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Remote photoplethysmography (rPPG) realizes contactless heart rate estimation by analyzing the color changes of facial video. However, the color changes in the facial video are not obvious, and the noise introduced by factors such as head movement and illumination changes is also not conducive to the extraction of rPPG signals. To address these challenges, we construct an end-to-end multi-task model called rPPGTR, which is based on the multi-head self-attention mechanism. rPPGTR captures local features and global dependencies by combining the convolution block and divided space-time attention, and fuses these two kinds of information. This paper takes the face sequences as the input of rPPGTR. rPPGTR first uses the convolution blocks to extract local features and process the face images into sequences of image patches. Then, the divided space-time attention is used to assign corresponding weights to image patches in different spatiotemporal positions and capture their long-range dependencies. The captured global dependencies will be fused with local features to enrich the extracted rPPG features. Finally, the features are decoded into rPPG signals and average heart rate values, and their relationship is used for multi-task learning. The experimental results on four public datasets show that the prediction accuracy of rPPGTR is better than the comparison methods. [ABSTRACT FROM AUTHOR]

Polymer electrolytes (PEs) synthesized from an in situ polymerization strategy are considered as promising candidates to improve interfacial compatibility. However, most in situ formed PEs still suffer from problems such as low lithium-ion transference number (tLi+) and insufficient ionic conductivity at room temperature (RT). Herein, a series of copolymer electrolytes (CPEs) consisting of 1,3-dioxolane (DOL) and 1,3,5-trioxane (TXE) monomers are synthesized. Due to the additive of succinonitrile (SN), and the promoted dissociation of lithium salt, the obtained polymer electrolyte (SN-CPE) exhibits an excellent ionic conductivity (4.06 × 10−4 S cm−1) and a high lithium-ion transference number (tLi+ = 0.881) at RT, as well as a high voltage oxidation window of 5.1 V. Thanks to the in situ formed intimate contacted electrode/electrolyte interface, the symmetric Li/Li cell can achieve long-term cycling stability over 1500 h without a short circuit. A LiF-rich organic–inorganic composite layer is formed on both the solid electrolyte interphase (SEI) and cathode electrolyte interphase (CEI) as demonstrated by XPS, TEM, and SEM analyses. Thereafter, the LiFePO4/Li cell has a high capacity retention of 84.1% after 900 cycles at RT, and it can still work effectively at high temperatures (e.g. 80 °C). Furthermore, SN-CPE exhibits excellent electrochemical performance and safety in the LiCoO2/Li cell and LiFePO4/graphite pouch cell, which again supports the promising application of SN-CPE. [ABSTRACT FROM AUTHOR]

Rather than just focusing on the catalyst itself in the electrocatalytic CO2 reduction reaction (eCO2RR), as previously reviewed elsewhere, we herein extend the discussion to the special topic of the microenvironment around the electrocatalytic center and present a comprehensive overview of recent research progress. We categorize the microenvironment based on the components relevant to electrocatalytic active sites, i.e. the catalyst surface, substrate, co‐reactants, electrolyte, membrane, and reactor. Supported by most of the reported articles, the relevant factors affecting the catalytic performance of eCO2RR are then discussed in detail, and existing challenges and potential solutions are mentioned. Perspectives for the future research on eCO2RR, including the integration of different microenvironment factors, the extension to industrial application by coupling with carbon capture and conversion, and separation of products, are also discussed. [ABSTRACT FROM AUTHOR]

Rather than just focusing on the catalyst itself in the electrocatalytic CO 2 reduction reaction (eCO 2 RR), as previously reviewed elsewhere, we herein extend the discussion to the special topic of the microenvironment around the electrocatalytic center and present a comprehensive overview of recent research progress. We categorize the microenvironment based on the components relevant to electrocatalytic active sites, i.e., the catalyst surface, substrate, co-reactants, electrolyte, membrane, and reactor. Supported by most of the reported articles, the relevant factors affecting the catalytic performance of eCO 2 RR are then discussed in detail, and existing challenges and potential solutions are mentioned. Perspectives for the future research on eCO 2 RR, including the integration of different microenvironment factors, the extension to industrial application by coupling with carbon capture and conversion, and separation of products, are also discussed., (© 2022 Wiley-VCH GmbH.)

Exploration of the versatility of materials is very important for increasing the utilization of materials. Herein, we successfully prepared Bi 4 O 5 I 2 powders via a facile solvothermal method. The Bi 4 O 5 I 2 photocatalyst exhibited significantly higher photocatalytic activity as compared to the common BiOI photocatalyst in the degradation of methyl orange, methylene blue and rhodamine B under visible light irradiation. Especially, for the degradation of methyl orange, the photocatalytic activity of Bi 4 O 5 I 2 is about 10 times that of BiOI. Moreover, Bi 4 O 5 I 2 exhibits an extremely high second harmonic generation response of about 20 × KDP (the benchmark) estimated by the unbiased ab initio calculations. The coexisting multifunction of Bi 4 O 5 I 2 is mainly because of the increased dipole moment due to the stereochemical activity of lone pairs that promotes separation and transfer of photogenerated carriers, then enhances the photocatalytic activity and results in a high second harmonic generation response. This indicates that Bi 4 O 5 I 2 may have good potential applications in photocatalytic and nonlinear optical fields., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.)