In this paper, we study the well-posedness and the asymptotic stability of a one-dimensional thermoelastic microbeam system, where the heat conduction is given by Gurtin-Pipkin thermal law. We first establish the well-posedness of the system by using the semigroup arguments and Lumer-Phillips theorem. We then obtain an explicit and general formula for the energy decay rates through perturbed energy method and some properties of the convex functions. 相似文献
Nonlinear Dynamics - In this paper, the current-controlled DC–DC buck converter from a new perspective are studied through the switching theory of flow, and the analytical conditions of the... 相似文献
To improve the numerical evaluation of weakly singular integrals appearing in the boundary element method, a logarithmic Gaussian quadrature formula is usually suggested in the literature. In this formula the singular function is expressed in terms of the distance between source point and field point, which is a real variable. When an anisotropic elastic solid is considered, most of the existing fundamental solutions are written in terms of complex variables. When the problems with holes, cracks, inclusions, or interfaces are considered, to suit for the shape of the boundaries usually a mapping function is introduced and then the solutions are expressed in terms of mapped complex variables. To deal with the trouble induced by the complex variables, in this study through proper change of variables we develop a simple way to improve the evaluation of weakly singular integrals, especially for the problems of anisotropic elastic solids containing holes, cracks, inclusions, or interfaces. By simple matrix expansion, the proposed method is extended to the problems with piezoelectric or magneto-electro-elastic solids. By using the dual reciprocity method, the proposed method employed for the elastostatic fundamental solution can also be applied to the elastodynamic analysis. 相似文献
By introducing a memristor into a chaotic system with a single non-quadratic term and substituting an absolute value function for conditional symmetry, a unique chaotic system is constructed. Firstly, the system shares a special structure of symmetry and conditional symmetry. Secondly, the amplitude and frequency of the system variables can be rescaled by the applied memristor. Interestingly it gives a new case of attractor control namely partial amplitude control and global frequency control. At last, as a new regime of extreme multistability, the memristive system shows relatively simple bifurcation according to the initial condition. This new class of chaotic system has never been reported to the best of our knowledge.
To activate electronic and optical functions of the redox-active metal–organic framework, (Me2NH2)[InIII(TTFTB)]⋅0.7 C2H5OH⋅DMF (Me2NH2@ 1 , TTFTB=tetrathiafulvalene-tetrabenzoate, DMF=N,N-dimethylformamide), has been exchanged by tetrathiafulvalenium (TTF.+) and N,N′-dimethyl-4,4′-bipyridinium (MV2+). These cations provide electron carriers and photosensitivity. The exchange retains the crystallinity allowing single-crystal to single-crystal post-synthetic transformation to TTF@ 1 and MV@ 1 . Both TTF.+ and MV2+ enhance the electrical conductivity by a factor of 102 and the visible light induced photocurrent by 4 and 28 times, respectively. EPR evidences synergetic effect involving charge transfer between the framework redox-active TTFTB bridges and MV2+. The results demonstrate that functionalization of MOF by cation exchange without perturbing the crystallinity extends possibilities to achieve switchable materials. 相似文献
Journal of Solid State Electrochemistry - Polyvinylpyrrolidone (PVP) and graphene (G)-modified iron oxides (Fe2O3-PVP-G) are prepared by a simple hydrothermal reaction. Their morphology and... 相似文献
This study reports the use of a layered-type birnessite δ-MnO2 nano-flake cathode for eco-friendly zinc-ion battery (ZIB) applications. The present δ-MnO2 was prepared via the simple low temperature thermal decomposition of KMnO4. The X-ray diffraction (XRD) pattern of the samples was well indexed to the δ-MnO2 phase. Field emission SEM and TEM images of the δ-MnO2 revealed flake-like morphologies with an average diameter of 200 nm. The electrochemical properties, investigated by cyclic voltammetry and constant current charge-discharge measurements, revealed that the nano-flake cathode exhibited first discharge capacity of 122 mAh g− 1 under a high current density of 83 mA g− 1 versus zinc. The discharge capacity thereafter increased until it reached 252 mAh g− 1 in the fourth cycle. On the hundredth cycle, the electrode registered a discharge capacity of 112 mAh g− 1. Coulombic efficiencies of nearly 100% were maintained on prolonged cycling and thereby indicate the long cycle stability of the δ-MnO2. Besides, the realization of specific capacities of 92 and 30 mAh/g at high current densities of 666 and 1333 mA g−1, respectively, clearly demonstrates the decent rate capabilities of δ-MnO2 nano-flake cathode. These results may facilitate the utilization of layered-type birnessite δ-MnO2 in ZIB applications. 相似文献