FEM model of the ohmic resistance of IP-SOFCs

In the present work, the ohmic resistance of an integrated planar-SOFC (IP-SOFC) has been evaluated by developing a model whose equations have been solved numerically through an FEM method. The model allows to estimate the distribution of voltage and current density in the cell. A comparison between simulated and experimental data of area specific resistance is reported, which shows satisfactory agreement. The mathematical model has also been used to carry out some parametric studies for optimisation purposes. Indeed, a reduction in cell pitch length and an increase in electrode thickness are predicted to lead to a reduction in ohmic losses in IP-SOFCs.     

Synthesis and applications of heterobifunctional poly(ethylene oxide) oligomers

Poly(ethylene oxide) (PEO) oligomers are employed extensively in pharmaceutical and biomedical arenas mainly due to their excellent physical and biological properties, including solubility in water and organic solvents, lack of toxicity, and absence of immunogenicity. PEO can be chemically modified and reacted with, or adsorbed onto, other molecules and surfaces. Sophisticated applications for PEO have increased the demand for PEO oligomers with tailored functionalities, and heterobifunctional PEOs are often needed. This review discusses the synthesis and applications of heterobifunctional PEO oligomers possessing amine, carboxylate, thiol, and maleimide functional groups.     

纳米涂料用金属氧化物粉体材料的开发

介绍了纳米金属氧化物的制作技术，纳米粉末团聚问题的解决以及纳米金属氧化物用于涂料中所引起的神奇功能。同时综述了国内外开发纳米涂料的现状。     

Photocatalytic degradation of methyl tert‐butyl ether (MTBE) in contaminated water by ZnO nanoparticles

BACKGROUND: Over the past several decades methyl tert‐butyl ether (MTBE) as additive to gasoline, intended to either boost ratings of fuel or to reduce air pollution, has been accepted worldwide. Since MTBE has high water solubility, the occurrence of fuel spills or leaks from underground storage tanks or transferring pipeline has led to the contamination of natural waters. In this study the degradation of aqueous MTBE at relatively high concentrations was investigated by a UV‐visible/ZnO/H₂O₂ photocatalytic process. The effects of important operational parameters such as pH, amount of H₂O₂, catalyst loading and irradiation time were also investigated. Concentration of MTBE and intermediates such as tert‐butyl formate and tert‐butyl alcohol were measured. RESULTS: Time required for complete degradation increased from 20 to 150 min when the initial concentration was increased from 10 to 500 mg L^?1. The first‐order rate constants for degradation of MTBE were estimated to be 0.183–0.022 min^?1 as the concentration increased from 10 to 500 mg L^?1. Study of the overall mineralization monitored by total organic carbon analysis showed that at an initial concentration of 100 mg L^?1 MTBE complete mineralization was obtained after 100 min under UV‐visible/ZnO/H₂O₂ photocatalysis. CONCLUSION: The data presented in this paper clearly indicated that UV‐visible/ZnO/O₂ as an advanced oxidation process provides an efficient treatment alternative for the remediation of MTBE‐contaminated waters. Copyright © 2008 Society of Chemical Industry     

导数火焰原子吸收法对调味品中锌的测定

将微量脉冲进样技术和导数火焰原子吸收法结合，建立了测定调味品中锌含量的新方法。该方法的检出限为0．013μg／mL，精密度4．46％，回收率96．67～113．33。     

Cu-Cr合金高温氧化行为分析

该文用热分析天平，结合金相、X射线衍射(XRD)、扫描电镜(SEM)和能谱(EXD)研究了Cu—Cr合金在不同温度下的氧化行为。结果表明，Cu—Cr合金在700℃-900℃氧化符合抛物线规律，其最外层氧化膜为CuO，内层为Cu2O和Cr2O3，铬有助于提高合金的抗氧化能力。     

氢化物发生原子吸收光谱法测定金属锌中的痕量汞

采用氢化物发生原子吸收光谱法测定金属锌中的痕量汞，研究了金属锌消解的最佳条件，本法简便、快速、重现性好，准确度高，灵敏度为0．73μg/L，检测限为0．22μg/L，相对标准偏差为3．1％，回收率为96％-102％。     

低工作温度的氧化钨气敏材料

本文报道了一种可以在１００℃左右工作的氢化钨气敏材料，它对氢气和一氧化氮有很高的灵敏度和良好的选择性，并可对空气中的一氧化氮进行探测     

Nitrogen dioxide effect in the reduction of nitric oxide by propane in oxidizing atmosphere

The role of nitrogen dioxide in the selective reduction of NO by propane over a Cu-MFI zeolite is investigated. NO₂ and NO reductions were carried out under similar conditions of reaction. In the presence of oxygen, the reduction of NO by C₃H₈ does not differ significantly from that of NO₂. In the absence of oxygen, the reduction of NO₂ by propane occurs with a partial decomposition of the nitric dioxide molecule. Such a decomposition leads to the formation of oxygen, which is responsible for the increase in catalytic activity by comparison with the same reaction performed with NO. NO₂ formed and released in the gas phase during the reduction of NO by propane in the presence of oxygen does not play a predominant role in the catalytic process.