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The structural design is a prerequisite for the creation of mechanical equipment. This study focuses on the structural synthesis of epicyclic chains (ECs), and proposes a new topological model and synthesis method of ECs to address the existing research problems (i.e. synthesis dependence on multiple graphic transformations and the generation of pseudo-isomorphism). First, the structural characteristics of ECs are analyzed to explore the relation between their axles, gears, and planet carriers, and the corresponding topological model and the adjacency matrix expression of ECs are provided. Then, the topological elements corresponding to the axles, gears, and gear pairs are added sequentially to the topological graph corresponding to the planet carriers, and the constraints are established based on similarity to inhibit the generation of isomorphism. Finally, all the databases of feasible ECs are obtained through gear loop discrimination. All processes are carried out with computer assistance. The synthesis results of the ECs with 1–3 degrees of freedom and up to 10 components are presented. The logic of this paper is to simplify (or optimize) the synthesis process to improve efficiency of structural synthesis, which will break through the threshold of computing power and provide more possibilities for the design of mechanical equipment. [ABSTRACT FROM AUTHOR]

The displacement graphs (d-graphs) are the final form of planetary gear trains (PGTs) synthesis. The existing configuration synthesis methods for the d-graphs of PGTs need rotation graphs (r-graphs) as the intermediate step and produce a large amount of isomorphic KCs. This paper proposes a method to obtain d-graphs directly from the geared graph. Meanwhile, a uniform isomorphism identification method suitable for parent graphs, geared graphs, and d-graphs is presented. Finally, a fully automatic method based on parent graphs is tested on synthesizing 1-DOF PGTs with up to nine links. Our synthesis results and those in the literature are comparatively analyzed, and the reasons for contradictory synthesis results are analyzed. [ABSTRACT FROM AUTHOR]

Isomorphism identification is an essential step in mechanism configuration synthesis. Although various detection methods have been proposed, some of them can only effectively identify kinematic chains (KCs) within 10 links or complex programs that are needed to identify multilink KCs. In this study, a new isomorphism identification method is proposed based on the distance concept of graphs and the graph theory definition of isomorphism. In addition to two complex 21- and 28-link planar simple-joint KCs (PSKCs), the proposed algorithm is tested on the complete atlas of 8-link 1-DOF, 9-link 2-DOF, 10-link 1-DOF, 12-link 1-DOF, and 13-link 2-DOF PSKCs. The algorithm is also tested on 6-link 1-DOF and 7-link 1-DOF planetary gear trains (PGTs) to detect isomorphism. All results are in agreement with those of the existing literature. The method is fully automated via a computer program and has been verified to be reliable and efficient. [ABSTRACT FROM AUTHOR]

Abstract: A KNbO3 nanoneedles (KNs) based hydrogen peroxide (H2O2) biosensor was first proposed. Perovskite-type KNs can directly catalyze H2O2. The mechanism can be explained by Molecular Orbital Principles, with the formation of σ-bonding between the e g orbital of surface niobium ions and surface adsorbed oxygen-related intermediate species. Direct electron transfer between the Horseradish peroxidase (HRP) and electrode surface was achieved. Co-catalyst system of both HRP and KNbO3 was introduced to the oxidation of H2O2, thus the as-prepared biosensor exhibited high sensitivity (750μAmM−1 cm−2) and ultrafast response (1–2s) to H2O2. Therefore, KNs provide a promising material for enzymes assembly and sensing application. [Copyright &y& Elsevier]