Spectroscopic measurements and terahertz imaging of the cornea using a rapid scanning terahertz time domain spectrometer

Spectroscopic measurements and terahertz imaging of the cornea are carried out by using a rapid scanning terahertz time domain spectroscopy(THz-TDS) system.A voice coil motor stage based optical delay line(VCM-ODL) is developed to provide a rather simple and robust structure with both the high scanning speed and the large delay length.The developed system is used for THz spectroscopic measurements and imaging of the corneal tissue with different amounts of water content,and the measurement results show the consistence with the reported results,in which the measurement time using VCM-ODL is a factor of 360 shorter than the traditional motorized optical delay line(MDL).With reducing the water content a monotonic decrease of the complex permittivity of the cornea is observed.The two-term Debye relaxation model is employed to explain our experimental results,revealing that the fast relaxation time of a dehydrated cornea is much larger than that of a hydrated cornea and its dielectric behavior can be affected by the presence of the biological macromolecules.These results demonstrate that our THz spectrometer may be a promising candidate for tissue hydration sensing and practical application of THz technology.     

考虑跨渠道退货的双渠道零售商定价与退货策略研究

本文以零售商线上线下销售和消费者退货并存的销售模式为背景，以零售商利润最大化为目标，构建线上线下统一定价和自主定价的双渠道和跨渠道退货两种不同的定价决策模型，分析了顾客渠道偏好和退货麻烦成本对零售商定价和退货策略选择与利润的影响。研究发现：给定退货麻烦成本，当顾客渠道偏好明显时，零售商应采取自主定价策略，否则应采取统一定价策略。顾客偏好线上渠道时，应该采取跨渠道退货政策；顾客偏好线下渠道时，应采取双渠道退货政策。零售商应根据顾客渠道偏好和退货麻烦成本选择合理的定价策略和退货策略，保证其利润最大化。本文研究对于采用线上线下渠道销售并允许退货的零售商设置最合理的退货方式和最优定价策略有一定的实际应用价值。