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To observe the chemical mechanical polishing (CMP) process at the atomic scale, reactive force field molecular dynamics (ReaxFF-MD) was employed to simulate the polishing of 6 H-SiC under three conditions: dry, pure water, and H2O2 solution. This study examined the reactants on the surface of 6 H-SiC during the reaction in the H2O2 solution, along with the dissociation and adsorption processes of H2O2 and water molecules. The mechanisms for atom removal during the CMP process were elucidated. Variations in the number of different bonds over time and changes in the number of amorphous SiC atoms across various environments were analyzed. A comparison was made regarding the surface morphology of SiC after polishing with diamond abrasives in the three distinct environments.The results indicate that H2O2 and water molecules can dissociate into -OH, -H, and -O-. Si atoms form Si-C bonds with carbon atoms in the abrasive or connect with carbon atoms via -O- bridges to form Si-O-C for removal. C atoms are primarily removed in the form of carbon chains. Abrasive grinding can promote the dissociation of -H2O and -OH. Both water and H2O2 solutions can mitigate surface structural damage during the polishing process, with the H2O2 solution showing superior effectiveness. [ABSTRACT FROM AUTHOR]

Electricity markets are intricate systems that facilitate efficient energy exchange within interconnected grids. With the rise of low-carbon transportation driven by environmental policies and tech advancements, energy trading has become crucial. This trend towards Electric Vehicles (EVs) is bolstered by the pivotal role played by EV charging operators in providing essential charging infrastructure and services for widespread EV adoption. This paper introduces a blockchain-assisted secure electricity trading framework between EV charging operators and the electricity market with renewable energy sources. We propose a single-leader, multi-follower Stackelberg game between the electricity market and EV charging operators. In the two-stage Stackelberg game, the electricity market acts as the leader, deciding the price of electric energy. The EV charging aggregator leverages blockchain technology to record and verify energy trading transactions securely. The EV charging operators, acting as followers, then decide their demand for electric energy based on the set price. To find the Stackelberg equilibrium, we employ a Deep Reinforcement Learning (DRL) algorithm that tackles non-stationary challenges through policy, action space, and reward function formulation. To optimize efficiency, we propose the integration of pruning techniques into DRL, referred to as Tiny DRL. Numerical results demonstrate that our proposed schemes outperform traditional approaches. [ABSTRACT FROM AUTHOR]

This paper proposes a chromium oxide (Cr2O3) gel abrasive tool with the coated aluminum nitride (AlN) powder to give the tool with self-sharpening ability. The SiO2/AlN powder (S/A powder) is prepared through the sol–gel method. Effect of acetic acid solution content on the Tetraethyl orthosilicate (TEOS) hydrolysis reaction is explored. Effect of sintering temperature on the moisture resistance of the S/A powder are studied. The viscosity experiments, porosity tests, pre-grinding experiments and hardness tests are conducted to test the properties of the abrasive tool. The force–displacement curves are tested to evaluate the uniformity of the tool. The grinding effect on the sapphire substrate of tool with S/A powder, normal abrasive tool and tool with pore forming agent are compared. Results show that the SiO2 gel has great stability when the acetic acid solution content reached 0.6 g, and the gel does not crack after a week's rest, which is suitable for the coating of the AlN powder. In the powder sintering experiment, 700 °C is found to be the optimal sintering temperature for the S/A powder preparation. The viscosity experiments show that the viscosity of the slurry will surge when the content of S/A powder reached 12 wt%, which impairs the uniformity of the gel abrasive tool. In the pre-grinding test, the abrasive tool with the S/A powder of 9 wt% shows great grinding stability, material removal rate (MRR) and wear resistance. The grinding experiments show that tool with S/A powder can achieve better surface quality and have a stable grinding process, and the glazing phenomena is ameliorated. After grinding, the average roughness Ra of the sapphire substrate reaches 1.57 nm and its flatness reached 0.725 μm. After chemical mechanical polishing (CMP), the average Ra of sapphire substrate reaches 0.64 nm and the scratch-free surface can be obtained. [ABSTRACT FROM AUTHOR]