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The borate glass 35B2O3–25SiO2–25Na2O-10ZnO3–5BaO (in wt.%) formed the basis for the glass system employed in this study. In air at various pressures and temperatures, 96 wt.% pure alumina ceramics (96 Al2O3) were brazed together using glass solder. At the same time, the wettability of the glass on the Al2O3 ceramics is researched at different temperatures and pressures. The results demonstrated that the contact angle of glass on Al2O3 ceramics was decreased with the temperature increasing, and attached 18 degrees as temperature was 580 °C with holding 120 mins. It was also concluded that the bubbles in the glass solder were changed from round to oval and the quantity was decreased with the pressure increasing. Furthermore, the thickness of the glass solder was decreased with the pressure and temperature. When the pressure was changed from 5 kPa to 20 kPa at 560 °C welding temperature, thickness of glass solder is decreased from 22.3 μm to 8.5 μm. Upon increasing the temperature at 10 Kpa, the thickness of glass solder was from 23.74 μm to 6.2 μm. The EDS analysis for Al2O3/glass/Al2O3 joints boned at 560 °C under 20 kPa and 580 °C under 10 kPa, respectively. The elements Si and O were observed in joint domain that penetrated into alumina ceramic layer forming the interface layer with ceramic substrate thoroughly.

Prefabricated MAX (Ti3SiC2, Ti3AlC2) phase coating materials with coefficient of thermal expansion Si and SiC as transition layers and excellent high-temperature antioxidant properties were used for ultra-high-speed laser melting on the surface of carbon/carbon composites, so that the produced coatings have good interfacial bonding and high-temperature antioxidant properties. In this study, we characterised and analysed the microscopic morphology and composition of the sample coatings using X-ray diffraction and scanning electron microscopy, investigated their interfacial bonding properties by scratch tests and studied the high temperature oxidation resistance of the samples at 1773 K for 1 h. The results show that the bonding strength between the coating and the substrate is good, the surface is flat without flaking, the coating thickness can be controlled below 60 μm, the microstructure is dense, and there is no obvious deformation or failure of the substrate, and the dense coating formed by laser melting has strong oxidation resistance, so that the substrate carbon/carbon composite is well protected at high temperature.

First time study for development of relationship between design and fabrication of thin film narrow-pass filters simulated using the Essential Macleod optical coating design program and verified through experimental data. In thin film narrow band-pass filter's design, can design better filter by changing some parameters, but the theoretical designs are often difficult to achieve. The sensitivity of thin film narrow band-pass filters are mainly influenced by the refractive index of cavity layers, number of mirror layers, interference order and number of cavities. Based on analysis of all these aspects, laws of influence are obtained. A narrow band-pass filter with super wide rejection band was designed and fabricated to verify the simulation results, showing a good agreement between the experimental and theoretical observations.

For further investigating the role of components in copper-cerium-barium composite oxide catalysts, a series of noble metal-free catalysts with different barium contents were synthesized by citric acid method. The prepared catalysts were characterized by X-ray diffraction, Brunauer-Emmett- Teller method, scanning electron microscopy, Raman spectroscopy, and Fourier transform infrared spectroscopy. Catalysts were evaluated by NO oxidation, NOx adsorption, and NOx temperature-programmed desorption. The results showed that barium content significantly affected the catalysts' properties. With barium addition, interactions among components considerably changed; hence, the microstructure and performance of catalysts were distinctly different. In general, the interactions of barium-copper and barium-cerium were not conducive to catalyst adsorption. Adsorption performance derived from barium carbonate was superior to those of the other two components.

Cu3SbSe4, featuring its earth-abundant, cheap, nontoxic and environmentally-friendly constituent elements, can be considered as a promising intermediate temperature thermoelectric (TE) material. Herein, a series of p-type Bi-doped Cu3Sb1 − xBixSe4 (x = 0-0.04) samples were fabricated through melting and hot pressing (HP) process, and the effects of isovalent Bi-doping on their TE properties were comparatively investigated by experimental and computational methods. TEM analysis indicates that Bi-doped samples consist of Cu3SbSe4 and Cu2 − xSe impurity phases, which is in good agreement with the results of XRD, SEM and XPS. For Bi-doped samples, the reduced electrical resistivity (ρ) caused by the optimized carrier concentrations and enhanced Seebeck coefficient derived from the densities of states near the Fermi level give rise to a high power factor of ~ 1000 µWcm− 1K− 2 at 673 K for the Cu3Sb0.985Bi0.015Se4 sample. Additionally, the multiscale defects of Cu3SbSe4-based materials involving point defects, nanoprecipitates, amorphous phases and grain boundaries can strongly scatter phonons to depress lattice thermal conductivity (κlat), resulting in a low κlat of ~ 0.53 Wm− 1K− 1 and thermal conductivity (κtot) of ~ 0.62 Wm− 1K− 1 at 673 K for the Cu3Sb0.98Bi0.02Se4 sample. As a consequence, a maximum ZT value ~ 0.95 at 673 K is obtained for the Cu3Sb0.985Bi0.015Se4 sample, which is ~ 1.9 times more than that of pristine Cu3SbSe4. This work shows that isovalent heavy-element doping is an effective strategy to optimize thermoelectric properties of copper-based chalcogenides.

This paper presents a novel thermopile chip in which the resonant cavity structure was fully utilized as an absorber by an optical design. The resonant cavity absorber structure was designed using Al as anthe bottom reflective metal layer, air as the intermediate dielectric layer, and SiO2/TiN/Si3N4 sandwich layers as the top absorption layer, while the bottom reflective metal (Al) was deposited on the cold junctions of the thermopile. The simulation and calculation results show that the thermopile chip with resonant cavity absorber structure not only has great infrared absorption in the wide infrared absorption range but also can effectively prevent the cold junctions from absorbing infrared radiation and inhibit the rise of temperature. As a result, the temperature difference between the hot junctions and the cold junctions is increased, and the responsivity of the thermopile chip is further improved. Moreover, the duty cycle of the thermopile chip is greatly improved due to the double-layer suspension structure. Compared with the traditional thermopile chip structure, the sizes of the thermopile chip with the resonant cavity absorber structure can be further reduced while maintaining responsivity and specific detectivity.

The wetting of molten Sn-3.5Ag-0.5Cu alloy on the Ni-P(-SiC) coated SiCp/Al substrates was investigated by electroless Ni plating process, and the microstructures of the coating and the interfacial behavior of wetting systems were analyzed. The SiC particles are evenly distributed in the coating and enveloped with Ni. No reaction layer is observed at the coating/SiCp/Al composite interfaces. The contact angle increases from ∼19° with the Ni-P coating to 29°, 43° and 113° with the corresponding Ni-P-3SiC, Ni-P-6SiC and Ni-P-9SiC coatings, respectively. An interaction layer containing Cu, Ni, Sn and P forms at the Sn-Ag-Cu/Ni-P-(0,3,6)SiC coated SiCp/Al interfaces, and the Cu-Ni-Sn and Ni-Sn-P phases are detected in the interaction layer. Moreover, the molten Sn-Ag-Cu can penetrate into the Ni-P(-SiC) coatings through the Ni-P/SiC interface and dissolve them to contact the SiCp/Al substrate.

Reduced graphene oxide (RGO)-loaded flower-like ZnCo2O4 nanohybrid (ZnCo2O4/RGO) was prepared and then used as counter electrode (CE) in dye-sensitized solar cells (DSSCs). Scanning electron microscopy showed that the flower-like structure of ZnCo2O4 was made up of a large number of thin nanosheets and that the RGO sheets reunited with ZnCo2O4 together commendably. The results and analysis illustrated that the distinctive ZnCo2O4 structure provided numberous catalytic reaction sites and that the RGO sheets served as a guide way to accelerate the transmission of electrons. Benefited from the synergetic effect of ZnCo2O4 and RGO, the ZnCo2O4/RGO nanohybrid exhibited excellent electrocatalytic performance. Finally, a competitive power conversion efficiency (PCE) of 7.22% was achieved for the DSSCs based on the ZnCo2O4/RGO nanohybrid CE.

Two percentages of TiB + TiC reinforced Ti-6Al-4V composites from Ti-B4C-C and Ti-TiB2-TiC systems were fabricated by reactive hot-pressed sintering. Their microstructures and mechanical properties involving elastic modulus, Vickers hardness, bending strength and wear property were investigated comparatively. The experimental results show that needle-like TiB whiskers and near-equiaxed TiC particles are evenly distributed in the Ti-6Al-4V matrix. The mechanical properties of the (TiB + TiC)/Ti-6Al-4V composites are closely related with the nominal composition and synthesis system of TiB + TiC reinforcement and the microstructures of composites. With increasing the nominal volume fraction of reinforcement, both elastic modulus and Vickers hardness increase more or less and the bending strength decreases in varying degrees. A certain increase of pores in the composites with the sintering temperature increasing to 1300 °C can markedly affect the bending strength. Moreover, no matter what the sintering temperature and nominal volume fraction of reinforcement, the elastic modulus and Vickers hardness of composites from the Ti-TiB2-TiC system are higher than those from the Ti-B4C-C system. Similarly, the composites from the Ti-B4C-C system present better abrasion resistance than those from the Ti-TiB2-TiC system due to the difference of interfacial bonding between the TiC particles and Ti-6Al-4V matrix in the two kinds of composites.

6H-SiC (0001) monocrystal substrates were implanted with 20 keV Pd ions at three doses of 5 × 1015, 5 × 1016 and 5 × 1017 ions/cm2 at room temperature. The surface characteristics of Pd-implanted SiC substrates were analyzed by Monte Carlo simulation software SRIM-2008 and Raman spectroscopy. The effects of the Pd ion implantation into the monocrystal substrate and of the Si additions (4.8, 11.6, 19.4 and 29.2 at.%) into Al on wettability of Al/6H-SiC system were investigated using the sessile drop technique in a high vacuum at 1323 K, and the surface and interfacial behaviors were analyzed and discussed. The experimental results showed that the equilibrium contact angle of Al/SiC system increased with increasing Pd implantation dose, which can be mainly attributed to the decreasing interfacial interactions between the Al drop and the SiC substrate. However, the Si concentration had an opposite effect on the wettability of Al/SiC system when the Si concentration was higher or less than the equilibrium Si content of Al-Si/SiC system, which can be related to the variation of σSL of Al-Si/SiC system with the Si content.

Cu3SbSe4, consisting of earth-abundant and inexpensive elements, is a promising p-type thermoelectric (TE) material. However, its thermoelectric performance is low in comparison with typical Pb-based materials. Here, we tune Ag content to optimize synergistically electrical and thermal transport properties for achieving high TE performance of Bi-doped Cu3SbSe4 materials. Dual-incorporation of Bi and Ag spontaneously generates multiple secondary phases involving CuSe and AgSbSe2. The multiscale defects including point defects, dislocations, nanoprecipitates and grain boundaries can enhance phonon scattering, thereby obtaining a low thermal conductivity (κ) of ~ 0.67 W m−1 K−1 at 673 K. The carrier concentration is improved due to the enhanced Cu vacancies caused by softening of Cu 3d–Se 4p bond after Ag doping, leading to the obviously increased electrical conductivity (σ). Meanwhile, the heavy element dopants (Bi and Ag) can modify the band structure to enhance Seebeck coefficient (S) by enlarging band gap (Eg) and increasing carrier effective mass (m*). The simultaneously enhanced σ and S result in a large power factor (S2σ) of ~1200 μW m−1 K−2 at 673 K. Consequently, a maximum ZT of ~1.18 (~136% higher than that of pristine Cu3SbSe4) at 673 K and an averaged ZT of ~ 0.51 at 300–673 K are achieved for Cu2.85Ag0.15Sb0.985Bi0.015Se4 sample due to a low κ and a high S2σ. This work offers a referential strategy to improve the comprehensive TE performance by dual-incorporation with isovalent heavy element doping for the diamond-like materials.

Ni–P(–SiC) composite coatings were successfully deposited on 70 vol% SiCp/Al composite by electroless plating. The surface microstructures and the phase structures of the Ni–P(–SiC) coatings were examined and analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD) before and after heat-treatment at 200–400 °C for 2 h. The thermal diffusivity of the deposited samples and the interface adhesion between the coating and the substrate were investigated. The experimental results show that SiC content in the coatings increases obviously and XRD peaks are enhanced with SiC content in the bath increasing from 3 to 9 g·L−1. After heat-treatment, the surface of the coating becomes smoother and no diffusion layer is produced at the interface. A new phase Ni3P forms in the coating during heat-treatment at 400 °C. The critical load (L c) of Ni–P–SiC composite coating on SiCp/Al composite reaches the maximum value of 84.9 N with SiC content of 3 g·L−1 after heat-treatment at 200 °C and more or less decreases with the increase in SiC content and heat-treatment temperature. The thermal diffusivity of deposited samples gradually increases as the temperature increases; however, it reduces firstly and then climbs with the increase in SiC content.

For further investigating the role of components in copper-cerium-barium composite oxide catalysts, a series of noble metal-free catalysts with different barium contents were synthesized by citric acid method. The prepared catalysts were characterized by X-ray diffraction, Brunauer-Emmett- Teller method, scanning electron microscopy, Raman spectroscopy, and Fourier transform infrared spectroscopy. Catalysts were evaluated by NO oxidation, NO

PbS-based thermoelectric (TE) materials in the intermediate temperature range have attracted extensive attentions for energy-conversion applications owing to their cost-effectiveness and earth-abundant constituent elements. However, the high TE properties are quite difficult to obtain due to the low carrier concentration and high lattice thermal conductivity (κlat). In this paper, the TE properties of n-type PbS-based materials are enhanced through synergistically optimizing the electrical conductivity (σ) and κlat by Cl doping and Bi alloying. It is found that the substitutions of Cl for S (ClS) and Bi for Pb (BiPb) in lattice remarkably increase the Hall carrier concentration and thus enhance σ, which brings about large power factors (S2σ) of ∼15 μWcm−1K−2 at 573 K and ∼12 μWcm−1K−2 at 823 K. Meanwhile, the introduced ClS and BiPb point defects and micro- or nano-scale precipitates (Bi and Pb) can effectively scatter heat-carrying phonons, resulting in a low κlat. As a consequence, a maxmium ZT value of ∼0.8 at 823 K is acquired for Pb0.99Bi0.01S-0.067%PbCl2, which is ∼1.78 times as high as that of undoped PbS.

The addition of active elements is an excellent method to improve the wettability and interfacial bonding strength between Ag and ZrB2. To quantitatively evaluate the interfacial behavior and structure stability of Ag (1 1 1)/ZrB2 (0 0 0 1) interface, the role of Ti, Zr and Hf additions in the interfacial bonding strength and electronic properties was investigated comprehensively by first-principle calculations. The B-terminated ZrB2 (0 0 0 1) surface is more active than the Zr-terminated surface under the lower B chemical potential. For the Ag (1 1 1)/ZrB2 (0 0 0 1) interface, the interface with center-site presents the largest work of adhesion ( W a ) and the lowest interfacial energy for both Zr- and B-terminations. The Ti, Zr and Hf additions can greatly improve the W a for Ag/ZrB2 interface (especially with the B-termination) when the Ag atom in 1st layer of Ag slab is substituted by active elements. The calculation on the electronic structure shows that the ionic bonding across Ag/ZrB2 interface is further enhanced while adding the active elements due to the strong interactions between the active elements and the closest B atomics. These results provide crucial fundamental insights to enhance the wettability of Ag/ZrB2 system by the addition of active elements.

In this work, for the first time, a three-component In2O3/In2S3/Ag nanocomposite heterostructured photoanode is prepared on a F-doped SnO2 (FTO) glass substrate. The three-component photoanode exhibits significantly enhanced photoelectrochemical properties compared with the single-component (In2O3) and two-component (In2O3/In2S3 or In2O3/Ag) systems. Ag nanoparticles deposited on the surface of In2O3/In2S3 nanocubes can facilitate the separation of photogenerated charge carriers and enhance the absorption of visible light. In I-V curves, the In2O3/In2S3/Ag photoanode generates a remarkable photocurrent density of 8.75 mA cm(-2) (at 0 V vs. SCE), which is higher than those of the two-component In2O3/In2S3 (4.47 mA cm(-2)) and In2O3/Ag (3.50 mA cm(-2)). Furthermore, it also gives efficiency as high as 67% around 350 nm in the incident photon to electron conversion efficiency (IPCE) spectrum. These results open up a promising avenue for the design and fabrication of novel heterojunctions for photoelectrochemical water splitting.