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71.
C. Price L. Pastor-Pérez E. le Saché A. Sepúlveda-Escribano T.R. Reina 《International Journal of Hydrogen Energy》2017,42(16):10747-10751
Cu-ZnO based catalysts are the benchmark materials for the low-temperature WGS reaction. However, they present a crucial drawback which limits their application in portable devices: they only work under very low space velocities. In this study, we have developed a series of multicomponent Cu-ZnO catalysts able to work at relatively high space velocities with outstanding activity and stability. Different reference supports have been utilised with CeO2-Al2O3 being the most promising system. Overall, this work describes a strategy to design advanced Cu-based catalysts that can overcome the residence time restrictions in the WGS reaction. 相似文献
72.
Based on the mood-behavior-model (Gendolla, 2000), this study tested the idea that moods only have effects on effort mobilization in settings that directly call for this and in which people can thus use their moods as task-relevant information. Fifty university students were randomly assigned to a 2 (Mood: negative vs. positive) × 2 (Memorizing: intentional vs. incidental) × 2 (Time: mood induction vs. task performance) mixed model design. Effort mobilization was operationalized as systolic blood pressure (SBP) reactivity. As expected, in the intentional-memorizing condition, SBP reactivity was stronger in a negative mood than in a positive mood. Mood had no impact in the incidental-memorizing condition, which did not call for effort mobilization. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
73.
Tiziana Armaroli Maria Bevilacqua Marcella Trombetta Aìda Gutirrez Alejandre Jorge Ramirez Guido Busca 《Applied Catalysis A: General》2001,220(1-2):181-190
The interaction of aromatic hydrocarbons benzene, toluene, o-, m- and p-xylene and of methyl pyridines (in particular 2,6-lutidine) with H-ZSM-5 and H-FER zeolites has been studied. Two different H-ZSM-5 samples with strongly different intensity ratios between the two main OH stretching bands have been used. Benzene, toluene and p-xylene enter easily the cavities and give rise to three different H-bonded complexes. Two of them are strongly bonded while the third is likely a very hindered and distorted one. o-Xylene enters slowly the cavities and m-xylene even more slowly. Faster diffusion occurs at higher temperatures. On the contrary, xylenes do not enter the FER cavities. In spite of its steric hindrance, supposed to be the same of m-xylene, 2,6-lutidine enters fast the ZSM channels and is protonated by the internal sites. On the contrary, it does not enter the FER cavities, but it is protonated too on the external silanols sites. Evidence is provided for some kind of heterogeneity of the internal sites of ZSM-5 zeolite. Additionally, it is concluded that other effects besides the molecular sieving effect may play a role in the access and diffusion of molecules into the zeolite channels. 相似文献
74.
Guido Radtke Klaus Knop Bernhard C. Lippold 《Drug development and industrial pharmacy》2013,39(3):287-296
ABSTRACTThe manufacture of slow-release matrix pellets with an aqueous dispersion of quaternary poly(meth)acrylates was investigated in the rotary fluidized bed. By considering the moisture content of the fluidized bed to be the key process parameter, it was measured on-line throughout the whole manufacturing process. A specially designed sampling device opened new ways to apply NIR spectrometry in laboratory scale processes. It was shown that reproducibly improved pellet properties can be achieved by reproducing the moisture content of the (rotary) fluidized bed. Moisture plateaus proved to be a suitable way to optimize the sphericity of the pellets. Premoisturizing was found to be a very effective tool to achieve slow-release dissolution of the model drug theophylline. 相似文献
75.
Abstract In this paper a two-photon Jaynes-Cummings model interacting with a Kerr-like medium is studied. It is assumed that the electromagnetic field is in different states such as coherent, squeezed vacuum and pair coherent, and that the atom is initially in the excited state. The temporal evolution of the population of the excited level, and the second-order coherence function are studied. The results obtained show that this system has some similarities with the two-mode Stark system. Two photon entanglement are analysed at different initial conditions. 相似文献
76.
77.
Michele Leonardi Urszula Skomra Monika Agacka Anna Stochmal Katarzyna E. Ambryszewska Wieslaw Oleszek Guido Flamini Luisa Pistelli 《International Journal of Food Science & Technology》2013,48(8):1770-1774
Polish cultivars of hop (Humulus lupulus L.) are well known as aroma and bitter raw material in the brewing industry. To characterise four popular Polish hop cultivars, Lubelski (Lublin), Marynka, Sybilla and Iunga (also known as Junga), the essential oil profiles were determined by gas chromatography/flame ionisation detector (GC‐FID) and gas chromatography/chemical ionisation mass spectrometry (GC‐CIMS) and the alpha/beta acids amounts by high‐performance liquid chromatography/diode array detector (HPLC‐DAD) analysis. In addition, the multivariate statistical analysis of the volatile profiles was performed. The results obtained evidenced qualitative and quantitative differences between the four cultivars studied and the foreign hops described in the literature. Lubelski and Iunga showed the typical chemical profile of the fine‐aroma and high‐alpha cultivars, respectively. In Marynka and Sybilla, the average amounts of alpha acids were similar to the bitter hops, but with a volatile profile characteristics of the fine‐aroma and aroma cultivars respectively. 相似文献
78.
Marcella Trombetta Tiziana Armaroli Aìda Gutirrez Alejandre Horacio Gonzalez Jorge Ramirez Solis Guido Busca 《Catalysis Today》2001,65(2-4):285-292
The interaction of HZSM5 and Mo-ZSM5 with benzene, naphthalene, toluene, ortho-xylene, para-xylene, n-butane, isobutane, n-heptane, and methylcyclohexane, in the range 100–773 K has been investigated using FT-IR spectroscopy. Hydrogen bonded species with the internal bridging and the external terminal OHs has been detected. The reactivity at high temperature has also been studied. The access to the internal cavities and to the strongly acidic OHs is at least partly hindered in the case of Mo-ZSM5. The catalytic activity of ZSM5 was moderated by the addition of molybdenum, with lower cracking and higher liquid yields. 相似文献
79.
Martina RosoAlessandra Lorenzetti Stefano BescoManuel Monti Guido BertiMichele Modesti 《Computers & Chemical Engineering》2011,35(11):2248-2256
Multistructured membranes based on ultrafine fibers of polymethylmethacrylate-co-methacrylic acid (PMMA-co-MAA) and TiO2 nanoparticles have been obtained by electrohydrodynamic (EHD) technologies, for active filter media manufacturing. Process optimization of the nanofibers based layers has been investigated by response surface methodology (RSM) in order to predict the domain of the parameters where the smallest fiber diameter can be achieved. A quantitative relationship between electrospinning parameters and the responses (mean diameter and standard deviation) was established and then the final multi-layers structure of nanofibers and nanoparticles has been achieved for a controlled and robust process. The nanostructured membranes have been characterized by SEM imaging, EDAX, TGA analysis and water vapour permeability and their photocatalytic activity has been tested on VOCs degradation. 相似文献
80.