Near-eye display with a triple-channel waveguide for metaverse.

We present a near-eye display featuring a triple-channel waveguide with chiral liquid crystal gratings. Our triple-channel waveguide is capable of dividing one field of view into three through both the polarization orthogonality and angular separation. To illustrate its principle, a k-space diagram, which takes into account the aspect ratio of field of view, is depicted. Our results demonstrate that its diagonal field of view reaches 90°, eye relief is 10 mm, exit pupil is 4.9 × 4.9 mm2, transmittance is 4.9%, and uniformity is 89%.

Adsorptive removal of phosphate from aqueous solutions using lead-zinc tailings.

This study explored the feasibility of utilizing lead-zinc tailings for phosphate removal in laboratory experiments. The adsorption isotherm, kinetics and pH effect were examined in batch experiments. The Freundlich and Langmuir isotherm models were used for data fitting. The adsorption kinetics can be best described by the simple Elovich equation. The phosphate adsorption tends to decrease with the increase of pH, from 0.37 mg P/g at pH 2.05 to 0.12 mg P/g at pH 7.01, and tends to increase from 0.12 mg P/g at pH 7.01 to 0.64 mg P/g at pH 12.52. The actual phosphate removal on the tailings could be a consequence of adsorption and precipitation reactions with Fe, Al and Ca. Due to their low cost, this type of tailings has the potential to be utilized for cost-effective removal of phosphate from wastewater.