排序方式: 共有31条查询结果,搜索用时 31 毫秒
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1-N型热交换链的(火用)传递分析 总被引:4,自引:0,他引:4
依据工程传递原理建立1-N型热交换链的传递模型,并确立相应的评价准则。对动力锅炉内热交换过程的 各输元及全过程进行了传递计算及分析,并与传统的传热分析及分析比较,提供了一些新的技术评价信息。 相似文献
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六角形孔径平面微透镜阵列的制作及基本特性研究 总被引:5,自引:4,他引:1
采用光刻离子交换工艺制作了六角形孔径平面微透镜阵列.离子交换后的变折射率区域有微小重叠,填充系数可达95%以上.对制作的六角形孔径平面微透镜进行了折射率分布、数值孔径和像差等光学特性测试,得到的六角形孔径平面微透镜阵列光学性能均匀,成像质量较好的结果.该透镜阵列的研制成功为制作高质量高填充系数透镜阵列及模拟生物复眼光学系统奠定了基础. 相似文献
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为了分析Gd吸附原子在Cu(110)表面的扩散机理,用分子动力学对该扩散过程进行模拟.模拟 结果表明在[1 1 0]方向Gd原子通过跳跃机理扩散,而且多步跳跃频率很高.而在[0 0 1]方向则通过交换机理扩散.吸附原子在[1 1 0]方向的扩散能力要比[0 0 1] 方向强.通过对扩散频率的拟合,发现两种扩散机理都符合Arrhenius公式,从而确定了跳跃 机理的扩散势垒为0.097eV,交换机理的扩散势垒为0.33eV.另外还用能量弛豫的方法确定了 跳跃机理的扩散势垒.
关键词:
分子动力学
表面扩散
跳跃机理
交换机理
扩散势垒 相似文献
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贺深泽 《数学的实践与认识》2009,39(3)
将选择交换向量分量的方法引入蒙特卡诺法,向量搜索速度大大提高,构造出了m×(m-1)维弱相关设计矩阵,只要m≠4k+2,k为正整数,便都包含一个零相关子阵,试验点分布均衡分散,回归系数估计简单且相关性小.给出了一个包含7×3维零相关子阵的7×6维弱相关矩阵的例子. 相似文献
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DongYangHUANG XiZhangYI ZhengWuWANG 《中国化学快报》2003,14(10):1077-1080
In order to study synergism of the mixed surfactants system with molecular exchanging energy ( ε ), the Lennard-Jones formula has been firstly introduced to evaluate the ε of the mixed system, CH3(CH2)nOSO 3^- /CH3(CH2)nN^ (CH3)3, directly from their molecular structure. The comparison of the calculated and the observed results showed that this method is practical. 相似文献
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We report the study of the growth of CeO2 nanoparticles on the external walls and Ce4+ intercalation within the titanate nanotubes. The materials were fully characterized by multiple techniques, such as: Raman spectroscopy, infrared spectroscopy (FTIR), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The ion exchange processes in the titanate nanotubes were carried out using different concentrations of Ce4+ in aqueous solution. Our results indicate that the growth of CeO2 nanoparticles grown mediated by the hydrolysis in the colloidal species of Ce and the attachment onto the titanate nanotubes happened and get it strongly anchored to the titanate nanotube surface by a simple electrostatic interaction between the nanoparticles and titanate nanotubes, which can explain the small size and even distribution of nanoparticles on titanate supports. It was demonstrated that it is possible to control the amount and size of CeO2 nanoparticles onto the nanotube surface, the species of the Ce ions intercalated between the layers of titanate nanotubes, and the materials could be tuned for using in specific catalysis in according with the amount of CeO2 nanoparticles, their oxygen vacancies/defects and the types of Ce species (Ce4+ or Ce3+) present into the nanotubes. 相似文献
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讨论了激光靶耦合数值模拟中电子-辐射能量交换项的处理。为了克服它给三温方程求解带来的困难,在非平衡区(Te>Tr)和接近平衡区(Te~Tr)采用了不同的能量交换项形式。此外,由于接近平衡时的能量交换项用辐射平均自由程表示,避免了此时计算束缚电子占据概率不准确的问题。 相似文献
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