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991.
Ⅱ-Ⅵ族半导体纳米材料具有特殊的物理化学性质,在光学、电学和光电子等领域都有着巨大的应用前景,因此是纳米材料制备领域的研究热点之一。文章主要综述了近年来溶液相中Ⅱ-Ⅵ族半导体纳米材料制备方法的若干进展情况,并展望了其发展趋势。 相似文献
992.
993.
The electrodeposition of polypyrrole on Al alloy from room temperature ionic liquids 总被引:1,自引:0,他引:1
Jun Nie Dennis E. Tallman Gordon P. Bierwagen 《Journal of Coatings Technology and Research》2008,5(3):327-334
The direct electrodeposition of conjugated polymers onto active metals such as aluminum and its alloys is complicated by the
concomitant oxidation of the metal that occurs at the positive potential required for polymer formation/deposition. We previously
described an approach that uses electron transfer mediation to reduce the deposition potential of polypyrrole (PPy) on aluminum
and aluminum alloy by nearly 500 mV, permitting film deposition from aqueous solution with nearly 100% current efficiency.
In this report, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMIM+TFSI−) has been successfully employed both as the growth medium and the supporting electrolyte for directly depositing uniform
and conductive PPy coatings onto Al alloy 2024-T3 surface via a potentiodynamic technique. The depositions of PPy were carried
out under cyclic voltammetric conditions from 0.3 M pyrrole in ionic liquid solutions. Film morphology was characterized by
atomic force microscopy, optical microscopy, and scanning electron microscopy (SEM). Energy dispersive X-ray analysis and
X-ray photoelectron spectroscopy verified that the TFSI− anion was incorporated into the polymer as the dopant ion. Thickness of the film was measured by SEM and film conductivity
was determined by both a four-point probe technique and by conducting atomic force microscopy. Electrochemical activity of
the film was assessed by cyclic voltammetry. Results from these preliminary studies will be reported.
Presented at the 2007 FutureCoat! conference, sponsored by the Federation of Societies for Coatings Technology, in Toronto,
Ont., Canada, on October 3–5, 2007. 相似文献
994.
Junli Zhang Jianguo Liu Chen Li Yongfeng Nie Yiying Jin 《Cement and Concrete Research》2008,38(5):675-680
The release potential and leaching behavior of five heavy metals (As, Cd, Cr, Cu and Pb) in raw material, clinker and mortar were studied by the three-step sequential extraction procedure proposed by the commission of the European Communities Bureau of Reference (BCR) and NEN7341 leaching test. The results of two experimental methods were compared to show the fixation difference of heavy metals among three kinds of samples. The results of NEN7341 leaching test show that the maximum leached concentration of cement products is low and the leached fraction of five heavy metals represents less than 15% of the total heavy metal content of the cement product. To refer to the bulk content as a criterion of environmental impact is not appropriate. The results of sequential extraction procedures show that the bonding forms of heavy metals change a lot in three samples. The contamination factor (Cf) and the leached fraction of each element in three samples indicate that all the elements are better fixed in cement products than in raw material due to calcination and hydration. To most elements, the relative metal retention is higher in mortar than in clinker. Compared within the five analyzed elements, Cd is better retained and Cu is worse retained in the same kind of sample. 相似文献
995.
996.
在分析平板状固体氧化物燃料电池电化学特性的基础上,建立了Simlink仿真模型,探讨了工作温度和燃料中水蒸气含量对燃料电池理想电势和有效电势的影响。仿真结果表明,低电流密度下,温度的升高会导致有效电势的降低;高电流密度下,有效电势会随着温度升高而增加。水蒸气含量越低,燃料电池的理想电势和有效电势越高。 相似文献
997.
998.
We report a study of a full-coverage octadecylphosphonic acid (OPA or ODPA) self-assembled monolayer (SAM) spin-coated on the native oxide layer (SiO2) of a single crystalline silicon (c-Si) wafer using spectroscopic ellipsometry (SE) and reflectometry (SR). The OPA SAM showed characteristics of being a dielectric film in visible range and becoming absorbing in deep-UV range. By assuming an optical stack model of OPA/SiO2/c-Si for the OPA monolayer system and adopting the parameterized Tauc-Lorentz dispersion model, we obtained an excellent fit of the model to the SE and SR data, from which dispersion of optical functions as well as thickness of the OPA film were deduced. The OPA film thickness measured by atomic force microscopy (AFM) on partial coverage OPA samples was used as the initial trial film thickness in the fitting processes. The deduced OPA film thickness from SE and SR data fitting was in good agreement with that obtained by AFM. 相似文献
999.
建立了电感耦合等离子体发射光谱(ICP-OES)测定印染废水中Al、Cr、Mn、Fe、V、Ni、Cu、Zn、As、Pb等金属元素的分析方法。样品经微波消解后直接用ICP-OES测定,对影响测定的各种因素进行了较为详细的研究,确定了仪器的最佳工作参数,选择了合适的分析谱线。研究结果表明,10种金属元素的检出限在0.26~58.24μg/L之间;线性关系良好,线性相关系数R2≥0.999 9;精密度良好,RSD<3.1%;回收率为90.48%~108.46%。 相似文献
1000.