Emotion is one of the most important higher cognitive functions of the human brain and plays an important role in transaction processing and decisions. In traditional emotion recognition studies, the frequency band features in EEG signals have been shown to have a high correlation with emotion production. However, traditional emotion recognition methods cannot satisfactorily solve the problem of individual differences in subjects and data heterogeneity in EEG, and subject-independent emotion recognition based on EEG signals has attracted extensive attention from researchers. In this paper, we propose a subject-independent emotion recognition model based on adaptive extraction of layer structure based on frequency bands (BFE-Net), which is adaptive in extracting EEG map features through the multi-graphic layer construction module to obtain a frequency band-based multi-graphic layer emotion representation. To evaluate the performance of the model in subject-independent emotion recognition studies, extensive experiments are conducted on two public datasets including SEED and SEED-IV. The experimental results show that in most experimental settings, our model has a more advanced performance than the existing studies of the same type. In addition, the visualization of brain connectivity patterns reveals that some of the findings are consistent with previous neuroscientific validations, further validating the model in subject-independent emotion recognition studies.
Cr was doped into LiMn2O4 compound in this study through the traditional solid-state reaction route. The pattern of X-ray diffraction (XRD) revealed that the structure of LiMn2O4 had not changed, and scanning electron microscopy (SEM) exhibited that all samples possessed similar morphology. It was seen that all the samples presented more than 100 mAh/g capacity under different discharge current rates. Because partial Mn3+ was replaced by Cr3+, the LiMn2-xCrxO4 revealed excellent cycling stability. Electrochemical result demonstrated that the optimal content of Cr-doping was 0.02, which had an initial discharged capacity of 133.9 mAh/g at 1C rate. These results suggest a new method for enhancing cycle stability of LiMn2O4 materials.
