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81.
为提高电镀厚金层的存储性能,采用优化镀层预处理工艺方法,利用换向脉冲电镀技术在铍青铜试件上制备镀厚金层,并研究不同预处理工艺对长时间存储条件下镀层结合力的影响规律;利用X-射线能谱仪研究了优化预处理工艺对存储1~5年后镀厚金层的成分变化规律的影响;利用扫描电子显微镜与能谱仪研究了存储1~5年后镀层与铜基体之间的扩散行为。研究结果表明,换向脉冲电镀厚金层储存5年后,镀铜作为镀金的预镀层,镀层结合力最为优异;换向脉冲电镀厚金层的金原子数分数高于99.9%,镀厚金层具有优异的存储性能,但是镀厚金层界面处存在1.0~1.5μm的相互扩散现象。 相似文献
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Because of rapid growth in population and industrialization, worldwide ethanol demand is increasing continuously. The first‐generation and second‐generation biofuels are unable to meet the global demand of bioethanol production because of their primary value of food and feed. Therefore, algae are among the most potentially significant sources of sustainable biofuels in the future of renewable energy because of the accumulating high starch/cellulose and because they are widely distributed in nature. The focus of this paper is to review the production and recent advances in research and development in the algae bioethanol, including pretreatment, hydrolysis, and fermentation of algae biomass. Despite the many developments made in the recent years, commercialization of algal bioethanol remains challenging chiefly because of the techno‐economic constraints. Technological breakthroughs in all major aspects must be overcome before it can be a successfully large‐scale and commercialized product. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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评述了金属涂装硅烷前处理技术的研究进展,对其成膜与防腐机理、工艺方法以及硅烷产品的改性做了详细的介绍。新型硅烷锆盐复合产品能够显著提高纳米膜层的耐蚀性,硅烷产品与高泳透力电泳涂料配套使用能够保证涂层的性能,硅烷产品稳定性的提高使其在工业生产中得到广泛应用。 相似文献
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针对当前配电网线损计算的特点及数据存在缺失、异常等情况,基于数据分组处理算法(GMDH)建立了配电网线损缺失数据的预处理模型,实现对线损缺失数据的预处理。模型基于最邻近算法确定因变量和自变量缺失值的上下限,并进行随机插补,建立所有变量的数据分组处理模型,寻找最优复杂度模型,计算缺失值并进行迭代循环。算例结果表明,模型计算结果误差小、运算速度快,对缺失的线损数据能进行有效的动态更新,提升了数据质量,优化线损计算分析结果。 相似文献
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Efficient tuning of microstructure and surface chemistry of nanocarbon catalysts for ethylbenzene direct dehydrogenation
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Zhongkui Zhao Yitao Dai Guifang Ge Guiru Wang 《American Institute of Chemical Engineers》2015,61(8):2543-2561
A facile and scalable approach to efficiently tune microstructure and surface chemical properties of N‐doped carbocatalysts through the controlled glucose hydrothermal treatment with diverse parameters and subsequent pyrolysis of pretreated carbonaceous materials with melamine (GHT‐PCM) was presented. Various characterization techniques including high resolution transmission electron microscopy (HRTEM), N2 adsorption desorption (BET), X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), Raman spectroscopy (Raman), and fourier transform infrared spectroscopy (FTIR) were employed to investigate the effect of prior GHT on the microstructure and surface chemical properties of N‐doped carbocatalysts, as well as to reveal the relationship between catalyst nature and catalytic performance in oxidant‐ and steam‐free direct dehydrogenation (DDH) of ethylbenzene for styrene production. It was found that the GHT process and its conditions significantly affect microstructure and surface chemical properties of the N‐doped carbocatalysts, which subsequently influences their catalytic performance in DDH reaction dramatically. Interestingly, the prior GHT can remove the carbon nitride layer formed on parent nanocarbon in the process of melamine pyrolysis, produce structural defects, and tune surface element component, through the “detonation” of polysaccharide coating on nanocarbon. The as‐prepared N‐doped CNT (M‐Glu‐CNT) by the established GHT‐PCM approach demonstrates higher catalytic performance (4.6 mmol g?1h?1 styrene rate with 98% selectivity) to the common N‐doped CNT (M‐CNT, 3.4 mmol g?1 h?1 styrene rate with 98.2% selectivity) as well as to pristine CNT (2.8 mmol g?1 h?1 styrene rate with 96.8% selectivity), mainly ascribed to increased structural defects, enriched surface ketonic C?O groups, and improved basic properties from N‐doping on the M‐Glu‐CNT, those strongly depend on GHT conditions. The excellent catalytic performance of the developed M‐Glu‐CNT catalyst endows it with great potential for future clean production of styrene via oxidant‐ and steam‐free conditions. Moreover, the directed GHT‐PCM strategy can be extended to the other N‐doped carbonaceous materials with enhanced catalytic performance in diverse reactions by tuning their microstructure and surface chemistry. © 2015 American Institute of Chemical Engineers AIChE J, 61: 2543–2561, 2015 相似文献