β-环糊精-氧化石墨烯超分子杂化体的构筑及应用进展

β-环糊精是由7个D-吡喃葡萄糖单元通过α-1,4-糖苷键键连成环的超分子主体分子，“内疏水、外亲水”的独特结构赋予了其优异的分子识别能力；氧化石墨烯类材料凭借其优良特性成为近几年的研究热点。由β-环糊精和氧化石墨烯构筑的超分子杂化体在兼具二者特有性能的基础上又有新功能的引入。本文综述了β-环糊精-氧化石墨烯超分子杂化体的构筑方式，按二者间的连接方式，分别为共价键和非共价键两种连接方式，其中通过共价键连接是目前最主要的构筑方式；此外对β-环糊精-氧化石墨烯超分子杂化体的特征和表征进行了简述。同时对β-环糊精-氧化石墨烯超分子杂化体在水污染处理、电化学检测、药物控释和催化等领域的应用进展进行了综述。最后对该超分子杂化体在构筑和应用上的发展趋势进行了展望。     

Interactions between Cytochrome c and DNA Strands Self-Assembled at Gold Electrode

In this work, we reported the investigation on the interaction between DNA strands self-assembled at gold electrodes and an electron transfer protein, cytochrome c. We observed that cytochrome c exhibited well-defined electrochemistry in both double-stranded and single-stranded DNA films. This suggested that the electron transfer reaction of cytochrome c arose possibly due to the electron hopping along DNA strands rather than wiring along the double helix. We also compared the heterogeneous electron transfer rate of cytochrome c with that of a ruthenium complex, which further confirmed this mechanism.     

竹红菌甲素衍生物13－SO_3Na－DDHA电化学及光诱导还原的研究

本工作研究了化合物１３－ＳＯ＿３Ｎａ－ＤＤＨＡ在不同ｐＨ的缓冲溶液中的电化学氧化还原行为．实验证明：化合物中羰基的还原电位与ｐＨ之间存在线性关系，其直线的斜率为６０ｍＶ／ｐＨ．并证明了此过程为一步两电子、两质子还原过程：Ｑ＋２Ｈ￣＋＋２ｅ＝ＱＨ＿２．ＤＭＦ作为非质子溶剂，具有很好的稳定自由基的作用．向缓冲溶液中加入ＤＭＦ后，化合物１３－ＳＯ＿３Ｎａ－ＤＤＨＡ为两步单电子还原过程，相应溶液中的光诱导电子转移吸收光谱证实了以上电化学的结果．     

Electrochemical copolymerization of carbazole and 3‐methylthiophene

The copolymerization of carbazole (CZ) and 3‐methylthiophene (3MeT) was successfully performed electrochemically in freshly distilled boron trifluoride diethyl etherate by direct anodic oxidation of the monomer mixtures, although the oxidation potentials of CZ and 3MeT were quite different. The electrochemical properties of the copolymers were studied with cyclic voltammetry. The influence of the applied polymerization potential on the synthesis of the copolymers was investigated. The higher potential favored the incorporation of 3MeT units into the copolymers. The insertion of 3MeT units into polycarbazole (PCZ) was helpful in improving the conductivity of PCZ. The novel copolymers had the advantages of both PCZ and poly(3‐methylthiophene), that is, good redox activity, good thermal stability, and high conductivity. The structure and morphology of the copolymers were investigated with ultraviolet–visible, infrared spectroscopy, thermal analysis, and scanning electron microscopy. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1877–1885, 2006     

生物脱氮工艺的新发展-半硝化和厌氧氨氧化

传统生物脱氮工艺耗能多，反硝化时还消耗碳源，半硝化一厌氧氨氧化（SHARON－ANAMMOX）是一种全新的脱氮工艺，其原理是首先由亚硝化细菌将废水中1／2氨氮氧化为NO2^-，剩余的氨氮与所生成的NO2^-以等摩尔比例ANAMMOX菌作用生成N2，因耗能少且不消耗碳源，故具有可持续发展意义。     

电化学氧化法处理生活污水的研究

采用电化学氧化法处理生活污水,探讨了电解质浓度、电流密度、pH值、反应温度、不同电极等对COD、浊度的影响。实验表明,处理水中COD、浊度的最佳条件是:电解质浓度为45 g/L,pH值为8,电流密度为60 mA/m2,温度为22℃,阳极为RuSn电极,阴极使用不锈钢电极。此时COD去除率达86.22%,浊度去除率达80%,悬浮固体去除率和细菌去除率94%和99%。     

重金属废水处理最新进展

详细论述了近年来一些处理重金属废水的新方法，并对各种方法进行了综合评述。这些新方法主要有：廉价吸附剂吸附、胶束增强超滤、络合—超滤耦合过程和电化学法。此外，将络合—超滤和电化学法集成起来处理重金属废水，可实现废水回用和重金属回收，因而具有广阔的应用前景。     

X-ray Photoelectron Spectroscopy of Cadmium Tin Oxide Ceramics in As-Fired and Electrochemically Reduced Forms

X-ray photoelectron spectroscopy (XPS) has been employed to investigate the chemical nature of samples of dicadmium stannate (Cd₂SnO₄) in the as-fired, electrochemically reduced, and reoxidized states. The reduction of Cd₂SnO₄ was found to be associated with a dramatic color change from bright yellow to dark green, a phenomenon commonly known as the electrochromic effect. Both quantitative XPS results and binding energy measurements proved that, upon exposure of the reduced ceramic bodies to air, the Sn²⁺ to Sn⁴⁺ transition readily took place to produce the intermediate compound, Cd₂SnO₃ with divalent tin. Prolonged exposure to the atmosphere did not result in further progress of reoxidation extending to monovalent cadmium. However, complete reoxidation of the reduced samples was possible by annealing in air at 350°C for a short period of time, e.g., 3 h, by which the original features of the as-fired state such as color and electrical conductivity were restored. The results also showed that reoxidized samples at high temperature assume the same XPS characteristics as those of as-fired ceramics.     

Electroreduction of laccase covalently bound to organothiol monolayers on gold electrodes

Cerrena unicolor laccase was immobilized on the gold electrode by covalent bonding to self-assembled monolayers of mercaptoundecanoic or mercaptopropionic acids. STM images of immobilized laccase proved high population of the laccase molecules on the monolayer modified electrode. The SERS experiments in concert with resonance Raman effect confirmed that the structure at the “blue” copper site of the immobilized protein remained intact. The accessibility of individual copper sites for electron exchange with the gold electrode surface was investigated by voltammetry. The electrode behavior of laccase is different in the presence and absence of oxygen, showing that the immobilized enzyme is reactive towards oxygen. Addition of two common mediators improved the electrical connectivity of the enzyme with the electrode, increased the catalytic efficiency of immobilized laccase and switched the onset of catalytic current to the potentials of the mediator. Immobilization of laccase on well-organized mercaptoundecanoic acid separates efficiently the enzyme from the electrode and does not allow easy access of mediators to the surface. Attachment of the enzyme at smaller distance from the electrode by means of significantly shorter spacer molecule—mercaptopropionic acid improved the efficiency of catalytic reduction of oxygen on the monolayer modified electrode.     

Reducing N losses (NH3, N2o, N2) and immobilization from slurry through optimized application techniques

In model, pot and field trials the effect of C reduced slurries and different application techniques on N losses and N immobilization were investigated. The C reduced slurries were produced by mechanical separation. Ammonia losses from surface-applied and injected cattle slurry were measured under field conditions using a wind tunnel system. Injection of slurry was the most efficient way to reduce volatilization of ammonia. After 6 days the total loss from the injected slurry was only 9% of that from surface band application. Furthermore, additional losses of N may occur through denitrification, specially after injection of slurry which may create an anaerobic environment abundant in readily oxidizable C. Therefore denitrification measurements by the acetylene inhibition technique were conducted. Until 100 days after application the loss from the injected slurry was 7.3 kg compared to 4.5 kg N ha^–1 from surface band applied slurry. After injection, denitrification was only 4.1 kg N ha^–1 for C reduced compared to 6.5 kg N ha^–1 for normal slurry. In pot trials the ammonium-¹⁵N of normal slurry and C-reduced slurry was utilized by oats between 52 and 60%, the ammonium sulfate by 67%. The increased biomass C confirmed a greater immobilization of the NH₄-N of the normal slurry resulting in a lower initial efficiency.Dedicated to Prof. Dr. A. Amberger on his 75th birthday