光子晶体非线性效应全光开关研究

全光化以其快速传输处理信息的优点已成为当前的研究热点,其中全光开关在全光化中发挥着重要作用。本文利用平面波展开法与超原胞技术相结合的方法,对光子晶体结构的能带分布进行了研究,并对其禁带特性进行了分析,确定了以四方晶系为结构基础进行全光开关的设计研究。此外,在四方晶系结构基础上设计了波导与谐振腔耦合的全光开关结构,利用时域有限差分法进行模拟仿真,对电磁场分布图进行了研究。并在此基础上对结构进行了设计优化,使开关的性能得到提升。通过对光子晶体禁带特性的研究和对全光开关的仿真结果的分析,本文证实基于光子晶体的非线性克尔效应可以设计出开关性能较为优异的全光开关结构,并可减小全光开关的尺寸和反应时间。     

应用DV－5 2000型直读光谱仪分析钢中的酸溶和酸不溶铝

本文描述了用火花原子发射光谱分析的方法，应用美国Ｂａｉｒｄ公司ＤＶ－５２０００（ＨＲ－４００光源）直读光谱分析钢中的酸溶和酸不溶铝。实验中采取虚拟酸溶铝分析通道、二次积分的方法进行测定。本法快速简便，所得分析值与标准值吻合，结果令人满意。     

ZnIn2S4/g-C3N4复合材料的制备及可见光催化制氢性能

采用水热方法制备了ZnIn₂S₄/g-C₃N₄复合材料, 并通过X射线衍射(XRD)、 傅里叶变换红外光谱(FTIR)、 紫外-可见漫反射光谱(UV-Vis DRS)、 透射电子显微镜(TEM)和荧光光谱(PL)等手段对其结构和性能进行表征. 结果表明, 当ZnIn₂S₄的负载量为20%(质量分数)时, 复合材料表现出最佳的光催化制氢性能, 制氢速率可达到637.08 μmol·g^-1·h^-1, 分别为纯ZnIn₂S₄和纯g-C₃N₄的4倍和37倍. 其原因在于ZnIn₂S₄和g-C₃N₄之间具有紧密的异质结结构, 两者有效的结合改善了组分的能带匹配和界面电荷转移, 从而大幅增强了载流子的分离和迁移, 进而提高光催化的性能.     

Identification of denatured and normal biological tissues based on compressed sensing and refined composite multi-scale fuzzy entropy during high intensity focused ultrasound treatment

In high intensity focused ultrasound(HIFU)treatment,it is crucial to accurately identify denatured and normal biological tissues.In this paper,a novel method based on compressed sensing(CS)and refined composite multi-scale fuzzy entropy(RCMFE)is proposed.First,CS is used to denoise the HIFU echo signals.Then the multi-scale fuzzy entropy(MFE)and RCMFE of the denoised HIFU echo signals are calculated.This study analyzed 90 cases of HIFU echo signals,including 45 cases in normal status and 45 cases in denatured status,and the results show that although both MFE and RCMFE can be used to identify denatured tissues,the intra-class distance of RCMFE on each scale factor is smaller than MFE,and the inter-class distance is larger than MFE.Compared with MFE,RCMFE can calculate the complexity of the signal more accurately and improve the stability,compactness,and separability.When RCMFE is selected as the characteristic parameter,the RCMFE difference between denatured and normal biological tissues is more evident than that of MFE,which helps doctors evaluate the treatment effect more accurately.When the scale factor is selected as 16,the best distinguishing effect can be obtained.