Inspections based on ionizing radiation have spread into various areas including our daily lives, industries, and scientific investigations and now face increasing demands with the development of society. Commercial X-ray detectors are mostly based on an indirect operation model in which the scintillator transforms X-ray photons into visible light and bottom photodiodes convert them into images. Obviously, the performance of the scintillator determines the final imaging properties, and the pursuit of scintillators with superior properties and lower cost is ongoing. Recently, inorganic lead halide perovskite nanocrystals (PNCs) emerged as promising scintillators for X-ray imaging. Here, we make a detailed conclusion of the superiority of PNC scintillators and take a new look at their scintillation performances. Discrepancies are discussed and some suggestions are proposed. Finally, perspectives on future developments, advice to the field, and proposed solutions to the problems toward full device performance and practical applications are provided.

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Asteroid detection has been the main research field of deep space exploration, and even in the future years. Countries have carried out missions to flyby and landing on the surface of asteroids, the sampling can help human explore the origins of small bodies, as well as origin of the solar system. While the particular environmental factors such as small size and low gravity of asteroids make the landing more difficult, this paper designs a four-legged inverted triangle soft lander, supplemented by thrust reversers and rope anchors for stable landing. A mathematical model of the lander landing on the surface of target asteroid is established, and the motion and dynamic response of lander in different landing modes is studied, conditions and safe landing range is well defined. Results of the analysis have demonstrated the effectiveness of dynamic landing model for the proposed lander.

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