SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4110-9
Flexible tactile sensors are pivotal for human-machine interaction, yet accurate decoupled sensing of three-dimensional (3D) forces and integration into functional systems remain challenging. Here, we present a piezoresistive 3D force sensor based on ionic hydrogels that detects and analyzes multi-directional forces. The sensor exhibits a linear response to normal forces from 1 to 25 N (R²=0.99) and maintains stable sensitivity for shear forces within 0–4 N. By incorporating both force magnitude and direction, the sensor enables multidimensional password input, expanding traditional one-dimensional passwords into numeric, alphabetic, and Morse code formats. Experimental results demonstrate significant potential for enhancing information security. The sensor's simple structure, mature fabrication, and ease of integration with flexible electronics underscore its practicality. This work addresses the bottleneck of unidirectional sensing in conventional flexible pressure sensors, offering a robust solution for multidimensional force acquisition in human-machine interfaces, soft robotics, and biomechanical monitoring.
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.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025112603
The cycloaddition of carbon dioxide (CO2) to epoxides (CCE) is a 100% atom-economical transformation yielding cyclic carbonates, which are valuable chemical products. This reaction valorizes CO2 as a carbon feedstock, mitigating the greenhouse effect and aligning with carbon neutrality goals. Conventional covalent organic framework (COF) catalysts often require co-catalysts to achieve high efficiency. To address this, we designed and prepared a series of ionic COFs, denoted EB-BT(nOH), that simultaneously incorporate acid (hydroxyl), base (nitrogen), and nucleophilic bromide (Br−) functionalities. These materials efficiently catalyze the CCE reaction without any co-catalyst. Among them, EB-BT(OH) exhibited the highest catalytic activity, achieving a 99% yield of the target product at 120 °C and 2.0 MPa CO2 pressure. By systematically varying the hydroxyl content in the COF backbone, we investigated the critical role of hydrogen bond donors (HBDs) in the CCE reaction. This work provides new design principles for COF-based catalysts for CCE, eliminating the need for co-catalysts and enhancing process sustainability.