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.

三位一体大学的丹尼尔·R·斯皮格尔（Daniel R. FRS技术可以刺激和探测伴随着杂质扩散驱动的不稳定的界面调制。 在此类转化系统的选定波长（频率）处的非均匀扰动将用于实验探测此类液体晶体系统的非线性反应扩散建模和模式形成。 FRS泵梁干扰条纹将用于实现定向固化液晶的近视界面的调节。 特定傅立叶成分振幅的时间演变将使用衍射的FRS探针梁跟踪。 与基本线性不稳定性相关的根本性分散关系将在实验上进行映射。在研究和化学工业中，诺线性动力学系统，包括产生非平衡模式形成的动力学系统。 此类系统的分析和建模对于开发用于控制这种现象的定量方法很重要。 三一大学的FRS实验应提供确定的手段，以改善我们开发此类模型的实验方法，并测试我们对此类模型的理解。 此外，将为参加该研究计划的本科生提供宝贵的最先进培训。