Liaoning University of Technology

Iron-containing zeolites have shown great potential in catalyzing phenol hydroxylation with H2O2 to produce dihydroxybenzenes (catechol and hydroquinone). However, their industrial application has been hindered by low selectivity and the complexity of active-site identification. This study addresses these challenges by synthesizing a series of Fe-ZSM-5 catalysts with iron contents up to 4 wt % via an ionic liquid-assisted interzeolite transformation route. Through systematic regulation of transformation temperature and calcination atmosphere, combined with an acid treatment step, a catalytically inert benchmark sample (T180-Air) was strategically prepared and compared with three active variants (T200-Air, T180-N2, T200-N2) to achieve the isolation and identification of active sites. Employing a “differential comparison strategy”, combined with DR UV–vis, Raman, Mössbauer, XANES/EXAFS, EPR, H2-TPR, in situ FT-IR characterizations, and DFT calculations, we systematically excluded the possibility of binuclear iron species, small FexOy clusters, and distorted tetrahedral iron as primary active sites. The evidence consistently points to extra-framework octahedrally coordinated mononuclear iron as the key active species, which effectively activates both phenol and H2O2 to generate reactive intermediates. Moreover, the high-selectivity formation of dihydroxybenzenes is driven by a synergistic interaction between these mononuclear octahedral iron sites and neighboring strong acid centers. The optimal catalyst (T200-Air) achieved a phenol conversion of 46.7% and a dihydroxybenzene selectivity of 95.6% under dark conditions, with its dihydroxybenzene selectivity surpassing that of state-of-the-art Fe-based catalysts at comparable phenol conversion levels. This work elucidates the critical importance of the synergistic design between the active iron species and the local acidic microenvironment, providing clear experimental evidence and structure-performance guidelines for the rational design of high-performance iron-zeolite catalysts for selective phenol hydroxylation reactions.

To compare two region-of-interest (ROI) measurement methods based on mDIXON-Quant for distinguishing healthy volunteers (HV), chronic kidney disease (CKD) patients with low (≤ 15%) and high (> 15%) glomerulosclerosis (GS), and establish a non-invasive auxiliary protocol. A total of 42 CKD patients and 25 HV underwent mDIXON-Quant MRI. CKD patients were stratified into low (n = 24) and high (n = 18) GS groups via renal biopsy. Two ROI methods were applied: Method 1 (cortex/medulla separation, 15–20 mm² circular ROIs at renal hilum, upper/lower poles) and Method 2 (whole-kidney contour tracing). R2* and fat fraction (FF) parameters were analyzed using ANOVA, LSD tests, and DeLong tests for diagnostic efficacy (AUC). R2* parameters (RcR2*, RR2*) showed significant differences across groups (P < 0.05), increasing with GS severity. LcR2* and RmR2* distinguished HV from high GS (P < 0.05), while LFF differentiated low vs. high GS (P < 0.05). Combining FF with R2* improved AUC from 0.685 to 0.877 (P < 0.05) for low/high GS discrimination. Method 1’s RcR2* (AUC = 0.957) and Method 2’s RR2* (AUC = 0.9) were most accurate for distinguishing high GS from HV, with no significant difference between them (P > 0.05). RcR2* outperformed medullary parameters (P < 0.05). The present study demonstrates that employing the Method 2(whole-kidney contour tracing) based on mDIXON-Quant technology enables auxiliary quantitative assessment of the severity of GS via the R2 parameter of the right kidney, thereby confirming its role as an adjunctive tool in GS evaluation.

ABSTRACT This paper focuses on the problem of optimized fuzzy prescribed performance control for nonlinear strict‐feedback systems under denial‐of‐service (DoS) attacks. DoS attacks disrupt communication channels, leading to the output signal and states of the system unavailable. A switched fuzzy observer is adopted to reconstruct unmeasurable states under DoS attacks. Simultaneously, a simpler prescribed performance error transformation is constructed to constrain the tracking error within a prescribed boundary, which can improve the transient and steady‐state performance of the control system. To achieve optimized fuzzy prescribed performance control under DoS attacks, an event‐based secure optimal control strategy is proposed. Specifically, the controller at each backstepping layer is designed as the optimal solution for the corresponding subsystem, such that the entire backstepping control process is optimized. Due to the difficulty in directly solving optimal solutions, a reinforcement learning (RL) algorithm with an actor‐critic architecture is incorporated into the control design process to obtain approximate optimal controllers. In addition, a dynamic event‐triggering mechanism (DETM) is proposed to improve the utilization rate of the communication resource. Through Lyapunov stability analysis, it is proved that the tracking error always evolves within the performance envelope, and the consumed control resources are minimized. Meanwhile, the Zeno behavior can be effectively eliminated. Finally, the effectiveness of the proposed strategy is verified via a simulation example.

With the rapid growth of e-commerce platforms, consumers increasingly make purchase decisions without direct physical interaction, particularly for tactile-dependent categories such as furniture and home décor. Drawing on embodied cognition, this study investigates how visual-based tactile cues influence consumers’ purchase intention on e-commerce platforms. Using experimental methods, two studies manipulate the level of visual-based tactile cues (high vs. low) and examine their effects on purchase intention. The results show that richer visual-based tactile cues significantly increase purchase intention. Contrary to traditional information overload assumptions that additional visual detail may hinder decision-making, this effect occurs through enhanced immersion rather than increased cognitive burden, suggesting that visual-based tactile cues operate as embodied sensory triggers instead of purely informational inputs. Furthermore, cross-modal mental imagery moderates this process in a counterintuitive way: the indirect effect of visual-based tactile cues on purchase intention via immersion is stronger when consumers’ imagery ability is lower, indicating a compensatory role of external sensory cues. By conceptualizing visual-based tactile cues as an innovation in interactive marketing within new media environments, this research offers actionable design implications for e-commerce platforms in enhancing tactile perception through visual presentation and improving conversion effectiveness.