α-Al2O3纳米粒子对Co-Ni合金异常共沉积电化学行为的影响

为了研究在电化学复合共沉积过程中,惰性纳米粒子和金属离子、电极表面的相互作用,以及由此产生的对合金电化学共沉积行为的影响.本文从两个吸附过程出发: 电解液中的金属离子和H＋在纳米粒子表面的吸附；纳米粒子迁移到阴极表面,在电极表面的吸附.采用Zeta电势和稳态极化以及电化学交流阻抗（EIS）研究了纳米Al2O3粒子和电解液中的金属离子，和电极表面的相互作用,进而分析了纳米粒子对Co2＋和Ni2＋还原沉积的影响规律.通过对阻抗数据的拟合,讨论了Al2O3纳米粒子对等效电路中各物理参数的影响.在H＋和不同金属离子在纳米粒子上发生竞争吸附的基础上,提出了纳米粒子和合金共沉积的可能反应历程.     

Raman spectra and structure of multicomponent oxide planar waveguides prepared by sol-gel

This work was aimed at understanding the structure of SiO₂–MO₂ (M = Ti, Zr, Hf) and SiO₂–HfO₂–MO₂ (M = Ti, Zr) materials, used as mixed oxide glass hosts for Er³⁺ ions in the fabrication of optical planar waveguides by sol-gel processing. This structural study was performed by Waveguide Raman Spectroscopy (WRS), complemented with X-ray diffraction (XRD). The admixture of TiO₂ to HfO₂, SiO₂–HfO₂ and HfO₂–ZrO₂ compositions was found to cause precipitation of nanocrystals of tetragonal HfO₂ or ZrO₂, or the formation of hafnia-titania mixed crystals, depending on the HfO₂/TiO₂ molar ratio.     

二-2,2′:6′,2″-三联吡啶-4′-(4-苯甲酰)-乙二胺的合成

二、三联吡啶作为螯合配体可以和过渡金属离子生成高度稳定的配合物,并具有有趣的物理性质。因此在过去的几十年里,二、三联吡啶金属配合物受到广泛而深入的研究。文章在前人的研究基础上获得了含官能化双(三联吡啶)单元结构的二-2,2′:6′,2″-三联吡啶-4′-(4-苯甲酰)-乙二胺配体,可以作为非共价聚合物的很有效的构建模块,合成有趣的金属超分子聚合物。     

Electrocatalytic Oxidation of Dopamine by Ferrocene in Lipid Film Cast on a Glassy Carbon Electrode

ＩｎｔｒｏｄｕｃｔｉｏｎＤＡｉｓｏｎｅｏｆｅｓｓｅｎｔｉａｌｐａｒｔｉｃｉｐａｎｔｓｉｎｔｈｅｎｅｕｒｏ ｔｒａｎｓｍｉｓｓｉｏｎｐｒｏｃｅｓｓｉｎｍａｍｍａｌｉａｎｃｅｎｔｒａｌｎｅｒｖｏｕｓｓｙｓ ｔｅｍ .ＡｌｏｓｓｏｆＤＡ ｃｏｎｔａｉｎｉｎｇｎｅｕｒｏｎｓｍａｙｒｅｓｕｌｔｉｎｓｏｍｅｓｅｒｉｏｕｓｄｉｓｅａｓｅｓｕｃｈａｓＰａｒｋｉｎｓｏｎｉｓｍ .1Ｓｉｎｃｅｉｔｓｄｉｓｃｏｖ ｅｒｙｉｎｔｈｅ 195 0ｓ ,ＤＡｈａｓｂｅｅｎｏｆｉｎｔｅｒｅｓｔｔｏｎｅｕｒｏｓｃｉｅｎ ｔｉｓｔｓａｎｄｃｈｅｍ…     

Enantioselective Addition of Phenylacetylene to Aldehydes Catalyzed by Polymer-Supported Sulfonamide

Enantioselective formation of C-C bonds is an area of intense research. Among them, the asymmetric addition of alkynyl reagents to aldehydes is very useful for the synthesis of chiral secondary propargyl alcohols.[1] Recently, many significant homogeneous chiral ligands have been disclosed,[2,3] but very few efficient heterogeneous catalysts have been reported. Herein, we report our research results in the asymmetric addition of phenylacetylene to aldehydes catalyzed by polymer-supported chiral sulfonamide.     

Synthesis of N—（4—Salicylideneiminoaryl）monoaza Crown Ethers and Dioxygen Affinities of Their Cobalt（Ⅱ）Complexes

The Schiff base‐containing pendant monoaza crown ether HL¹, HL², HL³ and HL⁴ have been synthesized by condensation of salicylaldehyde with N‐(4‐aminoaryl) monoaza crown ethers, which were prepared conveniently from 4‐nitro‐N, N‐di(hydroxyethyl) aniline or 4‐nitrobenzyl chloride via cyclization or condensation and reduction. The structures of HL¹—HL⁴ were verified by ¹H NMR, IR spectra, MS and elemental analysis. Moreover, the oxygenation constants (KO2) and thermodynamic parameters (δH⁰ and δS⁰) of their cobalt(II) complexes were determined in the range of ?5 °C to 25 °C, and the effect of crown ring bonded to a Schiff base on the dioxygen affinities of cobalt(II) complexes was also observed as compared to the uncrowned analogue (CoL).     

Optical Nanocomposite Planar Waveguides Doped with Rare-Earth and Noble Metal Elements

The present paper is focused on multilayer Er³⁺-doped silica-titania planar waveguides, co-doped with silver, which were prepared by spin-coating on silica glass, or buffered single crystal silicon substrates. The single layer thickness (0.4 m) and refractive index (1.60–1.63) were measured by spectroscopic ellipsometry at 715 nm. The thickness of the waveguides (measured by mechanical profilometry) was 1 m and their optical propagation losses were measured at different laser wavelengths (488 nm, 514 nm and 633 nm), exhibiting an approximately Rayleigh-like behavior. The thermal precipitation of silver nanocrystallites was achieved, both in air and under a controlled atmosphere (dry nitrogen) and these were characterized by visible absorption spectroscopy, which clearly showed the development of a plasmon absorption band near 415 nm, by X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM). The Er³⁺ metastable level lifetimes for the emission at ca. 1.54 m were found to be ca. 4–6 ms, for Er³⁺ concentrations varying between 0.2–2.0 mol% (or (0.4–4.4) × 10²⁰ ions/cm³), but no significant variation was observed with the Ag concentration added (up to 2.5 mol%).     

复合离子液体催化碳四烷基化反应性的研究

合成了一种新型的酸性离子液体催化剂——复合离子液体，该离子液体的阴离子具有双金属的配位中心。同时，研究了复合离子液体催化异丁烷与丁烯烷基化反应的规律。结果表明，在搅拌速率大于1500r/min，反应低于20℃，烃酸比2∶1~3∶1，烷烯比大于15，反应停留5min~10min，使用丁烯-2为碳四烯烃反应原料下，复合离子液体催化碳四烷基化所得烷基化油的研究法辛烷值（RON）最高可达100以上，明显优于常规氯铝酸离子液体催化所得烷基化油的质量。     

Preparation and evaluation of uniform-sized molecularly imprinted polymer beads used for the separation of sulfamethazine

Uniform-sized molecularly imprinted polymer (MIP) beads were prepared using a one-step swelling and polymerization method. The obtained sulfamethazine (SMZ)-imprinted polymer showed high affinity and selectivity toward SMZ and other structurally related sulfonamides in acetonitrile or water-acetonitrile mobile phases, particularly in high aqueous systems. The column performance of the MIPs for SMZ and its analogues could be improved by elevating the column temperature and optimizing the flow rate. The hydrogen-bonding effect plays a significant role in the recognition process of SMZ-imprinted polymer systems in organic media, while the ion-exchange effect, as well as hydrophobic effect, dominates the retention mechanism in aqueous-rich media, in addition to shape recognition.     

Preparation and Photocatalytic Characterization of Nanoporous TiO2

Nanoporous TiO2 photocatalysts were prepared by use of controlled drying method with surfactants. The surface area and porous properties are dependent on the chain length of incorporated surfactant cation. The TiO2 materials prepared in the presence of surfactant molecules during the gel formation exhibit much higher photocatalytic activity than that prepared in the absence of surfactants.