X-ray irradiated La 2 Ti 2 O 7 :Pr 3+ was found to show long-time sustainable mechanoluminescence (ML), which can realize the high sensitivity and real time detection of stress burst for more than 72 h. Under the excitation of X-ray, La 2 Ti 2 O 7 :Pr 3+ shows red ML emissions located at 610, 624 and 638 nm, which are similar to the afterglow emission spectrum and can be ascribed to 1 D 2 - 3 H 4 , 3 P 0 - 3 H 4 and 3 P 0 - 3 H 2 of Pr 3+ . And the linear increases of compressive load can induce the linear increases of ML intensity of the sample, indicating that the X-ray induced ML emission can be utilized to accurately detect the stress applied on the object. Furthermore, X-ray irradiated La 2 Ti 2 O 7 :Pr 3+ possesses excellent stability and the repeatability of ML emission and the ML signals can keep stable even 50 load cycles after 1 h decay. The thermoluminescence results suggest that abundant electrons are trapped in shallow and deep answered for stable ML emission. More importantly, the deeply trapped electrons induced ML emissions from X-ray irradiated La 2 Ti 2 O 7 :Pr 3+ can be utilized to detect the stress bursts for a long time. When the sample is recharged by 5 min X-ray irradiation once, within 24 h decay, the 1500 N burst among many 1000 N cycles can be clearly detected, and the signal to noise ratio (S/N) reaches 1.32 and 1.26 after 12 and 24 h decay, respectively. And even after 72 h decay, the S/N of 2500 N still arrives at 1.23 and that of 4000 N reaches 1.97, indicative of long-time high sensitivity detection of abnormal stress. All these results suggest that the X-ray-irradiated La 1.97 Ti 2 O 7 :0.03Pr 3+ /resin sample can realize the high sensitivity and real time detection of stress burst for more than 72 h, which thus possesses great potential application in early warning of the emergency disasters such as bridge fracture, tunnel collapse and so on.
Danyang Liang,Lin Luo,Haiyu Luo,Qing Liu,Khamiddolov Temirlan,Wenhao Li,Wenjie Yan
This study modified lentil starch stored in a vacuum and regular (Ziplock-packed) conditions using electron beam irradiation and X-rays. The effects of these irradiations and environments on starch modification were evaluated by comparing changes in physicochemical and functional properties. Both electron beam and X-ray irradiation significantly reduced the short-range order and molecular weight of the starch while increasing the content of short chains. Under a vacuum environment, all irradiations exhibited more substantial degradation effects than regular conditions. Electron beam irradiation significantly reduced the relative crystallinity and the content of long chains, whereas X-rays had a more pronounced impact on disrupting the crystal structure of lentil starch. The vacuum environment enhanced the effectiveness of irradiation in improving the antidigestive properties of starch, leading to an increase in resistant starch content from 75.75% to 79.22%. This study offers new insights into producing modified starches using irradiation in combination with specific treatment environments.
The current mainstream planar X-ray imaging techniques face significant challenges for accurately capturing the internal structure of curved objects, since the variable distances between the curved objects and the flat-panel scintillation screen cannot eliminate the distortion in X-ray imaging. Though large-area and transparent curved scintillation screens are much more desirable. Here, organic–inorganic hybrid Mn-based single crystals ([CH 3 Ph 3 P] 2 MnX 4 , X = Cl, Br, I) exhibiting high photoluminescence quantum yield (PLQY) and low melting temperature have been employed to prepare transparent glass for X-ray scintillation imaging application through a low-temperature melting strategy. The [CH 3 Ph 3 P] 2 MnBr 4 -glass shows high PLQY (47.8%), high-resolution X-ray imaging performance (12.3 lp mm −1 ), low limit of detection (25.33 nGy s −1 ), and impressive X-ray irradiation stability (102 Gy). Furthermore, high-contrast X-ray imaging at a low dose (6.865 µGy per exposure, 14.5 times lower than the chest radiograph) is achieved. Based on the low glass transition temperature ( T g = 53.6 °C) and easy-shapeable properties of [CH 3 Ph 3 P] 2 MnBr 4 -glass scintillator, the large-area curved scintillation screen with a series of sizes of Φ 2×4 – Φ 8×4 cm 2 can be easily fabricated and show high X-ray imaging quality. These findings provide a paradigm for future research in shapeable X-ray scintillators, unlocking new possibilities for curved and 3D X-ray imaging.
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