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Planar glass cover creates optical reflection loss and glare, which is harmful to energy efficiency and effective operation of PV modules, especially at larger angles of incidence (AOIs). Textured surfaces can reduce reflections and glare intensity. In this work, three textured glass surfaces are described and simulated numerically over a wide range of AOIs. The anti-reflection effect and light trapping effect are provided to analyze the transmission gain across a wide range of AOIs. The reflection times is proposed to assess the anti-glare effect of the textured surfaces. It is found that the hexagonal array structured surface exhibits the highest transmission gain and anti-glare effect. The optimized hexagonal array structured surface could improve the average transmission by ∼5% relative to planar surface for AOIs of 0°–80°. In addition, the reflection times is doubled, which helps to diminish the reflection and glare intensity. more...

Strategies to improve the efficiency of piezoelectric catalysis have long focused on piezo-optical coupling and construction of heterojunctions. However, it is a challenge to reinforce the performance of piezoelectric catalysis in a single material. Herein the built-in nanopores in single-crystal ZnO rods are employed to form stress to intensify piezo-catalytic efficiency. The piezo-catalytic efficiency of the ZnO rods with built-in nanopores (holey ZnO NRs) for degrading dyes was about 1.7 times that of the ZnO rods without built-in nanopores (ZnO NRs). X-ray diffraction and Raman peaks of holey ZnO NRs appeared blue-shifted in comparison to ZnO NRs, uncovering the existence of tensile stress in holey ZnO NRs. The piezoelectric coefficient d33 of holey ZnO NRs increased by 1.92 times, triggering the amplification of piezoelectric catalytic property. Additionally, the piezoelectric current, carrier lifetime, and diffusion length of holey ZnO NRs were larger than that of ZnO NRs, respectively. These factors all contribute to the enhanced piezoelectric catalytic efficiency of holey ZnO NRs. This work demonstrates that the method of induced stress with built-in nanopores is a promising strategy for improving the piezoelectric catalytic efficiency of single-crystal ZnO rods. more...

Large waves pose a significant threat to the safety of low-laying coastal bridges. In 2004 and 2005, many coastal bridges were destroyed by the large waves generated by Hurricane Ivan and Katrina. A series of studies have been conducted to investigate the wave action on bridge decks. However, the effect of seabed topography on wave forces is seldom considered. In this study, a numerical model of wave impact on bridge decks located close to a sloping seabed was set up based on OpenFOAM-v1912. The reliability of the present numerical model was checked against published experimental results. The wave forces acting on the bridge decks located before and after the sloping seabed were compared with a bridge deck located above a flat bottom. With the validated numerical model, the effect of the wave properties, coefficient of submergence, and the inclination on wave forces were investigated. The results show that the wave forces on the bridge are affected by the interaction among the incident and reflected waves, the position of the bridge relative to the sloping seabed, and the inclination. These findings emphasize the complex dynamic effects of wave forces on bridges and the importance of considering seabed topography in bridge design and strengthening strategies. This research contributes to an improvement in the safety of coastal bridges, especially in the face of increasing threats from climate change and sea level rise, as well as promotes the development of more resilient infrastructures. more...

Strain rate is a critical parameter in the mechanical application of nano-devices. A comparative atomistic study on both perfect monocrystalline silicon crystal and silicon nanowire was performed to investigate how the strain rate affects the mechanical response of these silicon structures. Using a rate response model, the strain rate sensitivity and the critical strain rate of two structures were given. The rate-dependent dislocation activities in the fracture process were also discussed, from which the dislocation nucleation and motion were found to play an important role in the low strain rate deformations. Finally, through the comparison of five equivalent stresses, the von Mises stress was verified as a robust yield criterion of the two silicon structures under the strain rate effects. more...

Mechanical anisotropy and point defects would greatly affect the product quality while producing silicon wafers via diamond-wire cutting. For three major orientations concerned in wafer production, their mechanical performances under the nanoscale effects of a point defect were systematically investigated through molecular dynamics methods. The results indicated anisotropic mechanical performance with fracture phenomena in the uniaxial deformation process of monocrystalline silicon. Exponential reduction caused by the point defect has been demonstrated for some properties like yield strength and elastic strain energy release. Dislocation analysis suggested that the slip of dislocations appeared and created hexagonal diamond structures with stacking faults in the [100] orientation. Meanwhile, no dislocation was observed in [110] and [111] orientations. Visualization of atomic stress proved that the extreme stress regions of the simulation models exhibited different geometric and numerical characteristics due to the mechanical anisotropy. Moreover, the regional evolution of stress concentration and crystal fracture were interrelated and mutually promoted. This article contributes to the research towards the mechanical and fracture anisotropy of monocrystalline silicon. more...

A simply and reproducible way is proposed to significantly suppress the nucleation density of graphene on the copper foil during the chemical vapor deposition process. By inserting a copper foil into a tube with one close end, the nucleation density on the copper foils can be reduced by more than five orders of magnitude and an ultra-low nucleation density of ∼10 nucleus/cm2 has been achieved. The structural analyses demonstrate that single crystal monolayer graphene with a lateral size of 1.9 mmcan be grown on the copper foils under the optimized growth condition. The electrical transport studies show that the mobility of such single crystal graphene is around 2400 cm2/Vs. [ABSTRACT FROM AUTHOR] more...