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Partial order formal structure analysis (POFSA) is an emerging theory in the field of concept cognitive learning (CCL). Attribute partial order structure diagram (APOSD) is the visual expression of the knowledge structure in POFSA. It has the advantages of explicit expression of the hierarchies of attributes and concise visual expression of the knowledge structure. This paper mainly focuses on the incremental CCL of APOSD in dynamic data circumstances. Firstly, the concept of location information coding of nodes in APOSD is proposed to express the position of nodes in the entire diagram as well as the relationships between nodes, which is an important tool throughout this paper. Secondly, by analyzing the relationship between new objects and objects in the original diagram, dynamic learning strategy for APOSD is proposed. Thirdly, in order to balance the efficiency and accuracy of dynamic learning, a dynamic-static alternating self-learning method for APOSD is proposed, which is an improved incremental learning strategy. Finally, comparative experiments illustrate that compared with non-incremental learning method of APOSD and concept lattice, the two proposed incremental learning methods of APOSD can effectively achieve dynamic self-updating of the knowledge base when processing dynamic data, and provide another perspective for discovering knowledge from the same data. Besides, the effectiveness of the improved incremental learning strategy is verified as well. [ABSTRACT FROM AUTHOR]

Density functional theory calculations were performed to investigate the molecular adsorption behaviors of hydrogen on small bimetallic AuCu clusters with n + m ≤ 5. H prefers to bind to a copper atom in AuCuH complexes when both Au and Cu sites co-exist. The adsorption energies of AuH are larger than CuH clusters with the same n and the adsorption energies of bimetallic cluster hydrides are between those of mono AuH and CuH. The adsorption of H on AuCu can enhance the stability of the whole cluster. The vertical ionization potentials of the cluster hydrides generally decrease as the Cu content increases for the given cluster size. The H-H and M-H stretching frequencies (M = Au or Cu) are highly correlated to the atoms to which the adsorbate is attached. The reaction paths for H dissociation on AuCu, AuCu and AuCu clusters were also investigated and discussed. [ABSTRACT FROM AUTHOR]

Density functional theory calculations were performed to investigate the structural and energetic properties of NO adsorption on small bimetallic AgCu clusters ( n + m ≤ 5). Generally NO is adsorbed in bridge configuration. The adsorbates prefer Cu sites when both Ag and Cu co-exist in the clusters. The adsorption energies and the dissociation energies of the complex clusters increase as the Cu content increases for the given cluster size. Our calculation suggests that the bimetallic AgCu may react with NO dissociatively by way of Ag atom, Ag or AgCu loss. The N-O vibrational properties of the complex clusters were also discussed and analyzed. [ABSTRACT FROM AUTHOR]