三维高斯拟合激光光强快速衰减算法

为缩短衰减倍率调整的时间,提高激光参数测试的效率,提出激光光强快速衰减算法。衰减倍率精确调整量由当前衰减倍率和采集到的光斑光强真实的最大灰度值共同决定。当因光电接收器件(CCD)饱和造成采集光斑图像失真时,即衰减倍率过小时,由于激光光斑的光强通常满足高斯分布,通过对光斑图像进行处理,去除饱和部分光强信息,对剩余部分光强信息利用最小二乘法进行三维高斯拟合,还原出激光光斑光强的真实分布并获得最大灰度值;当衰减倍率过大时,根据采集光斑图像可以直接获得当前最大灰度值,最后通过计算获得最佳的衰减倍率调整值,实现了激光光强快速准确的调整。算法的有效性通过步进电机带动的双轮可变衰减器及CCD配合得到验证。     

Template-free Polyoxometalate-assisted Synthesis of Au/ZnO Hollow Sphere Hererostructures for Photocatalytic Water Purification

The controlled synthesis of ZnO hollow spheres is successfully achieved through a facile solvothermal method using a Keggin-type silicotungstic acid(H_4 Si(W_3 O_(10))_4:HSW) as structure directing agent. The formation process of these hollow spheres is proposed based on a variety of controlled experiments. In addition, Au nanoparticles are loaded onto the surface of ZnO hollow spheres. It is found that the Au-loaded ZnO(Au/ZnO) composites exhibit greatly enhanced activity on oxidizing Rhodamine B(Rh B) under simulated UV or visible light irradiation, compared to the pristine ZnO hollow spheres. The improved performance of Au/ZnO heterostructures is mainly attributed to the enhanced optical absorption and the accelerated separation and migration of photogenerated charge carriers. Moreover, the photocatalytic reaction mechanisms are proposed based on the results of electron spin resonance(ESR) analysis, photoelectrochemical measurements, and photocatalytic evaluation. The results and findings are expected to provide significance to the synthesis of noble metal-semiconductor hybrids towards water purification.     

The basis of organic spintronics：Fabrication of organic spin valves

Organic spintronics focuses on utilizing the spin degree of freedom in organic materials because of the long spin relaxation time. The vertical organic spin valve (OSV) is a typical sample structure used to study the spin transport phenomena. However, the fabrication of high quality OSVs is difficult, which results in controversial experiment results and hence hinders the development of organic spintronics. In this work, we describe our recent study on the fabrication of typical vertical organic spin valves, La_0.67Sr_0.33MnO₃ (LSMO)/Alq₃/Co. The LSMO bottom electrodes are annealed to obtain an atomically smooth surface and improved magnetic properties. The top Co electrodes are deposited by an indirect deposition method to reduce the interfusion between Co and Alq3. The controlled fabrication process provides much better performance and sample yield of OSVs.     

修正的CES模型与印度经济增长分析

通过对CES模型的修正，反映技术水平对一国经济增长的影响，并将修正后的模型用于对印度过去近30年经济增长的实际分析，得出结论：20世纪90年代以来，印度经济增长过程中在劳动技术水平有所提高的同时，资本技术水平却较为显著地下降，因此印度政府应深化经济体制改革，提高资本的使用效率。     

平板式mLHP实验的稳定性分析

本文在充灌率、冷凝温度和初始状态三方面对mLHP系统的稳定性进行分析.研究发现,选择合适的充灌率有利于保证系统稳定运行.较少的充灌最时毛细芯容易缺液而导致系统启动失败,较多的充灌量时系统在低热负荷区易发生波动.过低的冷凝温度对系统稳定性有负面影响,系统容易出现温度波动甚至失稳.而毛细芯内气泡的存在,易导致了mLHP系统...