RUI: Forced Rayleigh scattering on heterogeneous liquid crystals: Directional solidification at forced wavevectors

RUI：异质液晶上的强制瑞利散射：强制波矢处的定向凝固

• 批准号: 0111143
• 负责人: Daniel Spiegel
• 金额: $ 11.68万
• 依托单位: Trinity University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-01 至 2005-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0111143&HistoricalAwards=false
• 关键词: RUI; Forced; Rayleigh; scattering; heterogeneous

Dr. Daniel R. Spiegel of Trinity University is funded for his research on forced Rayleigh scattering (FRS) on heterogeneous liquid crystals by the Physical Chemistry Program of the Chemistry Division. The interfacial modulation accompanying an impurity-diffusion-driven instability during nematic-directional solidification can be stimulated and probed by FRS techniques. Non-homogeneous perturbations at selected wavelengths (frequencies) of such transforming systems will be used to experimentally probe the nonlinear reaction-diffusion modeling and pattern formation of such liquid-crystal systems. FRS pump-beam interference fringes will be used to effect modulation of the nematic-isotropic interface of a directionally solidified liquid crystal. The temporal evolution of specific Fourier component amplitudes will be tracked using diffracted FRS probe beams. Fundamentally important dispersion relations relevant to the basic linear instability will be mapped experimentally.Nonlinear dynamical systems, including those that produce non-equilibrium pattern formation, are becoming increasingly upbiquitous in research and in chemcial industry. The analysis and modeling of such systems is important for developing quantitative methods for controlling such phenomena. The FRS experiments at Trinity University should provide definite means for improving our experimental approaches to developing such models, and for testing our understanding of such models. Furthermore, invaluable state-of-the-art training will be afforded the undergraduates participating in this research program.

美国三一大学Daniel R. Spiegel博士的非均相液晶强迫瑞利散射（FRS）研究获得了该校化学部物理化学项目的资助。向列定向凝固过程中伴随杂质扩散不稳定性的界面调制可以通过FRS技术进行模拟和探测。在这种转换系统的选定波长（频率）上的非均匀扰动将用于实验探索这种液晶系统的非线性反应-扩散建模和模式形成。本文将利用FRS抽束干涉条纹对定向凝固液晶的向列-各向同性界面进行调制。特定傅里叶分量振幅的时间演变将被跟踪使用衍射FRS探针光束。与基本线性不稳定性相关的重要色散关系将在实验中得到映射。非线性动力系统，包括那些产生非平衡模式形成的系统，在研究和化学工业中变得越来越普遍。这些系统的分析和建模对于开发控制这些现象的定量方法非常重要。三一大学的FRS实验应该为改进我们开发这些模型的实验方法提供明确的手段，并测试我们对这些模型的理解。此外，参与这项研究计划的本科生将获得宝贵的最先进的培训。