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•BCFZY and Ni doped BCFZY cathodes are synthetized.•Ni doped BCFZY improves the oxygen ion and proton conductivity of the cathode.•BCFZYN has a good thermal stability and a reduced ...thermal expansion coefficient.•Ni doping enhances the ORR activity in both O-SOFCs and PCFCs.•BCFZYN exhibits a prominent stability in both symmetrical cell and single cell test.
To develop a cathode with excellent oxygen reduction reaction (ORR) activity and durability at intermediate-to-low temperatures is significant to boost the advancement of solid oxide fuel cells (SOFCs), a fascinating energy conversion technology with low emissions and high efficiency. Perovskite oxides have been extensively developed as cathodes, and doping is an important strategy to alter the lattice diffusion and surface exchange properties of perovskites, to tailor catalytic performances for various redox reactions, including ORR for SOFCs. The reported BaCo0.4Fe0.4Zr0.1Y0.1O3-δ (BCFZY) is a promising cathode for SOFCs. Herein, to further improve the performance of BCFZY at reduced temperatures, we systematically investigate the partial doping of B-sites with different metal elements, including Mn, Ni, Cu and Zn at a fixed content of 5%. Among them, it is found that Ba(Co0.4Fe0.4Zr0.1Y0.1)0.95Ni0.05O3-δ (BCFZYN) exhibits the lowest polarization impedance in both oxygen ion and proton conducting fuel cells. Based on conductivity relaxation experiments and oxygen and hydrogen permeation tests, it is found that nickel doping improves oxygen mobility, surface exchange kinetics, and bulk oxygen ion and proton conductivity. Thereby, a high ORR activity on oxygen ion and proton conducting electrolytes is achieved, reaching 0.038 and 0.607 Ω cm2 at 550 °C, respectively. The cells with the BCFZYN electrode show outstanding operational stability (200 h of operation in a symmetrical cell and 1000 h of operation in a single cell). This suggests that the BCFZYN is a promising cathode of next-generation SOFCs.
Objective:This study proposed and validated an intelligent microcatheter-shaping algorithm for interventional embolization of intracranial aneurysms.Methods:A stepwise microcatheter simulation ...algorithm constrained by a vessel center line was developed based on the geometry of aneurysms and parent arteries, and a collision correction factor of vessel walls was introduced to automatically calculate the optimal microcatheter path and tip shape. The efficacy of this intelligent shaping method was verified in an in vitro aneurysm model experiment.Results:The microcatheter path can be automatically generated using the intelligent microcatheter-shaping algorithm. Furthermore, the experiment verified that the delivery performance of an intelligently shaped microcatheter was excellent with 100% placement accuracy, superior to that of three pre-shaped microcatheters: straight (0°), 45°, and 90°. In three typical cases, the microcatheter could not be placed in the aneurysms successfully within 5 min with the aid of a microwire using a manual shaping scheme; however, it can be placed in the aneurysms successfully within 5 min using an intelligent microcatheter- shaping scheme, and the time of microcatheter placement in aneurysms was short.Conclusion:This intelligent microcatheter-shaping algorithm based on three-dimensional image data is effective and reasonable. This approach has advantages over standard pre-shaped microcatheters, with a potential clinical application value.
In the distribution of international logistics, the choice of the ways of transportation is one of the key factors to reduce the costs of distribution. In view of the countermeasures for the ...outsourcing and self-run business of the distribution transportation, the author of present paper aims at establishing analytical models, providing solutions which are confirmed by a case study from the investigation conducted in the United States of America, solving the high-cost question that plagues the network of international distribution over a long time, and providing a kind of decisionmaking tools for Chinese products to squeeze into the international market and establish the distribution networks.
Several potential network structures are chosen to do a large number of experimental analysis, historical data is divided into training sample and testing sample, and the corresponding neural network ...model is established with BP learning algorithm. After checking the testing sample, a superior network integration model which can be applied for hydraulic metal structure health grade diagnosing is determined. By plenty of experimental tests and verification analysis, it is concluded that the two-hidden-layer neural network model suits hydraulic metal structure health diagnosing better. As for the gate health diagnosing, based on Bagging technology, the BP neural network integration model for hydraulic metal structure health diagnosing is researched and constructed. The analysis of the sample showed that its accuracy rate (78%) is obviously better than the single neural network model(67%). The BP neural network integration model will work together with the FAHP model the author studied, that can make the diagnosis results more reasonable and reliable.
Compared with planar SOFCs, tubular SOFCs have the advantages of facile sealing and easy scale up. In this study, a tubular anode-supported thin-film YSZ electrolyte SOFC was successfully fabricated ...by extrusion of the anode substrate in combination with wet powder spraying of the electrolyte layer. The fuel cell performance was tested by applying either hydrogen or methane as the fuel and ambient air as the cathode atmosphere. Peak power densities of 432 and 145 mW cm−2 were achieved respectively at 800 and 600 °C for a cell with conventional LSM and silver wire as the cathode and the current collector. The performance was further improved by adopting BSCF cathode with an SDC buffer layer. EIS demonstrated the large electrode polarization resistance is the main source of cell resistance, while the contact resistance is also not negligible. The performance of the cell directly operating on methane fuel was also investigated. A special operation mode by alternatively operating on methane and hydrogen fuels was adopted, which can effectively increase the cell operational stability.
► Tubular anode-supported thin-film YSZ electrolyte SOFC was successfully fabricated. ► Cell performance was optimized with SDC interlayer and BSCF cathode. ► The performance of the cell operating on methane fuel was also investigated. ► A special operation mode by alternatively operating on methane and hydrogen fuels was adopted.
Developing highly efficient and affordable noble-metal-free catalysts toward the hydrogen evolution reaction (HER) is an important step toward the economical production of hydrogen. As a ...nonprecious-metal catalyst for the HER, molybdenum nitride (MoN) has excellent corrosion resistance and high electrical conductivity, but its catalytic activity is still inadequate. Here we report our findings in dramatically enhancing the HER activity of MoN by creating porous MoN@nitrogen-doped carbon (MoN-NC) nano-octahedrons derived from metal–organic frameworks (MOFs). The composite catalyst displays remarkably high catalytic activity, demonstrating a low overpotential of 62 mV at a current density of 10 mA cm–2 (η10), a small Tafel slope of 54 mV dec–1, and a large exchange current density of 0.778 mA cm–2 while maintaining good stability. The enhancement in catalytic properties is attributed to the unique nanostructure of the MoN, the high porosity of the electrode, and the synergistic effect between the MoN and the nitrogen-doped carbon substrate. The performances are among the best ever reported for nonprecious-metal-based electrocatalysts (comparable to those of a 20% Pt/C commercial catalyst), making the porous MoN-NC nano-octahedrons some of the most active and acid-stable electrocatalysts for the HER.
Hundreds of rare risk factors have been identified for ASD, however, the underlying causes for ~70% of sporadic cases are unknown. Sporadic ASD models are thus essential for validating phenotypic ...commonality and drug suitability to the majority of patients. Here, we derived induced pluripotent stem cells (iPSCs) from one sporadic ASD child and one paternal control, using non-integrating Sendai viral methods. The iPSCs strongly expressed pluripotency markers and could be differentiated into three germ layers. Their normal karyotype was validated by genome SNP array. The availability of sporadic ASD-derived iPSCs offers an opportunity for phenotypic comparison with genetic ASD models.
As for thermal diffusion bonding of pure titanium to 304 stainless steel using aluminum interlayer, the temperature is ranged from 550 °C to 650 °C for 2 h under 2 MPa load in vacuum. The ...microstructures, chemical compositions and reaction products of the transition joints were revealed in SEM, EDS and XRD, respectively. The results have shown that the thickness of the diffusion layer increases with the increase of treatment temperature and the diffusion layer appears on the titanium side at the temperature of 650 °C. In this process, aluminum not only plays a mid sole element to prevent iron diffusion to titanium master alloys forming brittle intermetallic phase Fe-Ti, but also makes iron elements, titanium and the aluminum element form a stable diffusion layer.
A novel method for preparing polyaniline/graphene (PANI/GN) nanocomposites was demonstrated by liquid-liquid interface polymerization method. Then the gold nanoparticles (Au NPs) were uniformly ...decorated on the PANI/GN surface to form gold/polyaniline/graphene (Au/PANI/GN) nanohybrids. The Au/PANI/GN nanohybrids film showed good electron transfer ability, which ensured high sensitivity to detect AFB1 in a range from 0.05 to 25 ng/mL with a detection limit of 0.034 ng/mL obtained at 3σ (n = 10). The proposed immunosensor provided a simple tool for AFB1 detection.
Abstract
The single‐phase oxides with elemental complexity and compositional diversity, usually named high entropy oxides, feature homogeneously dispersed multi‐metallic elements in equiatomic ...concentration. The unusual properties of high entropy oxides endow their potential application in clean‐energy‐related electrocatalysis. However, the possible fundamental relationship between configuration entropy and the underlying catalytic mechanism is still not well understood and established. Herein, a high entropy perovskite cobaltate consisting of five equimolar metals in the B‐site (Mg, Mn, Fe, Co, and Ni) is employed as an electrocatalyst for oxygen evolution reaction (OER). The configuration entropy serves as an effective tool to promote the intrinsic activity of the Co reactive site and manipulate the OER mechanism. The high entropy cobaltate demonstrates a lower overpotential of 320 mV at a current density of 10 mA cm
−2
, outperforming other counterparts. The X‐ray spectroscopies disclose the synergistic charge‐exchange effect among different cations and the formation of a new oxygen hole state. Combinatorially computational and experimental results unveil the enigma that the high configuration entropy leads to the random occupation of cations, facilitates the surface reconstruction, and benefits the formation of stable surface oxygen vacancies. Owing to these merits, the O
2
formation is found to be kinetically favorable via the lattice oxygen mechanism.
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