25 research outputs found
A Universal Mirror-stacking Approach for Constructing Topological Bound States in the Continuum
Bound states in the continuum (BICs) are counter-intuitive localized states
with eigenvalues embedded in the continuum of extended states. Recently,
nontrivial band topology is exploited to enrich the BIC physics, resulted in
topological BICs (TBICs) with extraordinary robustness against perturbations or
disorders. Here, we propose a simple but universal mirror-stacking approach to
turn nontrivial bound states of any topological monolayer model into TBICs.
Physically, the mirror-stacked bilayer Hamiltonian can be decoupled into two
independent subspaces of opposite mirror parities, each of which directly
inherits the energy spectrum information and band topology of the original
monolayer. By tuning the interlayer couplings, the topological bound state of
one subspace can move into and out of the continuum of the other subspace
continuously without hybridization. As representative examples, we construct
one-dimensional first-order and two-dimensional higher-order TBICs, and
demonstrate them unambiguously by acoustic experiments. Our findings will
expand the research implications of both topological materials and BICs.Comment: 5 figures,accepted by Phys.Rev.Let
Observation of Hybrid-Order Topological Pump in a Kekule-Textured Graphene Lattice
Thouless charge pumping protocol provides an effective route for realizing
topological particle transport. To date, the first-order and higher-order
topological pumps, exhibiting transitions of edge-bulk-edge and
corner-bulk-corner states, respectively, are observed in a variety of
experimental platforms. Here, we propose a concept of hybrid-order topological
pump, which involves a transition of bulk, edge, and corner states
simultaneously. More specifically, we consider a Kekul\'e-textured graphene
lattice that features a tunable phase parameter. The finite sample of zigzag
boundaries, where the corner configuration is abnormal and inaccessible by
repeating unit cells, hosts topological responses at both the edges and
corners. The former is protected by a nonzero winding number, while the latter
can be explained by a nontrivial vector Chern number. Using our skillful
acoustic experiments, we verify those nontrivial boundary landmarks and
visualize the consequent hybrid-order topological pump process directly. This
work deepens our understanding to higher-order topological phases and broadens
the scope of topological pumps.Comment: 5 figure
Wastewater Treatment in Mineral Processing of Non-Ferrous Metal Resources: A Review
Water used by mining enterprises needs to be comprehensively recovered and utilized to achieve clean production. This requires the effective treatment of mineral processing wastewater. Wastewater produced during non-ferrous metal mineral processing contains a complex mixture of pollutants at high concentrations, making comprehensive treatment difficult. Here, the sources of and hazards posed by wastewater produced during non-ferrous metal mineral processing are introduced and the techniques for removing heavy metal ions and organic chemicals are reviewed. Chemical precipitation and adsorption methods are often used to remove heavy metal ions. Chemical precipitation methods can be divided into hydroxide and sulfide precipitation methods. Organic chemicals are mainly removed using oxidation methods, including electrochemical oxidation, photocatalytic oxidation, and ultrasonic synergistic oxidation. External and internal cyclic utilization methods for treating wastewater produced by mineral processing plants are introduced, and a feasibility analysis is performed
Wastewater Treatment in Mineral Processing of Non-Ferrous Metal Resources: A Review
Water used by mining enterprises needs to be comprehensively recovered and utilized to achieve clean production. This requires the effective treatment of mineral processing wastewater. Wastewater produced during non-ferrous metal mineral processing contains a complex mixture of pollutants at high concentrations, making comprehensive treatment difficult. Here, the sources of and hazards posed by wastewater produced during non-ferrous metal mineral processing are introduced and the techniques for removing heavy metal ions and organic chemicals are reviewed. Chemical precipitation and adsorption methods are often used to remove heavy metal ions. Chemical precipitation methods can be divided into hydroxide and sulfide precipitation methods. Organic chemicals are mainly removed using oxidation methods, including electrochemical oxidation, photocatalytic oxidation, and ultrasonic synergistic oxidation. External and internal cyclic utilization methods for treating wastewater produced by mineral processing plants are introduced, and a feasibility analysis is performed
Interaction of Manganese Ions with Scheelite Surfaces and Its Effect on Collector Adsorption and Flotation
Tungsten is a commercially important metal element that usually coexists with a variety of non-ferrous metals, which makes its extraction difficult. Scheelite is a commonly occurring tungsten-containing ore with the formula CaWO4. Improving the surface properties of scheelite to increase its adsorption of the collector for flotation separation is the focus of our current research. In this paper, the effects of manganese ions on scheelite flotation in benzohydroxamic acid (BHA) system were studied by micro-flotation tests, adsorption tests, fourier transform infrared spectroscopy (FTIR), zeta potential, and X-ray photoelectron spectroscopy (XPS) analysis. The addition of Mn2+ was found to improve the recovery of scheelite. The addition of Mn2+ greatly improved the recovery of scheelite. Infrared spectroscopy, adsorption tests, zeta potential measurements and XPS analysis all confirmed that BHA had a higher adsorption capacity and a stronger bond to the surface of scheelite after the addition of manganese ions, increasing the floatability of scheelite particles. Therefore, Mn2+ shows great potential for the improvement of the flotation index of scheelite in a system with BHA
Interaction of Manganese Ions with Scheelite Surfaces and Its Effect on Collector Adsorption and Flotation
Tungsten is a commercially important metal element that usually coexists with a variety of non-ferrous metals, which makes its extraction difficult. Scheelite is a commonly occurring tungsten-containing ore with the formula CaWO4. Improving the surface properties of scheelite to increase its adsorption of the collector for flotation separation is the focus of our current research. In this paper, the effects of manganese ions on scheelite flotation in benzohydroxamic acid (BHA) system were studied by micro-flotation tests, adsorption tests, fourier transform infrared spectroscopy (FTIR), zeta potential, and X-ray photoelectron spectroscopy (XPS) analysis. The addition of Mn2+ was found to improve the recovery of scheelite. The addition of Mn2+ greatly improved the recovery of scheelite. Infrared spectroscopy, adsorption tests, zeta potential measurements and XPS analysis all confirmed that BHA had a higher adsorption capacity and a stronger bond to the surface of scheelite after the addition of manganese ions, increasing the floatability of scheelite particles. Therefore, Mn2+ shows great potential for the improvement of the flotation index of scheelite in a system with BHA
Application of Differentially Methylated Loci in Clinical Diagnosis of Trisomy 21 Syndrome
Clostridium butyricum and carbohydrate active enzymes contribute to the reduced fat deposition in pigs
Abstract Pig gastrointestinal tracts harbor a heterogeneous and dynamic ecosystem populated with trillions of microbes, enhancing the ability of the host to harvest energy from dietary carbohydrates and contributing to host adipogenesis and fatness. However, the microbial community structure and related mechanisms responsible for the differences between the fatty phenotypes and the lean phenotypes of the pigs remained to be comprehensively elucidated. Herein, we first found significant differences in microbial composition and potential functional capacity among different gut locations in Jinhua pigs with distinct fatness phenotypes. Second, we identified that Jinhua pigs with lower fatness exhibited higher levels of short‐chain fatty acids in the colon, highlighting their enhanced carbohydrate fermentation capacity. Third, we explored the differences in expressed carbohydrate‐active enzyme (CAZyme) in pigs, indicating their involvement in modulating fat storage. Notably, Clostridium butyricum might be a representative bacterial species from Jinhua pigs with lower fatness, and a significantly higher percentage of its genome was dedicated to CAZyme glycoside hydrolase family 13 (GH13). Finally, a subsequent mouse intervention study substantiated the beneficial effects of C. butyricum isolated from experimental pigs, suggesting that it may possess characteristics that promote the utilization of carbohydrates and hinder fat accumulation. Remarkably, when Jinhua pigs were administered C. butyricum, similar alterations in the gut microbiome and host fatness traits were observed, further supporting the potential role of C. butyricum in modulating fatness. Taken together, our findings reveal previously overlooked links between C. butyricum and CAZyme function, providing insight into the basic mechanisms that connect gut microbiome functions to host fatness