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The potential signal generated in the process of coal rock deformation and failure can better characterize the damage evolution process of coal rock, and has a good application prospect in the field of coal rock dynamic disaster monitoring and early warning. At present, most of the researches focus on the potential characteristics and laws of the same type of coal rock failure, and there is a lack of systematic research on the comparative analysis of potential characteristics of different types of coal rocks. At the same time, there are few comparative studies on the effect of different lithology coal rock structure failure process and components on the surface potential signal generation mechanism at the micro level. In order to deeply study the response law and difference of potential signal of coal and rock with different lithology, four kinds of samples, graphite, raw coal, sandstone and granite, are selected for uniaxial loading and the potential signals generated in the process of damage and failure are collected synchronously. The variation characteristics of potential signals of four samples under loading and failure are analyzed. The results show that the potential signal value of graphite sample is relatively low, and the potential signal fluctuates greatly during the crack damage and unstable crack propagation stages. The fluctuation of the potential signal of the raw coal sample is consistent with the fluctuation of the load, and the variation of the overall potential signal is relatively stable. The potential signal value of the sandstone sample increases rapidly in the compaction stage and the elastic deformation stage. The potential signal of the granite sample fluctuates greatly in the crack damage and unstable crack propagation stages, and the potential signal value increases faster. By scanning electron microscope and X-ray fluorescence spectrometer, the generation mechanism of potential signals of coal samples with different lithology is explained from the aspects of microstructure and components. The results show that there are more mylonic scratches from the microscopic point of view in the graphite and raw coal samples in the compaction and elastic deformation stages of coal rock loading, which indicates that the friction effect is the important reason for the electrification of the graphite and raw coal samples. The sandstone and granite samples contain more O and Si elements, and the piezoelectric effect is the key reason for the electrification of the sandstone and granite samples, and the potential signal of the sandstone sample is more affected by the piezoelectric effect. In the crack initiation and stable crack growth stage, crack damage and unstable crack propagation and unloading stage, the potential signal generation of each coal sample is mainly caused by the crack propagation and friction effect inside the sample. Among them, crack propagation is an important reason for the generation of coal-rock potential signals. The charge separation at the crack tip mainly includes three aspects, including electron escape caused by stress concentration at the crack tip, crack surface charge separation caused by crack propagation and crack tip discharge.

Binocular stereo vision relies on imaging disparity between two hemispherical retinas, which is essential to acquire image information in three dimensional environment. Therefore, retinomorphic electronics with structural and functional similarities to biological eyes are always highly desired to develop stereo vision perception system. In this work, a hemispherical optoelectronic memristor array based on Ag‐TiO2 nanoclusters/sodium alginate film is developed to realize binocular stereo vision. All‐optical modulation induced by plasmonic thermal effect and optical excitation in Ag‐TiO2 nanoclusters is exploited to realize in‐pixel image sensing and storage. Wide field of view (FOV) and spatial angle detection are experimentally demonstrated owing to the device arrangement and incident‐angle‐dependent characteristics in hemispherical geometry. Furthermore, depth perception and motion detection based on binocular disparity have been realized by constructing two retinomorphic memristive arrays. The results demonstrated in this work provide a promising strategy to develop all‐optically controlled memristor and promote the future development of binocular vision system with in‐sensor architecture. [ABSTRACT FROM AUTHOR]

In response to the requirements of national energy conservation and environmental protection, the establishment of green energy heating mine, it is proposed to eliminate the existing coal-fired boiler in 2# air shaft of Xiaobaodang Coal Mine and use the waste heat resources of the mine to solve the thermal insulation and anti-freezing of the wellhead of the air wellsite and the heat demand for building heating. Based on existing four technical routes of exhaust air waste heat utilization, through the comparative analysis of their technical characteristics, we finally proposed adopting direct cooling deep enthalpy exhaust air heat pump technology to solve the coal mine in hot demand, and introduced 2# well site general situation of Xiaobaodang Mine, wind heating demand and direct cooling deep enthalpy exhaust air heat pump system of technical route. Finally, we carried out the economic analysis, and completely solved the environmental protection problems caused by coal burning after the implementation of the project, and the existing waste heat of coal mine is recycled to reduce the waste of energy.

In this work, a series of three and four-color tandem white organic light-emitting diodes (WOLEDs) are developed by using the optimized charge generating unit (CGU) to connect two electroluminescence (EL) units with symmetrical emitting layers, in which symmetrical emitting layers are constructed based on the mixed hosts; sandwiched between hole and electron-transporting hosts and the light emitted from two EL units that are absolutely complementary for forming white emission. All resulting tandem WOLEDs realize good white emission with maximum color rendering index (CRI) beyond 77 and 90 for three and four-color white devices and extremely high EL spectra stability, and also achieve high device efficiency with maximum external quantum efficiency (EQE) exceeding 33.10%. For example, for the optimized four-color tandem WOLED, the maximum CRI and EQE of 91 and 34.78% are demonstrated and only very slight CIE (Δx, Δy) variation of (0.002, −0.010) was observed at a wide luminance range from 170.9 cd/m2 to 13,870 cd/m2. To the best of our knowledge, this is the first tandem WOLED with only two EL units realizing such high device performances. More importantly, the proposed tandem WOLEDs here avoid introducing carrier or exciton blocking layer or using more EL units to realize high color quality white emission that provides a novel approach to develop simple, but high-performance tandem WOLEDs.

Regular inspection is an important task to ensure the normal production and safe operation of high-voltage power corridors. In view of the large space of power corridor, complex internal environment, high air humidity and harmful gas, a multi-sensor, remotely-controlled intelligent detection robot is designed to overcome the constraints of time and environment and guarantee the accuracy of the inspection results. The test shows that the inspection robot can not only complete the inspection task, but also has the advantages of strong adaptability, high reliability, flexible control and high anti-interference.

According to the non-stationary and nonlinearity of the fault signals from rolling bearing,a recognition method based on Modified Ensemble Empirical Mode Decomposition（ MEEMD） and Double Hiddenlayer Elman Neural Network（ DHENN） is proposed. The vibration signal is decomposed by MEEMD,and using variance contribution to select out the Principal Intrinsic Mode Function（ PIMF）,one can calculate the permutation entropy of the IMF which obtained by using Complementary Ensemble Empirical Mode Decomposition（ CEEMD）,it is basic to deal with the illusive component,and the others are reconstructed and decomposed by using EMD,the variance contribution is calculated,through Hilbert transform,characteristic matrix is constructed. The DHENN network model is constructed to recognize the fault type,getting the best combine of the double hidden neural network. Finally,compare EMD-DHENN and MEEMD-ENN,the result show that the proposed MEEMD-DHENN method has a high accuracy rate of 100% and only need 26 steps.

We achieved high-efficiency and low-roll-off green fluorescent and phosphorescent organic light-emitting diodes (OLEDs) simultaneously by adopting the thermally activated delayed fluorescence material of bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfone as the universal host. At a luminance of 1000 cd/m2, fluorescent OLEDs based on C545T get a current efficiency, power efficiency, and external quantum efficiency (EQE) of 31.8 cd/A, 25.0 lm/W, and 9.26%, respectively. This is almost the highest efficiency based on C545T at the luminance of 1000 cd/m2 to date. On the other hand, phosphorescent OLEDs with Ir(ppy)3 as the emitter realize a maximum current efficiency, power efficiency, and EQE of 64.3 cd/A, 62.4 lm/W, and 18.5%, respectively. More important, the EQE remains 17.8% at the representative luminance of 1000 cd/m2 and the roll-off ratio is just 3.78%. The transient photoluminescence decay measurement demonstrates that the up-conversion of host triplet excitons plays a key role in the high efficiency and low roll-off. More detailed discussions are also given.

For the CH3NH3PbI3-based optoelectronic memristor, the high ion-migration randomness induces high fluctuation in the resistive switching (RS) parameters. Grain boundaries (GBs) are well known as the ion-migration sites due to their low energy barrier. Herein, a polyacrylonitrile (PAN) passivation method is developed to reduce GBs of the CH3NH3PbI3 film and improve the switching uniformity of the memristor. The crystal grain size of CH3NH3PbI3 increases with the addition of PAN, and the corresponding number of GBs is consequently reduced. The fluctuations of the RS parameters of the memristor device are significantly reduced. With the memristor, nonvolatile image sensing, image memory, and image Boolean operations are demonstrated. This work proposes a strategy for developing high-performance CH3NH3PbI3 optoelectronic memristors. [ABSTRACT FROM AUTHOR]

Auditory motion perception is one crucial capability to decode and discriminate the spatiotemporal information for neuromorphic auditory systems. Doppler frequency‐shift feature and interaural time difference (ITD) are two fundamental cues of auditory information processing. In this work, the functions of azimuth detection and velocity detection, as the typical auditory motion perception, are demonstrated in a WOx‐based memristive synapse. The WOx memristor presents both the volatile mode (M1) and semi‐nonvolatile mode (M2), which are capable of implementing the high‐pass filtering and processing the spike trains with a relative timing and frequency shift. In particular, the Doppler frequency‐shift information processing for velocity detection is emulated in the WOx memristor based auditory system for the first time, which relies on a scheme of triplet spike‐timing‐dependent‐plasticity in the memristor. These results provide new opportunities for the mimicry of auditory motion perception and enable the auditory sensory system to be applied in future neuromorphic sensing. [ABSTRACT FROM AUTHOR]

Each year worldwide, [approximately equal to] 1.5 million children The Study A total of 10,021 fecal samples were obtained from patients with diarrhea or dysentery at hospitals in 8 provinces [...]