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With the hyperspectral imaging technology, hyperspectral data provides abundant spectral information and plays a more important role in geological survey, vegetation analysis and military reconnaissance. Different from normal change detection, hyperspectral anomaly change detection (HACD) helps to find those small but important anomaly changes between multi-temporal hyperspectral images (HSI). In previous works, most classical methods use linear regression to establish the mapping relationship between two HSIs and then detect the anomalies from the residual image. However, the real spectral differences between multi-temporal HSIs are likely to be quite complex and of nonlinearity, leading to the limited performance of these linear predictors. In this paper, we propose an original HACD algorithm based on auto-encoder (ACDA) to give a nonlinear solution. The proposed ACDA can construct an effective predictor model when facing complex imaging conditions. In the ACDA model, two systematic auto-encoder (AE) networks are deployed to construct two predictors from two directions. The predictor is used to model the spectral variation of the background to obtain the predicted image under another imaging condition. Then mean square error (MSE) between the predictive image and corresponding expected image is computed to obtain the loss map, where the spectral differences of the unchanged pixels are highly suppressed and anomaly changes are highlighted. Ultimately, we take the minimum of the two loss maps of two directions as the final anomaly change intensity map. The experiments results on public "Viareggio 2013" datasets demonstrate the efficiency and superiority over traditional methods.

Three-dimensional braided composite materials have been widely applied to engineering structure manufacturing. It is of a great importance to characterize the impact damage of the three-dimensional braided composite under various temperatures for optimizing the engineering structure. Here we conducted transverse impact deformation and damage of three-dimensional braided composite beams with different braiding angles at room and elevated temperatures. A split Hopkinson pressure bar with a heating device combined with high-speed camera was employed to test multiple transverse impact behaviors and to record the impact deformation developments. The results indicated that failure load, initial modulus, and energy absorption decreased with the increase of temperature, whereas the deformation increased slightly with elevated temperatures. We found that the impact brittle damages occurred earlier and the local adiabatic temperature raised higher when the temperature is lower than the glass transition temperature (Tg) of epoxy resin. While above the Tg, the impact ductile damages occurred later and the local temperature raised lower. The thermal stress distribution along the braiding yarn leads to cracks propagation in yarn direction. Part of the impact energy absorptions converted into thermal energy. In addition, the beam with larger braiding angle has high damage tolerance and crack propagation resistance.

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Four mononuclear terpyridine complexes [Cu(H-La)Cl2]·CH3OH (1), [Cu(H-La)Cl]ClO4 (2), [Cu(H-Lb)Cl2]·CH3OH (3), and [Cu(H-Lb)(CH3OH)(DMSO)](ClO4)2 (4) were prepared and fully characterized. Complexes 14 exhibited higher cytotoxic activity against several tested cancer cell lines...

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Converting CO2 into valuable solar fuels through photocatalysis has been considered a green and sustainable technology that is promising for alleviating global warming and providing energy in an environmentally friendly...