Search

In this paper, we improve a new mathematical model associated with glue applying of particleboard. First, we study the existence and stability of the equilibria and the existence of fold, Hopf, and Bogdanov–Takens bifurcations in above system. Second, the normal forms of Hopf bifurcation and Bogdanov–Takens bifurcation are derived, and the classifications of local dynamics near above bifurcation critical values are analyzed. Then, numerical simulation results show that the glue flow system associated with glue applying of particleboard exists stable equilibrium, stable periodic‐1, periodic‐2, and periodic‐4 solutions, and chaotic attractor phenomenon from a sequence of period‐doubling bifurcations. Finally, we compare the dynamical phenomena of glue flow system with frequency water supply system, showing that cubic terms which the latter lacks, could influence the dynamical behaviors of glue flow system. [ABSTRACT FROM AUTHOR]

Adv. Mater. Interfaces. 2023, 3, 2201625DOI: 10.1002/admi.202201625Correction needed only in the surname of an author:Change the author's surname from Joshua Buston to Joshua ButsonNo other details need to change, the name in this author list is already corrected.By Linlin Ye; Nitu Syed; Dingqi Wang; Jining Guo; Jianing Yang; Joshua Butson; Ranjeet Singh; Masood S. Alivand; Gang Kevin Li and Ali ZavabetiReported by Author; Author; Author; Author; Author; Author; Author; Author; Author; Author [Extracted from the article]

Dual‐reflux pressure swing adsorption (DR‐PSA) is a state‐of‐art adsorption technology claiming to achieve both high product purity and recovery. However, its performance is inevitably limited by the gas mixing problem at the feed inlet position in adsorption columns, where a discontinuity in the columns' axial concentration profiles disturbs the separation. Here, we developed a dynamic‐feed DR‐PSA (DF‐DR‐PSA) process to solve the mixing problem and obtain better separation performance by introducing multiple feed inlets along the column. The DF‐DR‐PSA process was demonstrated by enrichment methane (CH4) from a binary gas mixture containing 2.4 mol.% CH4 in nitrogen (N2) using activated carbon material. Non‐isothermal dynamic models were constructed to investigate the effects of operating parameters on the separation performance. The results showed the DF‐DR‐PSA process achieved both higher methane purity (53.5% vs. 47.5%) and recovery (81.1% vs. 72.2%) over the conventional DR‐PSA process at the same energy consumption. [ABSTRACT FROM AUTHOR]

Induction heating systems are characterized by model uncertainty, nonlinearity, and external disturbances, and the control accuracy of the system directly affects the performance of the heated workpiece. In order to improve the temperature control accuracy and anti-interference performance of induction heating systems, this paper proposes a composite control strategy combining fractional-order PID (FOPID) and active disturbance rejection control (ADRC). Meanwhile, for the problem of too many controller tuning parameters, an improved quantum behavior particle swarm optimization (QPSO) algorithm is used to transform the nine parameters to be tuned in fractional-order PID active disturbance rejection control (FOPID-ADRC) into a minimization value optimization problem for solving. The simulation results show that the FOPID-ADRC controller improves the anti-interference capability and control accuracy of the temperature control system, and the improved QPSO algorithm has better global search capability and local optimal adaptation value. [ABSTRACT FROM AUTHOR]

In order to improve the disturbance rejection ability and tracking accuracy of the hydraulic servo system of the rolling mill, this study combines nonsingular terminal sliding mode control (NTSMC) with active disturbance rejection control (ADRC). A fourth-order extended state observer was designed to estimate the disturbance of the system in real time. The stability of the control system was tested using the Lyapunov method. System effectiveness was verified through simulation experiments. Simulation results showed that the designed state observer can estimate the total disturbance of the system in real time and that the chattering of the control input can be eliminated by the introduction of a state observer. In terms of uncertainty in the system model caused by load changes and external interference signals, the nonsingular terminal sliding mode-active disturbance rejection control method exhibited better disturbance rejection capacity and a higher tracking accuracy than NTSMC. [ABSTRACT FROM AUTHOR]

Bismuth-based electrocatalysts are effective for carbon dioxide (CO 2 ) reduction to formate. However, at room temperature, these materials are only available in solid state, which inevitably suffers from surface deactivation, declining current densities, and Faradaic efficiencies. Here, the formation of a liquid bismuth catalyst on the liquid gallium surface at ambient conditions is shown as its exceptional performance in the electrochemical reduction of CO 2 (i.e., CO 2 RR). By doping a trace amount of bismuth (740 ppm atomic) in gallium liquid metal, a surface enrichment of bismuth by over 400 times (30 at%) in liquid state is obtained without atomic aggregation, achieving 98% Faradic efficiency for CO 2 conversion to formate over 80 h. Ab initio molecular simulations and density functional theory calculations reveal that bismuth atoms in the liquid state are the most energetically favorable sites for the CO 2 RR intermediates, superior to solid Bi-sites, as well as joint GaBi-sites. This study opens an avenue for fabricating high-performing liquid-state metallic catalysts that cannot be reached by elementary metals under electrocatalytic conditions., (© 2024 The Authors. Small published by Wiley‐VCH GmbH.)

Active regulation of pore accessibility in microporous materials by external stimuli has aroused great attention in recent years. Here, we show the first experimental proof that guest adsorption in a dielectric microporous material can be regulated by a moderate external E-field below the gas breakdown voltage. CO 2 adsorption capacity in MIL-53 (Al) was significantly reduced, whereas that of NH 2 -MIL-53 (Al) changed insignificantly under a direct current E-field gradient of 286 V/mm. Ab initio DFT calculations revealed that the E-field decreased the charge transfer between the CO 2 molecule and the adsorption site in the MIL-53 framework, which resulted in reduced binding energy and consequently lowered CO 2 adsorption capacity. This effect was only observed in the narrow pore state MIL-53 (Al) but not in its large pore configuration. Our results demonstrate the feasibility of regulating the adsorption of gas molecules in microporous materials using moderate E-fields.