To extend the traditional generalized grey incidence model, a novel grey incidence model based on inter- val grey numbers is constructed. Considering the numerical information of indexes cannot be accurately obtained ...To extend the traditional generalized grey incidence model, a novel grey incidence model based on inter- val grey numbers is constructed. Considering the numerical information of indexes cannot be accurately obtained and can be defined as interval grey numbers, the interval grey numbers are defined as standard interval grey num- bers which are split in white part and grey part. The absolute degree of incidence and relative degree of incidence based on the interval grey numbers are constructed and their arithmetic are given. Finally, an example about commercial aircraft index selection illuminates the effectiveness of the model. The results show that the model can sort indexes better and can extend the grey incidence models significantly.展开更多
Eu^2+/Eu^3+ mixed-valence couple co-doped material holds great potential for ratiometric temperature sensing owing to its different electronic configurations and electron-lattice interaction. Here, the correlation of ...Eu^2+/Eu^3+ mixed-valence couple co-doped material holds great potential for ratiometric temperature sensing owing to its different electronic configurations and electron-lattice interaction. Here, the correlation of nonstoichiometry in chemical composition, phase structures and luminescence propertis of Ca2 Al2 Si1-xO7:Eu is discussed, and controlled Eu^2+/Eu^3+ valence and tunable emission appear with decreasing Si content. It is found that the 2 Ca^2++ Si^4+←→ Eu^2++ Eu^3++ Al^3+ cosubstitution accounts for the structural stability and charge balance mechanism. Benefiting from the diverse thermal dependent emission behaviors of Eu^2+ and Eu^3+, Ca2 Al2 Si1-xO7:Eu thermometer exhibits excellent temperature sensing performances with the maximum absolute and relative sensitivity being 0.024 K-1(at 303 K) and 2.46% K-1(at 443 K) and good signal discriminability. We propose that the emission quenching of Eu^2+ is ascribed to 5 d electrons depopulation through Eu^2+/Eu^3+ intervalence charge transfer state, while the quenching of Eu^3+ comes from multiphonon relaxation. Our work demonstrates the potential of Ca2 Al2 Si1-xO7:Eu for noncontact optical thermometry, and also highlights mixed-valence europium-containing compounds toward temperature sensing.展开更多
基金Supported by the National Natural Science Foundation of China(70901041,71171113)the Joint Research Project of National Natural Science Foundation of China and Royal Society of UK(71111130211)+3 种基金the Major Program of National Funds of Social Science of Chinathe Doctoral Fund of Ministry of Education of China(20093218120032,200802870020)the Qinglan Project for Excellent Youth Teacher in Jiangsu Province(China)the Research Funding of Nanjing University of Aeronautics and Astronautics(NR2011002,NJ2011009)~~
文摘To extend the traditional generalized grey incidence model, a novel grey incidence model based on inter- val grey numbers is constructed. Considering the numerical information of indexes cannot be accurately obtained and can be defined as interval grey numbers, the interval grey numbers are defined as standard interval grey num- bers which are split in white part and grey part. The absolute degree of incidence and relative degree of incidence based on the interval grey numbers are constructed and their arithmetic are given. Finally, an example about commercial aircraft index selection illuminates the effectiveness of the model. The results show that the model can sort indexes better and can extend the grey incidence models significantly.
基金supported by the National Natural Science Foundation of China (51722202, 51972118 and 51572023)the Guangdong Provincial Science & Technology Project (2018A050506004)Innovation Projects of Department of Education of Guangdong Province (2018KQNCX265)
文摘Eu^2+/Eu^3+ mixed-valence couple co-doped material holds great potential for ratiometric temperature sensing owing to its different electronic configurations and electron-lattice interaction. Here, the correlation of nonstoichiometry in chemical composition, phase structures and luminescence propertis of Ca2 Al2 Si1-xO7:Eu is discussed, and controlled Eu^2+/Eu^3+ valence and tunable emission appear with decreasing Si content. It is found that the 2 Ca^2++ Si^4+←→ Eu^2++ Eu^3++ Al^3+ cosubstitution accounts for the structural stability and charge balance mechanism. Benefiting from the diverse thermal dependent emission behaviors of Eu^2+ and Eu^3+, Ca2 Al2 Si1-xO7:Eu thermometer exhibits excellent temperature sensing performances with the maximum absolute and relative sensitivity being 0.024 K-1(at 303 K) and 2.46% K-1(at 443 K) and good signal discriminability. We propose that the emission quenching of Eu^2+ is ascribed to 5 d electrons depopulation through Eu^2+/Eu^3+ intervalence charge transfer state, while the quenching of Eu^3+ comes from multiphonon relaxation. Our work demonstrates the potential of Ca2 Al2 Si1-xO7:Eu for noncontact optical thermometry, and also highlights mixed-valence europium-containing compounds toward temperature sensing.
