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731.
732.
733.
The selective oxidation of methane has been studied both in the presence and absence of solids (inert or catalysts) with and without NO added, at 1 bar of total pressure. NO enhances the yield to formaldehyde, while the solids favor its decomposition. These results, together with abundant literature data, show a maximum for formaldehyde yield of about 4.0%. 相似文献
734.
Most academic medical centers (AMCs) have developed mechanisms for tracking the financing of their faculty members' research and clinical activities. However, information systems for managing and reporting financial data often do not provide fully accurate or complete pictures of the accomplishments of an institution or its faculty. Modern information technology can help AMCs integrate more extensive information about their faculties from many different sources; in particular, Web publishing technologies permit large numbers of users to have easy secure access to databases across different platforms. The authors briefly describe five faculty information systems now in use. They then describe in detail the development and implementation of one of these systems, The Johns Hopkins University School of Medicine Faculty Information System (FIS), which uses Web publishing technologies, collecting and making available information about the clinical, teaching, and research activities of faculty members. 相似文献
735.
YB Lombardo S Drago A Chicco P Fainstein-Day R Gutman JJ Gagliardino CL Gomez Dumm 《Canadian Metallurgical Quarterly》1996,45(12):1527-1532
The aim of the present investigation was to study normal rats fed a sucrose-rich diet (SRD) for a prolonged period (up to 30 weeks) (1) to obtain additional data on the hormonal and metabolic patterns induced by this treatment and (2) to provide information on changes taking place in the pancreatic islet cell populations. We found that long-term feeding with a SRD resulted in a steady state of hypertriglyceridemia and hyperglycemia in which insulin levels remained unchanged and unable to compensate for the increased demands of the developing metabolic changes. The endocrine pancreas showed a significant increase of both islet number and B-cell area, as well as changes in the profile of islet cell distribution. However, these changes were not accompanied by an increase in the pancreatic content of immunoreactive insulin (IRI). It may therefore be postulated that the newly emerged B-cell mass has some sort of derangement with the increased insulin demand resulting from insulin resistance induced by the long-term SRD feeding. Thus, feeding a SRD to normal rats may prove to be an attractive animal model for studying the role of environmental nutritional factors in the unsettled issue of the relationship between insulin resistance and relative insulin deficiency. The model might provide key information for understanding the pathophysiology of human diseases such as type II diabetes, dyslipidemia, and a number of entities included in so-called syndrome X. 相似文献
736.
Soner Kara Özgür Alan Orkunt Sabuncu Samet Akp?nar Nihan K. Cicekli Ferda N. Alpaslan 《Information Systems》2012,37(4):294-305
In this paper, we present an ontology-based information extraction and retrieval system and its application in the soccer domain. In general, we deal with three issues in semantic search, namely, usability, scalability and retrieval performance. We propose a keyword-based semantic retrieval approach. The performance of the system is improved considerably using domain-specific information extraction, inferencing and rules. Scalability is achieved by adapting a semantic indexing approach and representing the whole world as small independent models. The system is implemented using the state-of-the-art technologies in Semantic Web and its performance is evaluated against traditional systems as well as the query expansion methods. Furthermore, a detailed evaluation is provided to observe the performance gain due to domain-specific information extraction and inferencing. Finally, we show how we use semantic indexing to solve simple structural ambiguities. 相似文献
737.
This paper deals with model predictive control of discrete event systems modelled by P-time event graphs. First, the model is obtained by using the dater evolution model written in the standard algebra. Then, for the control law, we used the finite-horizon model predictive control. For the closed-loop control, we used the infinite-horizon model predictive control (IH-MPC). The latter is an approach that calculates static feedback gains which allows the stability of the closed-loop system while respecting the constraints on the control vector. The problem of IH-MPC is formulated as a linear convex programming subject to a linear matrix inequality problem. Finally, the proposed methodology is applied to a transportation system. 相似文献
738.
A hybrid fuzzy MCDM approach to machine tool selection 总被引:2,自引:0,他引:2
Semih Önüt Selin Soner Kara Tuğba Efendigil 《Journal of Intelligent Manufacturing》2008,19(4):443-453
The selection of the appropriate machine tools for a manufacturing company is one of the important points to achieving high
competitiveness in the market. Besides, an appropriate choice of machine tools is very important as it helps to realize full
production quickly. Today’s market offers many more choices for machine tool alternatives. There are also many factors one
should consider as part of the appropriate machine tool selection process, including productivity, flexibility, compatibility,
safety, cost, etc. Consequently evaluation procedures involve several objectives and it is often necessary to compromise among
possibly conflicting tangible and intangible factors. For these reasons, multiple criteria decision making (MCDM) has been
found to be a useful approach to solve this kind of problem. Most of the MCDM models are basically mathematical and ignore
qualitative and often subjective considerations. The use of fuzzy set theory allows incorporating qualitative and partially
known information into the decision model. This paper describes a fuzzy technique for order preference by similarity to ideal
solution (TOPSIS) based methodology for evaluation and selection of vertical CNC machining centers for a manufacturing company
in Istanbul, Turkey. The criteria weights are calculated by using the fuzzy AHP (analytical hierarchy process). 相似文献
739.
Silica-supported vanadium (1–8 wt%) and vanadium (5 wt%)-sodium (0.4 wt%) catalysts have been characterized by laser Raman spectroscopy, temperature-programmed reduction, X-ray photoelectron spectroscopy, NO + NH3 rectangular pulses and oxygen chemisorption. The presence of different vanadium species was correlated with activity and selectivity during the methane partial oxidation reaction. The pre-impregnation of the silica support with sodium favors vanadium dispersion, but strongly diminishes V=O concentration due to the formation of orthovanadate-like compounds. As a result of these modifications, methane conversion is strongly inhibited while formaldehyde decomposition is favored. 相似文献
740.
Orit Shaer Consuelo Valdes Sirui Liu Kara Lu Kimberly Chang Wendy Xu Traci L. Haddock Swapnil Bhatia Douglas Densmore Robert Kincaid 《Personal and Ubiquitous Computing》2014,18(6):1515-1532
Reality-based interfaces (RBIs) such as tabletop and tangible user interfaces draw upon ideas from embodied cognition to offer a more natural, intuitive, and accessible form of interaction that reduces the mental effort required to learn and operate computational systems. However, to date, little research has been devoted to investigating the strengths and limitations of applying reality-based interaction for promoting learning of complex scientific concepts at the college level. We propose that RBIs offer unique opportunities for enhancing college-level science education. This paper presents three main contributions: (1) design considerations and participatory design process for enhancing college-level science education through reality-based interaction, (2) reflections on the design, implementation, and validation of two case studies—RBIs for learning synthetic biology, and (3) discussion of opportunities and challenges for advancing learning of college-level sciences through next-generation interfaces. 相似文献