Fabrication and microstructure evolution of monolithic bridged polysilsesquioxane-derived SiC ceramic aerogels

In this paper, a class of uncertain nonlinear multi-agent systems with unknown control directions and a dead-zone fault is addressed, where unknown control gains exist in each subsystem. In terms of the approximation characteristic of a fuzzy logic system, it is used to approximate uncertain nonlinear dynamics, and then the relevant adaptive control laws are designed. Considering the presence of unknown control directions and a dead-zone fault, the Nussbaum gain function technique is introduced to design the intermediate control law and the adaptive fuzzy control law. A theoretical analysis shows that the tracking control problem of the given multi-agent systems can be effectively solved through the application of the proposed adaptive fuzzy control law and the tracking errors can converge to a small neighborhood of zero through an adjustment of the relevant parameters. Finally, the effectiveness of the theoretical analysis results is verified by two simulation cases. 

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Adaptive Fuzzy Tracking Control of Uncertain Nonlinear Multi-Agent Systems with Unknown Control Directions and a Dead-Zone Fault

Optimized adaptive consensus tracking control for uncertain nonlinear multiagent systems using a new event-triggered communication mechanism

Event-triggered H∞ consensus for uncertain nonlinear systems using integral sliding mode based adaptive dynamic programming

The development of electrically conductive ceramics could achieve robust mechanical strength as well as practically high conductivity, offering applications in structural electrodes, conductors, catalyst supports, etc. However, its operating temperature is limited due to the intrinsic dense structures inevitably hindering the thermal management capability, thus resulting in a temperature-dependent electrical behavior in high-temperature environments. We report an additive manufacturing protocol through vat photopolymerization 3D printing to fabricate the architectured conductive silicon carbide (SiC) ceramics that simultaneously possess high electrical conductivity as well as low thermal conductivity, and demonstrate electric reliability under high-temperature environments above 600°C. The percolation of graphene into the ceramic scaffold establishes a uniform conductive network, exhibiting its electrical conductivity up to 1000 S m−1. The bulk density of the 3D-printed ceramic is measured from 0.366 g cm−3 to 0.897 g cm−3, with thermal conductivity ranging from 62 mW m−1 K−1 to 88 mW m−1 K−1. Furthermore, the mechanical performance of conductive ceramic can be effectively reinforced by densifying the microstructures via spark plasma sintering treatment. The proposed additive manufacturing strategy widens the potential of ceramics as a structural and functional material, offering a promising pathway toward high-temperature electronics applications. 

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Papers

Event-triggered coordination of multi-agent systems via a Lyapunov-based approach for leaderless consensus

Event-triggered coordination of multi-agent systems via a Lyapunov-based approach for leaderless consensus

Preparation and textural evolution: From organosilane aerogel to SiOC aerogels

Preparation and textural evolution: From organosilane aerogel to SiOC aerogels

Design and preparation of hollow SiO2 nanospheres/SiC-based nanocomposite fiber membrane for high temperature thermal insulators