The multi-wavelength tailoring of ZnGa₂O₄ nanosheets has been achieved via a defect engineering approach. Controlling the distortion of [GaO₆] octahedron and the formation of [GaO₄] tetrahedron and oxygen vacancy in ZnGa₂O₄ lattice can achieve the simultaneous emissions of ultraviolet/blue, green and red wavelengths.

In recent years, deep learning methods have gained much success in the area of intelligent fault diagnosis. However, due to the fact that the working condition is various and the noise is inevitable, degradation of previous model is very serious. To address the challenge of bearing fault detection under strong noise environment, this paper proposed a novel anti-noise deep residual multiscale convolutional neural network with attention mechanism named Attention-MSCNN. First, dynamic dropout is used to improve the anti-noise ability by introducing artificial noise into training process. Additionally, we design a residual connection between input and the convolved features to fully capture the characteristics of the initial input. Finally, a novel denoised multi-head attention mechanism is applied to remove excess noise in raw input and obtain relationships between long time series. The experimental results show that Attention-MSCNN can achieve robust anti strong noise performance with over 85% accuracy on CWRU dataset. On the self collected two-stage gear drive test bench, our model achieve an accuracy of over 99% under strong noise environment. Thus, Attention-MSCNN successfully solve the problem of low detection accuracy of previous models under strong noise environment.

Ga_0.51In_0.49P/In_0.01Ga_0.99As/Ge triple-junction solar cells for space applications were grown on 4 inch Ge substrates by metal organic chemical vapor deposition methods. The triple-junction solar cells were obtained by optimizing the subcell structure, showing a high open-circuit voltage of 2.77 V and a high conversion efficiency of 31% with 30.15 cm² area under the AM0 spectrum at 25 °C. In addition, the In_0.01Ga_0.99As middle subcell structure was focused by optimizing in order to improve the anti radiation ability of triple-junction solar cells, and the remaining factor of conversion efficiency for middle subcell structure was enhanced from 84% to 92%. Finally, the remaining factor of external quantum efficiency for triple-junction solar cells was increased from 80% to 85.5%.

In this study, a full-scale three-dimensional trapezoidal thermoelectric cooler model is constructed to study its cooling performance and mechanical reliability using finite element simulation. Temperature dependent material properties are considered in this work. The boundary conditions similar to those in a real experimental environment are applied. The effects of the input electrical current and geometry of the thermoelectric leg on the cooling performance and reliability of a trapezoidal thermoelectric cooler are analyzed, and a comparison is made with a rectangular thermoelectric cooler. The results indicate that increasing the leg height and the variable cross-sectional design of the leg can improve the cooling performance of the trapezoidal thermoelectric cooler. Compared to the original rectangular thermoelectric cooler, the minimum chip temperature was reduced by 0.87% under the trapezoidal thermoelectric cooler with optimized geometry. Furthermore, increasing the leg height enhances the mechanical reliability of the trapezoidal thermoelectric cooler, while the trapezoidal design of the leg reduces its mechanical reliability. The maximum von Mises stress of the leg for the trapezoidal thermoelectric cooler with optimal cooling performance increased by 40.1%. The results of this work provide useful guidance for the structural design of trapezoidal thermoelectric coolers.

In this paper, the edge strain relaxation of InGaN/GaN MQW micro-pillars is studied. Micro-pillar arrays with a diameter of 3–20 μm were prepared on a blue GaN LED wafer by inductively coupled plasma (ICP) etching. The peak wavelength shift caused by edge strain relaxation was tested using micro-LED pillar array room temperature photoluminescence (PL) spectrum measurements. The results show that there is a nearly 3 nm peak wavelength shift between the micro-pillar arrays, caused by a high range of the strain relaxation region in the small size LED pillar. Furthermore, a 19 μm micro-LED pillar’s Raman spectrum was employed to observe the pillar strain relaxation. It was found that the Raman E₂^H mode at the edge of the micro-LED pillar moved to high frequency, which verified an edge strain relaxation of = 0.1%. Then, the exact strain and peak wavelength distribution of the InGaN quantum wells were simulated by the finite element method, which provides effective verification of our PL and Raman strain relaxation analysis. The results and methods in this paper provide good references for the design and analysis of small-size micro-LED devices.