Nanocrystalline CdTe thin films were prepared by asymmetric rectangular pulse electrodeposition in organic solution at 110 degreesC. STM image shows a porous network morphology constructed by interconnected spherical ...Nanocrystalline CdTe thin films were prepared by asymmetric rectangular pulse electrodeposition in organic solution at 110 degreesC. STM image shows a porous network morphology constructed by interconnected spherical CdTe crystallites with a mean diameter of 4.2 nm. A pronounced size quantization was indicated in the action and absorption spectra. Potentials dependence dual conductive behavior was revealed in the photocurrent-potential (I-V) curves.展开更多
An improved scalar Costa scheme (SCS) was proposed by using improved Watson perceptual model to adaptively decide quantization step size and scaling factor. The improved scheme equals to embed hiding data based on an ...An improved scalar Costa scheme (SCS) was proposed by using improved Watson perceptual model to adaptively decide quantization step size and scaling factor. The improved scheme equals to embed hiding data based on an actual image. In order to withstand amplitude scaling attack, the Watson perceptual model was redefined, and the improved scheme using the new definition can insure quantization step size in decoder that is proportional to amplitude scaling attack factor. The performance of the improved scheme outperforms that of SCS with fixed quantization step size. The improved scheme combines information theory and visual model.展开更多
文摘Nanocrystalline CdTe thin films were prepared by asymmetric rectangular pulse electrodeposition in organic solution at 110 degreesC. STM image shows a porous network morphology constructed by interconnected spherical CdTe crystallites with a mean diameter of 4.2 nm. A pronounced size quantization was indicated in the action and absorption spectra. Potentials dependence dual conductive behavior was revealed in the photocurrent-potential (I-V) curves.
基金The National Basic Research Program (973) of China (No. 2005CB321804)
文摘An improved scalar Costa scheme (SCS) was proposed by using improved Watson perceptual model to adaptively decide quantization step size and scaling factor. The improved scheme equals to embed hiding data based on an actual image. In order to withstand amplitude scaling attack, the Watson perceptual model was redefined, and the improved scheme using the new definition can insure quantization step size in decoder that is proportional to amplitude scaling attack factor. The performance of the improved scheme outperforms that of SCS with fixed quantization step size. The improved scheme combines information theory and visual model.
