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81.
Effect of Constant‐Rate Reduction on the Performance of a Ternary Cu/ZnO/Al2O3 Catalyst in Methanol Synthesis
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A multi‐functional flow set‐up was developed for the rate‐ and temperature‐controlled reduction of copper catalysts, their application in high‐pressure methanol synthesis and the determination of the copper surface area by N2O frontal chromatography. The influence of constant‐rate reduction on the catalytic properties of a ternary Cu/ZnO/Al2O3 catalyst was investigated. The temperature during the constant‐rate reduction was found to decrease, indicating autocatalytic kinetics, but no significant catalytic effect of the milder reduction conditions was observed compared with a slow linear heating ramp. 相似文献
82.
Damage evolution of the alloy IN 738 LC at high temperature low cycle fatigue Herrn Professor K.-T. Rie zum 60. Geburtstag Interrupted Low-Cycle-Fatigue tests have been carried out with IN 738 LC at 850°C. The specimens were extensively examined by SEM to quantify the evolution of fatigue damage. Surface crack nucleation at oxidized grain boundaries occured during the whole experiments. The coalescence of cracks was the dominant mechanism which lead to macro crack evolution and the final fracture. 相似文献
83.
Kathrin Landgraf Andreas Kühnapfel Maria Schlanstein Ronald Biemann Berend Isermann Elena Kempf Holger Kirsten Markus Scholz Antje Krner 《International journal of molecular sciences》2022,23(8)
Obesity develops early in childhood and is accompanied by early signs of adipose tissue (AT) dysfunction and metabolic disease in children. In order to analyse the molecular processes during obesity-related AT accumulation in children, we investigated genome-wide expression profiles in AT samples, isolated adipocytes, and stromal vascular fraction (SVF) cells and assessed their relation to obesity as well as biological and functional AT parameters. We detected alterations in gene expression associated with obesity and related parameters, i.e., BMI SDS, adipocyte size, macrophage infiltration, adiponectin, and/or leptin. While differential gene expression in AT and adipocytes shared an enrichment in metabolic pathways and pathways related to extracellular structural organisation, SVF cells showed an overrepresentation in inflammatory pathways. In adipocytes, we found the strongest positive association for epidermal growth factor-like protein 6 (EGFL6) with adipocyte hypertrophy. EGFL6 was also upregulated during in vitro adipocyte differentiation. In children, EGFL6 expression was positively correlated to parameters of AT dysfunction and metabolic disease such as macrophage infiltration into AT, hs-CRP, leptin levels, and HOMA-IR. In conclusion, we provide evidence for early alterations in AT gene expression related to AT dysfunction in children and identified EGFL6 as potentially being involved in processes underlying the pathogenesis of metabolic disease. 相似文献
84.
Holger Junker 《Datenschutz und Datensicherheit - DuD》2012,36(11):801-804
85.
Döne Demirgöz Rodrigo Navarro Mónica Pérez Helmut Reinecke Alberto Gallardo 《应用聚合物科学杂志》2010,115(2):896-900
2‐Hydroxyethylmethacrylate (HEMA) and acrylamide (AA) have been copolymerized via free radical mechanism, in the presence of 5 mol % of four different crosslinker systems, the symmetric ethylenglycoldimethacrylate (EGDMA), bisacrylamide (BIS), a mixture of EGDMA and BIS, and the asymmetric acrylamideethylenmethacrylate (METAA). The polymerizations have been monitored with a rheometer, exhibiting the gel obtained with the asymmetric METAA, an elastic modulus that is dramatically increased compared with those of the gels prepared with the other three crosslinker systems. A kinetic analysis using the terminal model has been used to build probabilistic surfaces that give information about how the crosslinker is incorporated into the network. This analysis shows a high dissimilarity between the reactions using the asymmetric and the mixture of symmetric crosslinkers, what has been correlated to the difference in modulus. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
86.
Holger Becker Reinhard Caspary Christian Toepfer Manfred V. Schickfus Siegfried Hunklinger 《Journal of Modern Optics》2013,60(9):1715-1723
Abstract We have developed a fixed beam direct writing laser lithography system with a minimum feature size of 400nm at 457nm wavelength and a writing speed of 4·2mm/s with total system costs of less than 100 000 US$. 相似文献
87.
Gbor Erdlyi Lane A. Hemaspaandra Jrg Rothe Holger Spakowski 《Theoretical computer science》2009,410(38-40):3995-4000
We show that many NP-hard sets have heuristic polynomial-time algorithms with high probability weight of correctness with respect to generalizations of Procaccia and Rosenschein’s junta distributions. 相似文献
88.
A series of commercially available nanosized barium titanates has been investigated with respect to their use as high-k-ceramic
filler in polymer based composites with improved dielectric properties. The thermal treatment of the barium titanate powders
at 1,000°C causes a significant increase of the composite’s permittivity. X-ray diffraction experiments prior and after heat
treatment revealed that the barium titanate with smallest particle size and the largest specific surface area possesses the
thermodynamically unstable cubic phase. In case of the other investigated barium titanates the crystal lattice is distorted.
Thermal treatment induces the phase change into the tetragonal one and crystal lattice relaxation enabling higher permittivity
values. Composites with a solid load around 78 wt% with a bimodal particle size distribution show high permittivities around
50 and a low loss factor around 5‰ suitable for the realization of embedded capacitors via screen printing or tape casting. 相似文献
89.
90.
Four visual-world experiments, in which listeners heard spoken words and saw printed words, compared an optimal-perception account with the theory of phonological underspecification. This theory argues that default phonological features are not specified in the mental lexicon, leading to asymmetric lexical matching: Mismatching input (pin) activates lexical entries with underspecified coronal stops (tin), but lexical entries with specified labial stops (pin) are not activated by mismatching input (tin). The eye-tracking data failed to show such a pattern. Although words that were phonologically similar to the spoken target attracted more looks than did unrelated distractors, this effect was symmetric in Experiment 1 with minimal pairs (tin–pin) and in Experiments 2 and 3 with words with an onset overlap (peacock–teacake). Experiment 4 revealed that /t/-initial words were looked at more frequently if the spoken input mismatched only in terms of place than if it mismatched in place and voice, contrary to the assumption that /t/ is unspecified for place and voice. These results show that speech perception uses signal-driven information to the fullest, as was predicted by an optimal perception account. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献