Accuracy and analysis of long-radius measurement with long trace profiler

The long trace profiler(LTP) is proposed to measure radius of curvature(R) and surface figure of a longradius spherical surface in an optical shop.Equipped with a motorized rotary stage and a two-dimensional tilt stage,the LTP scans the full aperture and calculates the absolute radius of curvature of each scanning line based on the least square method.Nonlinear error and manufacture error difference between center and the edge are obtained by comparing R results.The R-limit is validated and expressed as D/R,where D is the aperture of the mirror under test.A full-aperture three-dimensional figure is also reconstructed based on triangle interpolation.     

Photovoltaic properties of ferroelectric solar cells based on polycrystalline BiFeO3 films sputtered on indium tin oxide substrates

To study the ferroelectric photovoltaic effect based on polycrystalline films,preparation of high-quality polycrystalline films with low leakage and high remnant polarization is essential.Polycrystalline Bi Fe O3(BFO)thin films with extremely large remnant polarization(2Pr=180μC/cm2)were successfully deposited on glass substrates coated with indium tin oxide using a modified radio frequency magnetron sputtering method.Symmetric and asymmetric cells were constructed to investigate the ferroelectric photovoltaic effect in order to understand the relationship between polarization and photovoltaic response.All examined cells showed polarization-induced photovoltaic effect.Our findings also showed that the ferroelectric photovoltaic effect is highly dependent on the material used for the top electrode and the thickness of the polycrystalline film.     

Super-Resolution for Face Image with an Improved K-NN Search Strategy

Recently, neighbor embedding based face super-resolution(SR) methods have shown the ability for achieving high-quality face images, those methods are based on the assumption that the same neighborhoods are preserved in both low-resolution(LR) training set and high-resolution(HR) training set. However, due to the "one-to-many" mapping between the LR image and HR ones in practice, the neighborhood relationship of the LR patch in LR space is quite different with that of the HR counterpart, that is to say the neighborhood relationship obtained is not true. In this paper, we explore a novel and effective re-identified K-nearest neighbor(RIKNN) method to search neighbors of LR patch. Compared with other methods, our method uses the geometrical information of LR manifold and HR manifold simultaneously. In particular, it searches K-NN of LR patch in the LR space and refines the searching results by re-identifying in the HR space, thus giving rise to accurate K-NN and improved performance. A statistical analysis of the influence of the training set size and nearest neighbor number is given, experimental results on some public face databases show the superiority of our proposed scheme over state-of-the-art face hallucination approaches in terms of subjective and objective results as well as computational complexity.     

Comparative study on thermal behaviors between micrites and thrombolites using thermogravimetric analysis

Journal of Thermal Analysis and Calorimetry - Although micrites (abiotic limestone) and thrombolites (typical biotic limestone), according to the sedimentation and biological action, can be...     

非均质材料力学研究进展: 热点、焦点和生长点 ————- ICHMM2008的观察和启迪

本文结合第二届国际非均质材料力学会议 (ICHMM2008,黄山)专题讨论会和部分特邀报告的情况, 以及2011年5月22$\sim$26日在上海崇明岛举行的ICHMM2011国际会议的内容, 对该领域的研究进展及其热点、焦点和生长点进行了综合性的评述. 重点讨论了多物理场与多尺度模拟、材料结构与力学行为从原子到连续介质的分析、随机微结构演化与退化、真实材料微结构的模拟、生物材料力学与仿生设计、在位实验和模型验证、功能梯度材料结构力学、微纳米功能器件开发等前沿性课题. 其中特别用较多的篇幅讨论了多物理场与多尺度模拟的背景、目标、必要性、现有方法的优缺点、障碍、应用例子与其他前沿研究领域的联系及其发展态势, 并阐述其研究焦点与值得注意的进展.      

国内化学史教育研究述评

包括化学史在内的科学史教育现代意义的复兴始于20世纪80年代,回顾改革开放以来我国化学史教育研究的进程,厘清与国际科学史教育的借鉴融合历史,从而为化学史教育的发展提供基于时间和空间维度的展望。     

科学史教育中应该防止的几种倾向

以历史哲学和科学哲学的视角反思当今一些防碍利用科学史实施科学教育的倾向,并通过科学史上相关实例加以解释,同时提出解决这些问题的方法。     

Hi540B型热转换标准的测量不确定

本文主要阐述了用热转换标准校准交流电压源的不确定度评定,本评定符合JJG410-1994和JJG410-1994要求.     

电压瞬时跌落、短时中断和电压渐变的干扰试验

本文介绍了电磁兼容测量及试验中的电压瞬时跌落、短时中断和电压渐变的干扰的试验方法及试验结果的评估方法.     

Bragg光纤光栅的非线性开关特性研究

从耦合模理论出发,通过单独改变入射波中心波长、光纤光栅长度及耦合系数,数值研究了光纤光栅双稳态开关特性,给出了输入输出特性与这些参数的单一依赖关系曲线,得出一些有意义的结论.在此基础上,对如何减小非线性开关阈值进行了总结和探讨,并提出运用稀土掺杂光纤光栅与F-P腔相结合的结构来降低光开关阈值.