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Overcoming rapid capacity decay and structural instability remains a key challenge for the commercialization of O3-type layered cathode materials. This study investigates the effect of yttrium (Y) doping on the performance of NaNi1/3Fe1/3Mn1/3O2 (NNFMO) cathode material for sodium-ion batteries. Compared to the TM-O bonds in the unmodified material, the Y-doped material has stronger Y–O bonds that form a stable structure. Y doping enhances the reversibility of Ni/Fe redox reactions and mitigates the irreversible P3-O'-P3' phase transition. Electrochemical analysis reveals that the Y-doped cathode material (NNFY-10000) exhibits excellent rate performance and remarkable cycle stability. Specifically, NNFY-10000 maintains a discharge capacity of 110.6 mAhg−1 at a 1 C rate and retains 72.26% of its capacity after 200 cycles, outperforming undoped NNFMO. These improvements are attributed to the stable structure formed by strong Y–O bonds, reduced polarization during the cycling process, and enhanced redox reaction reversibility due to Y doping. This study not only elucidates the mechanism by which Y doping improves the electrochemical performance of NNFMO but also provides valuable insights for the development of high-performance sodium-ion battery cathode materials. The strategic introduction of rare earth elements such as Y offers a promising approach to overcoming the inherent limitations of O3-type layered cathode materials, paving the way for their practical application in energy storage systems. [ABSTRACT FROM AUTHOR]

A grid-forming wind generation system exhibits exceptional grid frequency support abilities. The DC capacitor of the grid-forming wind generation system, which is characterized by rapid response and high sensitivity to minor disturbances, can provide short-term inertia support for the power system. This paper proposes the capacitor virtual inertia control for the grid-forming wind generation system, coupling the DC capacitor voltage with the power system frequency, which enables the DC capacitor to participate in the system frequency response process and reduces the rate of change of the system frequency during the disturbance. To analyze the inertia of the wind power generation system, this paper establishes an equivalent Philips-Heffron model for the grid-forming wind generation system and uses the equivalent inertia constant to quantify the inertia of the wind power generation system. The effectiveness of the proposed control strategy and the reasonableness of the inertia assessment method are verified through simulations in the single-turbine system and the IEEE four-machine two-area system. [ABSTRACT FROM AUTHOR]

AbstractHerein, a high-sensitive electrochemical sensor based upon a multi-walled carbon nanotubes modified screen-printed carbon electrode (MWCNTs-SPCE) was constructed for the determination of isoliquiritigenin (ISL). The electrochemical properties of ISL on the MWCNTs-SPCE were investigated systematically and a fast and cost-effective method for the determination of ISL was successfully established. A clear irreversible oxidation peak of the ISL was observed at 0.3 V (versus Ag/AgCl) on the MWCNTs-SPCE. The oxidation of ISL on MWCNTs-SPCE was an adsorption reaction accompanied by diffusion. Using differential pulse voltammetry (DPV), we observed that the oxidation peak current of the ISL in phosphate buffer (pH 7) showed a linear relationship from 0.50 to 100 µg/mL and a detection limit of 0.10 µg/mL. This method displayed good repeatability and stability, as well as exhibited excellent selectivity for ISL. Also, we successfully applied the method to determine ISL in Chinese herbal medicine licorice. Validation of the analyses via spike assays showed a recovery rate ranging from 95.39 to 101.00%, which was consistent with high performance liquid chromatography (HPLC). [ABSTRACT FROM AUTHOR]

The electronic structure and magnetic properties of Li(ZnMn)As with antisite defects have been investigated by using first-principles calculations within the Perdew–Burke–Ernzerhof generalized gradient approximation. The cation antisite defect induced by Zn substitution for As was considered. Mn-3d, As-4p, Zn-4s, and Zn-4p were involved in the formation of d-sp hybrid orbitals, which enhanced the non-localized properties of Mn-3d electrons and provided a channel of Mn(↑)–As(↓)–ZnAs(↓)–Mn(↑) for indirect exchange of electrons between the magnetic ions. The antisite defect of Zn-substituted As belonged to the acceptor doping, rendering the compound p-type characteristics. The existence of the extra free hole carriers regulated the magnetic ordering transition. The ferromagnetic coupling between the Mn magnetic dopants was more favorable in the system with an antisite defect. In this paper, a novel type of dilute magnetic semiconductor with controllable carriers was designed and the mechanism of ferromagnetic coupling was revealed, which provided a theoretical reference for the subsequent studies. [ABSTRACT FROM AUTHOR]

The pseudobinary Ti0.5Ni0.5-Ti0.5Cu0.5 system was analyzed using thermodynamic models for the Gibbs energy of individual phases in the system. The TiNi intermetallic phase crystallizes with the B2 CsCl-type structure and is an ordered form of the A2 BCC structure. It was treated with a two-sublattice model (Cu, Ni, Ti, Va)0.5(Cu, Ni, Ti, Va)0.5, where Va represents a vacancy and one sublattice is occupied predominantly by Ti and the other by Ni and Cu. Other phases such as B11 based on a TiCu compound and low-temperature phases B19′ and B19 were also described with two-sublattice models with different distribution of atoms on each sublattice. A thermodynamic description of the Ti0.5Ni0.5-Ti0.5Cu0.5 system was obtained from an optimization based on experimental information. The calculated diagram of the pseudobinary Ti0.5Ni0.5-Ti0.5Cu0.5 system at high temperatures exhibits eutectic solidification of liquid and shows satisfactory agreement with experimental data. The phase relations among the B2, B19′, and B19 phases at low temperatures were also assessed on the basis of experimental information from martensitic transformations. [ABSTRACT FROM AUTHOR]

The secondary aluminum ash is the black slag left after the primary aluminum ash is extracted from the metal aluminum. To address the environmental pollution and resource waste caused by the accumulation and landfill of aluminum ash, this study fabricated non-fired bricks by using secondary aluminum ash as the principal raw material, which was supplemented by cement, slaked lime, gypsum and engineering sand. The effects of mix proportions of various admixtures on the mechanical properties of non-fired bricks were investigated, and on this basis, the hydration mechanism was analyzed. The results showed that the mix proportions were 68.3% aluminum ash, 11.4% cement, 6.4% slaked lime, 4.2% gypsum and 9.7% engineering sand. The compressive strength of the fabricated bricks reached 22.19 MPa, and their quality indicators were in line with the MU20 requirements for Non-fired Rubbish Gangue Bricks. Evident hydration reaction occurred inside the non-fired bricks, with main products being calcium silicate hydrate (CSH), calcium aluminate hydrate (CAH) and ettringite (AFt). Besides, a dense structure was formed, which enhanced the brick strength. [ABSTRACT FROM AUTHOR]

Defect engineering is extensively utilized in 2D memory devices due to its effectiveness in enhancing charge‐trapping ability. However, conventional defect modulation techniques usually introduce only single types of carrier traps and cannot reconfigure trap types and densities after device fabrication. Here, for the first time, electrical stimulation‐driven long‐range migration of Cu ions within CuInP2S6 (CIPS) films is demonstrated to simultaneously introduce both electron and hole traps and enable reconfigurable modulation of interfacial defect trapping. This process is referred to as “electrical stimulation‐induced defect engineering”. By integrating these defect traps and the dual‐gate coupling effect, the memory window‐to‐scan range (MW/S.R) ratio, which reflects the device's charge trapping ability, doubled and peaked at 78.1% at Vbg = ± 80 V. Additionally, the dual‐gate memory device based on the graphene/CIPS/h‐BN/WSe2 heterostructure exhibits a maximum on/off ratio reaching 107 for multi‐level storage states, integrating neuromorphic computing and logic operations within a single platform. With 81 storage states and paired‐pulse facilitation (PPF), it achieves ≈90% accuracy in reservoir computing (RC) simulations. These results highlight the potential of electrical stimulation‐induced defect engineering for next‐generation electronics. [ABSTRACT FROM AUTHOR]