Event-Triggered Asymmetric Bipartite Consensus Tracking for Nonlinear Multi-Agent Systems Based on Model-Free Adaptive Control

In this paper,an asymmetric bipartite consensus problem for the nonlinear multi-agent systems with cooperative and antagonistic interactions is studied under the event-triggered mechanism.For the agents described by a structurally balanced signed digraph,the asymmetric bipartite consensus objective is firstly defined,assigning the agents'output to different signs and module values.Considering with the completely unknown dynamics of the agents,a novel event-triggered model-free adaptive bipartite control protocol is designed based on the agents'triggered outputs and an equivalent compact form data model.By utilizing the Lyapunov analysis method,the threshold of the triggering condition is obtained.Subsequently,the asymptotic convergence of the tracking error is deduced and a sufficient condition is obtained based on the contraction mapping principle.Finally,the simulation example further demonstrates the effectiveness of the protocol.

Cooperation of nitrogen-doping and catalysis to improve the Li-ion storage performance of lignin-based hard carbon

Hard carbon draws great interests as anode material in lithium ion batteries （LIBs） due to its high the- oretical capacity, high rate capability and abundance of its precursors. Herein we firstly synthesize the lignin-melamine resins by grafting melamine onto lignin. Afterwards, nitrogen doped hard carbon is pre- pared by the pyrolysis of lignin-melamine resins with the aid of catalyst （Ni（NO_3）2·6H_2O） at 1000 ℃. Compared with the samples without nitrogen-doping and catalysis, as-prepared nitrogen doped hard car- bon exhibits higher reversible capacity （345 mAh g-1 at 0.1 A g-1 ）, higher rate capability （145 mAh g-1 at 5 A g-1） and excellent cycling stability. The superior electrochemical performance is ascribed to the synergistic effect of nitrogen doping, graphitic structure and amorphous structure. Among them, nitro- gen doping could create the vacancies around the nitrogen sites, which enhance the reactivity and the electronic conductivity of materials. Additionally, graphitic structure also enhances the electronic con- ductivity of materials, thus improving the electrochemical performance of hard carbon. It is worthwhile that Iignin, renewable and abundant biopolymer, is converted to hard carbon with good electrochemical performance, which realizes the high value utilization of lignin.