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51.
This series of investigations was intended to clarify phenomena associated with electrochemical injection of the organic base corrosion inhibitors, ethanolamine and guanidine, into carbonated concrete. In Part 1, experiments were conducted with laminated specimens of carbonated cement paste, that were specially designed to facilitate analysis with adequate spatial resolution to assess changes in their pore solution phase chemistry after they had been subjected to constant current electrolysis between embedded cathodes and external anodes. The anolyte solutions provided sources of ethanolamine or guanidine in contact with the exterior specimen surfaces. Effects of variations in the applied current density and duration of electrolysis on the concentration profiles of the two inhibitors and the other main constituents of the pore solution phase were determined. The results have been used to underpin the development of a mathematical model, which is described in Part 2.  相似文献   
52.
Thermochromic poly(vinyl alcohol) (PVA)‐based material was synthesized and an extensive study of its thermochromic behavior with respect to response time was carried out. It was observed that it is possible to manipulate the response time by keeping control over chemical and physical parameters. The response time, which is the most important property of a smart material, has in this case been found to be very much influenced by rate of heat transfer into the material. Different compositions of the thermochromic material and their corresponding response time with respect to rate of heat transfer were studied and correlated. First, a theoretical equation was derived and later on it was experimentally verified to quantify the response time in PVA–metal complex‐based thermochromic systems. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4832–4834, 2006  相似文献   
53.
54.
The oxidation of benzyl alcohol to benzaldehyde has been investigated in the absence of solvent using zeolite-supported Au and Au–Pd catalysts. Three zeolites were investigated, ZSM-5, zeolite β and zeolite Y, and these were contrasted with the titanoslicalite TS-1 and TiO2 as supports. For the Au catalysts the best results are obtained with zeolite β as the support and the conversions were comparable or better than those observed with TiO2 in terms of turn over frequencies. However, the selectivities observed with the acidic zeolites were lower than the non-acidic TS-1 and TiO2. This is due to the subsequent reaction of benzaldehyde via acid catalysed reactions to give benzyl benzoate and its dibenzyl acetal, and, in some cases dibenzylether. Initial catalysts were evaluated with a gold loading of 2 wt% and increasing this to 4 wt% showed the expected increase in activity, indicating that there is scope to improve the performance of these catalysts. The most active catalysts were prepared by impregnation and catalysts prepared by deposition precipitation were considerably less active. Introduction of Pd into the catalyst improved the activity without significantly affecting the selectivity.  相似文献   
55.
通过在AEO3中添加不同加成数的AEO进行低温浑浊试验,并分析比较AEO3低温分层后的上清液与下层浑浊物中AEO的分布,发现EO加成数在5以上的AEO是导致AEO3低温浑浊的原因之一。在AEO3及其上清液中分别添加不同质量分数的脂肪醇、水以及醋酸钠进行低温浑浊试验,发现脂肪醇、水分和醋酸钠不是造成AEO3低温浑浊的原因,但会使AEO3在低温下容易冻结。  相似文献   
56.
讨论了一种快速测量AES中未硫酸化物的方法。首先将配制好的AES-乙醇溶液,通过离子交换树脂,然后收集、蒸馏、干燥得到的液体,称重后即可得到未硫酸化物的含量,采用该方法比国家标准节约2.5~3h的分析时间。  相似文献   
57.
通过一系列低温浑浊试验考察了聚乙二醇含量与分子质量对脂肪醇聚氧乙烯醚(AEO3)低温浑浊的影响,并分析AEO3低温分层后的上清液和下层浑浊物中聚乙二醇的含量与分布,发现分子质量在600以上的聚乙二醇是影响AEO3低温浑浊的重要原因。  相似文献   
58.
M.A. Gauthier  D. Calvet  X.X. Zhu  M. Garon 《Polymer》2004,45(24):8201-8210
The limited swellability in polar media of the commonly used polystyrene/divinylbenzene (PS-DVB) support materials for solid-phase organic synthesis has led to the development of novel, highly swellable hydrophilic gels designed for use in aqueous or polar media. Poly(vinyl alcohol) beads crosslinked with epichlorohydrin (PVA-EP) were prepared by a two-step inverse-suspension polymerization method. While it is known that the morphology of the resulting beads can be controlled by the ratio of EP versus PVA as well as by the pre-crosslinking time, the actual degree of crosslinking of the beads and their mechanical properties remain unknown. It is therefore the purpose of this study to evaluate the actual degree of crosslinking of beads prepared with different quantities of crosslinker in the feed by spectroscopic (Raman, nuclear magnetic resonance) and chemical (functional group loading) methods. The mechanical properties of these swollen PVA-EP beads will be evaluated by single-bead unconfined compression in solvents such as water, N,N-dimethylformamide (DMF), and tetrahydrofuran (THF) and compared to model PS-DVB beads commonly used for solid phase synthesis.  相似文献   
59.
We describe in this paper a new methodology for blood alcohol content (BAC) estimation of a subject. Rather than using external devices to determine the BAC value of a subject, we perform a behaviour analysis of this subject using intelligent systems. We monitor the user’s actions in an ordinary task and label those data to various measured BAC values. The obtained data-set is then used to train learning systems to detect alcoholic consumption and perform BAC estimation. We obtain good results on a mono-user base, and lower results with multiple users. We improve the results by combining multiple classifiers and regression algorithms.  相似文献   
60.
介绍了粗品四氢呋喃的除醇技术,过氧化物的生成机理与抗氧化技术。  相似文献   
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