Jinsong Rao

The annual economic loss caused by corrosion accounts for about 2%~4% of GDP, which exceeds the sum of losses caused by fires, floods, droughts, typhoons, and other disasters. Coating is one of the most effective methods to delay metal corrosion. With the development of technology and the intersection of disciplines, functional microcapsules have been applied to anticorrosive coatings, but microcapsules are still being updated. To understand the application progress of microcapsules in anticorrosive coatings, the future development trend of microcapsules is analyzed. The preparation methods, physical and chemical properties, functional characteristics, and development trends of organic, inorganic, and organic–inorganic hybrid microcapsules are described, respectively, from the perspective of material and molecular characteristics. Simultaneously, the influence of microcapsules of different materials on the properties of organic coatings is proved by examples. In addition, the research status and future development trends of microcapsule composite coating are introduced in detail. Finally, the great advantages of organic–inorganic hybrid microcapsules modified by functional materials based on natural inorganic materials in improving the utilization efficiency of loaded active substances and prolonging the life of coatings are foreseen.

Transition metal oxides have been widely used in microwave-absorbing materials, but how to improve impedance matching is still an urgent problem. Therefore, we introduced urea as a polymer carbon source into a three-dimensional porous structure modified by Co₃O₄ nanoparticles and explored the influence of different heat treatment temperatures on the wave absorption properties of the composite. The nanomaterials, when calcined at a temperature of 450 °C, exhibited excellent microwave absorption capabilities. Specifically, at an optimized thickness of 9 mm, they achieved a minimum reflection loss (RL_min) of −97.3 dB, accompanied by an effective absorption bandwidth (EAB) of 9.83 GHz that comprehensively covered both the S and Ku frequency bands. On the other hand, with a thickness of 3 mm, the RL_min was recorded as −17.9 dB, with an EAB of 5.53 GHz. This excellent performance is attributed to the multi-facial polarization and multiple reflections induced by the magnetic loss capability of Co₃O₄ nanoparticles, the electrical conductivity of C, and the unique three-dimensional structure of diatomite. For the future development of bio-based microwave absorption, this work provides a methodology and strategy.

Diatomite (DME) consists of natural ordered porous structures that are excellent candidates as microcontainers. However, to the best of our knowledge, the application of DME loaded with corrosion inhibitors in anti-corrosion coatings has not hitherto been reported. In this study, DME has been used as a source of microcontainers to load benzotriazole (BTA) inhibitor by an immersion method. In order to prevent unwanted early release of the small molecule BTA inhibitor from the DME microcontainers, inspired by the adhesion characteristics of catechol and amine in mussel adhesion protein, polydopamine (PDA) was coated on their surfaces to generate BTA@DME/PDA microcapsules. Because of the depolymerization characteristics of PDA at low pH, the synthesize microcapsules showed a controllable release function. The SEM morphology, chemical structure, and loading capacity of the synthesized BTA@DME/PDA microcapsules were characterized. The corrosion resistances of epoxy coatings with different contents of BTA@DME/PDA microcapsules were compared by saline immersion and electrochemical impedance tests. A scratched coating with 5wt.% BTA@DME/PDA microcapsules showed the best anti-corrosion effect.

In this work, a novel core-shell structure material, NiFe layered double hydroxide (NiFe LDH) loaded on SiO₂ microspheres (SiO₂@NiFe LDH), was synthesized by a one-step hydrothermal method, and the spontaneous electrostatic self-assembly process. The morphology, structure, and microwave absorption properties of SiO₂@NiFe LDH nanocomposites with different NiFe element ratios were systematically investigated. The results show that the sample of SiO₂@NiFe LDH-3 nanocomposite has excellent microwave absorption properties. It exhibits broadband effective absorption bandwidth (RL < −10 dB) of 8.24 GHz (from 9.76 GHz to 18.0 GHz) and the reflection loss is −53.78 dB at the matched thickness of 6.95 mm. It is expected that this SiO₂@NiFe-LDH core-shell structural material can be used as a promising non-precious, metal-based material microwave absorber to eliminate electromagnetic wave contamination.

Recently, the development of composite materials composed of magnetic materials and MXene has attracted significant attention. However, the thickness and microwave absorption performance of the composite is still barely satisfactory. In this work, the C-N@NiFe₂O₄@MXene/Ni nanocomposites were successfully synthesized in situ by hydrothermal and calcination methods. Benefiting from the introduction of the carbon-nitrogen(C-N) network structure, the overall dielectric properties are improved effectively, consequently reducing the thickness of the composite while maintaining excellent absorption performance. As a result, the minimum reflection loss of C-N@NiFe₂O₄@MXene/Ni can reach −50.51 dB at 17.3 GHz at an ultralow thickness of 1.5 mm, with an effective absorption bandwidth of 4.95 GHz (13.02–18 GHz). This research provides a novel strategy for materials to maintain good absorption performance at an ultralow thickness level.

Objective: To evaluate the recognition of acute respiratory infection (ARI) by a pretrained model based on electronic medical records (EMRs). Methods: 38 581 EMRs were obtained from Chongqing University Three Gorges Hospital in December 2021. Bidirectional encoder representation from transformers (BERT) pretrained model was used to identify ARI in EMRs. The results of medical professionals were considered as the gold standard to calculate the sensitivity, specificity, Kappa value, and area under the curve of the receiver operating characteristic (AUC). Results: There were 3 817 EMRs in the test set, with 1 200 ARIs. A total of 1 205 cases were determined as ARI by the model, with a sensitivity of 92.67% (1 112/1 200) and a specificity of 96.45% (2 524/2 617). The model identified ARI with similar accuracy in males and females (AUCs 0.95 and 0.94, respectively), and was more accurate in identifying ARI cases in those aged less than 18 than in adults 18-59 and adults 60 and older (AUCs 0.94, 0.89 and 0.94, respectively). The current model had a better identification of ARIs in outpatient patients than that in hospitalized patients, with AUCs of 0.74 and 0.95, respectively. Conclusion: The use of the BERT pretrained model based on EMRs has a good performance in the recognition of ARI cases, especially for the outpatients and juveniles. It shows a great potential to be applied to the monitoring of ARI cases in medical institutions.

Manganese dioxide@NiFe layered double hydroxide@montmorillonite (MNFM) with a nanoflower-like two-dimensional layered core–shell construction has been successfully synthesized by a two-step hydrothermal method. The structural and compositional influences on its electromagnetic wave (EW) absorption characteristics were discussed. MNFM with 8 mm thickness displayed excellent performance, which showed a minimum reflection loss (RL_min) of −21.8 dB at 15.4 GHz and an effective absorption bandwidth of 4.6 GHz. Meanwhile, RL_min was −13.5 dB at 13. 5 GHz when the thickness was 2.8 mm, and the effective absorption bandwidth was 3.31 GHz. The improved EW absorption performance may be attributed to the multilayer core–shell heterostructure leading to multipole relaxations and the ternary composite with excellent impedance matching. Hence, this work introduces a new idea for constructing core–shell clay-based nanocomposites, which are a promising material for EW absorption.