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In saline soil areas, the concrete piers of concrete bridges experience long-term corrosion, mainly caused by chloride salts due to alternating temperature changes. Waterborne concrete coatings are prone to failure in this aggressive salt environment. Implementing coating protection measures can improve the durability of concrete and enhance the service life of bridges. However, the effectiveness and longevity of coatings need further research. In this paper, three types of waterborne concrete anti-corrosion coatings were applied to analyze the macro and micro surface morphology under wet–dry cycles and long-term immersion conditions. Various indicators such as glossiness, color difference, and adhesion of the coatings were tested during different cyclic periods. The chloride ion distribution characteristics of the buried concrete coatings in saline soil, the macro morphology analysis of chloride ion distribution regions, and the micro morphology changes of the coatings under different corrosion times were also investigated. The results showed that waterborne epoxy coatings (ES), waterborne fluorocarbon coatings (FS), and waterborne acrylic coatings (AS) all gradually failed under long-term salt exposure, with increasing coating porosity, loss of internal fillers, and delamination. The chloride ion content inside the concrete decreased with increasing depth at the same corrosion time, while the chloride ion content at the same depth increased with time. The chloride ion distribution boundary in the cross-section of concrete with coating protection was not significant, while the chloride ion distribution boundary in the cross-section of untreated concrete gradually contracted towards the concrete core with increasing corrosion time. During the corrosion process in saline soil, the coatings underwent three stages: adherence of small saline soil particles, continuous increase in adhered material area, and multiple layers of uneven coverage by saline soil. The failure process of the coatings still required erosive ions to infiltrate the surface through micropores. The predicted lifespans of FS, ES, and AS coatings, obtained through weighted methods, were 2.45 years, 2.48 years, and 2.74 years, respectively, which were close to the actual lifespans observed in salt environments. The developed formulas effectively reflect the corrosion patterns of different resin-based coatings under salt exposure, providing a basis for accurately assessing the corrosion behavior and protective effectiveness of concrete under actual environmental factors. [ABSTRACT FROM AUTHOR]

Objective To research the feasibility and preliminary clinical effect of an implant ⁃ supported fixed bridge based on interactions with the posterior interocclusal space deficiency. Methods Four patients with multiple implant⁃supported fixed⁃bridge restorations for interocclusal space deficiency in posterior teeth were included in this study. The 8 total implant sites had an average interocclusal space size of 3.3 mm. Two abutments with an undercut area were performed, the fixed bridge was placed by rotating it without a common path of insertion, and the abutment screw was then tightened. In the production process, the interaction retention concept and methods were fully communicated to the technician. The abutments and bridges on the implants were placed, and the clinical effect was observed. Re⁃ sults The prosthesis was fixed well and presented appropriate functioning. At the 3⁃month and 18⁃month follow⁃up ex⁃ amination, the prosthesis and abutments were not loose, and the abutments did not release or break. No swelling or ten⁃ derness was observed in the margin of the implants. Conclusion The interaction retention is a good method of resolv⁃ ing the problem of interocclusal space deficiencies in the posterior teeth.

A copper‐mediated C(sp2)−H chalcogenation of heterocycles with readily available dichalcogenide, benzeneselenol and thiol is described. This protocol demonstrates scalability, good chemo‐ and regio‐selectivity, as well as broad functional group tolerance, which overall provides an accessible method to valuable aryl chalcogenides. The chalcogenated picolinamide products could be further transformed into selenoxanthones and thioxanthone scaffolds through intramolecular cyclization via a semi‐one pot process. [ABSTRACT FROM AUTHOR]

A magnetite mortar microwave-absorbing layer that could be applied to concrete pavement was studied to improve the deicing efficiency of roads in low-temperature conditions. The magnetite cement mortar (MCM) was prepared by using magnetite as the main absorbing material. The microwave absorption ability and heating characteristics of MCM with different magnetite contents were investigated. In addition, the mechanical and durability properties of MCM were studied. Furthermore, a microwave-absorbing layer was prepared and tested for outdoor field deicing. The result showed that adding magnetite effectively improved the mechanical strength and frost resistance of MCM, which could improve its load resistance and service life. Meanwhile, the microwave absorption ability of MCM was also improved with the increase of magnetite content. At the microwave frequency of 2.45 GHz, the average heating rate of MCM with 80% magnetite content was 2.27 times than that of ordinary cement mortar. In addition, the content of magnetite was positively correlated with the heat transfer ability of MCM. Magnetite conversion of microwave energy into heat energy could quickly transfer heat to the whole mortar system. The field deicing test verified the feasibility of efficiently deicing a magnetite mortar microwave-absorbing layer in low temperature conditions. [ABSTRACT FROM AUTHOR]

In this study, a novel ultra-broadband absorber is suggested and numerically analyzed to demonstrate that the suggested absorber can achieve an average absorbance of 98.6% in the visible to near-infrared wavelength range (496–2100 nm). The structure of the proposed new ultra-wideband absorber consists of four thin films of silicon dioxide (SiO2), iron (Fe), magnesium fluoride (MgF2), and chromium (Cr). We have examined the structure's electromagnetic field intensity distribution at numerous selected optical wavelengths and the influence of various structural parameters on the absorption performance of the absorber to offer a physical mechanism underlying the ultra-broadband absorption effect. Furthermore, in the presence of high-performance absorption, the structure has the effect of stabilizing absorption at large angles of incidence and is polarization-independent at vertical angles of incidence. The study also assesses the solar absorption capability of this structure, indicating that the structure has potential applications in solar absorption, such as solar energy collection and conversion, solar power generation, and thermal emitters. [ABSTRACT FROM AUTHOR]