In order to study the the mechanical behavior and the loading capacity of this special structure under different combined actions of load ,in this paper, the three-dimensional plate-shell element model was constructed...
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In order to study the the mechanical behavior and the loading capacity of this special structure under different combined actions of load ,in this paper, the three-dimensional plate-shell element model was constructed by the finite element procedure ANSYS, and one segment of composite box beam's special shape intersection of Beijing South Station Viaduct in positive bending region was analyzed. The mechanical behavior of the steel box-concrete composite beam at intersection was analyzed, such as the stress and deformation behavior of the composite beam under different combined actions of loads, the loading of the special shape intersection under the interaction of vertical bending and torsion and the bearing reaction under live load. Finally by the parametric analysis to the thickness of the steel girder web, the ratio of bending and torison stiffness, and the diaphragm, the influence of the parametric on the special girder was understanded clearly.
Background: An irregular bedtime schedule is a prevalent problem in young adults, and could be a factor detrimentally affecting sleep quality. The goal of the present study was to explore the association between an ir...
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Background: An irregular bedtime schedule is a prevalent problem in young adults, and could be a factor detrimentally affecting sleep quality. The goal of the present study was to explore the association between an irregular bedtime schedule and sleep quality, daytime sleepiness, and fatigue among undergraduate students in Taiwan. Methods: A total of 160 students underwent a semi-structured interview and completed a survey comprising 4 parts: Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), Fatigue Severity Scale (FSS), and a rating of irregular bedtime frequency. Participants were grouped into 3 groups in terms of irregular bedtime frequency: low, intermediate, or high according to their 2...ek sleep log. To screen for psychological disorders or distress that may have affected responses on the sleep assessment measures, the Chinese health questionnaire-12...HQ-12...as also administered. Results: We found an increase in bedtime schedule irregularity to be significantly associated with a decrease in average sleep time per day (Spearman r = -0.2...p = 0.05). Multivariate regression analysis revealed that irregular bedtime frequency and average sleep time per day were correlated with PSQI scores, but not with ESS or FSS scores. A significant positive correlation between irregular bedtime frequency and PSQI scores was evident in the intermediate (partial r = 0.18, p = 0.02...nd high (partial r = 0.15, p = 0.05) frequency groups as compared to low frequency group. Conclusion: The results of our study suggest a high prevalence of both an irregular bedtime schedule and insufficient sleep among university students in Taiwan. Students with an irregular bedtime schedule may experience poor sleep quality. We suggest further research that explores the mechanisms involved in an irregular bedtime schedule and the effectiveness of interventions for improving this condition.
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