Luminescent properties of thermally activated delayed fluorescence molecule with intramolecular π-π interaction between donor and acceptor

Influence of intramolecular π-π interaction on the luminescent properties of thermally activated delayed fluorescence(TADF) molecule(3, 5-bis(3,6-di-tert-butyl-9 H-carbazol-9-yl)-phenyl)(pyridin-4-yl) methanone(DTCBPY) is theoretically studied by using the density functional theory(DFT) and time-dependent density functional theory(TD-DFT).Four conformations(named as A, B, C, and D) of the DTCBPY can be found by relax scanning, and the configuration C corresponds to the luminescent molecule detected experimentally. Besides, we calculate the proportion of each conformation by Boltzmann distribution, high configuration ratios(44% and 52%) can be found for C and D. Moreover, C and D are found to exist with an intramolecular π-π interaction between one donor and the acceptor; the intramolecular interaction brings a smaller Huang-Rhys factor and reduced reorganization energy. Our work presents a rational explanation for the experimental results and demonstrates the importance of the intramolecular π-π interaction to the photophysical properties of TADF molecules.     

Crowe IV型发育性髋关节发育不良在全髋关节置换术中横行截骨最佳位置的有限元分析

Crowe IV型髋关节发育不良（developmental dysplasia of the hip,DDH）的全髋关节置换术（total hip arthroplasty, THA）中,多数患者需要截骨保证复位,目前横行截骨是运用最广泛的术式,但截骨的最佳高度仍存在争议。本文通过建立Crowe IV型DDH患者的有限元模型,分析了在不同载荷下,不同截骨高度模型的应力分布与位移情况。结果表明：在多项指标下,小转子下0 cm的截骨高度均表现出了较优性能。在不影响假体安放和断端对合情况允许的情况下,推荐在手术中使用0 cm的截骨高度。