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Dual-band photodetectors (PDs), which can sense two specific bands simultaneously or alternately, have great applications in spectral analysis, imaging, optical communication, and so on. However, some studies on dual-band PDs are mostly limited by drawbacks such as high cost, fixed dual-band range, and lattice mismatches between interfaces. Herein, we propose organic–inorganic halide perovskite single crystal heterojunctions (PSCHs) for dual-band detection via solution-processed epitaxial growth, with a structure of bismuth doped MAPbCl3/intrinsic MAPbBrxCl3−x/bismuth doped MAPbIyBr3−y/intrinsic MAPbIzBr3−z (where x, y, and z are between 0 and 1). The peak position and the full-width at half maximum (FWHM) value of dual-band PDs can be adjusted by changing the proportion of halide in the perovskite single crystal layers in the device, achieving different dual-band spectral response ranges. Eventually, a device exhibits two farthest peaks at 465 nm and 820 nm of visible (Vis)/near-infrared (NIR) range with the corresponding FWHM values of 22.6 nm and 19.4 nm under 2 V. The PSCH-based device can be called dual narrowband PD exhibiting good stability and a response speed of hundreds of microseconds, attributed to the small lattice mismatch and heterostructure. It also shows a high spectral rejection ratio (∼360). In conclusion, this article proposes an approach for customizing dual narrowband PDs with tunable spectral response ranges based on solution-processed epitaxial growth. [ABSTRACT FROM AUTHOR]

Heterogeneous pedestrian images are captured by visible and infrared cameras with different spectrums, which play an important role in night-time video surveillance. However, visible infrared person re-identification (VI-REID) is still a challenging problem due to the considerable cross-modality discrepancies. To extract modality-invariant features which are discriminative for the person identity, recent studies are inclined to regard modality-specific features as noise and discard them. Actually, the modality-specific characteristics containing background and color information are indispensable for learning modality-shared features. In this paper, we propose a novel Dual-Adversarial Representation Disentanglement (DARD) model to separate modality-specific features from tangled pedestrian representations and effectively learn the robust modality-invariant representations. Specifically, our method employs dual-adversarial learning, incorporating image-level channel exchange and feature-level magnitude change to introduce variations in modality-specific representations. This deliberate perturbation raises the learning difficulty for the model to learn modality-shared features. Simultaneously, to control the changing scope of modality-specific features, bi-constrained noise alleviation is introduced during adversarial learning, keeping the balance of feature generation and adversary. The proposed dual-adversarial learning methodology enhances the robustness against cross-modality visual discrepancy and strengthens the discriminative power of the learned modality-shared representations without introducing additional network parameters. This improvement further elevates the retrieval performance of VI-REID. Extensive experiments with insightful analysis on two cross-modality re-identification datasets verify the effectiveness and superiority of the proposed DARD method. [ABSTRACT FROM AUTHOR]

The increasing road maintenance projects lead to a large amount of construction waste and long-term closed traffic, enabling a rigid demand for early strength recycled cement-stabilized macadam (ERCSM), which can achieve rapid cold recycling. Given that ERCSM is prone to early drying shrinkage cracking, this study aimed to reduce the occurrence of early drying shrinkage cracking by adding early strength anti-cracking materials (EAMs). Therefore, a drying shrinkage test of cement mortar was carried out to determine the types, contents of anti-cracking materials, and their mixing proportions with early strength composite materials. The effect of EAM on the drying shrinkage of ERCSM was also studied. The results show that the anti-cracking material E1 has better crack resistance. Two types of EAMs (M1 and M2) composed of E1 and different early strength composite materials, were determined. EAM could reduce the drying shrinkage of the recycled cement-stabilized macadam base, and M2 had a better resistance to early shrinkage. After adding M2, the total drying shrinkage coefficient at 2 and 3 d decreased by 91.7% and 74.7% compared with the control group, respectively. Microscopic test show M2 can accelerate the hydration process of cement and promote the formation of expansion products at early ages. [ABSTRACT FROM AUTHOR]