We have developed a nev self-assembled quantum dot system where InGaAs dots are formed on an InAlAs wetting layer and embedded in the GaAs matrix. The structure is realized by special sample designation and demonstrat...We have developed a nev self-assembled quantum dot system where InGaAs dots are formed on an InAlAs wetting layer and embedded in the GaAs matrix. The structure is realized by special sample designation and demonstrated by low-temperature photoluminescence measurements. In contrast to the traditional InAs/GaAs quantum dots dominated by the ensemble effect, the temperature dependence of the photoluminescence of such a quantum dot structure behaves as decoupled quantum dots. This can be attributed to the enhanced potential confinement for the dots provided by a higher-energy barrier in the wetting layer。展开更多
[ Objective] The research aimed to study assessment index system of the rainstorm disaster in Fujian Province based on spectral cluste- ring model with grey correlation analysis. [Method] According to meteorological d...[ Objective] The research aimed to study assessment index system of the rainstorm disaster in Fujian Province based on spectral cluste- ring model with grey correlation analysis. [Method] According to meteorological disaster yearbook in Fujian Province, by comprehensively consider- ing disaster-inducing factor, disaster-inducing environment, disaster-sustaining body and regional disaster-prevention level, evaluation index system of the regional rainstorm disaster in Fujian was established. By spectral clustering model based on grey correlation analysis, dsk zoning of the rain- storm disaster was conducted in each area of Fujian. Finally, effect and application of the clustering model were analyzed by case research. [ Re- sult] In order to dig immanent connection among regional characteristics and improve disaster-preventing linkage performance of the evaluation unit, a spectral clustering model based on grey correlation analysis was used to conduct risk zoning of the rainstorm disaster in Fujian Province. Moreo- ver, combined weight was introduced to judge each evaluation index, so as to adjust clustering model. By case study, rainstorm disaster levels in 67 counties were obtained. Internal characteristics of each type were analyzed, and main correlation factors of each type were extracted. It was compared with statistical result of the rainstorm disaster, verifying validity and feasibility of the model. [ Conclusion] The method was feasible, and its evaluated result had better differentiation and decision accuracv.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.69736010the National Advanced Materials Committee of China。
文摘We have developed a nev self-assembled quantum dot system where InGaAs dots are formed on an InAlAs wetting layer and embedded in the GaAs matrix. The structure is realized by special sample designation and demonstrated by low-temperature photoluminescence measurements. In contrast to the traditional InAs/GaAs quantum dots dominated by the ensemble effect, the temperature dependence of the photoluminescence of such a quantum dot structure behaves as decoupled quantum dots. This can be attributed to the enhanced potential confinement for the dots provided by a higher-energy barrier in the wetting layer。
基金Supported by Special Item of the Public Sector(Meteorological) Science Research(GYHY201106040)
文摘[ Objective] The research aimed to study assessment index system of the rainstorm disaster in Fujian Province based on spectral cluste- ring model with grey correlation analysis. [Method] According to meteorological disaster yearbook in Fujian Province, by comprehensively consider- ing disaster-inducing factor, disaster-inducing environment, disaster-sustaining body and regional disaster-prevention level, evaluation index system of the regional rainstorm disaster in Fujian was established. By spectral clustering model based on grey correlation analysis, dsk zoning of the rain- storm disaster was conducted in each area of Fujian. Finally, effect and application of the clustering model were analyzed by case research. [ Re- sult] In order to dig immanent connection among regional characteristics and improve disaster-preventing linkage performance of the evaluation unit, a spectral clustering model based on grey correlation analysis was used to conduct risk zoning of the rainstorm disaster in Fujian Province. Moreo- ver, combined weight was introduced to judge each evaluation index, so as to adjust clustering model. By case study, rainstorm disaster levels in 67 counties were obtained. Internal characteristics of each type were analyzed, and main correlation factors of each type were extracted. It was compared with statistical result of the rainstorm disaster, verifying validity and feasibility of the model. [ Conclusion] The method was feasible, and its evaluated result had better differentiation and decision accuracv.
