Nonprecious metal (NPM) catalysts are considered as the most promising candidate to replace Pt‐based electrocatalysts for oxygen reduction reaction (ORR). However, in comparison with the commercial Pt catalyst, the development of high efficiency and low cost NPM catalysts for ORR still remains a big challenge. Here, a simple but efficient way to fabricate porous N‐doped graphene immobilized molybdenum nitride (MoN) nanoparticles is reported, and simultaneously, the introduction of H2O2 plays a key role in modulating the particle size of MoN and the microstructure of the composite to achieve different configuration. As results, it is shown that the as‐prepared material owns outstanding ORR activity and excellent stability in an alkaline medium. To the best knowledge, this catalyst possesses the best performance among the same class catalysts as reported. It is believed that the H2O2‐assisted strategy can provide new insights in synthesis of high efficient metal nitride/carbon hybrid materials toward advanced energy conversion and storage.
In this stu4, classical PD control for direct drive motor system is enhanced to suppress disturbing torque by incorporating an acceleration feedback loop. This intends to achieve a stable and high stiffness control without the need of adjusting the PD controllec either the structure or the parameters. The acceleration feedback control is presented with a focus on designing the acceleration closed-loop in terms of its stability and ability in resisting the dynamic disturbances. The sensing and modeling of angular acceleration via servo-type linear accelerometers is dealt with in viewpoint of practical implementation. Extensive experiments are conducted on the second joint of a three-link direct drive robot. Results are given against those obtained by classical PD control without the acceleration feedback loop, to mainly investigate the ability of the acceleration feedback control in resisting disturbing torque, and its influence to the conventional PD control.0-7803-6348-5/00/$10.00 02000 IEEE.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.