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Aiming at the fatigue problem of casting cranes in service process,considering the actual service load spectrum,the fatigue performance of casting cranes was analyzed based on the non⁃linear cumulative damage principle.Firstly,the stress time history of the key fatigue hot spots of the in⁃service casting crane in a steel plant was measured.Then,the one⁃dimensional load spectrum was compiled based on the two⁃parameter rain flow counting method and Goodman equal life equation.In addition,the commonly used linear cumulative damage model and low⁃high and high⁃low non⁃linear cumulative damage model were used to calculate and analyze the damage and life characteristics of the key parts.The results show that the fatigue load spectrum of casting cranes is closely related to the location of fatigue calculation point and the actual service process.Compared with the commonly used linear cumulative damage model,the non⁃linear cumulative damage model has higher prediction accuracy,and more conservative life prediction results can be obtained by using the high⁃low load loading sequence.

Fatigue cracks of the welded structure often initiate at the weld toe. Under the complex metallurgical-physical process, the grain sizes and their distribution morphology at the weld toe site show obvious variation. In order to investigate the influence of grain distribution morphology on the fatigue behavior of the weld toe short cracks, metallographic tests were carried out for different areas of the weld toe for the cruciform joint specimen to obtain the average grain sizes of the coarse-grain region and the fine-grain region. Two-dimensional representative volume element（RVE） models considering grain distribution morphology were constructed. Based on FIP parameters and McDowell model, the nucleation and fatigue propagation behavior of the weld toe short cracks with different grain distribution morphology were simulated. The results showed that grain size and orientation are important factors influencing the nucleation behavior of the weld toe short cracks. The grain distribution morphology has little effect on the early behavior of short cracks, but the effect is gradually significant with the cracks propagating to a certain threshold length. In general, the fine-to-coarse grain transition mode can reduce the growth rate of short cracks.

Rechargeable magnesium batteries (RMBs) have received increased attention due to their high volumetric capacity and safety. Nevertheless, the sluggish diffusion kinetics of highly polarized Mg2+ in host lattices severely hinders the development of RMBs. Herein, we report an electron injection strategy for modulating the Mo 4d-orbital splitting manner and first fabricate a dual-phase MoO2.8F0.2/MoO2.4F0.6 heterostructure to accelerate Mg2+ diffusion. The electron injection strategy triggers weak Jahn–Teller distortion in MoO6 octahedra and reorganization of the Mo 4d-orbital, leading to a partial phase transition from orthorhombic phase MoO2.8F0.2 to cubic phase MoO2.4F0.6. As a result, the designed heterostructure generates a built-in electric field, simultaneously improving its electronic conductivity and ionic diffusivity by at least one order of magnitude compared to MoO2.8F0.2 and MoO2.4F0.6. Importantly, the assembled MoO2.8F0.2/MoO2.4F0.6//Mg full cell exhibits a remarkable reversible capacity of 172.5 mAh g−1 at 0.1 A g−1, pushing forward the orbital-scale manipulation for high-performance RMBs. [ABSTRACT FROM AUTHOR]

Coordinating the relationship between the digital economy, green innovation, and the urban-rural income gap is conducive to promoting common prosperity in high-quality development. This study aims to show that, in the short term, the development of the digital economy will promote the level of green innovation, which, in turn, will promote the development of the digital economy, but will also widen the urban-rural income gap. The study uses panel data of 273 prefecture-level cities from 2011 to 2019, and adopts the panel vector error correction model for quantitative analysis, combined with the theoretical analysis of the long- and short-term causal relationship among the digital economy, green innovation, and urban-rural income gap. The results reveal that, in the long term, the digital economy, green innovation, and urban-rural income gap demonstrate a double-circular causality that is positively promoting each other. The robustness test validates the conclusions. Therefore, while promoting the development of the digital economy and green innovation, the government should control the urban-rural income gap within a reasonable range, to provide theoretical and practical support for promoting the sustainable development of China's economy and realizing the goal of common prosperity. [ABSTRACT FROM AUTHOR]

Hybrid or composite heterostructured electrode materials have been widely studied for their potential application in electrochemical energy storage. Whereas their physical or chemical properties could be affected significantly by modulating the heterogeneous interface, the underlying mechanisms are not yet fully understood. In this work, we fabricated an electrochemical energy storage device with a MoS2 nanosheet/MnO2 nanowire heterostructure and designed two charge/discharge channels to study the effect of the heterogeneous interface on the energy storage performances. Electrochemical measurements show that a capacity improvement of over 50% is achieved when the metal current collector was in contact with the MnO2 instead of the MoS2 side. We propose that this enhancement is due to the unidirectional conductivity of the MoS2/MnO2 heterogeneous interface, resulting from the unimpeded electrical transport in the MnO2-MoS2 channel along with the blocking effect on the electron transport in the MoS2-MnO2 channel, which leads to reaction kinetics optimization. The present study thus provides important insights that will improve our understanding of heterostructured electrode materials for electrochemical energy storage. [ABSTRACT FROM AUTHOR]