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Electrochemical CO2 conversion offers a sustainable approach to alleviate the energy crisis but remains a long-standing challenge. Herein, atomically dispersed FeN5 sites anchored on N-doped carbon matrix templated by zeolitic imidazole framework-8 (ZIF-8) are facilely synthesized for efficient catalyzing CO2 reduction. The FeN5 single-atom catalyst (Fe-SA/ZIF) presents the Faradaic efficiency of 98% at −0.7 V vs. RHE and over 95% in a wide potential range from −0.4 to −1.0 V vs. RHE, surpassing most of the reported single-atom catalysts for CO2RR. Further density functional theory (DFT) calculations reveal that the outstanding activity of FeN5 sites mainly originates from the lowered d-band center modulated by the out-of-plane coordinated pyridinic N, which reduces the CO adsorption energy from −1.71 to −1.49 eV compared to FeN4 moieties. Thus, the synergistic effect between FeN4 sites and the coordinated pyridine offers new insight in designing outstanding electrocatalysts for multiple applications.

The dynamic response and the failure of the different composite structures subjected to impulsive loadings are performed experimentally with metallic foam projectile. The composite lattice core based sandwich structure is reinforced with polyurethane foam and shows a significant improvement in impulsive mitigation. The effects of core and loading intensity are carried out to identify and quantify the dynamic response, failure mode, and energy absorption efficiency of the composite structures. The results show that the foam filled lattice sandwich has an outperformed deflection resistance and remains better intact due to the loading transferring and weak effect of localization of the out-of-plane deflection. Although the energy absorption efficiency per unit mass of the lattice/foam sandwich is lower, the energy absorption capacity of the structure is confirmed to have been improved significantly, and the difference in the efficiency decreases noticeably with the increasing impulsive intensities. Both the sandwich structures have superior performance of impulsive resistance in comparison with the composite laminate.

The Chinese mitten crab (Eriocheir Sinensis) is a popular aquatic product in China. However, these crabs accumulate heavy metals from the ecosystem. The occurrence, source, and risk assessment of heavy metals in crabs from the main production area in China were investigated. The abundance of the metals in crabs was Mn >> As > Se > Ni > Cr > Cd > Pb> Hg. Each metal was present at a level less than the national standard (A standard for the limits of contaminants in food from China). Agricultural activities, industrial discharges, and urban sewage were the three main sources of heavy metals accumulation in Chinese mitten crab. Based on an assessment of the target hazard quotient (THQ), arsenic is the most harmful heavy metal in the crabs. In addition, mercury and lead also pose risks. The results indicate that the estimated daily intake (EDI) of mitten crabs in China would not pose a high dietary risk. (THQ

Multiscale hybrid method is reported to enhance thermal ablative and insulative properties of lightweight ablative materials in high temperature oxidation extreme environment. A novel lightweight hybrid carbon-quartz fiber fabric reinforced phenolic-silica (C-QF/PSi) aerogel nanocomposite was fabricated through impregnation using C-QF hybrid needled felt as three-dimensional reinforcement and PSi hybrid aerogel as matrix. The prepared aerogel nanocomposite perfectly inherits their nanoporous microstructure and fascinating properties, resulting in remarkable high compressive strength (5.96–17.01 MPa), low thermal conductivity (~0.112 W/(mK)). In particular, good thermal ablative and insulative properties in oxy-acetylene oxidizing flame (linear ablation rate as low as 0.017 mm/s and internal temperature peaks below 100 °C at 80 mm in-depth position when the surface temperature exceeds 2000 °C). From mentioned above, this lightweight composite presents huge application prospects in thermal protection and heat insulation field, especially in aerospace industry.

Although considerable progress has been achieved by Cu nanoparticles for catalyzing CO2 reduction reaction (CO2RR), Cu single atom catalysts (Cu SACs) are generally suffered from inferior performance to that of widely investigated Fe, Co, Ni SACs. This phenomenon mainly ascribes to the lack of effective geometry and electronic engineering of copper active center from an atomic level. Herein, highly exposed atomically dispersed Cu-Nx (x denotes Cu–N coordination number) sites anchored on 3D porous carbon matrix are successfully synthesized through facile one step thermal activation, and Cu-N4 sites exhibit boosted activity and selectivity compared to its nearly inert Cu-N3 counterparts. Aided by density functional theory (DFT) calculations, the edge-hosted Cu-N4 moieties are revealed as key active sites for efficient CO generation via optimized local coordination environment and electronic properties, which strongly interact with *COOH intermediate and facilitate the desorption of *CO. As a result, Cu-N4 catalyst achieves high CO Faradaic efficiency (FECO) of over 90% from −0.6 to −1.1 V vs. RHE with a maximum value of 98%, surpassing the previously reported Cu SACs for CO2-to-CO conversion. This work provides new insight into proper Cu SACs design and fundamental mechanism understanding to boost CO2RR.

Quasi-static and dynamic compressive tests are undertaken on the polyurethane (PU) foam and fumed silica reinforced polyurethane (PU/SiO2) foam experimentally. The ceramic microspheres with varying mass fractions are adopted to mix with the PU/SiO2 foam to fabricate the composite particle-reinforced foams. The effects of strain rate and particle mass fraction are discussed to identify and quantify the compressive response, energy-absorbing characteristic, and the associated mechanisms of the composite foams. The results show the initial collapse strength and plateau stress of the foams are improved significantly by reinforcing with the ceramic microsphere within 60 wt% at quasi-static compression. The rate sensitivity is observed on all the foams, but in different patterns due to the influence of ceramic microsphere. The compressive response affected by ceramic microsphere can be attributed to the particle cluster effect and stress wave propagation. Together with the deformation, the compressive characteristic experiences non-monotonic change from the low to high strain rates. The specific energy absorption (SEA) of the foam with 41 wt% ceramic microsphere show the largest magnitude at quasi-static compression. With the increasing strain rate, the ceramic reinforced foam exhibits superior energy absorption efficiency at high strain rates to that of the pure foams.

The ceramic particle reinforced foam-filled carbon fiber reinforced composites sandwich unit cell subjected to quasi-static and dynamic compressions are studied experimentally. The weight fraction of the ceramic particle is discussed to analyze its effect on the failure and energy absorption of the composite cells. The results show that the failure modes and energy absorption mechanisms of the cell are influenced significantly by the strain rate and ceramic particle reinforcement effects. The cluster of the particle makes the strut experience node failure under impulsive loadings, not the strut buckling and fracture shown at other cells. The mechanical property, especially the plateau stress, is enhanced noticeably as the foam is reinforced with the higher weight fraction of ceramic particles. The filling foams improve the impact resistance of the cells by transmitting less impulses and absorbing more energy. With a higher energy absorption efficiency, the foam-filled cell with higher weight fraction of ceramic particle has the highest energy absorption capacity under the quasi-static compression. Under the impulsive loading, the increasing ceramic particles can reduce the transmitted impulse, but cannot absorb additional energy.

In this research, fan-shaped ZnMoO4 is deposited on flower-like ZnCo2O4 nanowire arrays by two-step hydrothermal method. ZnCo2O4 nanowire is synthesized first and used as the backbone to support ZnMoO4. The flower-like ZnCo2O4 nanowire arrays are fully overspread by ZnMoO4. And this unique structure shows a high capacitance of 1506 F g−1 when used as electrode for supercapacitor at a current density of 1 A g−1 and a good cycling ability (5000 cycles).