Mathematical Notes - The well-posedness of the initial-value problem associated with the dissipative Kadomtsev–Petviashvili equation in the case of two-dimensional space is studied. It is... 相似文献
The fixed-time stabilization problem is addressed in this paper for a kind of nonholonomic systems in chained form with unmatched uncertainties and time-varying output constraints. A novel tan-type barrier Lyapunov function is introduced to deal with time-varying output constraints. Under the unified framework of the considered system with and without output constraints, a state feedback controller is designed with the aid of adding a power integrator technique and switching control strategy. It is shown that the suggested controller ensures the states of closed-loop system to zero in a given fixed time without disobeying the constraints. Finally, simulation results are given to confirm the efficacy of the presented control scheme.
By implementing heterogeneous sampling communication mechanism, this article addresses the exponential synchronization issue of drive–response chaotic neural networks (CNNs) with interval time-varying delays by simultaneously taking into account the semi-Markovian switchings and saturating actuators. More specifically, a semi-Markovian jumping model whose transition rates (TRs) are not constant but depends on the sojourn time (ST) is introduced to characterize the stochastic changing among the interaction of CNNs, which makes the NNs model under consideration more suitable for some actual circumstances. More particularly, we assume that the sampling intervals are heterogeneous and time-varying, which may be more practical in real-life applications than homogeneous sampling policy. Additionally, by introducing some new terms, one novel time-dependent Lyapunov–Krasovskii function (LKF) is ingeniously constructed, which can fully capture the characteristic information of heterogeneous sampling pattern. Benefitting from the introduced relaxed free-weighting matrices (FWM) and resorting to the formed LKF, some sampling-interval-dependent sufficient conditions for controller design of the resulting semi-MJNNs error system are established and expressed by linear matrix inequalities (LMIs). These LMIs-based constraints can be effectively checked by utilizing the available software packages. Therein, the developed synchronization criteria dependent on both the lower and upper bounds of sampling periods, and the available information about the actual sampling pattern is fully considered. Ultimately, two numerical examples are provided to demonstrate the feasibility and practicability of our theoretical findings. 相似文献
A novel Cu-catalyzed intermolecular chemoselectivity dithiocyanation of styrenes with ammonium thiocyanate has been developed under mild conditions. This reaction exhibits a wide range of functional-group tolerance in styrenes to afford various dithiocyanates. The reaction mechanism was primarily investigated and a radical process was proposed. 相似文献
Abstract. Two cadmium(II) coordination polymers, {CdL2[(CH3)2NH2]2 · 2DMF}n ( 1 ) and {[Cd3L4[(CH3)2NH2]2] · EtOH · 2DMF}n ( 2 ) were synthesized from the solvothermal reactions of Cd(OAc)2 · 2H2O with 3,3′‐(diazenediyl)dibenzoic acid (H2L) in different solvents. Both complexes were characterized by elemental analysis, IR spectroscopy, powder X‐ray diffraction, TG analysis, and single‐crystal X‐ray diffraction. In compound 1 , central cadmium(II) atoms were linked with the surrounding L ligands to generate an infinite 1D chain with repeated rings. Compound 2 displayed a 3D threefold interpenetrating framework based on cage‐like [Cd3L6]8 species and exhibited a 41263 topological structure. The results demonstrated that the different solvents had significant effect on the construction of different coordination compounds from the same components. In addition, they exhibited excellent stability and good photocatalytic activity towards the degradation of methylene blue in aqueous solution under UV irradiation. 相似文献
The organic‐inorganic hybrid H5[Ag2(hyp)2]2[BW12O40] · 9H2O ( 1 ) (hpy = hypoxanthine), based on Keggin‐type polyoxometalate and hypoxanthine, was prepared by hydrothermal synthesis and characterized by single‐crystal and powder X‐ray diffraction, IR spectroscopy, elemental analysis, and thermogravimetry. The title compound has a two‐dimensional layer structure constructed by Keggin‐type [BW12O40]5– anion, silver, and the biomolecule hyp. In addition, compound 1 exhibited excellent stability and superior activity in the electro‐catalytic oxidation of glucose. 相似文献
We investigate the question of finding discrete Lax pairs for the six discrete Painlevé equations (Pn). The choice we make is to discretize the pairs of Garnier, once converted to matrix form. 相似文献