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In this work, flaky aluminum was coated with bismuth oxide to obtain low reflection in near-infrared range and low emission in long-wave infrared stealth material. The composites were prepared through coprecipitation method, characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), and measured by ultraviolet spectrophotometer and dual band infrared emissometer. The morphology and microstructure show that the flaky aluminum was coated by bismuth oxide nanoparticles. The optimal reaction temperature was 50 °C, and the optimized amount of Al was 20 wt%. Meanwhile, the infrared emissivity in 8–14 μm infrared waveband range was 0.462 and the reflectivity was 39.1% at wavelength of 1.064 μm. In addition, it could also achieve good thermal insulation in a thinner thickness. When the temperature of heating platform reached 100 °C, the temperature of the disk with 0.30 mm thickness was 26.9 °C which was only 2.7 °C higher than that of the disk with 0.94 mm thickness. It may shed light on a new material design orientation to obtain high performance infrared and laser compatible stealth materials. [ABSTRACT FROM AUTHOR]

Background: The dysregulation of circular RNAs (circRNAs) has been identified in various human diseases, including osteoarthritis (OA). The purpose of this study was to identify the role and mechanism of circ_SLC39A8 in regulating the progression of OA. Methods: The expression levels of circ_SLC39A8, miR-591, and its potential target gene, interleukin-1-receptor-associated kinase 3 (IRAK3), were identified by quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability and apoptosis were determined by Cell Counting Kit-8 (CCK-8) assay and flow cytometry, respectively. The relationship between miR-591 and circ_SLC39A8 or IRAK3 was predicted by bioinformatics tools and verified by dual-luciferase reporter. Results: Circ_SLC39A8 and IRAK3 were upregulated and miR-591 was downregulated in OA cartilage tissues. Knockdown of circ_SLC39A8 inhibited apoptosis and inflammation in OA chondrocytes, while these effects were reversed by downregulating miR-591. Promotion cell viability effects of miR-591 were partially reversed by IRAK3 overexpression. Conclusion: Our findings indicated that knockdown of circ_SLC39A8 delayed the progression of OA via modulating the miR-591-IRAK3 axis, providing new insight into the molecular mechanisms of OA pathogenesis. [ABSTRACT FROM AUTHOR]

In this paper, nanosized ZnFe 2 O 4 with different morphologies were prepared by electrospinning method. The choice of initial parameters, such as PVP concentration, metal salt concentration, electrostatic voltage, calcination temperature and calcination rate, were investigated to prepare desired morphologies. The as-prepared samples exhibited various shapes of nano-particle, nano-rods, nano-beads and nano-fiber. The relationship between microstructure and electromagnetic properties was discussed in detail. It has been found that the saturation magnetization of ZnFe 2 O 4 ferrite not changed significantly with the various morphologies and the values were nearly 13 emu/g. However, the coercivity was varied with the different morphologies, and the maximum value of 48.79 Oe was observed in the ZnFe 2 O 4 nano-fiber. Moreover, the magnetic loss capacity of ZnFe 2 O 4 was improved with the enhancement of the morphology anisotropy. The various shaped ZnFe 2 O 4 can be promising lightweight microwave absorbers and it is significant to develop novel microwave absorption mechanism of ZnFe 2 O 4 ferrite. [ABSTRACT FROM AUTHOR]

In this work, an Al powder was coated with antimony-doped tin oxide (ATO) to obtain an infrared-laser compatible stealth material. The composites are prepared via a coprecipitation method, characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), and measured by ultraviolet spectrophotometer and dual band infrared emissometer. The morphology and microstructure show that the flaky Al powder was coated by the ATO nanoparticles and doped into the SnO 2 rutile structure by an Sb5+ ion. The optimal Al content was 20%, and the optimized Sn/Sb molar ratio was 10: 1. Meanwhile, the reflectivity of the composites was 43.454%, and the infrared emissivity in 8–14 μm far infrared waveband range was 0.708. It may shed light on a new material design orientation to obtain high performance laser-infrared compatible stealth materials. [ABSTRACT FROM AUTHOR]

Abstract Based on the superior semiconducting and dielectric properties of traditional ZnO microwave absorbers, we report a significant enhancement of microwave absorption performance using a bead-like Co doping technique with an optimized morphology, fewer functional defects and multiple electromagnetic loss mechanisms. The bead-like ZnO is prepared by electrospinning and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), X-ray photoelectron spectroscopy (XPS) and vector network analyzer (VNA). The results show that the phase composition of ZnO is not changed, but lattice shrinkage and defects are caused by the Co doping. The as-prepared Co-doped ZnO exhibits ferromagnetic properties and excellent electromagnetic loss performance. The dielectric loss is caused by interfacial polarization and dipole polarization. The magnetic loss is derived from magnetic hysteresis loss and residual loss. The optimal microwave absorption properties are obtained when the Co doping content is x = 0.09. The effective microwave absorption bandwidth with reflection loss less than − 10 dB can reach 11.6 GHz (6.4–18 GHz) at a coating thickness of 1.0–4.0 mm. This study demonstrates a promising method to improve the microwave absorption properties of ZnO. [ABSTRACT FROM AUTHOR]