“本博学位论文连做”培养模式的探索与研究*

“本博学位论文连做”培养模式是学士论文阶段在夯实理论基础的同时,改变本科阶段以学习课程为主的思维模式为以创新研究为主的思维模式;短暂的硕士阶段在理论知识进一步升华的基础上掌握本学科的研究现状和发展方向,提升发现问题、分析问题和解决问题的能力;博士阶段瞄准学科前沿,启发其发掘“新方法”和“新思路”,有效地实现学士学位论文和博士学位论文连做。     

NiCo_2O_4对H_2O_2在碱性溶液中电化学还原反应的催化行为(英文)

利用溶胶-凝胶法合成纳米NiCo2O4,并利用X射线衍射和透射电镜分析其结构和表面形貌.结果表明NiCo2O4具有尖晶石结构,平均粒径约为15 nm.利用电势线性扫描和恒电势法测定了其对H2O2在碱性溶液中电化学还原反应的催化性能.发现NiCo2O4对H2O2电化学还原具有高的催化活性和稳定性,在H2O2浓度低于0.6 mol.L-1时,其电化学还原反应主要通过直接还原途径进行.以NiCo2O4为阴极催化剂的Al-H2O2半燃料电池在室温下的开路电压达1.6 V;在1.0 mol.L-1 H2O2溶液中,峰值功率密度达209 mW.cm-2,此时电流密度为220mA.cm-2.     

磷钼酸作为低温碳燃料电池的碳间接电氧化介质

以磷钼酸作为低温下碳间接电氧化的介质构建新型碳燃料电池。通过线性电位扫描和计时电流法研究不同碳材料、不同反应条件、不同反应时间、不同磷钼酸浓度对碳间接电氧化性能的影响。采用循环伏安法研究碳在磷钼酸介质中的间接电氧化机理。研究结果表明,椰壳活性炭的间接电氧化活性要明显高于煤和煤质活性炭。以磷钼酸为介质时,采用光照与升温80oC避光的条件均可以提高碳间接电氧化性能,且提高程度接近。由循环伏安测试分析出磷钼酸中+6价Mo可将碳氧化,且被还原成+5价Mo,随后又在阳极上重新被电氧化回+6价Mo,通过该过程将从碳材料上获得的电子转移到阳极上,从而实现碳在低温条件下的间接电氧化过程。并且通过对光照条件的分析,证实光对磷钼酸催化碳电氧化反应有两方面的促进作用:一方面光的热效应使反应温度升高,从而提高反应速率;另一方面磷钼酸利用其特有结构吸收光能,提高磷钼酸与碳的反应速率,且后者促进作用更明显。以VO2+/VO2+为阴极构建的碳燃料电池全电池室温下功率是0.087m W?cm-2,验证了碳燃料电池在常温条件下运行的可行性。     

含吡啶鎓阳离子的阴离子受体的研究进展

本文综述了近年来含吡啶鎓阳离子受体在阴离子识别领域的研究进展。系统阐述了以吡啶鎓阳离子为主要识别位点的环状、非环状和互锁型阴离子受体的设计合成以及在阴离子识别领域的应用。     

以泡沫镍载NiCo2O4纳米线阵列为阴极催化剂的Al-H2O2半燃料电池

研究了以泡沫镍载NiCo2O4纳米线阵列为阴极催化剂的Al-H2O2半燃料电池的性能. 以无模板生长法制备了泡沫镍载NiCo2O4纳米线阵列阴极材料, SEM测定结果表明, NiCo2O4纳米线几乎垂直于泡沫镍载体表面生长. 以电压和功率密度-电流密度曲线研究了H2O2浓度、电解液流速和温度对电池性能的影响, 结果显示, 以铝片为阳极, 0.6 mol/L H2O2为氧化剂的电池的开路电压约为1.40 V; 在室温和57 ℃下, 电流密度为98和172 mA/cm2时, 最大功率密度分别达到79和120 mW/cm2.  在5000 s的测试时间内, 0.70 V的恒电流密度和75 mA/cm2 的恒电压值几乎为一常数, 这表明以泡沫镍载NiCo2O4纳米线阵列为催化剂电还原H2O2具有很好的活性、稳定性和传质性能.     

集值局部平方可积鞅

介绍集值类（D）过程和集值局部鞅的概念和有关性质，进而讨论了集值局部平方可积鞅的概念和性质。     

A one-pot combination of amine and heterocyclic carbene catalysis: direct asymmetric synthesis of β-hydroxy and β-malonate esters from α,β-unsaturated aldehydes

The one-pot combination of amine and heterocyclic carbene catalysis (AHCC) enabled the synthesis of β-hydroxy, β-malonate and β-amino esters from α,β-unsaturated aldehydes with high enantioselectivity (91-97% ee).     

Common Features in Electronic Structure of the Oxypnictide Superconductors from Photoemission Spectroscopy

High resolution photoemission measurements are carried out on non-superconducting LaFeAsO parent com- pound and various superconducting RFeAs（O1-ZFx） （R=La, Ce and Pr） compounds. It is found that the parent LaFeAsO compound shows a metallic character. By extensive measurements, several common features are identified in the electronic structure of these Fe-based compounds： （1） 0.2 eV feature in the valence band, （2） a universal 13-16 meV feature, （3） near EF spectral weight suppression with decreasing temperature. These uni- versal features can provide important information about band structure, superconducting gap and pseudogap in these Fe-based materials.     

Catena-dichloro（4,4＇-dimethyl-2,2＇-bipyridine） Cadmium（Ⅱ）, a New One-dimensional Chain with Blue Fluorescent Emission

A new μ-chloro-bridged one-dimensional coordination polymer [Cd（dmbpy）Cl2]a （dmbpy = 4,4＇-dimethyl-2,2＇-bipyridine） has been synthesized and structurally characterized by elemental analyses, IR, UV spectra and single-crystal X-ray diffraction. The complex crystallizes in the monoclinic system, space group C2/c with a = 17.745（4）, b = 10.326（2）, c = 7.3382（15）A, β = 106.85（3）°, V = 1286.9（4）A^3, Z = 4, C12H12N2Cl2Cd, Mr = 367.54, Dc = 1.897 g/cm^3, F（000） = 720, 2（MoKα） = 0.71073 A,μ= 2.089 mm^-1, R = 0.0368 and wR = 0.1048 for 1041 observed reflections （I 〉 2σ（I））. Cadmium（Ⅱ） adopts a distorted octahedral coordination geometry and adjacent coordination chains are intercalated in a zipper-like fashion into 2D layers through the π-π stacking interactions between dmbpy. Fluorescent analyses show that it exhibits intense blue photoluminescence in both DMF and DMSO solutions at room temperature.     

One-pot organocatalytic domino Michael/alpha-alkylation reactions: direct catalytic enantioselective cyclopropanation and cyclopentanation reactions

The development of one-pot organocatalytic domino Michael/alpha-alkylation reactions between bromomalonates or bromoacetoacetate esters and alpha,beta-unsaturated aldehydes is presented. The chiral-amine-catalyzed reactions with bromomalonates as substrates give access to the corresponding 2-formylcyclopropane derivatives in high yields with excellent diastereoselectivity and up to 99 % ee. The catalytic domino Michael/alpha-alkylation reactions between 4-bromo-acetoacetate and enals provide a route for the synthesis of functionalized cyclopentanones in good to high yields with 93-99 % ee. The products from the organocatalytic reactions were also reduced with high diastereoselectivity to the corresponding cyclopropanols and cyclopentanols, respectively. Moreover, one-pot combinations of amine and heterocyclic carbene catalysis (AHCC) enabled the highly enantioselective synthesis of beta-malonate esters (91-97 % ee) from the reaction between bromomalonates and enals. The tandem catalysis included the catalytic domino reaction followed by catalytic in situ chemoselective ring-opening of the 2-formylcyclopropane intermediates.