On the Origin of the Anomalous Upper Critical Field in Quasi-One-Dimensional Superconductors

Upper critical field, H_c2, in quasi-1D superconductors is investigated by the weak coupling renormalization group technique. It is shown that H_c2 greatly exceeds not only the Pauli limit, but also the conventional paramagnetic limit of the Flude-Ferrell-Larkin-Ovchinnikov (FFLO) state. This increase is mainly due to quasi-1D fluctuations effect as triggered by interference between unconventional superconductivity and density-wave instabilities. Our results give a novel viewpoint on the large H_c2 observed in TMTSF-salts in terms of a d-wave FFLO state that is predicted to be verified by the H_c2 measurements under pressure.Comment: 5 pages, 4 figure

Cold Positions of the Restricted Wythoff\u27s Game

Wythoff\u27s game is a kind of 2-pile Nim game, which admits taking the same number of stones from both piles. It differs only a little from the 2-pile Nim game, but their winning strategies are quite different from each other. Amazingly the winning strategy of Wythoff\u27s game is directly related to a real number, specifically the golden ratio. In this paper we add two restrictions to this game, and investigate the winning strategy of the revised game

One-Step Coating of Full-Coverage CsPbBr₃ Thin Films via Mist Deposition for All-Inorganic Perovskite Solar Cells

In this work, one-step coating of CsPbBr₃ thin films using the mist deposition method is demonstrated. The CsPbBr₃ layer is composed of large grains with an average size of approximately 1.4 μm, and it fully covers the substrate surface, unlike the layers prepared by conventional one-step spin-coating methods, so that efficient carrier transport is realized. Carbon-based CsPbBr₃ perovskite solar cells (PSCs) fabricated using the mist deposition method exhibit a stabilized power conversion efficiency of 7.7%, which is a record value for carbon-based CsPbBr₃ PSCs prepared via a one-step solution process

Fabrication of CsPbBr₃ Thick Films by Using a Mist Deposition Method for Highly Sensitive X-ray Detection

X-ray imaging is a valuable technique used for medical imaging and non-destructive inspection of industrial products. However, the radiation may put humans at risk of developing cancer. Consequently, highly sensitive X-ray detectors, which enable X-ray imaging at a low dose rate, are required. Metal halide perovskite materials have demonstrated excellent X-ray detection performance including a high sensitivity owing to their high absorption coefficient, high carrier mobility, and long carrier lifetime. However, perovskite thick films with a large area, which is essential to realize the application of such materials to X-ray imaging devices have not been extensively investigated. To this end, in this study, a polymer is employed as a buffer layer to avoid film exfoliation, which makes it difficult to fabricate perovskite thick films, and a 110-μm-thick CsPbBr₃ film is successfully obtained using a scalable solution method. In addition, an X-ray detector based on the CsPbBr₃ thick film is fabricated, which demonstrates a sensitivity of 11, 840 μC Gyair⁻¹ cm⁻². This sensitivity is approximately 600 times higher than that of the existing commercial a-Se X-ray detectors

The Production of Safety School Space from Climate Disasters in Doi Mae Salong Forest, Upland Northern Thailand

This research is conducted in Santikhiri, a hilltop village on the highest peak in the Doi Mae Salong forest, where climate change increases the intensity and frequency of natural disasters that immensely affect the local children in the mountainous area in Chiang Rai province, northern Thailand. There is only one secondary-level school in this forest landscape educating around 900 schoolchildren from various minority hill-tribe ethnic groups. This paper examines everyday life experiences recentering the village school's role as the producer of safe space for the forest children from climate disasters. School safety is a global framework for recognizing the importance of child-centered efforts in building disaster resilience for the education sector. Parameters and variables used to measure the disaster resilience of schools are adapted from the Climate Resilience Model and School Safety Model by Tong et al. (2012), covering three dimensions: 1) institutional issues, 2) physical conditions, and 3) external relationships. Lefebvre's Spatial Triad Framework is applied to dialectically interconnect dimensions to produce a safe space at the village school to protect the students from climate disaster threats. A mix-method method is applied with several techniques to collect data, including participant observation, semi-structured interviews, and content analysis. Furthermore, a scale Likert survey examined statements on school safety from educational practitioners in the rural forest area. The research argues that the production of safe space at the school is intertwined with budget allocation for disaster preparedness and response (institutional issue as l'espace concu), environmental protection campaign to create a hygienic school environment (physical conditions as l'espace percu), and support from the local community (external relations as l'espace vecu). However, the school is also two contradicting spaces of conceived and lived. Through the critical examination of the production of safe space, the school is a planned space of hierarchical power relations in institutional issues focusing on impacts from rapid-onset disasters. Concurrently, the forest children are still marginalized from external relationships and natural conditions' slow-onset climate change impacts