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In order to solve the problem of untimely monitoring of tool wear status during laser-ultrasonic compound cutting (LUCC), which leads to the reduction of process accuracy and product quality damage, a method of tool wear status monitoring based on acoustic emission (AE) and deep learning is proposed in this paper. The AE signal is collected and analyzed in the frequency and time-frequency domains by using Fourier transform (FT) and wavelet packet decomposition (WPD), it is found that the AE signal energy is mainly concentrated in the 1st, 2nd, 3rd, and 4th frequency bands, and the energy of each frequency band in the signal increases gradually when the tool wear degree increases, however, the percentage of energy of each frequency band in the total energy shows different change trend. According to the amount of flank wear of the tool, the tool wear degree is divided into four tool wear states. The SVM model and BP neural network model were established based on MATLAB software to realize the tool wear state monitoring. The results show that the tool wear monitoring based on BP neural network is better than that of SVM for tool wear status monitoring. The model identification correct rate reaches 99 %, which is more suitable for the tool wear state monitoring designed in this paper. [ABSTRACT FROM AUTHOR]

Magnetic nanoparticle (MNP)-based immunochromatographic tests (ICTs) display long-term stability and an enhanced capability for multiplex biomarker detection, surpassing conventional gold nanoparticles (AuNPs) and fluorescence-based ICTs. In this study, we innovatively developed zwitterionic silica-coated MNPs (MNP@Si-Zwit/COOH) with outstanding antifouling capabilities and effectively utilised them for the simultaneous identification of the nucleocapsid protein (N protein) of the severe acute respiratory syndrome coronavirus (SARS-CoV-2) and influenza A/B. The carboxyl-functionalised MNPs with 10% zwitterionic ligands (MNP@Si-Zwit 10/COOH) exhibited a wide linear dynamic detection range and the most pronounced signal-to-noise ratio when used as probes in the ICT. The relative limit of detection (LOD) values were achieved in 12 min by using a magnetic assay reader (MAR), with values of 0.0062 ng/mL for SARS-CoV-2 and 0.0051 and 0.0147 ng/mL, respectively, for the N protein of influenza A and influenza B. By integrating computer vision and deep learning to enhance the image processing of immunoassay results for multiplex detection, a classification accuracy in the range of 0.9672–0.9936 was achieved for evaluating the three proteins at concentrations of 0, 0.1, 1, and 10 ng/mL. The proposed MNP-based ICT for the multiplex diagnosis of biomarkers holds substantial promise for applications in both medical institutions and self-administered diagnostic settings. [Display omitted] • Zwitterionic magnetic immunochromatographic assay systems were prepared. • Multiplex and diagnosis of biomarkers were performed under a magnetic reader. • Integration of computer vision and Deep-Learning were employed for imaging. [ABSTRACT FROM AUTHOR]

The break accident process of a supercritical carbon dioxide (SCO2) reactor system presents a transcritical phenomenon. Operating under high pressure and a wide parameter range, the SCO2 system introduces multiphase characteristics to the critical flow of carbon dioxide (CO2) at various system positions. Nevertheless, current research lacks a comprehensive critical flow model capable of accommodating a broad parameter range with high precision. Data-driven approaches offer the potential to enhance accuracy by leveraging an expanding training database. To precisely forecast SCO2 critical flow efficiency, this study established an SCO2 critical flow model using deep learning techniques. The conservation equations and sensitivity analysis of experimental data informed the feature selection for the deep learning model, accomplished through the recurrent neural network (RNN) method, employing K-fold cross-validation and L2 regularization. The result was the SCO2-RNN critical flow model, boasting improved prediction accuracy and enhanced generalization capabilities. Subsequently, the optimal hyperparameters were determined by using a genetic algorithm. This model yielded an average error of 4.88% in predicted results, with a maximum error of 14.24%. The average error when extrapolating to the generalization data was 5.73%, with a maximum error of 20.45%. After the implementation of transfer learning, the average error decreased to 1.75%, with a final maximum error of 4.15%. Generalization results, using new data based on the trained model, underscore that the deep learning model meets engineering requirements for both efficiency and accuracy. • A wide-parameter, high-precision critical flow model was constructed based on the RNN deep learning model. • K-fold cross-validation was used to overcome the problem of insufficient training data, whereas L2 regularization was used to prevent overfitting. • A genetic algorithm was used to optimize the hyperparameters, and transfer learning was introduced to expand the applicability of the model. • The average model error is as low as 1.68% and the maximum error is as low as 4.15%. [ABSTRACT FROM AUTHOR]