The Spectroscopic Properties of Tm and Ho Co-doped YVO_4 Crystal

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　　ＴｈｅｓｔｕｄｙｏｎｔｈｅＹＶＯ4ｃｒｙｓｔａｌｃａｎｂｅｔｒａｃｅｄｂａｃｋｔｏ 1 970′ｓ.Ｈｏｗｅｖｅｒｄｕｅｔｏｉｔｓｐｏｏｒｈｅａｔｃｏｎｄｕｃｔｉｖｉｔｙ ,ｉｔｈａｓｎｏｔｂｅｅｎｃｏｎｓｉｄｅｒｅｄａｓａｇｏｏｄｃａｎｄｉｄａｔｅｆｏｒｆｌａｓｈｌａｍｐ ｐｕｍｐｅｄｌａｓｅｒｓｙｓｔｅｍ .Ｌａｔｅｌｙ ,ｔｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆＬＤｌａｓｅｒａｎｄｎａｒｒｏｗｂａｎｄＬＤ ｐｕｍｐｉｎｇｔｅｃｈｎｏｌｏｇｙａｉｍｅｄａｔｔｈｅａｂｓｏｒｐｔｉｏｎ ｐ…     

Model Studies of Doped Iron Oxides. Reduction process of magnetite doubly doped with calcium and magnesium

The paper presents results of research on the effect of the presence of calcium and magnesium in magnetite structure on its reducibility. These are model studies of the phase which mostly affects reducibility of superfluxed sinter. Examinations were carried out on samples melted and crystallized in a single crystal growing process. This revised version was published online in August 2006 with corrections to the Cover Date.     

Phosphorized zirconium oxide nanoparticles

In this work a simple method to phosphorize the surface of nanometric particles of crystalline zirconia is described. The reaction rate of phosphorization was regulated by adding acetic acid and the observed particle size was in the range 40–60 nm. A proton conductivity of the order of 10^?3 S cm^?1 was measured for phosphorized nanoparticle powder mixed with micro‐fine teflon powder (3:1) at room temperature. Phosphorized nanoparticles are stable when dispersed in acetic acid and are suitable for composite material preparation. Copyright © 2005 John Wiley & Sons, Ltd.     

Twin Junctions in Monoclinic Zirconia

Analysis of high-resolution transmission electron microscopy images of the microstructure of monoclinic zirconia film has revealed that some areas are built entirely of twins. Twin boundaries form triple and quadruple junctions. While the misorientations of the constituent boundaries are completely balanced at quadruple junctions, there is a small rotational mismatch at the junctions of three twin boundaries. This mismatch is compensated by wedge disclinations. Crystallography of the triple junctions is considered and factors stabilizing intrinsic junction disclinations are discussed.     

功能化荧光素掺杂二氧化硅纳米粒子用于免疫层析试验

A simple but effective approach was developed to synthesize amino functionalized fluorescein isothiocyanate-doped silica nanoparticles based upon polycondensation of tetraethoxysilane. Organic dye molecule (fluorescein isothiocyanate) coupled with a silane coupling agent, 3-aminopropyltriethoxysilane, was incorporated into silica sphere through controlled hydrolysis and polymerization of tetraethoxysilane. The dye was connected with silica sphere through 3-aminopropyltriethoxysilane, which avoided the leakage of the dye. The cohydrolysis and polymerization of tetraethoxysilane and 3-aminopropyltriethoxysilane outside the surface of the silica sphere formed another thin silica shell with the functionalized amino groups on the surface. With amino groups on the surface, the nanoparticle surface was affluent in positive charges. The amino-functionalized nanoparticles were linked with mouse monoclonal antibody against hepatitis B virus surface antigen through electrostatic interaction to form fluorescence probes, which were tested by immunochromatographic assay using immunochromatography test strip. It was indicated that the fluorescence probe was suitable for immunoassay.     

La0.8Sr0.2MnO3/YSZ电极氧电化学还原反应动力学

用线性极化、循环伏安、电位阶跃等方法详细研究了Ｌａ０．８Ｓｒ０．２ＭｎＯ３／ＹＳＺ高温电极上进行的氧化学还原反应。实验结果表明，该反应存在两条路径：低温下氧还原反应主要发生在气相－ＬＳＭ电极－ＹＳＺ电解质接触的三相界面（ＴＰＢ），速度控制步骤为氧原子在ＬＳＭ表面的浓差扩散，高温下由于氧空位在ＬＳＭ表面的形成，氧还原反应区扩展至ＬＳＭ电极表面，速度控制步骤为氧的电荷转移反应，实验同时发现：氧空位的形     

Selective Detection of Ascorbic Acid Using Octacyanomolybdate‐Doped‐Glutaraldehyde‐Cross‐Linked Poly‐L‐Lysine Film Modified Glassy Carbon Electrode

The present work describes oxidation of ascorbic acid (AA) at octacyanomolybdate‐doped‐glutaraldehyde‐cross‐linked poly‐L ‐lysine (PLL‐GA‐Mo(CN) film modified glassy carbon electrode in 0.1 M H₂SO₄. The modified electrode has been successfully prepared by means of electrostatically trapping Mo(CN) mediator in the cationic film of glutaraldehyde‐cross‐linked poly‐L ‐lysine. The dependence of peak current of modified electrode in pure supporting indicates that the charge transfer in the film was a mixed process at low scan rates (5 to 200 mV s^?1), and kinetically restrained at higher scan rates (200 to 1000 mV s^?1). Cyclic voltammetry and rotating disk electrode (RDE) techniques are used to investigate the electrocatalytic oxidation of ascorbic acid and compared with its oxidation at bare and undoped PLL‐GA film coated electrodes. The rate constant of catalytic reaction k obtained from RDE analysis was found to be 9.5×10⁵ cm³ mol^?1 s^?1. The analytical determination of ascorbic acid has been carried out using RDE technique over the physiological interest of ascorbic acid concentrations with a sensitivity of 75 μA mM^?1. Amperometric estimation of AA in stirred solution shows a sensitivity of 15 μA mM^?1 over the linear concentration range between 50 and 1200 μM. Interestingly, PLL‐GA‐Mo(CN) modified electrode facilitated the oxidation of ascorbic acid but not responded to other electroactive biomolecules such as dopamine, uric acid, NADH, glucose. This unique feature of PLL‐GA‐Mo(CN) modified electrode allowed for the development of a highly selective method for the determination of ascorbic acid in the presence of interferents.     

氧化硅掺杂对硫酸化氧化锆酸性中心浓度和强度的提高

用氧化硅掺杂硫酸化氧化锆可以增强硫酸化氧化锆的酸性. 以413～453 K下甲醇液相脱水为模型反应考察了改进催化剂的性能. 结果表明,在掺杂和未掺杂氧化硅的硫酸化氧化锆催化剂上甲醇均相继脱水生成二甲醚和乙烯. 在掺杂了氧化硅的催化剂上还有一定量的丙烯生成,而未掺杂氧化硅的催化剂上则没有丙烯生成.     

Comparative study of the textural and structural properties of the aerogel and xerogel sulphated zirconia

Aerogel and xerogel sulphated zirconia with defined atomic ratio S/Zr = 0.5 and molar hydrolysis ratio h = nH₂O/nZrO₂ = 3 show different textural and structural properties after calcination at high temperatures. The aerogel obtained just after solvent evacuation develops only the tetragonal phase, whereas the xerogel dried in an oven is amorphous. Heating to a temperature above 833 K, leads to transition of the tetragonal phase to the monoclinic one for the two solids, due to sulphur loss but the tetragonal phase remains stable for the aerogel . Raman, Infrared and XPS spectroscopies show that the loss of the sulphur at high temperatures seems to be easier for the xerogel than for the aerogel.     

Anodic Oxidation Behaviors of Formaldehyde at Boron‐Doped Diamond Electrodes

The electrochemical behaviors of formaldehyde (FA) at boron‐doped diamond (BDD) electrodes are investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and linear scanning voltammetry (LSV) techniques. The CV results show that the oxidation reaction of FA is influenced by the hydroxyl concentration in the solution, and the peak current response with the FA concentration is linear at the range from 10 to 100 mM. The differential capacitance from EIS results indicate that the FA molecules adsorb at the BDD electrode surface at low potential (from 1.0 to 1.4 V). The kinetic studies have been examined with the various concentrations of FA, pH, and temperature. The activation energy of FA oxidation is also calculated. The results of kinetic study indicate that the adsorption of FA molecules at the BDD electrode is the rate‐determining step at low potential (from 1.0 to 1.40 V).