Magnetic field-modulated exciton generation in organic semiconductors: an intermolecular quantum correlation effect

Magnetoelectroluminescence (MEL) of organic semiconductor has been experimentally tuned by adopting blended emitting layer consisting of both hole and electron transporting materials. A theoretical model considering intermolecular quantum correlation is proposed to demonstrate two fundamental issues: (1) two mechanisms, spin scattering and spin mixing, dominate the two different steps respectively in the process of the magnetic field modulated generation of exciton; (2) the hopping rate of carriers determines the intensity of MEL. Calculation successfully predicts the increase of singlet excitons in low field with little change of triplet exciton population.Comment: 16 pages, 4 figure

Perovskite-molecule composite thin films for efficient and stable light-emitting diodes

Abstract: Although perovskite light-emitting diodes (PeLEDs) have recently experienced significant progress, there are only scattered reports of PeLEDs with both high efficiency and long operational stability, calling for additional strategies to address this challenge. Here, we develop perovskite-molecule composite thin films for efficient and stable PeLEDs. The perovskite-molecule composite thin films consist of in-situ formed high-quality perovskite nanocrystals embedded in the electron-transport molecular matrix, which controls nucleation process of perovskites, leading to PeLEDs with a peak external quantum efficiency of 17.3% and half-lifetime of approximately 100 h. In addition, we find that the device degradation mechanism at high driving voltages is different from that at low driving voltages. This work provides an effective strategy and deep understanding for achieving efficient and stable PeLEDs from both material and device perspectives

Socioeconomic status index is an independent determinant of breast cancer screening practices: Evidence from Eastern China.

BackgroundBreast cancer is the most prevalent malignancy affecting Chinese women, and early routine screening is incredibly important for its prevention and control. This study aimed to investigate the role of socioeconomic status (SES) in female breast cancer screening practices using the composite SES index.MethodsThis cross-sectional study involved 1816 women in Eastern China. Data were collected using an online self-administered questionnaire from January 2020 to May 2021. We used principal component analysis to construct the composite SES index using educational level, annual household income, and occupation. Logistic regression was used to analyze the association between the SES index and breast cancer screening utilization.ResultsOf the participants, 19.27% reported having performed breast self-examination, 12.89% reported having undergone clinical breast examination, and 3.52% reported having received mammography. The SES has a significant influence on the patronage of female breast cancer screening in Eastern China. The composite SES index was found to have a positive and significant association with breast cancer screening practices. An interaction was found between the SES index and patient characteristics, such as health awareness, marital status, and location of residence. In addition, the SES index had a positive effect on breast cancer-related knowledge.ConclusionsSocioeconomic inequalities existed in Eastern China and were related to breast cancer screening patronage. The composite SES index was identified as a significant determinant of breast cancer screening practices. Our results highlighted the negative impacts of socioeconomic inequities on female breast cancer screening utilization. This suggests that reducing socioeconomic inequalities in breast cancer screening requires more focused interventions and concerted outreach activities for groups with lower education levels, lower income, or lower occupational classes

Structural equation modeling analysis of determinants of barriers to breast self-examination among Eastern Chinese women.

BackgroundThis study aimed to establish a structural equation model to determine the associations among knowledge of breast cancer, beliefs about breast self-examination (BSE), BSE practice, socio-economic status (SES), and barriers to BSE among Eastern Chinese women.MethodsAn online cross-sectional correlational survey of 2026 women from Eastern China was undertaken by a self-administered questionnaire in 2020. Structural equation modeling was utilized for examining the interrelationships between BSE barriers and other variables.ResultsOur results suggested that BSE barriers were significantly and negatively related to SES, BSE beliefs, and BSE practices (β = -0.176, p ConclusionsBSE barriers were influenced by SES, breast cancer knowledge, BSE beliefs and BSE practices. Our results warn that breast cancer prevention education should strengthen knowledge of practical methods rather than general knowledge. Therefore, intervention strategies designed to develop BSE and breast cancer prevention should take into account multiple factors, in particular finding more effective ways for the public to turn knowledge into a motivator rather than a barrier

Component-based Cascade Linear Discriminant Analysis for Face Recognition

Abstract. This paper presents a novel face recognition method based on cascade Linear Discriminant Analysis (LDA) of the component-based face representation. In the proposed method, a face image is represented as four components with overlap at the neighboring area rather than a whole face patch. Firstly, LDA is conducted on the principal components of each component individually to extract component discriminant features. Then, these features are further concatenated to undergo another LDA to extract the final face descriptor, which actually have assigned different weights to different component features. Our experiments on the FERET face database have illustrated the effectiveness of the proposed method compared with the traditional Fisherface method both for face recognition and verification.