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151.
Dr. Daniel Peitz Dr. Andreas M. Bernhard Dr. Max Mehring Martin Elsener Dr. Oliver Kröcher 《化学,工程师,技术》2013,85(5):625-631
In order to reduce the NOx concentration in car exhausts usually the selective catalytic reduction with ammonia is used. However, to avoid the transport of ammonia in vehicles urea is applied as NH3 precursor. Controlled urea decomposition before the injection into the exhaust gas system itself may be accomplished by the use of a separate reactor. Urea decomposition to ammonia in the liquid phase under pressure in a heated reactor was compared to its decomposition in the gas phase. In the liquid phase, higher conversion rates relative to the reactor volume were realized than in the gas phase. Catalysts which showed high activity in the gas phase influenced the decomposition in the liquid phase only slightly. 相似文献
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Hiromichi Yanagihara Wilhelm Brandstätter Nobumoto Ohashi Bernhard Gschaider Johannes Leixnering Igor Stankovic 《Topics in Catalysis》2009,52(13-20):1842-1846
Wall-flow channel models and soot deposition models based on micro scale considerations are integrated into global 3D diesel particulate filter simulations. In addition, transient and steady-state simulations are combined to understand at the same time short- and long-time behaviour of the diesel particulate filter (DPF). The functionality of the simulation tool is achieved and correlations with measured data encourage the use of the model as a tool to predict DPF behaviour. 相似文献
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Bernhard Zimolong Shimon Y. Nof Ray E. Eberts Gavriel Salvendy 《Behaviour & Information Technology》1987,6(1):15-36
The review is based on an analysis of current literature of expert systems and of system engineering models in dynamic process control. It starts with an analysis of the mental operations and cognitive requirements needed for supervisory control. Mental models are discussed as a function of situational requirements as well as of personal strategies. Systems engineering models and expert systems are briefly described and their function as decision support tools evaluated. Criteria are the overall functionality, similarity of knowledge bases and reasoning strategies of the human and the support system, adaptability to the operator's skill level and self-explanation of the support system in the interaction mode. As a result, system engineering models are only of limited value for knowledge-based process control. Expert systems seem to be very valuable tools for augmenting human decision making in process control, if the interaction problem can be solved. 相似文献
159.
Bernhard Ostrick Maximilian Fleischer Hans Meixner 《Journal of the American Ceramic Society》1997,80(8):2153-2156
Simultaneous Hall and conductivity measurements were performed in situ between 650° and 1050°C on n-type semiconducting BaSnO3 ceramics. The variation of the Hall mobility and the Hall carrier density as a function of oxygen partial pressure between 102 and 105 Pa and of temperature was investigated. At temperatures below 900°C the conductivity exhibits a dependence on temperature and oxygen partial pressure which is mainly determined by variations of the Hall mobility. Above 900°C most of the significant dependence is due to a variation in carrier density. Furthermore, a simple defect model assuming doubly ionized oxygen vacancies and acceptor impurities is discussed for BaSnO3 . 相似文献
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Bernhard Wolf 《Microscopy research and technique》1987,7(3):185-189
Cryoultramicrotomy is gaining in significance and use as technical improvements are made. In comparison with epoxy resin procedures, cryopreparations are more rapid; there is only a negligible loss of material and thus antigenicity is well preserved. The present work contains some newly developed details for the exact determination of the advancement of the sample in the direction of the knife in a microtome. It is a software-controlled ultramicrotome advance drive system with feedback regulation as well as repeatedly patented devices for advancement sensors. 相似文献