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In view of the problem of taking the loose layer as the uniform cloth load while ignoring thickly sticky loose layered arch (TSLLA) of the traditional mining rock overburden structure analysis, combined with the geological conditions of shallow buried thickly sticky loose layer in Shendong mining area, the mechanical model of the mining TSLLA bearing structure is established, the variation law of arch height under different loose layers is analyzed, and the formation conditions of TSLLA are given. The first theory deduced the dynamic evolution mechanism of TSLLA structure advancing. The dynamic evolution of TSLLA structure in 22207 coalface is simulated. The formula for the limit height of TSLLA is derived. A classification method of mining loose layer structure is proposed. The loose layer structure type is divided into load type, arch beam type damage type, and limit arch height type. On this basis, the mechanical model of “arch beam” is constructed. The influence mechanism of the TSLLA on the surface cracks is revealed. The methods and calculation steps for initial surface cracks are presented. The results are verified by the measured data of surface subsidence of the typical thickly sticky layer in Shendong mining area.

One important parameter for evaluating the safety and reliability of a ship is o the dynamic ultimate load capacity of ship structures. Because of the importance of this parameter, its determination is essential. In this paper, a novel "two-step" approach for determining the dynamic ultimate load capacity of ship structures is proposed. The main idea of two-step approach is to determine the dynamic ultimate load capacity based on the static ultimate load capacity after accounting for impacts that cause strain on the ship structures. This approach is based on nonlinear finite element method. Here, taking stiffened plate as a case study, the practical application of thus two-step approach is discussed in detail. The results of this approach reveal that the static ultimate load capacity decreases by less than 3% after a stiffened plate is subjected to an impact load whose amplitude corresponds to the dynamic ultimate load capacity. Then, the influence of the impact duration on the failure mode and the effect of the impact load cycles and the impact load sequence on the dynamic ultimate load capacity of the stiffened plate were investigated. Finally, the applicability of the two-step approach to a hull girder is demonstrated. The two-step approach and the conclusions presented in this paper can provide guidance for the evaluation of dynamic ultimate load capacity. [ABSTRACT FROM AUTHOR]

Herein, hollow hZrO2/g-C3N4 composite photocatalysts were successfully fabricated using polymethylacrylic acid (PMAA) nanospheres as sacrificial templates via reflux-precipitation polymerization and subsequent ZrO2 layer coating by sol–gel method over PMAA nanospheres, calcining process, and forming composites with g-C3N4 in sequence. The formation mechanism of the unique composites was proved by FESEM, TEM, XPS, XRD, and EDX mapping characterizations. The photodegradation tests of methylene blue (MB) and ciprofloxacin (CIP) were used to investigate the photocatalytic activity. The results revealed that hZrO2/g-C3N4 exhibited significantly boosted photocatalytic activity for degrading 99.7% methylene blue and 81.5% ciprofloxacin in 120 min under simulated sunlight irradiation (Xe lamp, 500 W), which was much better than that of hZrO2 (42.1% for MB and 19.1% for CIP). The enhanced performance is presumably attributed to the synergetic interaction of the two components and the efficient separation of the photoproduced electron–hole pairs between ZrO2 and g-C3N4, which was verified using photocurrent and EIS characterizations. On the basis of the scavenging studies of free radicals (e−, h+, ˙O2−, and ˙OH), the mechanism of the boosted photocatalytic activity was proposed. More significantly, the composites presented excellent reusability confirmed by cyclic photocatalytic degradation experiments, which is crucial for the sustainable and green applications of photocatalysts. [ABSTRACT FROM AUTHOR]

Atomic-level structure engineering has proven indispensable for fast ion transport kinetics. Herein, a unique framework of NiSe/Ni heterostructure with abundant heterointerface encapsulated hollow carbon spheres, namely NiSe/Ni@C, is synthesized as an anode for SIBs. The NiSe/Ni@C electrode delivers enhanced Na+ storage performance in terms of high specific capacity (490 mA h g−1) and excellent rate capability (546 mA h g−1) at a current of 5.0 A g−1 over 2000 cycles. This study can provide in-depth insights into the interface effect in hybrid structures and shed light on designing energy storage materials. [ABSTRACT FROM AUTHOR]