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61.
T-junctions are common elements in flow duct networks. It is shown that for low Strouhal numbers, based on the duct diameter, their acoustic scattering properties can be described using an incompressible quasi-steady model. Models are derived for systems subjected to combinations of grazing and bias mean flow, and are shown to work in both the limiting cases—that is, grazing or bias flow alone—as well as for the joining or dividing flow configurations. The upper Strouhal number for which the quasi-steady models are applicable is limited by flow-acoustic interaction effects, which differ significantly between the different flow configurations. Generally the models are applicable up to Strouhal numbers of approximately 0.1-0.2, which is comparable with previous published models for other configurations such as bends and orifices. This range is sufficient to make the model useful in many important engineering applications. 相似文献
62.
Shape verification aimed for manufacturing process control 总被引:1,自引:0,他引:1
63.
Elisabeth Kallin Hans Lönn Thomas Norberg Mikael Elofsson 《Journal of carbohydrate chemistry》2013,32(4):597-611
Abstract Reducing oligosaccharides were converted in good yields into the corresponding primary glycosylamines by treatment with aqueous ammonium bicarbonate. The glycosylamines were then acryloylated and the obtained oligosaccharide N-acryloyl glycosylamines were copolymerized with acrylamide. High molecular weight, linear copolymers were obtained, which were useful as antigens in immunoassays. 相似文献
64.
Javier Ramos Víctor L. Cruz Javier Martínez‐Salazar Mikael Brasse Pilar Palma Juan Campora 《Journal of polymer science. Part A, Polymer chemistry》2010,48(5):1160-1165
The present computational study was designed to study the polymerization of ethylene catalyzed by a new Ni‐based PymNox organometallic compound. Recently, we have synthesized and tested the behavior of this type of catalyst in olefin polymerization. It has been experimentally observed that the unsubstituted catalyst Ni2 (aldimino PymNox catalyst ) is less active than the methyl substituted Ni1 (acetaldimino PymNox catalyst ) analogue. The reactivity of both catalysts was examined using density functional theory (DFT) models. Our results indicate that the methyl substituted Ni1 introduces some additional steric hindrance that probably renders a more suitable catalyst conformation for the monomer incorporation. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1160–1165, 2010 相似文献
65.
Per Martin Björemark Dr. Susanne Olsson Dr. Theonitsa Kokoli Prof. Mikael Håkansson 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(24):8750-8753
Even though the isolation of tetrahedral stereoisomers usually presents a synthetic challenge, a highly enantioenriched tetrahedral silver complex could be easily accessed by either crystallization or Viedma ripening. The overall preparation may be regarded as an example of absolute asymmetric synthesis. Experimental results indicate that both crystallization and Viedma ripening follow a similar cluster‐controlled mechanism. 相似文献
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68.
Simon D. NielsenGarrick P. Smith Mikael BegtrupJesper L. Kristensen 《Tetrahedron》2011,67(29):5261-5267
The development of a new fluorous-tagged ammonia-equivalent for the synthesis of N-alkylated amino acids is described. The required building blocks were readily accessed in high yield and purity using F-SPE purification technique. Coupling of the fluorous-tagged hydroxylamines with a selection of boronic acids and glyoxalic acid gave the desired N-alkylated amino acids. Subsequent removal of the fluorous tag via catalytic hydrogenation was investigated using a number of different catalysts and solvents. A more robust de-tagging procedure involves the transformation of the amino acid to the corresponding methyl ester followed by a Mo(CH3CN)3(CO)3 mediated N-O bond cleavage. 相似文献
69.
An oxidative chemical vapor deposition (OCVD) process was used to coat flexible textile fiber (viscose) with highly conductive polymer, poly (3,4‐ethylenedioxythiophene) (PEDOT) in presence of ferric (III) chloride (FeCl3) oxidant. OCVD is a solvent free process used to get uniform, thin, and highly conductive polymer layer on different substrates. In this paper, PEDOT coated viscose fibers, prepared under specific conditions, exhibited high conductivity 14.2 S/cm. The effects of polymerization conditions, such as polymerization time, oxidant concentration, dipping time of viscose fiber in oxidant solution, and drying time of oxidant treated viscose fiber, were carefully investigated. Scanning electron microscopy (SEM) and FT‐IR analysis revealed that polymerization of PEDOT on surface of viscose fiber has been taken place and structural analysis showed strong interactions between PEDOT and viscose fiber. Thermogravimetric analysis (TGA) was employed to investigate the amount of PEDOT in PEDOT coated viscose fiber and interaction of PEDOT with viscose fiber. The effect of PEDOT coating on the mechanical properties of the viscose fiber was evaluated by tensile strength testing of the coated fibers. The obtained PEDOT coated viscose fiber having high conductivity, could be used in smart clothing for medical and military applications, heat generation, and solar cell demonstrators. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
70.
Altun M Kramer HB Willems LI McDermott JL Leach CA Goldenberg SJ Kumar KG Konietzny R Fischer R Kogan E Mackeen MM McGouran J Khoronenkova SV Parsons JL Dianov GL Nicholson B Kessler BM 《Chemistry & biology》2011,18(11):1401-1412
Converting lead compounds into drug candidates is a crucial step in drug development, requiring early assessment of potency, selectivity, and off-target effects. We have utilized activity-based chemical proteomics to determine the potency and selectivity of deubiquitylating enzyme (DUB) inhibitors in cell culture models. Importantly, we characterized the small molecule PR-619 as a broad-range DUB inhibitor, and P22077 as a USP7 inhibitor with potential for further development as a chemotherapeutic agent in cancer therapy. A striking accumulation of polyubiquitylated proteins was observed after both selective and general inhibition of cellular DUB activity without direct impairment of proteasomal proteolysis. The repertoire of ubiquitylated substrates was analyzed by tandem mass spectrometry, identifying distinct subsets for general or specific inhibition of DUBs. This enabled identification of previously unknown functional links between USP7 and enzymes involved in DNA repair. 相似文献