In modern manufacturing, the prediction of the remaining useful life (RUL) of computer numerical control (CNC) milling cutters is crucial for improving production efficiency and product quality. This study proposes a hybrid CNN-LSTM-Attention-PSA model that combines convolutional neural networks (CNN), long short-term memory (LSTM) networks, and attention mechanisms to predict the RUL of CNC milling cutters. The model integrates cutting force, vibration, and current signals for multi-channel feature extraction during cutter wear. The model’s hyperparameters are optimized using a PID-based search algorithm (PSA), and comparative experiments were conducted with different predictive models. The experimental results demonstrate the proposed model’s superior performance compared to CNN, LSTM, and hybrid CNN-LSTM models, achieving an R² score of 99.42% and reducing MAE, RMSE, and MAPE by significant margins. The results validate that the proposed method has significant reference and practical value for RUL prediction research of CNC milling cutters.

Oil sludge is an organic solid waste produced in oilfield exploitation, transportation, and petroleum refineries. Pyrolysis is one of the most effective ways to reduce oil sludge and realize energy re-utilization. In the present work, the amounts and distributions of pyrolysis products at different reaction time and with different amounts of NiO catalyst were investigated with PY-GC/MS. The results suggest that the degree of the pyrolysis reaction increased and more macromolecules were degraded into smaller hydrocarbons as the reaction time prolonged. The addition of NiO catalyst effectively promoted the conversion of aromatic and paraffin products, and increased the production of small molecule olefins.

In this paper, the physical adsorption of volatile organic compounds (VOCs) such as methyl chloride (CH₃Cl), carbon disulfide (CS₂), dimethyl sulfide (C₂H₆S), and benzene (C₆H₆) by three models of activated carbon (without a functional group, with a pyridine-containing functional group, and with a pyrrole-containing functional group) was simulated. The surface electrostatic potential (ESP), physical adsorption energy, and non-covalent interaction between activated carbon and VOC molecules were analyzed based on the density functional theory (DFT). The effect mechanism of nitrogen-containing functional groups on VOC adsorption by activated carbon was determined. Our simulations showed that nitrogen-containing functional groups can change the surface ESP and polarity of activated carbon. The pyrrole functional group is conducive to CH₃Cl and CS₂ adsorption on the activated carbon plane, while the pyridine functional group is relatively small or even unfavorable for CH₃Cl and CS₂ adsorption on the activated carbon plane. The promotional effect of the pyrrole functional group on the adsorption of C₂H₆S is more significant than that of the pyridine functional group. The adsorption of C₆H₆ on activated carbon occurs through parallel-displaced π–π stacking interactions, in which functional groups have little influence on it. The adsorption energy of VOCs on the activated carbon plane is higher than that at the edge, so VOCs are more likely to be adsorbed on the activated carbon plane.

Higher education accreditation within the Washington Accord has played a crucial role in advancing the global recognition of engineering training, greatly benefiting the professional sustainability of graduates. However, the existence of substantial disparities in higher engineering education systems among countries poses challenges for international engineering education accreditation, primarily due to information asymmetry. To address this issue, this study focuses on a comparative analysis of representative undergraduate programs in the field of ship engineering from the Ocean University of China in China and the University of Southampton in the UK. By examining the curriculum systems in the field of ship engineering in both countries, this study aims to shed light on the variations and similarities between the two. Moreover, the study delves into the specific example of the “Marine Engineering English” module to illustrate how an independent module can effectively fulfill the requirements for international recognition in higher engineering education accreditation while also serving the curriculum system. Serving as a significant practical case within the framework of the Washington Accord, this research provides valuable insights for the establishment of engineering education curriculum systems that are aligned with international standards. Ultimately, its findings hold considerable significance for promoting the international recognition of engineering education and fostering sustainable professional development for graduates.