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471.
Abstract: The problem of a bistable magnetoelastic beam under base excitation was discussed in [1] under the aspect of chaotic behaviour in mechanical systems. Three decades later the system was used in [2] to design an energy harvesting system which performs well under harmonic excitation for a broad range of excitation frequencies due to its bistability. The initial modeling was tailored to obtain a model with one degree of freedom based on the assumption that the magnetic force acts on the beam tip only. A more appropriate model can be found when considering a distributed force along the beam. The authors present the force distribution on a ferromagnetic beam due to the magnetic field of two permanent magnets. A semi-analytic method is used to compute the magnetic field. The force distribution can in future be used to derive a refined nonlinear dynamical model for the ferromagnetic elastic beam. (© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
472.
Jürgen Schmidt Dietmar Kuck Katrin Franke Haider Sultani Annegret Laub Ludger A. Wessjohann 《Journal of mass spectrometry : JMS》2019,54(6):549-556
Long‐chain ferulic acid esters, such as eicosyl ferulate ( 1 ), show a complex and analytically valuable fragmentation behavior under negative ion electrospay collision‐induced dissociation ((?)‐ESI‐CID) mass spectrometry, as studied by use of a high‐resolution (Orbitrap) mass spectrometer. In a strong contrast to the very simple fragmentation of the [M + H]+ ion, which is discussed briefly, the deprotonated molecule, [M – H]?, exhibits a rich secondary fragmentation chemistry. It first loses a methyl radical (MS2) and the ortho‐quinoid [M – H – Me]‐? radical anion thus formed then dissociates by loss of an extended series of neutral radicals, CnH2n + 1? (n = 0–16) from the long alkyl chain, in competition with the expulsion of CO and CO2 (MS3). The further fragmentation (MS4) of the [M – H – Me – C3H7]? ion, discussed as an example, and the highly specific losses of alkyl radicals from the [M – H – Me – CO]‐? and [M – H – Me – CO2]‐? ions provide some mechanistic and structural insights. 相似文献
473.
We consider discretizations for reaction–diffusion systems with nonlinear diffusion in two space dimensions. The applied model allows to handle heterogeneous materials and uses the chemical potentials of the involved species as primary variables. We propose an implicit Voronoi finite volume discretization on arbitrary, even anisotropic, Voronoi meshes that allows to prove uniform, mesh-independent global upper and lower bounds for the chemical potentials. These bounds provide one of the main steps for a convergence analysis for the fully discretized nonlinear evolution problem. The fundamental ideas are energy estimates, a discrete Moser iteration and the use of discrete Gagliardo–Nirenberg inequalities. 相似文献
474.
Annegret Glitzky 《PAMM》2007,7(1):2040055-2040056
We consider electro-reaction-diffusion systems consisting of continuity equations for a finite number of species coupled with a Poisson equation. We take into account heterostructures, anisotropic materials and rather general statistical relations. We investigate thermodynamic equilibria and prove for solutions to the evolution system the monotone and exponential decay of the free energy to its equilibrium value. Here the essential idea is an estimate of the free energy by the dissipation rate. The same properties are obtained for a fully implicit time discretized version of the problem. Moreover, we provide a space discretized scheme for the electro-reaction-diffusion system which is dissipative (the free energy decays monotonously). (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
475.
This review aims to provide a comprehensive overview of the recent advances made in the field of ionic liquids in peptide chemistry and peptide analytics. 相似文献
476.
Annegret Paul 《Proceedings of the American Mathematical Society》2000,128(10):3129-3136
A previous paper by the author describes the Howe correspondence for dual pairs of the form with , in terms of Langlands parameters. We extend these results to the case .
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Aiidrf Noll 《偏微分方程通讯》2013,38(3-4):759-775
This paper introduces the notion of capacity in abstract Hilhertl spaces. It is proved that the spectral shift of aa self-adjoi at operator which is subjected to a, domain perturbation can he estimated in forms of this capacity. The results -are finally applied to higher-order partial differential operators 相似文献