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61.
Photoluminescence and atomic force microscopy studies on pre- and post-irradiated ruby with Fe3+ ion
Photoluminescence spectra measured for pristine ruby and its two irradiated samples with Fe3+ ion show R1, R2, N lines and a broad band. Decrease in intensities of these features is observed with irradiation of Fe3+ ion in ruby. Progressive structural changes and modifications on surface of irradiated rubies with Fe3+ ion have been observed by atomic force microscopy. Decrease in intensities is discussed in terms of pair formation. 相似文献
62.
Xi Jiang Qi Liao Jianjun Zhou Zhaohui Wang Chiming Chan Lin Li 《Journal of Polymer Science.Polymer Physics》2013,51(11):907-914
We have developed a morphologic method to investigate the relaxation processing of the stretched polymer chains in melts, in which an atomic force microscope probe was used to shear the surface of an isotactic polypropylene melt to obtain the isolated shish‐kebab structure. We present the results of the time dependence of length of the isolated shish‐kebab structure and the stress dependence of the kebab density along the direction of shish in this paper. Our results demonstrate that the shear‐oriented polymer melts show the relaxation dynamics of worm‐like chain where the length deficit of the isolated shish‐kebab structure is scaled with the relaxation time as a power of 1/3. The melting behavior of shish‐kebab structure was also investigated. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 907–914 相似文献
63.
Koel Adhikary 《哲学杂志》2013,93(33):4075-4087
We report on the successful fabrication of polycrystalline silicon films by aluminium-induced crystallisation (AIC) of Radio frequency (rf) plasma-enhanced chemical vapour deposited (PECVD) a-Si films. The effects of annealing at different temperatures (300 and 400°C), below the eutectic temperature of the Si–Al binary system, on the crystallisation process have been studied. This work emphasises the important role of the position of the Al layer with respect to the Si layer on the crystallisation process. The properties of the crystallised films were characterised using X-ray diffraction, Raman spectroscopy, ellipsometry, field-emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). With an increase in the annealing temperature, it was found that the degree of crystallisation of annealed a-Si/Al and Al/a-Si films increased. The results showed that the arrangement where the Al was on top of the a-Si had a more prominent effect on crystallisation enhancement than when Al was below the a-Si. The interfacial layer between the Al and a-Si film is crucial because it influences the layer-exchange process during annealing. The oxide layer formed between the Al and the a-Si layers greatly retards the crystallisation process in the case of the Al/Si arrangement. Our investigations suggest that polycrystalline Si films formed by AIC can be used as a seed layer in solar cell fabrication. 相似文献
64.
用单光束扫描法测量了在532nm处一种新型非晶态分子材料5,5′Bis(dimesitylboryl)2,2′bithiophene的非线性折射率和吸收系数样品非线性透射特性的分析表明,在靠近线性吸收区的532nm处有饱和吸收存在由三能级饱和模型和Zscan法确定了饱和强度、非线性折射率的实部和虚部研究结果表明:这种新型非晶态分子材料具有非常好的光子学应用前景. 相似文献
65.
考虑二阶非线性椭圆型微分方程∑^n_{i,j}∂/∂x_i{A_{i,j}(x,y)∂/∂x_j}+q(x)f(y)=0 (E),其中q(x)在外区域 Ω∈R\+n上变号. 利用偏Riccati变换和积分平均技巧, 建立了方程(E)所有解振动的充分准则. 相似文献
66.
引入厚度偏差Δd, 修正了薄膜透射率表达式.基于Ag/AAO纳米有序阵列复合结构实验透射光谱(500—2700nm)的两条极值包络线, 定义了一个优化函数, 结合最优化数值算法尝试确定具有较强吸收的Ag/AAO纳米有序阵列复合结构的等效光学参量. 由此计算了该结构的等效折射率n、等效消光系数k、平均等效厚度d以及厚度偏差Δd. 该方法对Ag/AAO纳米复合结构平均等效厚度的相对计算误差仅为0.3%, 与实测厚度基本一致, 且Ag/AAO纳米复合结构的模拟透射谱与实验透射光谱在500—2700nm波段范围内相符. 这表明该计算方法可有效确定Ag/AAO纳米复合结构的等效光学参量, 并与实验结果是自洽的.
关键词:
薄膜光学
光学参量
纳米复合结构
最优化算法 相似文献
67.
本文用自旋捕捉术技与ESR相结合的方法,研究取代环成二烯锆、铪络物(RC5H4)2ZrCl2(R=H,CH3,C3H7,C4H9,C5H11,C6H11)及(RC5H4)2HfCl2(R=CH3,C2H5,C3H7)光解的活泼自由基。结果表明,取代环成二烯锆、铪络合物与取代环戊二烯钛结合物光解机理相同,即光解初级过程是M-(RC5H4)(M=Ti,Zr,Hf)π键的均裂。其差别在于RCpMCl2(M=Zr,Hf)可为PBN及ND捕获,并后者的加合物表现出氯核的分裂。 相似文献
68.
提出了一种光滑积分伪弱形式,将光滑积分拓展至被积函数非偏导项求解。结合光滑应变技术和伪弱形式,可实现有限元系统方程统一光滑积分求解,即对刚度矩阵和质量矩阵中的应变矩阵和形函数矩阵均可进行光滑积分处理,并转化为光滑子域的边界积分。光滑积分伪弱形式与光滑应变技术比较,增加了形函数矩阵不定积分处理过程,且没有降低有限元求解对形函数连续性的要求。不过,伪弱形式改变了单元积分的求解形式,连续质量矩阵求解也无需坐标映射和雅可比矩阵计算。以轴对称二维问题为研究对象,结果表明极度不规则三角形和四边形单元光滑积分伪弱形式在静态和动态有限元方程求解中也具有很好的精度。 相似文献
69.
A comparison among three weakly nonlinear approaches for thermo‐gravitational instability in a Newtonian fluid layer heated from below is presented. First, the dynamical systems describing the time evolution of the problem from different weakly nonlinear approaches, namely, the Lorenz model, the amplitude equations and the perturbation expansion approaches are obtained. Next, the steady states and their stability, as well as the transient behaviour are obtained from each dynamical system. The similarity and difference among the three models are emphasized. The role of each of the nondimensional groups, the Rayleigh number and the Prandtl number is compared for the three models. The different approaches lead to similar behaviours when the Rayleigh number is just above its critical value and Prandtl number is high. However, only the dynamical system obtained from the amplitude equations is able to reflect the role of the Prandtl number. On the other hand, the amplitude equations and perturbation expansion techniques are not suitable for predicting the uniform oscillatory behaviour observed frequently in Rayleigh–Bénard convection. The novelty of the current work lies in studying the critical differences in the findings of the three popular approaches to investigate weakly nonlinear thermal convection for the first time. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
70.
Quentin Araud Pascal Finaud‐Guyot Vincent Guinot Robert Mosé José Vazquez 《国际流体数值方法杂志》2012,70(12):1590-1604
Discontinuous Galerkin (DG) methods have shown promising results for solving the two‐dimensional shallow water equations. In this paper, the classical Runge–Kutta (RK) time discretisation is replaced by the eigenvector‐based reconstruction (EVR) that allows the second‐order time accuracy to be achieved within a single time‐stepping procedure. Moreover, the EVRDG approach yields stable solutions near drying and wetting fronts, whereas the classical RKDG approach yields instabilities. The proposed EVRDG technique is compared with the original RKDG approach on various test cases with analytical solutions. The EVRDG solutions are shown to be as accurate as those obtained with the RKDG scheme. Besides, the EVRDG scheme is 1.6 times faster than the RKDG method. Simulating dambreaks involving dry beds confirms that EVRDG scheme gives correct solutions, whereas the RKDG method yields instabilities. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献