Low-temperature Catalytic Reduction of Nitrogen Monoxide with Carbon Monoxide on Copper Iron and Copper Cobalt Composite Oxides

通过共沉淀法, 在低温下制备了铜铁复合氧化物CuO/Fe2O3和铜钴复合氧化物CuO/Co3O4．利用GC微反应器评价了这些复合氧化物的催化活性和热稳定性,结果表明, CuO/Fe2O3和CuO/Co3O4的NO100%转化温度分别为80和90 ℃,该催化活性和热稳定性在较宽的温度和较长的时间范围内都能得以保持．此外,还系统研究了试剂的摩尔比率、NaOH的体积、陈化时间、煅烧温度和煅烧时间对该复合氧化物催化活性的影响．     

锂离子电池正极材料Li[Li0.2Mn0.54Ni0.13Co0.13]O2的合成及电化学性能研究

以LiOH•H₂O, Ni₂O₃, Co₃O₄和MnO₂为原料, 经过机械活化后在空气气氛下经高温烧结, 合成了锂离子电池正极材料Li[Li_0.2Mn_0.54Ni_0.13Co_0.13]O₂. 通过X射线衍射(XRD)、扫描电子显微镜(SEM)和电化学性能测试对所得样品的结构、形貌及电化学性能进行了表征. 结果表明, 900 ℃下烧结10 h后可获得晶粒细小均匀的层状Li[Li_0.2Mn_0.54Ni_0.13Co_0.13]O₂材料, 并具有良好的电化学性能, 在室温下以60 mA/g的电流充放电, 首次放电比容量可达到248.2 mAh/g, 循环50次后放电比容量为239.4 mAh/g, 容量保持率为96.45％. 测试了该材料的高低温循环性能.     

各种形貌的纳米Co3O4的制备及其应用*

本文综述了各种形貌的纳米Co₃O₄的制备及其应用。制备纳米Co₃O₄的方法有很多,包括热分解、水热法、溶剂热法、化学喷雾热分解、化学气相沉积和溶胶-凝胶法。各种形貌的Co₃O₄被制备,如纳米球、纳米立方体、纳米管、纳米棒、纳米片、纳米纤维和介孔结构。Co₃O₄是一种重要的磁性P-型半导体,在锂离子电池、超级电容器、电致变色、磁性材料、气体传感器和催化剂等诸多领域有比较广泛的应用。     

Synthesis of arnebinol,an ansa-type prenylated phenol with effects inhibitory to prostaglandin biosynthesis

Arnebinol, a new ansa-type prenylated phenol, was synthesized in 12 steps from geraniol and p-benzoquinone in 5.1 % overall yield.     

Reactions of co-ordinated ligands: Kinetics and mechanisms in the charge transfer interaction between dichloro or diaquo triethylene tetramine Co(III) and ferrocyanide

The cherry red-coloured solid state product obtained by the reaction ofcis-σ diaquo Co (III) triethylene tetramine with ferrocyanide was examined by thermogravimetric, infrared and M?ssbauer techniques. Its electronic spectrum in aqueous medium was interpreted to consist of charge transfer IT transition at 440 nm and a ligand field transition around 330 nm. The kinetics of formation of this 1:1 product in solution was also studied.     

Elimination of zinc interference in the voltammetric determination of cobalt by using iminodiacetic acid

The voltammetric determination of cobalt carried out by adsorbing cobalt dimethylglyoxime onto a mercury electrode and subsequently measuring the current for the reduction of the adsorbed species is subject to interference by zinc. If this interference is neglected and the determination carried out by standard additions large errors may result. The interference can be eliminated by adding iminodiacetic acid.     

Cytotoxic and radiosensitizing effects of nano-C<Subscript>60 </Subscript>on tumor cells in vitro

There is growing evidence in recent years that the pristine fullerene may be endowed with strong pro-oxidant capacity to biological samples. In this investigation we tested the hypothesis that water-soluble fullerene-C₆₀ (nano-C₆₀) may interact with ionizing radiation enhancing its antiproliferative effects. The two tumor cell lines with different radiosensitivity B16 and SMMU-7721 were treated by a combination of pristine fullerene and ⁶⁰Co γ irradiation. We measured cell survival rates, apoptotic characteristics, reactive oxygen species (ROS) production and alteration of cell diameter with or without γ-irradiation. There was reduced survival with B16 and SMMU-7721 cells exposed to nano-C₆₀, with the inhibitory concentrations reducing the viability by 50% to 65 part per billion (ppb) and 150 ppb respectively. For cells exposed to nano-C₆₀ prior to γ-irradiation, damage to cell membranes and increased numbers of apoptotic cells were detected by morphologic Hoechst-staining analysis and Annexin V/propidium iodide double-staining. In cells exposed to nano-C₆₀, there were increased levels of ROS, as measured by fluorescence detection under laser confocal microscopy. Preincubation with non-toxic pristine C₆₀ before γ-ray caused enlargement of cells with increased diameter. The results show that nano-C₆₀ inhibits the growth of tumor cells at certain concentrations and increases the effects of ⁶⁰Co γ-irradiation, possibly through the elevated production of cellular ROS and the membrane disruption. Data in this study indicates a possible consideration of using C₆₀ as a candidate of sensitization modifier in tumor radiation biology.     

The quasicrystal-crystal interface between icosahedral Al-Pd-Mn and deposited Co: Evidence for the affinity of the quasicrystal structure to the CsCl structure

We have evaporated Co on the pentagonal surface of an icosahedral Al-Pd-Mn quasicrystal kept at room temperature. For submonolayer Co deposits, five AlCo domains are formed exposing their (1 1 0) faces parallel to the surface and rotated by 72° with respect to each other. The orientational relationship between these domains and the substrate is determined by the optimum matching of the average quasicrystal structure and the CsCl structure with a lattice constant of about 2.88 Å. For further deposition, body-centred cubic Co domains grow epitaxially on the AlCo domains.     

Magnetic properties of single crystalline Zn1−xCoxO thin films

We report on the magnetic properties of single crystalline thin films of Zn_1−xCo_xO (x=0.003–0.14) grown by plasma-assisted molecular beam epitaxy. In order to understand the role of intermediate charge carriers in the magnetic properties of this material two types of films were fabricated, with and without Ga-codoping. Magnetic measurements were made between 2 and 300 K in fields up to 5 T with a Quantum Design SQUID magnetometer. We found that all the tested films exhibit paramagnetic behavior following the Curie–Weiss law, χ=C/(T−θ), with negative Curie–Weiss temperatures and that this behavior holds even under strong n-doping. We show that the magnetization data, M(H), in function of the Co content provide additional evidence in favor of the antiferromagnetic Co–Co interaction in this material. We also observe that these data exhibit an ‘easy plane’ magnetic anisotropy for all the studied Co concentrations. Finally, we develop a simple cluster model, in order to describe the magnetic properties of ZnCoO, which is found to be in good agreement with our experiments.