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This study employed magnetic filtered cathodic vacuum arc deposition to fabricate TiN/Ti multilayer coatings, examining the impact of nitrogen flow rates—4, 8, 12, and 16 sccm—on their performance, with an emphasis on gradient flow rates from 4 to 12 sccm. The coatings' phase composition shifted from TiN0.26 to a Ti2N and TiN composite, optimizing the microstructure and significantly increasing the hardness to 24.37 GPa and the elastic modulus to 219.84 GPa at the 16 sccm rate. The surface roughness reduction further improved erosion resistance. Coatings made under gradient flow exhibited reduced mass loss and an erosion rate of 0.07 mg·g−1, outperforming single flow rates. Erosion failure analysis highlighted that while 12 sccm coatings failed due to extensive crack interconnection, 16 sccm coatings showed spalling from crack expansion. Gradient flow coatings, despite the presence of a crack, demonstrated a more confined damage area and enhanced erosion resistance, indicating the benefits of varied nitrogen flow rates in coating optimization. [ABSTRACT FROM AUTHOR]

Erosive damage of nitride coatings is predominantly attributed to coating delamination caused by crack initiation, propagation, and coalescence. For brittle nitride coating materials, inhibiting the crack initiation and propagation within the coating may enhance their erosion resistance. This paper focuses on TiAlN/TiAl multilayer coatings, and by increasing the thickness of the metallic sublayers, the initiation and propagation of cracks in ceramic/metal multilayer coatings are significantly suppressed. As the metallic sublayer thickness increases from 1 to 4 μm, the TiAlN/TiAl coating erosion rate decreases from 0.032 to 0.002 mg⋅g−1, resulting in an improvement in the erosion resistance of over ten times. Based on the failure mechanism of ceramic/metal multilayer coatings under sand erosion conditions and finite element analysis, there are two reasons for improving the erosion resistance of ceramic/metal multilayer coatings by increasing the toughness of the metal layer. On one hand, increasing the thickness of the ductile metal layer can effectively reduce the maximum tensile stress value on the coating surface and decrease the equivalent plastic deformation of the ductile metal layer, thereby improving the crack initiation suppression ability of the coating. On the other hand, increasing the TiAl layer thickness effectively suppresses the downward propagation of longitudinal cracks and the coalescence of transverse cracks in nitride coatings. This research proposes a new approach for enhancing the erosion resistance of nitride coatings. [ABSTRACT FROM AUTHOR]

This paper addresses the challenge of ranking the factors that affect the erosion resistance of lightweight alloys, with a specific focus on aluminum alloys. A three-factor, four-level orthogonal experimental design was employed to examine the influence of various sand particle sizes, erosion speeds, and sand concentrations on the abrasion qualities of these alloys. Parameters such as mass loss, depth, residual stresses, and failure mechanisms were assessed to determine erosion performance. Analysis of variance (ANOVA) and regression analysis of the three key factors were performed. Our findings resulted in an erosion rate formula: erosion rate = 0.679 sand particle size +0.067 sand concentration −0.002 erosion velocity +0.285. Our findings indicate that particle size is the most significant factor affecting erosion rate, with sand concentration and erosion velocity being secondary factors. The failure mechanism reveals that larger sand particles tend to produce deeper slides, and higher sand concentrations result in an increased number of slides. A lower concentration leads to the appearance of erosion pits. And the test conditions of high concentration and low velocity lead to more serious brittle fractures of the substrate, often accompanied by the appearance of cracks. [ABSTRACT FROM AUTHOR]

With the increasing prevalence of renewable energy (RE) companies equipped with private energy storage (ES) systems, a dual capability emerges to offer strategic pricing and strategic constraints in market competition. Specifically, these RE companies can strategically leverage their own private ESs to modulate the variability of RE output limits and introduce modified constraints within the market. To examine these new strategic behaviors and the resulting market equilibria, we introduce an innovative bilevel strategic behavior model. The upper level of the model delineates the strategy for RE profit maximization through the imposition of strategic constraints and pricing schemes, while the lower level calculates the revenue outcomes for all entities in the day-ahead energy market clearing. The integration of the bilevel models from all strategic entities leads to the formulation of a new equilibrium problem with equilibrium constraints (EPEC), the solution of which indicates a novel market equilibrium. The impacts of these market equilibria on critical system operation metrics are then evaluated across two representative market mechanisms. Our numerical experiments reveal that RE exhibits low sensitivity to the private ES's cost, suggesting that the behavior of imposing strategic constraints may be widespread among RE companies owning private ESs. Furthermore, the introduction of strategic constraints enhances the competitiveness of RE, significantly affecting social welfare, energy pricing, and RE integration rate. The study concludes with insights that could inform practical market transactions and system operations. [ABSTRACT FROM AUTHOR]

Conventional methods for measuring viscosity rely on macroscopic device components, which are difficult to miniaturize. The magnetic nano‐stirbars are small enough to enter tiny spaces and can spin without precise installation, making them an ideal candidate for exploring new methods. It is shown that a dense layer of Au nanowires can be grown on the silica surface of the nano‐stirbars, as a means to modulate the viscous resistance during their spinning and to make them visible under an optical microscope. The uniform growth of Au nanowires and the slight fluctuation of the spinning rates are investigated. It is shown that the nano‐stirbars with the hairy layer of Au nanowires can be used to measure the viscosity in microscopic liquid systems, such as microfluidic chambers and capillary tubes, involving cell media and blood samples. It is believed that the success with the proof‐of‐concept tests will open a window for further miniaturization of the nano‐stirbars for measuring in ultrasmall systems. [ABSTRACT FROM AUTHOR]

Determining subduction‐related processes is crucial for understanding lithological heterogeneity, as substantial quantities of slabs are recycled into the mantle. Molybdenum isotopes are valuable for distinguishing sources materials due to the significant isotope differences between the crust and the mantle. In this study, we systematically investigate Mo isotopes in a suite of well‐characterized continental basalts from Keluo and Halaha‐Chaoer, located in Northeast China. The δ98Mo values of Keluo range from −0.41 to −0.23‰, with an average of −0.34‰, while Halaha‐Chaoer samples ranged from −0.18 to −0.12‰, with an average of −0.15‰. The δ98Mo values of Keluo basalts are lighter than the mean value of fresh oceanic basalts (−0.21‰), whereas those of Halaha‐Chaoer basalts are similar to oceanic basalts. Combined with other geochemical indications (LOI, Ce/Pb, La/Yb and so on), the Mo isotopic variations cannot be attributed to chemical weathering, continental crust contamination or magmatic processes. Instead, the δ98Mo variations in this study are explained by the incorporation of different oceanic crustal materials into the magma sources. Correlations of δ98Mo with Ba/Th, Th/U, 143Nd/144Nd indicated that both sediment and altered oceanic crust have significantly influenced these variations. This study demonstrates the potential of Mo isotopes to distinguish different types of recycled oceanic crust materials. [ABSTRACT FROM AUTHOR]

Cost-effective electrocatalysts is a key constituent to establish the balance of cost and catalytic efficiency for oxygen evolution reaction (OER) via water electrolysis in the area of energy conversion and storage. NiFe phosphide decorated with trace amount of iridium (Ir) species in-situ grown on carbon cloth was prepared by a facile wet chemistry approach followed by a phosphorization post-treatment at a relative low temperature. The optimal electrocatalyst, Ir2-NiFePx/CC, exhibits excellent OER activity, with an low overpotential of 190 mV at 10 mA cm-2 for alkaline OER, and a desirable long-term durability over 90 h. The outstanding OER performance stems from the structural evolution via phosphorization process, Ir decoration with more high-valence stated Ir4+ species, and tight connection between individual components of the electrode, which gives rise to the strong activity to the active sites and faster reaction kinetics in the alkaline OER process. Mover, the Ir loading was as low as approximately ~1.7 wt% (0.29 mg cm-2), showing promissing propective in cost-effective OER., (© 2024 Wiley‐VCH GmbH.)