This paper first analyzes the reason that agricultural geographic information gives rise to semantic heterogeneity and solution thereof. Although OWL （web ontology language） is the standard of ontology representatio...This paper first analyzes the reason that agricultural geographic information gives rise to semantic heterogeneity and solution thereof. Although OWL （web ontology language） is the standard of ontology representation language in semantic web, it is insufficient in representing spatial characteristics, especially spatial relationship. Consequently it is pointed out to build geo-ontology by virtue of three theories such as mereology, location theory and topology in this paper. This paper introduces mereology, location theory and topology, and then discusses how to adopt these three theories to build geo-ontology. The outcome of experiment shows that solution put forward by this paper is feasible.展开更多
RbTiOAsO_(4)(RTA)crystals of high optical quality were grown with flux method.The defects of RTA crystals are mainly growth striations,growth sector boundaries and sometimes ferroelectric domains.The refractive indice...RbTiOAsO_(4)(RTA)crystals of high optical quality were grown with flux method.The defects of RTA crystals are mainly growth striations,growth sector boundaries and sometimes ferroelectric domains.The refractive indices and electrooptic coefficients were measured together with dielectric constants,ionic conductivity and direct current resistivities.It is shown that RbTiOAsO_(4) is not only as good a nonlinear optical crystal as KTiOPO4 but also a superior electrooptic crystal.展开更多
基金supported by the National Basic Research Program of China (2010CB950603)the Science and Technology Research Project of Hubei Provincial Department of Education,China (Q20112905)+1 种基金the Key Science Research Project of Huanggang Normal University,China(2011CA070)the Doctoral Foundation Project of Huanggang Normal University,China (09cd151)
文摘This paper first analyzes the reason that agricultural geographic information gives rise to semantic heterogeneity and solution thereof. Although OWL （web ontology language） is the standard of ontology representation language in semantic web, it is insufficient in representing spatial characteristics, especially spatial relationship. Consequently it is pointed out to build geo-ontology by virtue of three theories such as mereology, location theory and topology in this paper. This paper introduces mereology, location theory and topology, and then discusses how to adopt these three theories to build geo-ontology. The outcome of experiment shows that solution put forward by this paper is feasible.
基金the National 863 High Technology Program of China。
文摘RbTiOAsO_(4)(RTA)crystals of high optical quality were grown with flux method.The defects of RTA crystals are mainly growth striations,growth sector boundaries and sometimes ferroelectric domains.The refractive indices and electrooptic coefficients were measured together with dielectric constants,ionic conductivity and direct current resistivities.It is shown that RbTiOAsO_(4) is not only as good a nonlinear optical crystal as KTiOPO4 but also a superior electrooptic crystal.
