In this paper, superlattice patterns have been investigated by using a two linearly coupled Brusselator model. It is found that superlattice patterns can only be induced in the sub-system with the short wavelength. Th...In this paper, superlattice patterns have been investigated by using a two linearly coupled Brusselator model. It is found that superlattice patterns can only be induced in the sub-system with the short wavelength. Three different coupling methods have been used in order to investigate the mode interaction between the two Turing modes. It is proved in the simulations that interaction between activators in the two sub-systems leads to spontaneous formation of black eye pattern and/or white eye patterns while interaction between inhibitors leads to spontaneous formation of super-hexagonal pattern. It is also demonstrated that the same symmetries of the two modes and suitable wavelength ratio of the two modes should also be satisfied to form superlattice patterns.展开更多
Several image fusion approaches for CCD/SAR images are studied and the performance evaluation of these fusion approaches is completed in this paper. Firstly, the preprocessing of CCD/SAR images before fusion is fulfil...Several image fusion approaches for CCD/SAR images are studied and the performance evaluation of these fusion approaches is completed in this paper. Firstly, the preprocessing of CCD/SAR images before fusion is fulfilled. Then, the image fusion methods including linear superposition, nonlinear operator method and multiresolution methods, of which the multiresolution methods include Laplacian pyramid, ratio pyramid, contrast pyramid, gradient pyramid, morphological pyramid and discrete wavelet transform, are adopted to fuse two types of images. Lastly, the four performance measures, standard deviation, entropy, cross entropy and spatial frequency, are calculated to compare the fusion results by different fusion approaches in this paper. Experimental results show that contrast pyramid, morphology pyramid and discrete wavelet transformation in multiresolution approaches are more suitable for CCD/SAR image fusion than other ones proposed in this paper and the objective performance evaluation of CCD/SAR image fusion approaches are effective.展开更多
The authors extend Hua’s fundamental theorem of the geometry of Hermitian matri- ces to the in?nite-dimensional case. An application to characterizing the corresponding Jordan ring automorphism is also presented.
Hot electron emission means that electrons move over potential barriers to come out of the metal when the metal is being heated.Obviously,voltage will generate between electrons and the metal.Based on this,the model o...Hot electron emission means that electrons move over potential barriers to come out of the metal when the metal is being heated.Obviously,voltage will generate between electrons and the metal.Based on this,the model of metal hot-electron power generation is built.Free electron model of Sommerfeld is used to describe the movement of electrons in metal.According to the different width of potential barriers,two models are built.One assumes that electrons move from one metal to another mainly by moving over the potential barrier as the barrier is wide enough.The other assumes that the potential barrier is so narrow that electrons mainly move through the potential barrier by tunnel effect.The first model is analyzed and proved strictly,including the building of model,the calculation of open-circuit voltage and the drawing of volt-ampere characteristic curve.The second model is analysed simply.This paper shows that power generation by metal hot-electron is possible based on the theory and can provide reference for researching in power generation of metal hot-electron.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos. 10975043, 10947166 and 10775037the Foundation of Bureau of Education, Hebei Province, China under Grant No. 2009108the Natural Science Foundation of Hebei Province, China under Grant No. A2008000564)
文摘In this paper, superlattice patterns have been investigated by using a two linearly coupled Brusselator model. It is found that superlattice patterns can only be induced in the sub-system with the short wavelength. Three different coupling methods have been used in order to investigate the mode interaction between the two Turing modes. It is proved in the simulations that interaction between activators in the two sub-systems leads to spontaneous formation of black eye pattern and/or white eye patterns while interaction between inhibitors leads to spontaneous formation of super-hexagonal pattern. It is also demonstrated that the same symmetries of the two modes and suitable wavelength ratio of the two modes should also be satisfied to form superlattice patterns.
基金Under the auspices of Astronautical Innovation Fund of China.
文摘Several image fusion approaches for CCD/SAR images are studied and the performance evaluation of these fusion approaches is completed in this paper. Firstly, the preprocessing of CCD/SAR images before fusion is fulfilled. Then, the image fusion methods including linear superposition, nonlinear operator method and multiresolution methods, of which the multiresolution methods include Laplacian pyramid, ratio pyramid, contrast pyramid, gradient pyramid, morphological pyramid and discrete wavelet transform, are adopted to fuse two types of images. Lastly, the four performance measures, standard deviation, entropy, cross entropy and spatial frequency, are calculated to compare the fusion results by different fusion approaches in this paper. Experimental results show that contrast pyramid, morphology pyramid and discrete wavelet transformation in multiresolution approaches are more suitable for CCD/SAR image fusion than other ones proposed in this paper and the objective performance evaluation of CCD/SAR image fusion approaches are effective.
基金Project supported by the National Natural Science Foundation of China (No.10471082) and the ShanxiProvincial Natural Science Foundation of China.
文摘The authors extend Hua’s fundamental theorem of the geometry of Hermitian matri- ces to the in?nite-dimensional case. An application to characterizing the corresponding Jordan ring automorphism is also presented.
文摘Hot electron emission means that electrons move over potential barriers to come out of the metal when the metal is being heated.Obviously,voltage will generate between electrons and the metal.Based on this,the model of metal hot-electron power generation is built.Free electron model of Sommerfeld is used to describe the movement of electrons in metal.According to the different width of potential barriers,two models are built.One assumes that electrons move from one metal to another mainly by moving over the potential barrier as the barrier is wide enough.The other assumes that the potential barrier is so narrow that electrons mainly move through the potential barrier by tunnel effect.The first model is analyzed and proved strictly,including the building of model,the calculation of open-circuit voltage and the drawing of volt-ampere characteristic curve.The second model is analysed simply.This paper shows that power generation by metal hot-electron is possible based on the theory and can provide reference for researching in power generation of metal hot-electron.
