Search

Cephalopods can change their skin color by using high‐speed electron transduction among receptors, neural networks, and pigmentary effectors. However, it remains challenging to realize a neuroelectrical transmission system like that found in cephalopods, where electrons/ions transmit on nanoscale, which is crucial for fast adaptive electrochromic tuning. Inspired by that, hereby an ideal, rapidly responsive, and multicolor electrochromic biomimetic skin is introduced. Specifically, the biomimetic skin comprises W18O49 nanowires (NWs) that are either colorless or blue, Au nanoparticles@polyaniline (Au NPs@PANI) ranging from green to pink, and a flexible conductive substrate. As the applied voltage changes from 0.4 V to ‐0.7 V and back to 0 V, the color of the biomimetic skin transforms from green to blue and ultimately to pink. This color change is attributed to the electrically induced redox reaction of Au NPs@PANI and W18O49 NWs, triggered by the transfer of electrons and ions. Furthermore, the high versatility and adaptability of electrical stimulus enable the creation of a highly interactive electrochromic biomimetic skin system through the integration of sensitive acoustic sensors, providing a perfect environment‐responsive platform. This work provides a biomimetic multicolor electrochromic skin that depends on electron/ion transfer on nanoscale, expands potential uses for camouflage skin. [ABSTRACT FROM AUTHOR]

In order to apply the back propagation neural network in artificial intelligence technology to the prediction of roof strata pressure data, 11 main factors affecting the prediction of roof rock pressure data of working faces are taken as input parameters, and roof rock pressure parameters of four working faces are taken as output parameters. The number of hidden layers is determined as 1 layer and the number of hidden layer neural units is 24. On this basis, the prediction model of roof pressure data based on the back propagation neural network is established. Based on the representative roof pressure data for working face of Wangjialing and its surrounding coal mines, the study samples are established, and the measured mine pressure data of 12309 working face in Wangjialing Coal Mine were used as the verification samples to test the accuracy of the prediction. After analysis, the relative errors between the predicted values and the measured values of the first weighting interval, the first weighting strength, the periodic weighting interval and the periodic weighting strength are 0.043 343 653, 0.006 077 606, 0.006 401 138 and 0.020 223 608 8, respectively, which means that the overall relative errors of the mining pressure data are less than 5%, which is in line with the allowable error range of the engineering application. This indicates that the established back propagation neural network model has high accuracy and reliability.

In order to study the influence of the aspect ratio of the short-wall filling roadway on the stability of surrounding rock, the theory of numerical analysis and numerical simulation were used to analyze the principle of cooperative roof control of the short-wall filling roadway. The change laws of the stability of surrounding rock under different aspect ratios are presented.Research indicates that: when the height of the roadway is fixed, the maximum approach of the top floor and the two sides increases slowly with the increase of the width to height ratio and then decreases slightly, and then increases rapidly after the width to height ratio is greater than 1.0. And when the width to height ratio of the roadway is 1.0, the deformation of the panel per unit area is the smallest, which is most beneficial to the stability of the surrounding rock of the panel. Combined with the specific conditions of Bailiang Xusheng Coal Mine, the reasonable width-to-height ratio of the short-wall filling roadway was determined to be 1.0, and a specific support scheme was given based on the asymmetric deformation characteristics of the roof.

Near-infrared (NIR) phosphors with emission peak wavelength longer than 800 nm have attracted significant attention due to their wide applications. However, a key challenge lies in developing high photoluminescence (PL) thermal stability phosphors. Herein, we synthesized a NIR phosphor Na3Al2(PO4)2F3:Cr3+ (NAPOF:Cr3+) through the solid-state reaction method. The NAPOF:Cr3+ phosphor exhibits an intense broadband emission peak at 810 nm and covers a wide spectral range from 650 to 1100 nm. Notably, this phosphor demonstrates zero PL thermal quenching even at 398 K. This outstanding thermal stability can be primarily ascribed to the inherent structural rigidity and wide bandgap of the NAPOF crystal together with the medium electron–photon coupling effect. The fabricated broadband NIR light-emitting diodes (LEDs) using the NAPOF:Cr3+ phosphor exhibits a highest NIR light output power of 28.1 mW under a drive current of 150 mA, and a corresponding electro-optical conversion efficiency of 8.6%. Our findings highlight the tremendous potential of the NAPOF:Cr3+ phosphor for broad-spectrum NIR-LED applications. [ABSTRACT FROM AUTHOR]