246 resultados para 305.896


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Using AlN as a buffer layer, 3C-SiC film has been grown on Si substrate by low pressure chemical vapor deposition (LPCVD). Firstly growth of AlN thin films on Si substrates under varied V/III ratios at 1100 degrees was investigated and the (002) preferred orientational growth with good crystallinity was obtained at the V/III ratio of 10000. Annealing at 1300 degrees C indicated the surface morphology and crystallinity stability of AlN film. Secondly the 3C-SiC film was grown on Si substrate with AlN buffer layer. Compared to that without AlN buffer layer, the crystal quality of the 3C-SiC film was improved on the AlN/Si substrate, characterized by X-ray diffraction (XRD) and Raman measurements.

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Temperature-dependent bimodal size evolution of InAs quantum dots on vicinal GaAs(100) substrates grown by metalorganic chemical vapor deposition (MOCVD) is studied. An abnormal trend of the evolution on temperature is observed. With the increase of the growth temperature, while the density of the large dots decreases continually, that of the small dots first grows larger when temperature was below 520 degrees C, and then there is a sudden decrease at 535 degrees C. Photoluminescence (PL) studies show that QDs on vicinal substrates have a narrower PL line width, a longer emission wavelength and a larger PL intensity.

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The goal of image restoration is to restore the original clear image from the existing blurred image without distortion as possible. A novel approach based on point location in high-dimensional space geometry method is proposed, which is quite different from the thought ways of existing traditional image restoration approaches. It is based on the high-dimensional space geometry method, which derives from the fact of the Principle of Homology-Continuity (PHC). Begin with the original blurred image, we get two further blurred images. Through the regressive deducing curve fitted by these three images, the first iterative deblured image could be obtained. This iterative "blurring-debluring-blurring" process is performed till reach the deblured image. Experiments have proved the availability of the proposed approach and achieved not only common image restoration but also blind image restoration which represents the majority of real problems.

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复制技术是提高移动数据库系统性能的一项关键技术 .该文提出了一种新的移动复制数据库系统模型——事务级结果集传递 (TL RSP)移动复制模型 ,重点分析了该模型中的冲突检测及消解策略 ,并给出了具体的实现算法 ;TL RSP移动复制模型允许移动用户在系统断连时存取数据库的本地副本并提交事务 ,重新连接时进行冲突的检测及消解 ,同时进行事务结果集的合并 ,最后通过增量刷新的方式进行同步处理 ,使得系统最终收敛于一致性的状态 .此外 ,通过引入简化的事务日志、数据版本号以及权限控制等概念 ,TL RSP模型有效地降低了移动数据库系统的资源消耗 ,保证了数据库的一致性 ,从而为移动数据库系统复制提供了一个可行的解决方案

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专利是除论文外的又一非常重要的科技成果。目前专利申请工作并未得到足够重视,并且文献中对专利技术成果的反映甚少。文章对中国国家知识产权局(SIPO)专利数据库中海洋能专利授权情况进行了分类统计。介绍了波浪能、潮汐能、温差能的最新专利,并指出了该领域专利申请的热点和空白领域。最后根据统计数据从专利的角度分析了中国海洋能研究的进展和前景。

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The optical properties of Au nanoparticles deposited on thermochromic thin films of VO2 are investigated using spectroscopy. A localized modification on the transmittance spectrum of VO2 film is formed due to the presence of Au nanoparticles which exhibit localized surface plasmon resonance (LSPR) in the visible-near IR region. The position of the modification wavelength region shows a strong dependence on the Au mass thickness and shifts toward the red as it increases. On the other hand, it was found that the LSPR of Au nanoparticles can be thermally tunable because of the thermochromism of the supporting material of VO2. The LSPR wavelength, lambda(SPR), shifts to the blue with increasing temperature, and shifts back to the red as temperature decreases. A fine tuning is achieved when the temperature is increased in a stepwise manner.