To alleviate the amount of work involved in constructing a domain ontology, starting with the base of an existing terminological-rich thesaurus is better than starting from scratch. With a case study of reengineering ...To alleviate the amount of work involved in constructing a domain ontology, starting with the base of an existing terminological-rich thesaurus is better than starting from scratch. With a case study of reengineering the Defense Science and Technology Thesaurus into a prototype military aircraft ontology, a four-phase thesaurus-based methodology is introduced and investigated, which consists of identifying the application purpose, overall design, designing in detail and evaluation. Designing in detail is the core step, converting the terms and semantic relationships of the thesaurus into an ontology and supplementing richer semantic relationships. The resulting prototype ontology includes 87 concepts and 34 relationships, and can be extended and scaled up to a full-fledged domain ontology in the future. Eight universal genres of relationships of this ontology are preliminarily summarized and analyzed, including equivalent relationships, approximate relationships, generic/abstract relationships, part/whole relationships, cause/effect relationships, entity/location relationships etc., and the normalization of semantic relationships is critical to the merging and reusing of follow-up multiple ontologies.展开更多
CdS/ZnS core-shell microparticles were prepared by a simple two-step method combining ultrasonic spray pyrolysis and chemical bath deposition.The core-shell structures showed enhanced photocatalytic properties compare...CdS/ZnS core-shell microparticles were prepared by a simple two-step method combining ultrasonic spray pyrolysis and chemical bath deposition.The core-shell structures showed enhanced photocatalytic properties compared with those of CdS or ZnS spherical particles.CdS/ZnS photocatalysts with different amount of ZnS loaded as shells were prepared by adjusting the concentrations of Zn and S precursors during synthesis.The optical properties and photocatalytic activity for hydrogen production were investigated and the amount of ZnS loaded as shell was optimized.Thermal annealing and hydrothermal sulfurization treatments were applied to the core-shell structure and both treatments enhanced the material＇s photocatalytic activity and stability by eliminating crystalline defects and surface states.The result showed that thermal annealing treatment improved the bulk crystallinity and hydrothermal sulfurization improved the surface properties.The sample subjected to both treatments showed the highest photocatalytic activity.These results indicate that CdS/ZnS core-shell microspheres are a simple structure that can be used as efficient photocatalysts.The hydrothermal sulfurization treatment may also be a useful surface treatment for metal sulfide photocatalysts.The simple two-step method provides a promising approach to the large-scale synthesis of core-shell microsphere catalysts.展开更多
文摘To alleviate the amount of work involved in constructing a domain ontology, starting with the base of an existing terminological-rich thesaurus is better than starting from scratch. With a case study of reengineering the Defense Science and Technology Thesaurus into a prototype military aircraft ontology, a four-phase thesaurus-based methodology is introduced and investigated, which consists of identifying the application purpose, overall design, designing in detail and evaluation. Designing in detail is the core step, converting the terms and semantic relationships of the thesaurus into an ontology and supplementing richer semantic relationships. The resulting prototype ontology includes 87 concepts and 34 relationships, and can be extended and scaled up to a full-fledged domain ontology in the future. Eight universal genres of relationships of this ontology are preliminarily summarized and analyzed, including equivalent relationships, approximate relationships, generic/abstract relationships, part/whole relationships, cause/effect relationships, entity/location relationships etc., and the normalization of semantic relationships is critical to the merging and reusing of follow-up multiple ontologies.
基金supported by the National Natural Science Foundation of China(51202186,51323011)the Fundamental Research Funds for the Central University(xjj2016039)~~
文摘CdS/ZnS core-shell microparticles were prepared by a simple two-step method combining ultrasonic spray pyrolysis and chemical bath deposition.The core-shell structures showed enhanced photocatalytic properties compared with those of CdS or ZnS spherical particles.CdS/ZnS photocatalysts with different amount of ZnS loaded as shells were prepared by adjusting the concentrations of Zn and S precursors during synthesis.The optical properties and photocatalytic activity for hydrogen production were investigated and the amount of ZnS loaded as shell was optimized.Thermal annealing and hydrothermal sulfurization treatments were applied to the core-shell structure and both treatments enhanced the material＇s photocatalytic activity and stability by eliminating crystalline defects and surface states.The result showed that thermal annealing treatment improved the bulk crystallinity and hydrothermal sulfurization improved the surface properties.The sample subjected to both treatments showed the highest photocatalytic activity.These results indicate that CdS/ZnS core-shell microspheres are a simple structure that can be used as efficient photocatalysts.The hydrothermal sulfurization treatment may also be a useful surface treatment for metal sulfide photocatalysts.The simple two-step method provides a promising approach to the large-scale synthesis of core-shell microsphere catalysts.
