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In this paper, Al2O3/Cr composite coatings were prepared on the surface of Inconel 718 alloy by cathodic liquid plasma electrolytic deposition (CLPED) and double-glow plasma surface alloying (DGPSA) processes. The microstructure and high-temperature oxidation behavior of Al2O3/Cr composite coating were investigated. The results showed that the Al2O3interlayer surface was fully covered with Cr coating. The interface between the Al2O3layer and the Cr metal layer presents a mechanical interlock effect, which can absorb the deformation caused by thermal expansion, thereby reducing the adverse effects of thermal stress. The surface roughness of the Al2O3coatings decreased after depositing Cr coating. The oxidation weight gain of the Al2O3/Cr composite coatings were significantly lower than that of the substrate, indicating that the Al2O3/Cr composite coatings improved the high-temperature oxidation resistance of Inconel 718 alloy. The oxidation weight gain of the Al2O3/Cr composite coatings at different frequencies were similar, while the Al2O3/Cr composite coating at 400 Hz was lowest. During the high-temperature oxidation process, the Al2O3interlayer can effectively inhibit the external diffusion of Ni, Fe and other elements in the matrix, which helps to prevent the cracking of the outer oxide film, thereby reducing the oxidation rate.

Multimetallic alloys have demonstrated promising performance for the application of metal-air batteries, while it remains a challenge to design multimetallic single-atom catalysts (MM-SACs). Herein, metal-C3N4and nitrogen-doped carbon are employed as cornerstones to synthesize MM-SACs by a general two-step method, and the inherent features of atomic dispersion and the strong electronic reciprocity between the multimetallic sites have been verified. The trimetallic FeCoZn-SACs and quatermetallic FeCoCuZn-SACs are both found to deliver superior oxygen evolution reaction and oxygen reduction reaction activity, respectively, as well as outstanding bifunctional durability. Density functional theory calculations elucidate the crucial contribution of Co sites of FeCoCuZn-SACs to the efficient catalysis of both the ORR and the OER. More importantly, Zn-air batteries with FeCoCuZn-SACs as cathodic catalysts exhibit a high power density (252 mW cm–2), high specific capacity (817 mAh gZn–1), and considerable stability (over 225 h) for charging–discharging processes. This work provides a visual perspective for the advantages of MM-SACs toward oxygen electrocatalysis.

Laser shock peening (LSP) was used to prepare a fine-grained transition layer on the surface of titanium alloy (TC4), followed by micro-arc oxidation (MAO) to prepare composite coatings. The influence of LSP on the microstructure, phase structure, adhesion, microhardness, corrosion resistance, and wear resistance of the MAO coatings was studied. The results showed that, after LSP treatment, the diffraction peaks of TC4 became wider, the surface grains were significantly refined, and a high-density dislocation was introduced on the TC4 surface forming a nano-crystal cluster. Compared with the MAO coating, the LSP-MAO composite coating had a smaller pore size, increased coating thickness, microhardness, and depth of strengthening layer. The adhesion, corrosion resistance, and wear resistance of the LSP-MAO coating were better than those of the MAO coating.

Microbial fuel cells (MFCs) can be capable of both wastewater treatment and electricity generation, which necessarily depends on the increasing cathodic performances and stability at low cost to realize industrialization. Herein, cellulose, a commercially available and sustainable material, was oxidized as a carbon precursor to produce the oxygen species synergizing the nitrogen-doped carbon (CON-900) catalyst by a facile in situ nitrogen doping method. The incorporation of nitrogen and oxygen with a high content creates more active centers. Meanwhile, the hierarchical porosity of CON-900 contributes to a high specific surface area (652 m2g–1) and the exposure of accessible active sites. As expected, CON-900 exhibits considerable activity for the oxygen reduction reaction, excellent operating stability, and high poisoning resistance. In addition, the MFC fabricated with CON-900 as a cathode catalyst demonstrates a maximum power density of 1014 ± 23 mW m–2, which is comparable with that of the Pt/C cathode (1062 ± 14 mW m–2). This work offers a facile and versatile strategy for various biomass materials to develop low-cost and high-efficiency carbon-based catalysts for MFCs and beyond.

Exploring effective, stable, and affordable oxygen reduction reaction (ORR) catalysts is very significant for the practical application of proton-exchange membrane fuel cells. In this work, a facile and expandable method is developed to prepare ultrathin PtNi nanowires (NWs) with various Pt/Ni contents, and the ORR performance of the synthesized samples is thoroughly investigated. Pt3.2Ni NWs show the best ORR performance among the studied samples and, notably, exhibit much better ORR activity and stability than those of the Pt/C catalyst even after a 300,000-continuous cycling test. This work confirms that the initial Pt/Ni ratio plays a critical role in the ORR activity and stability of PtNi NWs, and the structure of the PtNi NWs can be well retained after the durability test. Additionally, the structure and performance of Pt3.2Ni NWs are investigated in detail during various cycles, and the performance decay is attributed to the dealloying of Ni and the corrosion of the one-dimensional structure after a prolonged durability test. This work provides a desirable method for rationally synthesizing a highly efficient ORR electrocatalyst with remarkable stability.

The compositional design of diffusion source plays a crucial role in improving magnetic properties of Nd-Fe-B magnet. In this work, Dy80–xCexAl20(x=0–50, in at%) alloy was employed as the diffusion source for grain boundary diffusion. The results show that Dy-Ce co-diffusion can effectively enhance the infiltration ability of diffusion source. The maximum coercivity increment of up to 795 kA/m can be achieved when x=10 due to the deeper diffusion depth and higher Dy content in the shell, while a significant degradation of remanence is also exhibited due to the formation of a larger number of Dy-rich grains. Thus, Ce content is regulated to inhibit the deterioration of remanence. Increasing Ce content to above x=30, it is found that the formed CeFe2phase near the surface can regulate the infiltration ability of diffusion source, reducing the area fraction of Dy-rich grain region that is detrimental to the remanence, and eventually, when x=50, the remanence is recovered to be comparable to that of as-prepared magnet, with a coercivity increment of 430 kA/m concurrently. This suggests that rationally designing the diffusion source composition enables the preparation of cost-effective magnets.

Biomedical porous Ti-15Mo alloys were prepared by microwave sintering using ammonium hydrogen carbonate (NH4HCO3) as the space holder agent to adjust the porosity and mechanical properties. The porous Ti-15Mo alloys are dominated by β-Ti phase with a little α-Ti phase, and the proportion of αand βphase has no significant difference as the NH4HCO3content increases. The porosities and the average pore sizes of the porous Ti-15Mo alloys increase with increase of the contents of NH4HCO3, while all of the compressive strength, elastic modulus and bending strength decrease. However, the compressive strength, bending strength and the elastic modulus are higher or close to those of natural bone. The surface of the porous Ti-15Mo alloy was further modified by hydrothermal treatment, after which Na2Ti6O13layers with needle and flake-like clusters were formed on the outer and inner surface of the porous Ti-15Mo alloy. The hydrothermally treated porous Ti-15Mo alloy is completely covered by the Ca-deficient apatite layers after immersed in SBF solution for 14 d, indicating that it possesses high apatiteforming ability and bioactivity. These results demonstrate that the hydrothermally treated microwave sintered porous Ti-15Mo alloys could be a promising candidate as the bone implant. 本文采用微波烧结制备了生物医用多孔Ti-15Mo合金, 并以碳酸氢铵为造孔剂调节合金孔隙率及力学性能. 多孔Ti-15Mo合金是由主晶相β-Ti和少量α-Ti组成, 其中α/β的比例随碳酸氢铵含量的增加无明显变化. 随着碳酸氢铵含量的增加, 多孔Ti-15Mo合金的孔隙率和孔径均随之增加, 而抗压强度、 弹性模量和抗弯强度随之下降. 然而, 合金的抗压强度、 抗弯强度和弹性模量均高于或接近于自然骨. 采用水热法对多孔Ti-15Mo合金进行表面活化处理后, 多孔Ti-15Mo合金外表面和内表面均形成了针片状的Na2Ti6O13涂层. 水热处理试样经SBF溶液浸泡14天后, 内外表面均完全被缺钙的磷灰石层所覆盖, 说明水热处理的多孔Ti-15Mo合金具有优异的磷灰石形成能力和生物活性. 由此可见, 水热处理的微波烧结多孔Ti-15Mo合金是一种非常有前途的骨植入材料.

Developing cheap and stable electrocatalysts is considered the key factor to achieve the large-scale application of fuel cells. In this paper, three-dimensional (3D) porous Co-doped vanadium nitride (VN) nanosheet-assembled microflowers are prepared with a facile solvothermal approach followed by nitridation at 500 °C in NH3. It is found that the microflower morphology and the Co doping both significantly enhance the oxygen reduction reaction (ORR) performance of the materials. Because the unique 3D porous structure provides higher specific surface area and more active sites as well as enriching the d electrons of V via doping, Co also improves the intrinsic activity of VN. Our optimal V0.95Co0.05N microflowers achieve a half-wave potential for the ORR of up to 0.80 V in 0.1 M KOH solution, which is almost comparable to that of commercial 20% Pt/C. More importantly, the catalysts show superior durability with little current decline (less than 12%) during chronoamperometric evaluation for over 25 000 s. These features make the V0.95Co0.05N microflowers attractive for fuel cell applications.

The severe dissolution of the cathode catalyst, caused by an undesired oxygen reduction reaction at the anode during startup and shutdown, is a fatal challenge to practical applications of polymer electrolyte membrane fuel cells. To address this important issue, according to the distinct structure-sensitivity between the σ-type bond in H2and the π-type bond in O2, we design a HD-Pt/TiN material by highly dispersing Pt on the TiN surface to inhibit the unwanted oxygen reduction reaction. The highly dispersed Pt/TiN catalyst exhibits excellent selectivity toward hydrogen oxidation and oxygen reduction reactions. With a Pt loading of 0.88 wt %, our catalyst shows excellent hydrogen oxidation reaction activity, close to that of commercial 20 wt % Pt/C catalyst, and much lower oxygen reduction reaction activity than the commercial 20 wt % Pt/C catalyst. The lack of well-ordered Pt facets is responsible for the excellent selectivity of the HD-Pt/TiN materials toward hydrogen oxidation and oxygen reduction reactions. Our work provides a new and cost-effective solution to design selective catalysts toward hydrogen oxidation and oxygen reduction reactions, making the strategy of using oxygen-tolerant anode catalyst to improve the stability of polymer electrolyte membrane fuel cells during startup and shutdown more affordable and practical.

ABSTRACTγ-aluminium oxynitride (AlON) has an excellent thermal and chemical stability, which makes AlON an attractive candidate for a wide range of applications. Production of transparent AlON is extremely challenging because residual porosity must be reduced to an absolute minimum. This can be achieved by spark plasma sintering (SPS) and introducing sintering additives. This article provides a review of research activities that concentrate on the development of spark plasma reaction sintering of AlON ceramics with and without sintering additives. Influence of the most important operating parameters (atmosphere, temperature, processing time, heating rate, etc) on product characteristics and process dynamics is reviewed for AlON ceramics. Comparison of SPS over conventional methods including pressureless sintering, hot pressing sintering and others is demonstrated. Recent advances and challenges in the synthesis of AlON ceramics by SPS are also discussed.

For the first time, transparent La_0.2Y_1.8O_3 nanostructured polycrystalline scintillators were fabricated by sintering nanoparticle powders at high temperatures and their scintillation properties are reported. La_0.2Y_1.8O_3 is a host material that has never been investigated as scintillators for radiation detection. Our observations found that La_0.2Y_1.8O_3 has an intense scintillation luminescence, a detection efficiency higher than that of YAG:Ce and a comparable energy resolution to NaI and CsI scintillators. In addition, La_0.2Y_1.8O_3 is stable and has luminescence decay lifetime in the picosecond range which is favorable for radiation detection. The luminescence of La_0.2Y_1.8O_3 has a large Stokes-shift and a large emission bandwidth, and the luminescence is highly temperature dependent. Different from most doped scintillators, the luminescence of La_0.2Y_1.8O_3 is most likely from the self-trapped excitons. The discovery of La_0.2Y_1.8O_3 scintillators opens a new door for the research of new materials for radiation detection.

Primary myofibroblastic sarcomas of the pulmonary artery are very uncommon, but early detection is critical. Common clinical symptoms include shortness of breath, chest discomfort, and syncope. Patients diagnosed with a pulmonary tumor have a high risk of fatal pulmonary embolism. In this case study, we identified and diagnosed pulmonary artery myofibroblastic sarcoma in a young man by its imaging and pathologic characters. Surgery to excise the tumor was successfully performed and the operation was considered to have improved his prognosis. Postoperative examinations did not show any evidence of residual tumor, recurrence, or metastasis in the lungs or cardiac tissue. Based on the results of this case study, we concluded that the imaging and pathologic features of primary pulmonary artery myofibroblastic sarcoma can assist physicians in making a prompt diagnosis and an immediate surgical and treatment plan to greatly improve prognosis.

Plasma electrolytic oxidation (PEO) coatings, formed under various anodic voltages (320–440 V) on biomedical NiTi alloy, are mainly composed of γ-Al2O3 crystal phase. The evolution of discharging sparks during the PEO process under different anodic voltages was observed. The surface and cross-sectional morphologies, composition, bonding strength, wear resistance and corrosion resistance of the coatings were investigated by scanning electron microscopy (SEM), thin-film X-ray diffraction (TF-XRD), energy dispersive X-ray spectrometry (EDS), surface roughness, direct pull-off test, ball-on-disk friction and wear test and potentiodynamic polarization test, respectively. The results showed that the evolution of discharging sparks during the PEO process directly influenced the microstructure of the PEO coatings and further influences the properties. When the anodic voltage increased from 320 V to 400 V, the corrosion resistance and wear resistance of the coatings slowly increased, and all the bonding strength was higher than 60 MPa; further increasing the anodic voltages, especially up to 440 V, although the thickness and γ-Al2O3 crystallinity of the coatings further increased, the microstructure and properties of the coatings were obviously deteriorated. [ABSTRACT FROM AUTHOR]

Ternary Pt3Bi3Zn nanoplates are synthesized by a facile and general solvothermal method, which exhibits both high activity and durability for methanol oxidation reaction.

Mutations in the gene encoding matrilin-3 (MATN3), a noncollagenous extracellular matrix protein, have been reported in a variety of skeletal diseases, including multiple epiphyseal dysplasia, which is characterized by irregular ossification of the epiphyses and early-onset osteoarthritis, spondylo-epimetaphyseal dysplasia, and idiopathic hand osteoarthritis. To assess the role of matrilin-3 in the pathogenesis of these diseases, we generated Matn3functional knockout mice using embryonic stem cell technology. In the embryonic growth plate of the developing long bones, Matn3null chondrocytes prematurely became prehypertrophic and hypertrophic, forming an expanded zone of hypertrophy. This expansion was attenuated during the perinatal period, and Matn3homozygous null mice were viable and showed no gross skeletal malformations at birth. However, by 18 weeks of age, Matn3null mice had a significantly higher total body bone mineral density than Matn1null mice or wild-type littermates. Aged Matn3null mice were much more predisposed to develop severe osteoarthritis than their wild-type littermates. Here, we show that matrilin-3 plays a role in modulating chondrocyte differentiation during embryonic development, in controlling bone mineral density in adulthood, and in preventing osteoarthritis during aging. The lack of Matn3does not lead to postnatal chondrodysplasia but accounts for higher incidence of osteoarthritis.

Objectives Liver echinococcosis is a severe zoonotic disease caused by Echinococcus(tapeworm) infection, which is epidemic in the Qinghai region of China. Here, we aimed to explore biomarkers and establish a predictive model for the diagnosis of liver echinococcosis.Methods Microarray profiling followed by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis was performed in liver tissue from patients with liver hydatid disease and from healthy controls from the Qinghai region of China. A protein–protein interaction (PPI) network and random forest model were established to identify potential biomarkers and predict the occurrence of liver echinococcosis, respectively.Results Microarray profiling identified 1152 differentially expressed genes (DEGs), including 936 upregulated genes and 216 downregulated genes. Several previously unreported biological processes and signaling pathways were identified. The FCGR2B and CTLA4 proteins were identified by the PPI networks and random forest model. The random forest model based on FCGR2B and CTLA4 reliably predicted the occurrence of liver hydatid disease, with an area under the receiver operator characteristic curve of 0.921.Conclusion Our findings give new insight into gene expression in patients with liver echinococcosis from the Qinghai region of China, improving our understanding of hepatic hydatid disease.

Fiber-shaped asymmetric supercapacitors (FSASCs) have great potential as a future wearable energy storage system because of good weavability, wide operating voltage window, and high energy density. Conventional bottom-up construction methods for fiber supercapacitors are time-consuming or highly costly. This work proposes a novel facile top-down cutting method to construct FSASCs. FSASCs with desired sizes can be rapidly constructed and easily scaled up by cutting a thin-film supercapacitor into fiber-shaped devices. Serial and parallel FSASCs free of external wire connection were assembled by cutting stacked film supercapacitors and multiplying the cutting width, respectively. Besides, the as-prepared FSASCs exhibit superior comprehensive electrochemical performance, including a high volumetric capacitance of 14.7 F cm-3, a high energy density of 93.5 μWh cm-2, and excellent flexibility. The cutting method with high simplicity, low cost, and high efficiency may be a general construction method for fiber-shaped energy storage devices.