Investigation on Cutting Power of Wood–Plastic Composite Using Response Surface Methodology

For the sake of improving the benefit of enterprise by reducing energy waste. RSM (response surface methodology) was used to investigated the cutting power of wood–plastic composite at different cutting conditions (rake angle, cutting speed, depth of cut, and flank wear). Based on the experimental results, a cutting power model with a high degree of fitting was developed, which can be used to predict cutting power and optimal cutting conditions. Meanwhile, the effects of rake angle, cutting speed, depth of cut, and flank wear and their interaction on the cutting power were probed by analysis of variance, and the significant terms were determined. Finally, the optimal cutting condition was obtained as follows: rake angle of 10°, cutting speed of 300 m/min, depth of cut of 1.5 mm, and flank wear of 0.1 mm. This parameter combination is suggested to be used for industrial manufacturing of wood–plastic composite in terms of the incredible machining efficiency and the lowest energy consumption

Influence of air-gap and thickness on the upward flame spread over discrete wood chips

The fire hazard has frequently destroyed wooden cultural heritages. The discrete wood chips allow fire propagation quickly in practice. This study aims to clarify the effect of air-gap and thickness of wood chips in the fire propagation mechanism by experimental investigating the mass loss rate (MLR), flame spread rate (FSR), total burning duration (TBD) and the flame characteristic length (MFL). The 2 cm long and 10 cm wide wood chips were uniformly installed on a vertical sample holder. The air-gap distance and the thickness of wood chips changed from 1.0 cm to 3.0 cm and 1 mm to 4 mm, respectively. The flame spreads across with the wood grain orientation. The experimental result shows that FSR and MFL are sensitive to the air-gap distance. It is concluded that, TBD versus thickness of the sample is linear with an equation TBD (s) = 7.7 x thickness (mm) + 18.6. Concerning the fixed thickness of the sample, the TBD varies a little from the air-gap distance. The MFL increases to a peak then decreases to a low value as the thickness differing from 1 mm to 4 mm. It is observed that the air-gap makes little contribution to the TBD. The MLF history as the air-gap distance changing from 1.0 cm to 3.0 cm indicates that the distance of air-gap imposed little effect on the MFL. The a-MLR profiles mainly depend on the thickness of the sample

Symmetry-breaking-induced multifunctionalities of two-dimensional chromium-based materials for nanoelectronics and clean energy conversion

Structural symmetry-breaking that could lead to exotic physical properties plays a crucial role in determining the functions of a system, especially for two-dimensional (2D) materials. Here we demonstrate that multiple functionalities of 2D chromium-based materials could be achieved by breaking inversion symmetry via replacing Y atoms in one face of pristine CrY (Y=P, As, Sb) monolayers with N atoms, i.e., forming Janus Cr2NY monolayers. The functionalities include spin-gapless, very low work function, inducing carrier doping and catalytic activity, which are predominately ascribed to the large intrinsic dipole of Janus Cr2NY monolayers, making them having great potentials in various applications. Specifically, Cr2NSb is found to be a spin-gapless semiconductor, Cr2NP and Cr2NHPF could simultaneously induce n- and p-type carrier doping for two graphene sheets with different concentrations (forming intrinsic p-n vertical junction), and Cr2NY exhibits excellent electrocatalytic hydrogen evolution activity, even superior to benchmark Pt. The results confirm that breaking symmetry is a promising approach for the rational design of multifunctional 2D materials