SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4263-3
Monolayer black phosphorus (phosphorene) exhibits a direct bandgap and strong in-plane anisotropy, making it a promising candidate for near-infrared (NIR) optoelectronic devices. However, the precise modulation of its excitonic emission via anisotropic strain remains insufficiently understood, particularly regarding the contrasting strain responses of phosphorene versus transition metal dichalcogenides (TMDs). Here, we combine experimental characterization with tight-binding (TB) modeling to elucidate the strain-dependent bandgap evolution in phosphorene. Using a four-band TB model, we derive the bandgap at the Γ point as E_g^BP = 4t1 + 2t2 + 4t3 + 2t5, with hopping parameters t1 = -1.220 eV, t2 = 3.665 eV, t3 = -0.205 eV, t4 = -0.105 eV, and t5 = -0.055 eV. Under tensile strain along the zigzag (ZZ) direction, the interatomic distance associated with t1 increases, reducing the magnitude of |t1|. Since t1 is negative, the bandgap increases, contrary to the behavior of monolayer MoS2, where tensile strain decreases the bandgap due to positive hopping parameters t11, t22, and t12. This anisotropic strain response enables selective tuning of NIR exciton emission. Our findings provide a quantitative framework for strain engineering in phosphorene-based NIR devices, highlighting the critical role of hopping parameter signs in determining bandgap modulation.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202509009
Air-supplied jet aerators, combining hydraulic jet and gas induction principles, are critical equipment in aerobic biological wastewater treatment. However, low energy conversion efficiency and insufficient local gas-liquid mixing are core bottlenecks limiting their competitiveness. A three-dimensional flow field analysis method for jet aerators was developed based on the k-ε turbulence model and Euler-Euler multiphase flow model. The effects of different orifice plate distributions, shapes, sizes, hole numbers, and installation positions on average pressure, turbulent kinetic energy, and turbulent dissipation rate were systematically studied. Results show that the asterisk-shaped orifice plate yields the highest gas-liquid two-phase turbulent mixing intensity, followed by the annular shape, while the parallel arrangement yields the lowest. With increasing hole number and single-hole size, average pressure, velocity, turbulent kinetic energy, and turbulent dissipation rate for different plate shapes initially fluctuate downward and then stabilize. When the number of triangular holes is 9, mass transfer efficiency is significantly enhanced, and overall aerator performance is excellent. When the triangular hole diameter is 7 mm, the device achieves an optimal match between energy utilization and mixing efficiency across pressure distribution, velocity field, turbulent kinetic energy, and dissipation rate. The farther the porous thin plate is installed from the sewage nozzle, the further gas-liquid two-phase turbulence is enhanced. Experiments confirm that the boundary layer is fully developed, liquid and air are thoroughly mixed, and the orifice plate promotes bubble breakup and refinement through throttling and collision, significantly improving oxygen transfer efficiency. This research provides a theoretical basis and technical support for the transformation and upgrading of aeration technology towards high efficiency and low carbon, and for extending equipment service life.