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To study the seed dormancy and germination mechanism of Xanthoceras sorbifolium, the seeds of four cultivars [‘Putong’(PT),‘Qihong’(QH), ‘Wofeng’(WF) and‘Woshi’(WS)] were stored at -20 ℃ for different periods (30, 60, 90, 120, 150 d). The seed germination indexes were determined in each treatment, and the changes of reserve substance and hormone content were also analyzed in three stages including before storage, after storage, and 7 days of germination. The results were as follows: (1) Cold storage could significantly promote the germination rate and germination potential of small seeds (PT, QH). The best treatment was cold storage for 60 d, and the germination rate was up to 48.3% and 58.3%, respectively. The effects of cold storage on large seeds (WF and WS) was lower than that of small seeds. (2) The kernel oil content, seed shell thickness (SST) in four cultivar seeds all decreased significantly during periods of cold storage and germination, especially in 3-7 days of germination, the oil content and SST (except WS cultivar) decreased notably. However, water content in kernels increased rapidly within 1-3 days of germination and then slowly increased to the peak value on the 7th day. The contents of soluble sugar in kernels increased significantly at the 3-4 days of germination. (3) Cold storage increased GA/ABA and tHor/ABA ratios in small seeds (PT, QH), promoted oil degradation, made seed shell thinning and break seed dormancy. In conclusion, the main factors leading to dormancy in X. sorbifolium seeds are larger in size, higher shell thickness and more hardness, physiological post-ripening, and belongs to comprehensive dormancy type. Cold storage at -20 ℃ for 60 d can improve the germination rate of PT, QH and WF seeds, reduces dormancy degree, while the cold storage time of WS seeds needs prolonging to 150 d. The method using -20 ℃ storage with wet sand germination is a rapid and simple method to promote X. sorbifolium seeds germination. This study provides a reference for the promotion of superior varieties and the research on the seed breaking dormancy mechanism in X. sorbifolium.

Current X-ray imaging technologies involving flat-panel detectors have difficulty in imaging three-dimensional objects because fabrication of large-area, flexible, silicon-based photodetectors on highly curved surfaces remains a challenge.sup.1-3. Here we demonstrate ultralong-lived X-ray trapping for flat-panel-free, high-resolution, three-dimensional imaging using a series of solution-processable, lanthanide-doped nanoscintillators. Corroborated by quantum mechanical simulations of defect formation and electronic structures, our experimental characterizations reveal that slow hopping of trapped electrons due to radiation-triggered anionic migration in host lattices can induce more than 30 days of persistent radioluminescence. We further demonstrate X-ray luminescence extension imaging with resolution greater than 20 line pairs per millimetre and optical memory longer than 15 days. These findings provide insight into mechanisms underlying X-ray energy conversion through enduring electron trapping and offer a paradigm to motivate future research in wearable X-ray detectors for patient-centred radiography and mammography, imaging-guided therapeutics, high-energy physics and deep learning in radiology. Using lanthanide-doped nanomaterials and flexible substrates, an approach that enables flat-panel-free, high-resolution, three-dimensional imaging is demonstrated and termed X-ray luminescence extension imaging., Author(s): Xiangyu Ou [sup.1] , Xian Qin [sup.2] , Bolong Huang [sup.3] , Jie Zan [sup.1] , Qinxia Wu [sup.1] , Zhongzhu Hong [sup.1] , Lili Xie [sup.1] , Hongyu [...]

Long‐lasting radioluminescence scintillators have recently attracted substantial attention from both research and industrial communities, primarily due to their distinctive capabilities of converting and storing X‐ray energy. However, determination of energy‐conversion kinetics in these nanocrystals remains unexplored. Here we present a strategy to probe and unveil energy‐funneling kinetics in NaLuF4:Mn2+/Gd3+ nanocrystal sublattices through Gd3+‐driven microenvironment engineering and Mn2+‐mediated radioluminescence profiling. Our photophysical studies reveal effective control of energy‐funneling kinetics and demonstrate the tunability of electron trap depth ranging from 0.66 to 0.96 eV, with the corresponding trap density varying between 2.38×105 and 1.34×107 cm−3. This enables controlled release of captured electrons over durations spanning from seconds to 30 days. It allows tailorable emission wavelength within the range of 520–580 nm and fine‐tuning of thermally‐stimulated temperature between 313–403 K. We further utilize these scintillators to fabricate high‐density, large‐area scintillation screens that exhibit a 6‐fold improvement in X‐ray sensitivity, 22 lp/mm high‐resolution X‐ray imaging, and a 30‐day‐long optical memory. This enables high‐contrast imaging of injured mice through fast thermally‐stimulated radioluminescence readout. These findings offer new insights into the correlation of radioluminescence dynamics with energy‐funneling kinetics, thereby contributing to the advancement of high‐energy nanophotonic applications. [ABSTRACT FROM AUTHOR]