Acta Energiae Solaris Sinica•2026•DOI: 10.19912/j.0254-0096.tynxb.202608_9728
Adaptive super-twisting sliding mode control (ASTSMC) for permanent magnet synchronous motors (PMSM) suffers from prolonged convergence and insufficient disturbance rejection under complex operating conditions. This paper proposes an improved ASTSMC incorporating a fixed-time disturbance observer (FTDO). A power term is introduced into the adaptive super-twisting controller to accelerate convergence far from the origin, while the discontinuous sign function is replaced by a continuous h(s) function to mitigate chattering. The FTDO ensures disturbance estimation converges within a fixed time independent of initial states, overcoming the limitations of traditional and finite-time observers. The estimated disturbance is fed forward to the sliding mode controller for compensation, enhancing robustness. The FTDO design is based on an auxiliary state variable z and its derivative, with error dynamics analyzed via Lyapunov stability. Comparative simulations against conventional disturbance observers and sliding mode controllers validate the proposed strategy. The results demonstrate shorter convergence time, improved dynamic performance, and superior disturbance rejection, making the approach suitable for high-performance servo systems. The method addresses the critical need for robust, fast-response control in electric vehicles, rail transit, and aerospace applications where PMSM drives face significant uncertainties and external disturbances.
Power Automation Equipment•2026•DOI: 10.16081/j.epae.202606001
The increasing penetration of renewable energy sources has introduced novel instability phenomena in power grids, such as sustained and repeated low-voltage ride-through events, which existing models fail to analyze or explain. This paper addresses the typical continuous-discrete hybrid characteristics of renewable energy generation systems at both the unit and station levels. It discusses the interwoven discrete multi-mode switching and continuous state evolution during faults, emphasizing the necessity of hybrid models. Four classes of hybrid models are compared, including hybrid automata, hybrid Petri nets, switching models, and piecewise affine models, with their applicable scenarios. For switching models and piecewise affine models, parameter identification methods are proposed, and their applicable scenarios are discussed. To tackle the challenge of aggregating dispersed renewable units with diverse discrete event states, a mechanism-data fusion hybrid model aggregation method is proposed. Future research directions for hybrid characteristic modeling of renewable energy generation systems are outlined. The review highlights that current hybrid models remain in an early stage, and mechanism-data fusion modeling is a promising supplement. Key challenges include balancing model complexity and accuracy, and addressing the contradiction between diverse transient behaviors and model universality.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3798-x
Ulcerative colitis (UC) is a chronic inflammatory disorder of the colorectal mucosa, where conventional enema therapies suffer from poor retention and limited inflammation modulation. Here, we report a highly fluid probiotic-containing enema solution (s-BSA-Fe+EcN) integrating bovine serum albumin (BSA), Fe2+, and probiotic Escherichia coli Nissle 1917 (EcN). The solution's high fluidity enables comprehensive coverage of irregular colorectal mucosa. Upon encountering reactive oxygen species (ROS)-rich inflamed lesions, Fe2+ mediates H2O2 scavenging and hydroxyl radical generation, triggering BSA crosslinking and in situ gelation into a conformal hydrogel (h-BSA-Fe+EcN). This targeted adhesion mitigates oxidative damage to host tissues and preserves probiotic viability. In a porcine model, endoscopic imaging confirmed inflammation-targeted gelation in vivo. In a dextran sulfate sodium-induced mouse colitis model, h-BSA-Fe+EcN demonstrated excellent therapeutic efficacy, reducing disease activity index and restoring colonic architecture. This strategy addresses the dual challenges of fluid perfusion and rapid ROS-responsive gelation, offering an advanced transanal treatment for UC.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025030403
Microplastics (MPs) act as vectors for co-migrating antibiotics and heavy metals, forming complex pollution systems with potential joint toxicity. However, the differential adsorption behaviors and underlying mechanisms of MPs toward organic versus inorganic pollutants remain insufficiently understood. This study selected polypropylene (PP) microplastics, a major component of agricultural plastic films, and investigated the adsorption of sulfamethoxazole (SMX) and Cr(VI) onto aged PP under varying environmental conditions. Results demonstrated that aging increased the maximum adsorption capacity by 2–3 times for both pollutants. Notably, aged PP exhibited approximately 30 times higher adsorption capacity for SMX than for Cr(VI). Characterization revealed that aging introduced oxygen-containing functional groups (e.g., carbonyl) on the MP surface, enhancing adsorption. Mechanistic analysis indicated that hydrogen bonding and electrostatic interactions dominated SMX adsorption, while Cr(VI) adsorption was primarily governed by electrostatic interactions and pore-filling. The stronger intermolecular forces for SMX compared to reversible pore-filling for Cr(VI) explained the observed differences. Increasing pH induced electrostatic repulsion, reducing adsorption of both pollutants. High concentrations of Na+ and Mg2+ caused charge shielding, potentially enhancing Cr(VI) adsorption but inhibiting SMX adsorption due to competition for active sites. The presence of organic matter (humic acid) had negligible effects on Cr(VI) adsorption but reduced SMX adsorption, likely due to complexation. These findings elucidate distinct molecular-level pathways for organic versus inorganic pollutant adsorption on aged MPs, highlighting the roles of hydrogen bonding and pore-filling in driving differential behaviors.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202607010
The impact of low concentrations of perfluorooctane sulfonate (PFOS) on anaerobic fermentation of waste activated sludge (WAS) remains poorly understood. This study applied three PFOS levels (0.5, 1.0, and 4.5 μg/g TSS) to systematically evaluate effects on organic matter solubilization and nitrogen/phosphorus transformations. Monitoring of soluble chemical oxygen demand (SCOD), soluble protein, polysaccharides, NH4+-N, PO43--P, and three-dimensional excitation-emission matrix (3D-EEM) fluorescence revealed that PFOS significantly enhanced release of SCOD, protein, and polysaccharides. At 45 °C after 14 days with 4.5 μg/g TSS, SCOD peaked approximately 28% higher than control, indicating increased biodegradable organic matter accumulation. NH4+-N concentrations rose overall with fluctuations, while PO43--P release was inhibited, suggesting interference with nutrient transformation pathways. 3D-EEM analysis showed strengthened signals of aromatic proteins and microbial by-products, confirming matrix solubilization. These findings demonstrate a dual effect of low-level PFOS: initial promotion of organic matter release followed by potential inhibition of nutrient transformation. This study provides data support for understanding PFOS environmental behavior in anaerobic digestion and informs sludge resource utilization and risk assessment of emerging contaminants.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4143-9
High-Ni (Ni ≥ 0.9) layered cathodes are being developed to endure high-voltage operations above 4.5 V to boost energy density. However, they face exacerbated chemo-mechanical and electrochemical degradation under high-voltage operation, primarily due to excessive lattice strain and phase distortion during cycling. Here, we engineer a high-Ni, Co-free cathode featuring a multicomponent complex doping-modulated bulk structure, coupled with surface modification via a multifunctional atomic layer deposition-coated LiAlO2 layer. Such a unique framework achieved by surface-to-bulk integrated modification can not only greatly prevent lattice stress-induced mechanical degradation but also effectively mitigate the accumulation of by-products due to surface side-reactions. Moreover, the LiAlO2 nanoshell with exceptional ion conductivity markedly enhances the sur-/interfacial Li-ion migration kinetics, thus rendering low electron/ion-diffusion resistance. The developed cathode breaks through existing voltage constraints without compromising on performance, achieving an exceptional balance between capacity and cycle stability during operation at 4.8 V. Notably, the pouch-type cells utilizing graphite and Li metal anodes demonstrate excellent cyclability under demanding conditions, even operating at high charging cut-off voltages of 4.5 and 4.6 V, respectively.
SCIENCE CHINA Materials•2025•DOI: 10.1007/s40843-025-3374-x
Industrial nitric acid production relies on the Haber-Bosch process for ammonia synthesis followed by the Ostwald process for oxidation, consuming vast fossil energy and emitting substantial greenhouse gases. Direct photocatalytic conversion of dinitrogen (N2), oxygen (O2), and water (H2O) into nitric acid (HNO3) under ambient conditions offers a sustainable alternative. This review critically examines recent advances in photocatalytic nitrogen oxidation (NOF), focusing on catalyst design, mechanistic insights into N2 activation, and performance metrics. The NOF pathway requires only 4 electrons versus a minimum of 6 for nitrogen reduction (NRF), lowering reaction energy barriers and potentially enhancing efficiency. Key challenges include the extreme inertness of the N≡N triple bond (bond dissociation energy 940.95 kJ mol−1), competing oxygen evolution reaction (OER), and the need for precise control over product selectivity. We analyze state-of-the-art photocatalysts, including tungsten oxide, bismuth oxychloride, and titania-based systems, and discuss strategies such as vacancy engineering, heterojunction construction, and co-catalyst loading. Performance benchmarks from recent studies reveal nitrate yields ranging from micromolar to millimolar levels, with apparent quantum efficiencies (AQE) often below 1% under visible light. The review identifies critical gaps in mechanistic understanding, particularly regarding the role of oxygen vacancies and reactive oxygen species, and proposes standardized testing protocols to enable meaningful comparison. We conclude that while NOF holds promise for decentralized fertilizer production, substantial improvements in catalyst stability, selectivity, and solar-to-chemical conversion efficiency are required for practical implementation.