Despite the remarkable recent progress, person reidentification (Re-ID) approaches are still suffering from the failure cases where the discriminative body parts are missing. To mitigate such cases, we propose a simple yet effective Horizontal Pyramid Matching (HPM) approach to fully exploit various partial information of a given person, so that correct person candidates can be still identified even even some key parts are missing. Within the HPM, we make the following contributions to produce a more robust feature representation for the Re-ID task: 1) we learn to classify using partial feature representations at different horizontal pyramid scales, which successfully enhance the discriminative capabilities of various person parts; 2) we exploit average and max pooling strategies to account for person-specific discriminative information in a global-local manner. To validate the effectiveness of the proposed HPM, extensive experiments are conducted on three popular benchmarks, including Market-1501, DukeMTMC-ReID and CUHK03. In particular, we achieve mAP scores of 83.1%, 74.5% and 59.7% on these benchmarks, which are the new state-of-the-arts. Our code is available on Github .

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In this work, an effective strategy through doping of univalent Na+ ions, which are stable against oxidation and reduction, was proposed to enhance the emission efficiency and stability of orthorhombic CsPbBr3 nanocrystals (NCs). Compared with the fresh CsPbBr3 NCs, a better color purity and a higher photoluminescence quantum yield were achieved, accompanied with a gradual blue shift of the emission peak with an increasing Na+ doping ratio. On the one hand, the passivation effect with Na+ doping substantially reduces the nonradiative trap centers in NCs. On the other hand, the density functional theory calculations indicate that the doping of Na+ ions forms the energetically preferred substitution NaPb, which increases the optical band gap of CsPbBr3 and the diffusion barrier of Br vacancy in CsPbBr3 structures. Experimentally, the as-synthesized Na+-doped CsPbBr3 NCs present obvious enhancements in stability against ultraviolet light, heat, and moisture. The above advantages allow us to use such CsPbBr3:Na NCs as solid-state phosphors for white light-emitting device (WLED) applications. Finally, the prepared WLED exhibits a pure white light with Commission International de I’Eclairage color coordinates at (0.31, 0.33), with a color temperature of 6652 K, a color rendering index of 75.2, and a high power efficiency of 67.3 l m/W. More importantly, the WLED shows only 15% decay after continuous runs for as long as 500 h, which demonstrates a great superiority to the reference device with the fresh CsPbBr3 NCs as the phosphors. The approach used here provides an effective strategy to improve the emission efficiency and stability of perovskite NCs, showing promising potentials for their applications in lighting and display fields.

All‐inorganic semiconductor perovskite quantum dots (QDs) with outstanding optoelectronic properties have already been extensively investigated and implemented in various applications. However, great challenges exist for the fabrication of nanodevices including toxicity, fast anion‐exchange reactions, and unsatisfactory stability. Here, the ultrathin, core–shell structured SiO2 coated Mn2+ doped CsPbX3 (X = Br, Cl) QDs are prepared via one facile reverse microemulsion method at room temperature. By incorporation of a multibranched capping ligand of trioctylphosphine oxide, it is found that the breakage of the CsPbMnX3 core QDs contributed from the hydrolysis of silane could be effectively blocked. The thickness of silica shell can be well‐controlled within 2 nm, which gives the CsPbMnX3@SiO2 QDs a high quantum yield of 50.5% and improves thermostability and water resistance. Moreover, the mixture of CsPbBr3 QDs with green emission and CsPbMnX3@SiO2 QDs with yellow emission presents no ion exchange effect and provides white light emission. As a result, a white light‐emitting diode (LED) is successfully prepared by the combination of a blue on‐chip LED device and the above perovskite mixture. The as‐prepared white LED displays a high luminous efficiency of 68.4 lm W−1 and a high color‐rendering index of Ra = 91, demonstrating their broad future applications in solid‐state lighting fields.

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