Inorganic lead-free halide perovskites (LFHPs) are emerging as eco-friendly alternatives to toxic Pb-based counterparts in photodetectors. This review establishes a ‘composition–dimension–interface triadic optimization framework’ to advance LFHPs. We first elucidate the stability rules of ABX3 and derivatives (e.g., A2B+B3+X6 double perovskites), emphasizing the critical role of Bi3+ lone-pair electrons in defect tolerance. Next, dimensional engineering is explored, revealing 3DOM architectures as ideal platforms for light harvesting, while 0D nanocrystals enable ultrahigh quantum yields. Innovations in transport layers, particularly SnO2 ETLs paired with Cs2AgBiBr6, achieve >180-day stability. Despite detectivities up to 1013 Jones, LFHPs lag in carrier mobility (<10 cm2 V−1 s−1) due to interfacial recombination. We propose a hierarchical roadmap: defect suppression via Rb+/Cu+ doping (short-term), scalable 2D/3D hybrid fabrication (mid-term), and perovskite/Si tandem cells (long-term). This work not only benchmarks the progress of LFHPs but also provides actionable strategies to bridge the efficiency gap with Pb-based devices.
Growing literature on the experiences of Black students in science, technology, engineering, and mathematics (STEM) at Historically Black Colleges or Universities (HBCUs) has illustrated HBCUs' success in graduating Black students in STEM. However, little research has examined the intersection of race and gender and psychological factors that may influence students' commitment to obtaining a STEM degree and/or career. The purpose of the present study was to identify whether gender moderates the impact of Africultural coping strategies (cognitive emotional debriefing and spiritual-centered) and psychological distress on commitment to persist in STEM among Black STEM students at-tending HBCUs. Using the intersectionality theoretical framework, we administered an online survey via Qualtrics to collect data on the coping strategies, distress, and STEM commitment from 463 Black women and 139 Black men STEM students across several HBCUs. The results indicated that gender was not a significant moderator: there were no significant interactions when predicting short-term commitment (while controlling for college-level courses), long-term commitment, nor career commit-ment to STEM. However, there was a significant main effect of spiritual-centered coping in predicting greater long-term intentions to commit to STEM. There was also a significant main effect of gender on career commitment, with Black men having greater intentions to commit to a STEM career rela-tive to Black women. This research will contribute to the limited research on gender differences in the retention of Black STEM students at HBCUs, using measures of Africultural coping strategies and psychological distress.
Social technology use can increase access and opportunities for social engagement, yet little is known about how these associations vary across racial/ethnic groups in late life. This study aimed to examine associations between social technology use and social engagement within each racial and ethnic group. Using data from the 2015 National Health and Aging Trends Study (N = 5,648), we conducted survey-weighted logistic regression analyses separately for non-Hispanic Whites (N = 4,147), non-Hispanic Blacks (N = 1,165), and Hispanics (N = 312). Non-Hispanic Whites reported the highest levels of social technology use and social engagement, but distinct social technology-social engagement patterns emerged within each racial/ethnic group. For both non-Hispanic Whites and non-Hispanic Blacks, email/texting was positively associated with visiting family/friends, going out for enjoyment, and attending clubs/organized activities. SNS use was positively associated with visiting family/friends and attending clubs/organized activities for non-Hispanic Whites, but with volunteering for Hispanics. These differential associations suggest that targeted interventions should consider group-specific preferences for social technology types and social activities, as they may reflect cultural, linguistic, or access-related differences. Future research exploring barriers to and opportunities for social technology use across racial/ethnic groups may help develop effective and inclusive interventions for older adults.
Abstract Current precipitation analysis focuses on extreme events or total amounts but misses a critical question: when does the majority of precipitation occur during the year? We introduce a framework that separates two fundamental aspects of precipitation patterns: how many of the wettest individual days contribute to annual totals versus what is the minimum number of consecutive days required to reach the same totals. Using ERA5 data spanning 1980–2024 over global land surfaces, we first compute multi‐threshold indices for 25%, 50%, and 75% of annual precipitation through both approaches—selecting the wettest days scattered throughout the year (WD25, WD50, WD75) and then find the shortest consecutive periods (WD25R, WD50R, WD75R). Results show these two dimensions evolve independently: notably, the Amazon Basin shows 15%–18% fewer days needed through both approaches (more concentrated and more consecutive), while continental regions like eastern North America show 12%–25% increases (more scattered and less consecutive). Monsoon regions demonstrate strong alignment between wettest days and consecutive periods (concentrated rainy seasons), while mid‐latitude regions show large misalignments (scattered patterns). These findings demonstrate that identical changes in precipitation intensity can produce opposite changes in seasonal timing—a distinction critical for flood risk, drought duration, and water storage that traditional extreme event indices cannot capture.
This study assesses the institutionalisation of sustainable procurement (SP) practices in South African state-owned enterprises (SOEs), evaluating their alignment with economic, social, and environmental sustainability objectives. It further explores the challenges hindering SP implementation and the variations in adoption across Schedule 2 and Schedule 3 SOEs. We employed a mixed-methods approach based on semi-structured interviews with 51 procurement professionals across 26 SOEs. The quantitative data was analyzed using descriptive and inferential statistical techniques in SPSS while the open data using thematic analysis. The findings indicate that economic sustainability receives the highest emphasis, social sustainability is moderately integrated, and environmental sustainability is the weakest. Notably, Schedule 3 SOEs demonstrate greater adherence to government mandated sustainability policies, while Schedule 2 SOEs prioritize financial autonomy and cost-driven procurement strategies. Governance issues, corruption, and lack of SP training further impede comprehensive sustainability adoption. This study advances the empirical understanding of SP practices in SOEs within a developing economy. It also provides practical recommendations for government policymakers, SOE leadership, and procurement professionals, emphasizing the need for a comprehensive national SP framework, regulatory enforcement, and capacity-building initiatives to enhance SP integration.
