranes. The unhydrolyzed phosphatidylinositol in membranes was also determined. The results indicate that the hydrolysis of phosphatidylinositol can be promoted by lanthanides (La³⁺, Ce³⁺, Y³⁺, Tb³⁺) and the effects of La³⁺ and Ce³⁺ are stronger than those of Y³⁺ and Tb³⁺.     

Soft chemical synthesis and luminescence properties of red long-lasting phosphors Y2O2S:Sm3+

Sm³⁺-activated Y₂O₂S red phosphors were prepared by the combustion method and microemulsion method at the first time. X-ray characterization and electron diffraction show that, Y₂O₂S:Sm³⁺, Ti⁴⁺, Mg²⁺ samples prepared by these two methods are pure hexagonal crystals in structure with a trivial change due to dopants. Scanning electron microscopy (SEM) results show that the product presents an almond-like sheet in uniform size. Under the excitation of 269 nm ultraviolet light, Y₂O₂S:Sm³⁺ samples fabricated by these two methods exhibit three main groups of red emission lines located at 564, 604, and 656 nm, respectively, which are attributed to the transitions of 4G_5/2 →6H_5/2, 4G_5/2 →6H_7/2, 4G_5/2 →6H_9/2, respectively. The samples prepared by microemulsion are seven times higher in fluorescent emission intensity and half time longer in afterglow time than that prepared by combustion.     

The strong cross relaxation of Er3+ and yb3+ ions in the oxyfluoride glass ceramics

Oxyfluoride glass ceramic is a new up-conversion fluorescent material with the low phonon energy just like fluoride and the good mechanical stability like oxide. In the oxyfluoride glass ceramics co-doped with Er³⁺ and yb³⁺ ions, the red radiation is dominant while it is excited by the violet light. But in the general fluorescent material, the green radiation is dominant because the multi-phonon relaxation occurs step by step. The strong cross relaxation process of Er³⁺ and yb³⁺ ions is mainly responsible for enhancement of the red radiation intensity in the oxyfluoride glass ceramics. The increase of the red radiation intensity of Er³⁺ ions by the violet light excitation shows that the rare earth ions are doped into fluoride micro-crystals which are planted into oxide host in the oxyfluoride glass ceramics.     

Development of a new method for analyzing free aluminum ions （Al3＋） in seafood using HPLC-ICP-MS

This paper presents a novel method for simultaneous online examination of free aluminum ions （Al3＋） in seafood, using solid- phase extraction and high-performance liquid chromatography online with inductively coupled plasma mass spectrometry （SPE- HPLC-ICP-MS）, without post-column reaction. The optimum conditions for chromatographic separation of Al3＋ were achieved using an IonPac CS5A analytical column with an IonPac CG5A guard column. The mobile phase consisted of 0.040 mol/L LiOH, 0.0060 mol/L 2,6-pyridinedicarboxylic acid, and 0.090 mol/L CH3COOH （pH 4.7）. The free Al3＋ ions in seafood were extracted by shaking with the mobile phase at 70℃ for 2 h. SPE was conducted using an Oasis MCX, 3cc/60 mg, 30 μm column, which was activated and equilibrated with 2 mL of methanol and 4 mL of deionized water before use. HCl （0.075 mol/L, 2 mL） was used to wash inorganic Al from the SPE column. The standard recoveries of Al3＋ were all above 89% and the relative standard deviations were all below 5%. The proposed method was successfully used for the examination of Al3＋ in seafood samples, and the results were similar to those obtained using the static equilibrium method.     

Properties and characterization of Au3+-adsorption by mycelial waste ofStreptomyces aureofaciences

Mycelial waste of Streptomyces aureofaciences procured from the aureomycin fermentation industry is used as biosorbent for Au³⁺  The properties of Au³⁺ adsorption by the mycelial waste are studied. The results indicate that the optimum pH value of Au³⁺ adsorption is 3.5. The biosorption is a rapid and non-temperature-dependent process. The bio-sorptive capacity with 45.6 mg/g and efficiency with 91.2% are achieved under the conditions of pH 3.5 and 30 ℃ for 45 min, in which the ratio is 50 mg/g dry weight for the concentrations of initial Au³⁺ and the mycelial waste. The Au³⁺ ions adsorbed on the mycelial waste can be eluted. The observation in a transmission electron microscope shows that the Au³⁺ ions can be reduced to Au particles by the mycelial waste and the Au⁰ can become gold crystals with differentforms and sizes. X-ray photoelectron spectroscopy analysis further proves that the Au³⁺ can be reduced to Au⁰ by the mycelial waste.     

Bi~(3+)/Yb~(3+)共掺GdVO_4近红外发光性能研究

使用高温固相法制备了一种新的Bi3+,Yb3+共掺杂GdVO4量子裁剪近红外发光材料,该材料在波长为250~400nm的紫外光激发下发射出很强的近红外光(900~1100nm).由于体系中Bi3+离子的引入,相对于Gd0.9Yb0.1VO4,Gd0.87Yb0.1Bi0.03VO4在989nm处的近红外发光强度提高近120%,且其激发峰也从323nm红移至341nm,整个激发谱带更宽,更有利于实际应用.由于Yb3+离子既可以利用基质中的VO3-4电荷迁移态跃迁的能量,也可以同时利用Bi3+的1S0-3P1能级跃迁传递能量,相对于目前报道的理论量子裁剪效率最高的YVO4:Bi3+,Yb3+,GdVO4:Bi3+,Yb3+无论其近红外发光强度还是可见光发光强度强度皆有提升,是一种很有希望的紫外宽带激发近红外发光材料.     

Multi-color long-lasting phosphorescence of rare earth ions in CdSiO<Subscript>3</Subscript> matrix

A series of rare earth ions doped CdSiO3:RE^3 (RE=Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho,Er, Tin, Yb, Lu) multi-color long-lasting phosphorescence phosphors are prepared by the conventional hightemperature solid-state method. The results of XRD measurement indicate that the products fired under 1050~C for 3h have a good crystallization without any detectable amount of impurity phase. Rare earth ions doped CdSiO3 phosphors possess excellent Inmiuescence properties. When rare earth ions such as Y^3 , La^3 , Gd^3 , Lu^3 , Ce^3 , Nd^3 , Ho^3 , Er^3 ,Tm^3 and Yb^3 are introduced into the CdSiO3 host, one broadband centered at about 420 nm resulting from traps can be observed. In the case of other earth ions such as Pr^3 ,Sm^3 , Eu^3 , Tb^3 and Dy^3 , their characteristic line emitting as well as the -420 nm broadband luminescence can be obtained. The mixture of their characteristic line emitting with the -420 nm broadband Inminescence results in various afterglow color.