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Total antioxidant capacity (TAC) has become an important index to evaluate the food quality. Effective antioxidant detection has been the research hotspot of scientists. In this work, a novel three-channel colorimetric sensor array founded on Au 2 Pt bimetallic nanozymes for the discrimination of antioxidants in food was constructed. Benefiting from the unique bimetallic doping structure, Au 2 Pt nanospheres exhibited the excellent peroxidase-like activity with K m of 0.044 mM and V max of 19.37 × 10−8 M s−1 toward TMB. The density functional theory (DFT) calculation revealed that Pt atom in the doping system was active sites and there was no energy barrier in catalytic reaction which made Au 2 Pt nanospheres had excellent catalytic activity. Accordingly, a multifunctional colorimetric sensor array was constructed based on Au 2 Pt bimetallic nanozymes for rapid and sensitive detection of five antioxidants. Based on the different reduction ability of antioxidants, oxidized TMB could be reduced in different degrees. In the presence of H 2 O 2 , the colorimetric sensor array could generate differential colorimetric signals (fingerprints) by using TMB as the chromogenic substrate, which could be accurately discriminated through linear discriminant analysis (LDA) with a detection limit of <0.2 μM. The sensor array was able to the evaluate TAC in three actual samples (milk, green tea and orange juice). Furthermore, we prepared a rapid detection strip to meet the needs of practical application, making a positive contribution to food quality evaluation. • Au 2 Pt bimetallic nanozymes exhibited excellent peroxidase-like activity. • A nanozyme colorimetric sensor for detection of five antioxidants was constructed. • Pt atoms in the bimetallic nanozyme were active sites. • The evaluation of TAC in food was achieved by this bimetallic nanozyme sensor. • A rapid detection strip based on the bimetallic nanozyme was prepared. [ABSTRACT FROM AUTHOR]

The construction of Smart Cities is inseparable from the healthy operation of markets. Reasonable data analysis can provide a crucial foundation for the development of market behavior by considering the enormous amount of data generated by a market economy. To this end, we propose enhanced cluster generative adversarial networks (eClusterGAN) to achieve latent space clustering. However, data storage security is crucial. Moreover, we suggest a GAN-based network intrusion detection system (GAN NIDS) that uses adversarial learning to assist the generator in learning the spatial distribution of normal network flows. The simulation results showed that the proposed eClusterGAN and GAN NIDS outperformed the benchmarks in terms of clustering accuracy, running time, precision, recall, and F1, which can support researchers in studying economic data trends. The construction of Smart Cities can effectively ensure healthy market development by discovering and disseminating the potential value of market economic data. [ABSTRACT FROM AUTHOR]

• We propose a personalized course recommendation method based on BERT model, which integrates deep learning and big data technology based on MOOC system. • We design a domain feature difference learning strategy, which is able to learn the difference features between course contents to better extract information in the text and improve the recommendation performance of the model. • We experimentally demonstrate the effectiveness of the method proposed in this paper on the open MoocCube datasets. Finding the courses that users are interested in quickly in the massive data can make a very important contribution to the accurate dissemination of knowledge. In this paper, we integrate the deep learning and big data technology to investigate a personalized recommendation method based on Massive Open Online Course (MOOC) system. Based on the Bidirectional Encoder Representations from Transformers (BERT) model, we propose some corresponding strategies to improve the accuracy of the recommendation system. First, we introduce the acquisition and preprocessing of the open dataset. Second, we design a recommendation model framework by taking advantage of the BERT model and incorporating a self-attention mechanism. Finally, to obtain deep feature information between course texts, we design a domain feature difference learning strategy to improve the model's recommendation performance. The results of our experiments prove that the proposed model in this paper performs good recommendation results compared with other methods. [Display omitted] [ABSTRACT FROM AUTHOR]