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(1‐x)Na2WO4–xNi0.2Cu0.2Zn0.6Fe2O4 (NWO‐NCZO) ceramic composites (x = 0–0.6) were successfully prepared by the cold sintering method under a uniaxial pressure of 200 MPa at 150°C for 30 min. The microstructures and electromagnetic properties of (1‐x)NWO‐xNCZO ceramic composites with different NCZO contents have been systematically investigated. The obtained biphasic NWO‐NCZO ceramic composites possess dense microstructures. The 0.4NWO–0.6NCZO ceramic composite exhibits a matched relative permittivity and relative permeability of around 8 in the frequency range from 10 to 200 MHz, which is beneficial for impedance matching between antenna and free space. A prototype of microstrip antenna based on the developed NWO‐NCZO ceramic composite is designed and to demonstrate its application in miniaturized antennas. The simulation results revealed that the size of the radiation patch of the antenna can be reduced by 60% yet with bandwidth being enhanced 26.5 times when the 0.4NWO–0.6NCZO ceramic composite is selected as the substrate instead of pure NWO ceramic. [ABSTRACT FROM AUTHOR]

Diamond coating has gained intensive attraction in the tribological field due to its high hardness. However, its weak flexibility always gives rise to the fragile crack, which causes the delamination and peeling off from substrate. In this work, a novel deposition method combining the conventional hot filament chemical vapor deposition (HFCVD) and particles doping technique is proposed to balance the hardness and flexibility of diamond coating, by which the diamond coating with tungsten particles is deposited on the co-cemented tungsten carbide substrate. The as-deposited diamond coating is characterized by scanning electron microscopy (SEM) analysis, surface roughness and Raman spectrum. The indentation tests are conducted to evaluate the crack propagation of diamond coating. Tribological behavior is examined on a reciprocating ball-on-plate tribometer. The results indicate that tungsten carbide may be formed between tungsten particles and diamond coating. The W–WC–amorphous carbon–diamond structural coating can validly inhibit the crack propagation and decrease the friction coefficient. Hence, adding embedding particles into the diamond coating may provide a useful way in enhancing the mechanical properties of diamond coating. [ABSTRACT FROM AUTHOR]

A series of (Fe 2. 2 Mn 0. 8 Cu x ) 1 − δ O4 (x = 0 , 0.2, 0.5, and 0.8) was synthesized for elemental mercury capture. The as-synthesized adsorbents were characterized by Brunauer–Emmett–Teller (BET), powder X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The experimental results show that (Fe 2. 2 Mn 0. 8 Cu 0. 5 ) 1 − δ O4 catalyst adsorbent exhibits the best elemental mercury capture capacity with the increase in mercury removal efficiency by 20% as compared to the (Fe 2. 2 Mn 0. 8 ) 1 − δ O4 adsorbent. The XPS results indicate Cu dopant can provide the lattice oxygen on the adsorbent surface due to the transformation from Cu 2 + cations to Cu + cations, which increases the active sites for elemental mercury adsorption. The Mn 4 + cations on the adsorbent surface may oxidize the adsorbed mercury to mercury oxidization. Meanwhile, the Mn 3 + cations formed are also oxidized to the Mn 4 + cations by the gaseous oxygen phase in the reactor gas. However, the large Cu content may block the collision between Mn 4 + cations and adsorbed mercury, and thus decrease the oxidization capability of adsorbent surface for mercury. Therefore, the Cu dopant with the suitable content may be a potential modified method for the adsorbent to further increase the elemental mercury capture. [ABSTRACT FROM AUTHOR]

Copper oxide (CuO) is proved to be a potential adsorbent for elemental mercury in the flue gas emitted from coal-fired power plant. However, the O-terminated CuO(110) surface has relatively week adsorption capacity for Hg. In this work, the doped method is applied to enhance the mercury adsorption capacity of O-terminated CuO(110). Mn, Si, Ti, Al and Zn are selected as the doped atom. It is found that only Zn-doped CuO (110) surfaces have the higher adsorption energy than the pure O-terminated CuO(110) surface. The mercury adsorption capacity is a complex issue, which depends on a combination of oxygen and doped element. The results suggest that the lower electropositive doped element is favorable for the improvement of mercury adsorption capacity. However, the lower electronegativity of oxygen atoms does not facilitate the mercury capture, which is different from the organic material. Cu and doped metal element, rather than oxygen atom, mainly determine mercury adsorption capacity of O-terminated CuO(110) surface, which leads to the lower adsorption capacity of the O-terminated CuO(110) surface than the Cu-terminated CuO(110) surface. The conclusions can also offer a valuable reference for the other metal oxide regarding mercury capture. [ABSTRACT FROM AUTHOR]

Interaction potential plays a vital role on the friction. Potential energy of two contacts directly determines on the friction force. However, many mathematic models proposed, always abandon the instantaneous status during sliding to devote to a weighted average over lateral force, which might miss some information about friction behavior. In this work, the relation among potential energies, separation distances of two contracts, and positions in the sliding direction are studied to evaluate the instantaneous friction characteristics. Two hydrogenated diamond surfaces are used as the examined model. The results show that a watershed between positive and negative friction forces locates at the position with the minimum adsorption energy. A rapid decrease in potential energy occurs near the 2.5 nN external force, where the friction coefficient approaches zero at each position in the sliding direction. Therefore, a novel method may be developed to greatly reduce the friction coefficient between two surfaces by adjusting the contract pressure. [ABSTRACT FROM AUTHOR]

The electronic and optical properties of -doped 3- films are investigated by the first-principles calculation. The structure of -doped 3- is modeled by substituting atom for or atom in 3- lattice. The results suggest that - and - bonds can exist in the -doped 3-. location in 3- lattice significantly affects the crystal structure of -doped 3-, and the atom substitution for or sites of 3- lattice can induce to the difference of indirect or direct band structure. The calculated results also show that some new impurity energy levels occur in the band gap of -doped 3-, and the imaginary part of dielectric function of -doped 3- shifts toward the infrared region in comparison with the primitive 3-. The adsorption spectrum of -doping 3-, due to the transition of electrons between 3d states, presents some new prominent peaks at low frequency. These results can further confirm -doped 3- to act as a potential material for optical applications. [ABSTRACT FROM AUTHOR]