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Deep-sea hydraulic collection is a key technology for seabed mineral resource extraction, offering higher efficiency and environmental protection compared to other collection methods. However, due to their complex characteristics, the suction properties and influencing factors of polyhedral particles in hydraulic suction collection remain elusive. This study utilized dimensionless methods and conducted experiments to analyze the flow characteristics in cone-shaped collection hoods and the distribution of suction force on polyhedral particles, and researched the effect of various parameters, such as Φ, H/R, R/S, and H/dp (referring to the nomenclature given in the last part of this paper), on the suction force coefficients of polyhedral particles based on the suction force coefficients of spheres by acquiring the suction coefficient ratio (kc). The results indicate the following: (1) the presence of suction and coherent vortices in the horizontal positions of 0.1R to 0.2R within the central region, which move with changes in pump suction or cove height, benefiting particle collection; (2) the particle suction force (Fd) decreases with increasing sphericity (Φ), with a more pronounced decline in high-speed flow fields, exhibiting two peaks and one trough in the Fd curve within the hood's flow field; (3) the kc generally increases with decreasing Φ at the same collection position, showing increasingly stable fluctuations, and kc is sensitive to surrounding flow velocities with a rapid growth trend at higher speed, revealing that the suction coefficient (Cd) of polyhedral particles is significantly larger than that of spherical particles with increasing flow speed in high-speed flow fields; (4) Fd decreases with increasing H/dp, with a noticeable slowdown when H/dp exceeds 3.5. This study reveals the force characteristics and influencing factors of non-spherical coarse particles in hydraulic suction collection flow fields, providing insights for the development of collection technologies and equipment for deep-sea solid mineral resources, particularly irregular coarse particles. [ABSTRACT FROM AUTHOR]

A heterostructure composed of ZIF-67-derived nitrogen and cobalt-doped carbon enfolded silicon (C@Si) nanoparticles anchored on 2D MXene layers was constructed for boosting the performance of lithium-ion batteries (LIBs). The heterostructure anode demonstrated a high initial discharge capacity of 3021 mA h g−1 at 0.2 A g−1, retaining outstanding cycling stability with a reversible capacity of 520 mA h g−1 at 2000 mA g−1, and the coulombic efficiency remained above 97% after 500 cycles. The introduced Ti3C2 nanosheets and the cobalt-doped carbon can not only contribute to the interfacial transfer of Li+ and electrons but also buffer the volume expansion of Si. [ABSTRACT FROM AUTHOR]

Subtle perturbations in interlayer twist angles offer a novel investigational avenue for revealing intriguing optical characteristics within the domain of 2D materials. In this study, a homogeneous bilayer structure featuring precisely defined interlayer twist angles is meticulously engineered by stacking monolayer single‐crystal MoS2 in a controlled, layer‐by‐layer manner. Scanning tunneling microscopy (STM) reveals an unexpected lattice reconstruction, particularly at twist angles of ≤ 2°, which induces the emergence of expansive rhombohedral‐stacked large triangular domains. Furthermore, a second‐harmonic generation (SHG) is utilized as a sensitive modality to demonstrate profound transformations in the local electron band structures. By combining the linear spectra with SHG, the change in the C‐exciton optical response in the band‐nesting region of the small‐angle twisted bilayer MoS2 before and after crossing a critical twist angle of 2° is discussed. The study shows that SHG can be used as a nondestructive method to characterize the lattice structure of small‐angle twisted bilayer samples. Furthermore, determining the potential relationship between the lattice reconstruction and the linear and nonlinear spectra further demonstrates the regulatory effect of the interlayer twist angle on the nonlinear optical effects of 2D materials. [ABSTRACT FROM AUTHOR]