Theoretical Study on the Optical Properties for 2,7- and 3,6-Linked Carbazole Trimers by Time-dependent Density Functional Theory

Electronic properties, such as HOMO and LUMO energies, band gaps, ionization potential (IP) and electron affinity (EA) of 2,7- and 3,6-linked carbazole trimers, two conjugated oligomers with different linkages of carbazole, were studied by the density functional theory with Becke-Lee-Young-Parr composite exchange correlation functional (B3LYP). The absorption spectra of these compounds were also investigated by time-dependent density functional theory (TD-DFT) with 6-31G* basis set. The calculated results indicated that the HOMO and LUMO of the 2,7- and 3,6-linked carbazole trimers are both slightly destabilized on going from methyl substitution to sec-butyl substitution. Both IP and EA exhibit their good hole-transporting but poor electron- accepting ability. The presence of alkyl groups on the nitrogen atoms does not affect the intra-chain electronic delocalization along the molecular frame. Thus no significant effect on the band gap and absorption spectra of compounds has been found.     

Self-rated Changes of Health Status during Stay-at-home Orders among Older Adults Using the Long-term Care Insurance System of Japan: A Cross-sectional Study

Objectives: To reveal self-rated changes of health status during stay-at-home orders among older adults and to verify whether decrease in frequency of going outdoors during these orders was related to self-rated changes in health status. Method: A self-completed questionnaire for older adults was provided in 2 dayservice facilities and a nursing station. We operationally defined health status with 4 domains (motor function, oral and swallowing function, depression, and social networks) and designed the questionnaire to determine self-rated changes in health status using factor analysis. After factor analysis, regression analyses were conducted. Dependent variable was each factor score (self-rated changes of health status), and independent variable was decrease in frequency of going outdoors. Results: Approximately 80% of participants answered that their health status had “worsened” in motor function (75.0%-87.2%). Moreover, more than 70% of participants answered “worsened” in “Feeling energy” and “Getting together and speaking with friends” (72.3% and 75.7%, respectively). Regression analyses demonstrated that, after adjusting for covariates, the decrease in frequency of going outdoors was related to self-rated changes of motor function and friend network. Conclusion: During stay-at-home orders, older adults felt deterioration in their motor function, in feeling energy, and in their friend network, especially people who had decreased their frequency of going outdoors felt more deterioration in their motor function and in their friend network.     

A classification model based on goal programming with non-standard preference functions with application to the prediction of cinema-going behaviour

This paper presents a goal programming model that allows for the flexible handling of the two group classification problem. The goal programming model is based around the concepts of non-standard preference functions and penalty function modelling. An extension to a generalised distance metric case is given. The inclusion of multiple levels of classification based upon different levels of certainty is incorporated into the model. The model is tested on a real-life data set pertaining to cinema-going attendance and conclusions are drawn both in the context of the methodology and of the application.     

圆柱圆锥正交相贯的数学模型及其交线画法

在工程制图中,圆柱圆锥正交相贯时,其交线上的某些特殊点总是近似求出.以正投影理论为基础,以圆柱圆锥正交相贯的数学模型为依据,提出了一种准确、简便、可靠的求解方法.方法对于手工或计算机准确绘制该交线、对圆管平交正锥台三通下料等工程问题,都很有实用价值.