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SiC‐based porous ceramic wave‐absorbing materials have attracted much attention due to their excellent properties such as low density, high‐temperature resistance, and oxidation resistance. In this work, the impedance matching of SiC ceramics is improved by introducing Si3N4 wave‐transparent phase, and the dielectric loss capability of SiC ceramics is enhanced by introducing FeSi wave loss phase. To achieve a balance between impedance matching and absorption loss in porous ceramics, different molar contents of Al were introduced into FeSi to tailor electromagnetic parameters. The effects of introducing FeAlxSi1−x on the phase composition, microstructure, dielectric loss, and microwave absorption mechanism of SiC–Si3N4 porous ceramics were systematically investigated. When FeAl0.25Si0.75 is added, the minimum reflection loss of the porous ceramics is as low as −58.02 dB, and the flexural strength is as high as 87.23 MPa. The presence of Al promotes the transformation of the Si3N4 crystal and the generation of Al2O3. The introduction of FeAl0.25Si0.75 into SiC–Si3N4 has constructed "inductor–capacitor–resistance" microcircuit, which enhances polarization loss, conductivity loss, and magnetic loss, and realized the double enhancement of the mechanical and wave‐absorbing properties of porous ceramics. [ABSTRACT FROM AUTHOR]

4D printing technology is advantageous for developing new shape memory effects and new functionalities. Herein, a new type of photo-thermal staged-responsive shape memory polymer (SMP) was prepared using fused granular fabrication (FGF) 4D printing technology. The integration of an azobenzene containing oligomer (Bisdi) with commercialized thermal-responsive SMP granules (PEC) resulted in composites (PEC-Bisdi) with good compatibility and higher thermal stability, suitable for FGF 4D printing. The granules made from the composite can also be used directly in the FGF printing technology. The specimens named PEC-Bisdi printed by FGF illustrated excellent photo-thermal staged responses with ultraviolet light (UV) responsive bending, thermal-responsive shape recovery, and good fixation at room temperature. The FGF-printed specimens also displayed good mechanical properties with up to 380% elongation at break and a 1.5 GPa glassy storage modulus. The influences of material factors and printing parameters were systematically investigated and the results showed an increase in the curvature of the spline as a function of Bisdi content and elongation, while a decrease was recorded as a function of the spline thickness. The optimal printing parameters for the highest curvature were determined to be an extrusion rate of 140, an extrusion temperature of 230 °C, a routing rate of 80, and a parallel infill pattern. Overall, the proposed PEC-Bisdi composites showing programmable and remotely controllable shape memory capabilities have the potential for use in advanced engineering and soft robotics. [ABSTRACT FROM AUTHOR]

In this study, high-performance zirconium carbide (ZrC) ceramics prepared by gel-casting method were reported for the first time. A water-based slurry with 40 vol% solids was prepared using TMAH and PVP as dispersants, and the resulting green body had a flexural strength of 21.11 ± 1.84 MPa after curing, which was sufficient for machining. Dense ZrC ceramics (relative density >97 %) were obtained by sintering at 2000 °C under atmospheric pressure, and a 387 ± 23.21 MPa flexural strength and 15.48 ± 0.28 GPa hardness were achieved. This study offers a new strategy for preparing ZrC ceramics with complex structures. [ABSTRACT FROM AUTHOR]

Simultaneous partial nitrification, anammox, denitrification, and fermentation (SNADF) is a novel process achieving simultaneous advanced sludge reduction and nitrogen removal. The influence of low temperatures on the SNADF reactor was explored to facilitate the application of mainstream anammox. When temperature decreased from 32 to 16 °C, efficient nitrogen removal was achieved, with a nitrogen removal efficiency of 81.9–94.9%. Microbial community structure analysis indicated that the abundance of Candidatus Brocadia (dominant anaerobic ammonia oxidizing bacteria (AnAOB) in the system) increased from 0.03% to 0.18%. The abundances of Nitrospira and Nitrosomonas increased from 1.6% and 0.16% to 2.5% and 1.63%, respectively, resulting in an increase in the ammonia-oxidizing bacteria (AOB) to nitrite-oxidizing bacteria (NOB) abundance ratio from 0.1 to 0.64. This ensured sufficient nitrite for AnAOB, promoting nitrogen removal. In addition, Candidatus Competibacter, which plays a role in partial denitrification, was the dominant denitrification bacteria (DNB) and provided more nitrite for AnAOB, facilitating AnAOB enrichment. Based on the findings from microbial correlation network analysis, Nitrosomonas (AOB), Thauera, and Haliangium (DNB), and A4b and Saprospiraceae (fermentation bacteria), were center nodes in the networks and therefore essential for the stability of the SNADF system. Moreover, fermentation bacteria, DNB, and AOB had close connections in substrate cooperation and resistance to adverse environments; therefore, they also played important roles in maintaining stable nitrogen removal at low temperatures. This study provided new suggestions for mainstream anammox application. [ABSTRACT FROM AUTHOR]

This paper introduced the degradation mechanism and research status of cellulose acetate biodegradation, hydrolysis, and photolysis. The factors that affect the degradation rate of cellulose acetate were explored. Based on the current studies, the molecular structure of cellulose acetate was the main factor that affects the degradation rate of cellulose acetate. The physical modification, chemical modification, and plasticizing modification affected the degradation performance of cellulose acetate through changing the molecular structure of cellulose acetate. Finally, the application fields of acetate fiber were summarized and its prospect was analyzed. [ABSTRACT FROM AUTHOR]