不等长双缝夫琅禾费衍射光强分布     

史勤益  梁华秋 《台州学院学报》2011,33(6):17-20

根据夫琅禾费衍射与傅立叶变换的关系,数值计算了由宽度相同而长度不同双缝组成衍射平面的夫琅禾费衍射光强分布,结果表明双缝长度之比是影响干涉条纹的可见度的主要因素。  相似文献   

Regulating surface wrinkles using light     

Liangwei Zhou  Kaiming Hu  Wenming Zhang  Guang Meng  Jie Yin  Xuesong Jiang 《国家科学评论(英文版)》2020,7(7):1247

Regulating existing micro and nano wrinkle structures into desired configurations is urgently necessary yet remains challenging, especially modulating wrinkle direction and location on demand. In this work, we propose a novel light-controlled strategy for surface wrinkles, which can dynamically and precisely regulate all basic characteristics of wrinkles, including wavelength, amplitude, direction and location (λ, A, θ and L_c), and arbitrarily tune wrinkle topographies in two dimensions (2D). By considering the bidirectional Poisson''s effect and soft boundary conditions, a modified theoretical model depicting the relation between stress distributions and the basic characteristics was developed to reveal the mechanical mechanism of the regulation strategy. Furthermore, the resulting 2D ordered wrinkles can be used as a dynamic optical grating and a smart template to reversibly regulate the morphology of various functional materials. This study will pave the way for wrinkle regulation and guide fabrication technology for functional wrinkled surfaces.  相似文献   

烧结温度对La_1.2Sr_1.8Mn₂O₇结构和磁性的影响     

东艳晖  赵旭  张彩霞  刘继宏  陈伟 《石家庄学院学报》2011,13(3):69-72

采用溶胶-凝胶法在不同的烧结温度下制备了La1.2Sr1.8Mn2O7多晶样品.磁性测量表明,1 200℃热处理的样品存在3个磁转变温度,且在116 K～365 K温区范围内磁化强度显著高于1 400℃热处理的样品;同时,1 400℃热处理的样品,在整个温区只存在2个磁有序转变温度,并且呈现出类自旋玻璃态.结合这2个样品的结构分析发现,较高温度处理更有利于双层钙钛矿结构的形成.  相似文献   

Re-turning feelings that matter using reflexivity and diffraction to think with and through a moment of rupture in activist work     

Sherilyn Lennon 《International journal of qualitative studies in education》2017,30(6):534-545

Over the past three decades, calls for alternative forms of qualitative research that require of the researcher to think deeply, differently, disruptively and diffractively have been gathering momentum. This article adds to a growing bank of possibilities for this type of work by re-turning feelings that emerged while doing insider activist work related to issues of gender in an isolated rural Australian community. The original five-year study drew on emancipatory, poststructural feminist and critical research paradigms; however, this paper takes a paradigmatic leap to fold in posthumanist and new materialist thinking as it re-turns feelings that mattered and were produced as part of the mangle of doing activist research. The paper foregrounds a different way of knowing by embracing a researcher identity that is an assemblage of shifting feelings, thoughts, physical realities, identities, temporalities, speech acts and practices. This postmodern paradox is a superposition of knowings and unknowings; certainties and uncertainties; power and powerlessness; an entanglement of relations and productions that are troubled and troubling, determined and indeterminate, comfortable and uncomfortable.  相似文献   

不规则形状粒子Fraunhofer衍射计算     

赵剑琦 《中国科学院研究生院学报》2011,28(4)

讨论了半透明不规则形状粒子Fraunhofer衍射积分的计算问题,借助于标量Kirchhoff理论,推导出关于衍射的3种新的相互等价的1D围线积分形式,直接摆脱了通常2D面积分中繁琐的区域划分的束缚.在此基础上求得投影截面为任意多角形粒子衍射的解析结果.  相似文献   

多缝菲涅耳衍射的数值模拟     

阿不都热苏力 《喀什师范学院学报》2014,(6):20-22

从惠更斯-菲涅耳原理出发,利用matlab软件对多缝菲涅耳衍射进行分析,基于菲涅耳衍射积分法,提出了一种针对多缝菲涅耳衍射的数值算法,同时给出了相应的Matlab程序以及仿真结果.从数值分析结果可以看出,该研究结果对于实验验证多缝菲涅耳衍射现象具有重要的理论参考意义.  相似文献   

斜入射条件下平面光栅的光栅方程研究     

张明霞  郭小花 《天水师范学院学报》2006,26(5):44-47

分析和讨论了光波在一般斜入射条件下光栅平面内的相位分布,通过理论分析及数学推导,得到一般斜入射条件下光栅的光栅方程。这个光栅方程不仅可以解释常见《光学》课程理论与实验教科书中光波在垂直入射以及特殊斜入射条件下透过光栅时的衍射现象,也可以解释光波在一般斜入射条件下透过光栅时的所有衍射现象,是对常见《光学》理论和实验教科书中平面光栅衍射理论及实验原理的进一步补充和完善。  相似文献   

讨论光的干涉和衍射问题时引入光程差概念的物理意义     

吐尔逊·买买提 《和田师范专科学校学报》2013,(5):68-71

本文主要论述结合光的干涉,衍射现象的本质,讨论引入光程差概念的物理意义,从波动性概念解释光的干涉和衍射现象的本质,最后得到光程差概念的物理意义。  相似文献   

倒棱工艺对激光角反射器衍射特性的影响     

石岩  周辉  文翔 《实验室研究与探索》2013,32(8):41-46

基于激光角反射器的几何结构模型及倒棱方式,采用光线的折反射定律,推导了在倒棱条件下激光角反射器有效衍射区域的分布模型,并结合激光角反射器位相分布及衍射理论,建立了在不同光束入射角下,棱宽对角激光反射器近场和远场衍射特性影响的数学模型。采用数值仿真的方法分析了棱宽对综合发散角为5"的激光角反射器衍射强度的影响规律。结果表明,随着棱宽的增加,激光角反射器近场衍射的总强度及远场衍射图样中心点强度都出现了不同程度的下降。在整个光束入射角范围内,若棱宽不超过激光角反射器半径的5‰时,近场衍射总强度的下降程度小于1%,远场衍射图样中心点强度的绝对下降量为1.2%。当棱宽接近激光角反射器半径的5%时,近场衍射总强度下降程度达到9.3%,而远场衍射图样中心强度的绝对下降量为12.0%。  相似文献   

A—SiNx:H/A—Si:H超晶格材料制备X射线衍射及光学性质的研究     

黄文勇 《韩山师范学院学报》1994,(3)

本文报道了对A—SiNx:H/A—Si:H超晶格材料X射线和光学性质等方面的研究。提出一个非晶超格材料X射线衍射模型,和实验符合得较好,由此得到一个根据衍射峰相对强度获得界面情况的简单方法。观察到量子阱效应使光学带隙移动,发光峰移动,发光强度增大等现象。  相似文献