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291.
Mingaleev SF Gaididei YB Mertens FG 《Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics》2000,61(2):R1044-R1047
We study the influence of long-range interatomic interactions on the properties of supersonic pulse solitons in anharmonic chains. We show that in the case of ultra-long-range (e.g., screened Coulomb) interactions three different types of pulse solitons coexist in a certain velocity interval: one type is unstable but the two others are stable. The high-energy stable soliton is broad and can be described in the quasicontinuum approximation. But the low-energy stable soliton consists of two components, short-range and long-range ones, and can be considered as a bound state of these components. 相似文献
292.
We present a novel solar cell structure, the “buried emitter solar cell”. This concept is designed for decoupling the metallisation geometry from the geometry of the carrier collecting p–n junction in back‐contacted (and in particular back‐junction) solar cells without requiring electrical insulation by dielectric layers. The most prominent features of this device structure are a carrier collecting emitter that covers close to 100% of the total cell area and an effective electrical insulation between emitter and base metallisation via a p+–n+ junction. The experimental results presented in this paper report a 19.5% efficient “buried emitter solar cell”, where 50% of the solar cell's rear side exhibit a p+–n+ junction. This preparation technique implies covering a boron‐doped p‐type emitter with an n‐type surface layer that can be efficiently surface‐passivated by thermal oxidation. All structuring of this cell has been performed by laser processing without any photo‐lithography. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
293.
Johann Mertens Olivier Heintz Vincent Eyraud Guillaume Legay Alain Dereux 《Applied Surface Science》2007,253(11):5101-5108
HF acid attack of SiO2 and Si3N4 substrates is analyzed to improve the sensitivity of a sensor based on microcantilever. Ex situ analysis of the etching using XPS, SIMS and AFM show significant changes in the anisotropy and the rate of the etching of the oxides on SiO2 and Si3N4 surface. Those differences influence the kinetic evolution of the plastic bending deflection of the cantilever coated with SiO2 and Si3N4 layer, respectively. The linear dependence between the HF concentration and the Si3N4 cantilever bending corresponds to a deep attack of the layer whereas the non-linear behavior observed for SiO2 layer can be explained by a combination of deep and lateral etching. The cantilever bending is discussed in terms of free surface energy, layer thickness and grain size. 相似文献
294.
295.
The effect of a wave with a varying traveling component on the bubble activity as well as the physical force generated by microbubbles on a surface has been studied. The acoustic emission from a collection of bubbles is measured in a 928 kHz sound field. Particle removal tests on a surface, which actually measures the applied physical force by the bubbles on that surface, indicate a very strong dependence on the angle of incidence. In other words, when the traveling wave component is maximized, the average physical force applied by microbubbles reaches a maximum. Almost complete particle removal for 78 nm silica particles was obtained for a traveling wave, while particle removal efficiency was reduced to only a few percent when a standing wave was applied. This increase in particle removal for a traveling wave is probably caused by a decrease in bubble trapping at nodes and antinodes in a standing wave field. 相似文献
296.
Bart De Ketelaere Kristof Mertens Frank Mathijs Daniel Sabin Diaz Josse De Baerdemaeker 《商业与工业应用随机模型》2011,27(4):367-376
Statistical process control (SPC) is a powerful framework that is used in many industries to decrease process variability and to pinpoint special cause variation. Although a broad range of techniques have been developed to do so, often the real‐life situation does not fully comply with the basic assumptions that are made in SPC resulting in poor results. One of the main violations against the assumptions is the fact that industrial processes rarely behave in a stationary manner — this is evidently the case for biological processes but is also an important issue when monitoring industrial processes. Besides, the ever increasing amount of data, with a clear shift towards multivariate and even multiway quality control, makes the classical univariate approach not feasible anymore. These two observations pose important challenges to statisticians to develop novel SPC algorithms that are broadly applicable in modern industries. In this contribution we discuss both issues and use two very different case studies to show the reader recent directions and developments in the SPC landscape. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
297.
298.
Deepali Waghray Arvid Cloet Prof. Dr. Kristof Van Hecke Dr. Stijn F. L. Mertens Prof. Dr. Steven De Feyter Prof. Dr. Luc Van Meervelt Prof. Dr. Mark Van der Auweraer Prof. Dr. Wim Dehaen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(36):12077-12085
Diazadithia[7]helicenes were synthesized from the readily available building block ethyl 7‐chloro‐8‐formylthieno[3,2‐f]quinoline‐2‐carboxylate by a Wittig reaction–photocyclization strategy. The helicene core was functionalized by nucleophilic aromatic substitution with a variety of nucleophiles (e.g., O‐, N‐, and C‐centered) and palladium‐catalyzed reactions such as Suzuki coupling and Buchwald–Hartwig amination. Racemization studies confirmed that the enantiopure forms of these [7]helicenes are conformationally stable compared to their lower analogues. The solid‐state structures of the novel diazadithia[7]helicenes were determined by single‐crystal X‐ray diffraction. The crystal structures of these azathia[7]helicenes show columnar stacking in antiparallel fashion. The HOMO–LUMO gaps of the new compounds were determined on the basis of electrochemical and optical measurements. 相似文献
299.
J. L. H. Eersels J. Mertens J. D. M. Herscheid 《Journal of Radioanalytical and Nuclear Chemistry》2011,288(1):291-296
To apply the Cu+-assisted nucleophilic exchange based radioiodination of aromatic compounds for more lipophilic compounds the reaction is
carried out in mixed solvent conditions. Due to its physicochemical properties acetonitrile is an attractive solvent. Although
acetonitrile forms complexes with Cu+ decreasing the labeling yield. This article describes a method for the determination of the complex constant at labeling
temperature based on a Lineweaver–Burk approach, relating the reaction rate constant and the concentration of precursor in
presence of different amounts of acetonitrile. The method also allows to calculate the adjusted amount of copper salt in order
to obtain the same high labeling yield as obtained in absence of acetonitrile. 相似文献
300.
Fustero S Cuñat AC Flores S Báez C Oliver J Cynamon M Gütschow M Mertens MD Delgado O Tresadern G Trabanco AA 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(52):14772-14784
The preparation of novel fluorinated allylamines and their use as key fragments for the stereoselective synthesis of hydroxyethyl secondary amine (HEA)-type peptidomimetics is described. Our strategy employs chiral sulfinyl imines as synthesis intermediates, by treatment of hemiaminal precursors with two equivalents of vinylmagnesium bromide. The subsequent oxidation of the allylic amines to the corresponding epoxides was achieved by treatment with methyl(trifluoromethyl)dioxirane. Finally, epoxide ring opening with a range of nitrogen nucleophiles provided a library of HEA-derived peptidomimetics with a phenyldifluoromethylene moiety. The biological evaluation of these derivatives revealed compounds with remarkable BACE1 inhibitory activity. Docking studies revealed the influence of the fluorine atoms in the binding mode of the synthesized ligands. Furthermore, the biological evaluation of our final products and synthesis intermediates led to the discovery of compounds with antimicrobial activity against Mycobacterium and Nocardia species. 相似文献