Search Results (1,238)

The growing flexibility of load dispatching in modern smart grids has exposed critical limitations in conventional capacity pricing mechanisms, which calculate charges based solely on monthly maximum demand without distinguishing when peak demand occurs. This approach fails to reflect the temporal value of capacity and provides insufficient incentives for demand-side optimization. To address these challenges, this paper proposes a time-of-use (TOU) capacity pricing method that integrates user load characteristics to enable more equitable cost allocation and optimized electricity consumption patterns. The methodology employs K-means clustering analysis of user load profiles to partition pricing periods, accurately capturing differential capacity value across temporal intervals. We validate the clustering approach through the elbow method and silhouette analysis, confirming k = 3 as optimal and demonstrating K-means superiority over hierarchical and density-based alternatives. This data-driven approach ensures that period delineation reflects actual consumption patterns of commercial and industrial users. A capacity cost allocation model is established using the Shapley value method, incorporating maximum demand in each designated period while maintaining revenue neutrality for the grid operator. The 80% load simultaneity factor is empirically validated using 12 months of Shanghai industrial data (May 2023–April 2024). A Stackelberg game-based pricing model for TOU capacity tariffs is developed, incentivizing users to deploy energy storage systems and optimize charging strategies. We prove game convergence theoretically and demonstrate equilibrium achievement within 3–5 iterations across diverse initialization scenarios. Energy storage capacity is optimized by sector (3.5–6.5% of peak demand) rather than uniformly, and realistic battery self-discharge rates (0.006%/hour) are incorporated. Case study analysis using real operational data from 11 commercial and industrial sub-sectors in Shanghai demonstrates effectiveness. Extended to 12 months with seasonal analysis, results show the proposed strategy reduces the peak-to-valley difference ratio by 2.4% [95% CI: 1.9%, 2.9%], p < 0.001; increases the system load factor by 1.3% [95% CI: 0.9%, 1.7%], p < 0.001; and achieves reductions in users’ total capacity costs of 3.6% [95% CI: −4.2%, −3.0%], p < 0.001. Comparative analysis shows the proposed method significantly outperforms simple TOU (improvement +1.2 pp) and peak-responsibility pricing (improvement +0.6 pp). Monte Carlo robustness analysis (1000 scenarios) confirms performance stability under demand uncertainty. This research provides theoretical foundations and practical methodologies for capacity cost allocation, offering valuable insights for policymakers and utilities seeking to enhance demand-side response mechanisms and improve power resource allocation efficiency. Full article

In this study, the electrochemical reduction of CO₂ to CO within a bilayer cobalt phthalocyanine (CoPc)₂ confinement system was systematically investigated using density functional theory (DFT). The results reveal that the (CoPc)₂ architecture creates a well-defined catalytic microenvironment, in which the synergy between vertical spacing (regulated by moderate interlayer interactions) and lateral displacement gives rise to an optimal “Goldilocks zone”. This zone is characterized by a vertical distance (D) of 4.25–4.5 Å and a parallel displacement (L) of approximately 1 Å. Within this confined environment, the adsorption and desorption of key intermediates are optimally balanced, leading to enhanced catalytic activity. Electronic structure analysis further demonstrates that such spatial confinement induces asymmetric charge redistribution in the CO₂ molecule, resulting in distinct regioselectivity. This work provides a general design strategy for developing high-performance and site-selective catalysts through precise engineering of interlayer geometric environments. Full article

Plastic pyrolysis is widely used to treat polyolefin-rich waste; however, wax byproducts generated during these processes are typically regarded as low-value intermediates. Here, a byproduct-compatible upcycling strategy is proposed to convert polyethylene (PE) pyrolysis wax into activated carbon, enabling integration of functional carbon production into existing recycling value chains. Thermal oxidation was employed to stabilize the wax prior to carbonization, and stabilization at 300 °C yielded a mechanically stable precursor with a high carbon yield. Subsequent carbonization and KOH activation at 900 °C produced an activated carbon (PEWax_AC) with a specific surface area of 1704 m²/g, exceeding that of a representative commercial activated carbon (1575 m²/g). Microstructural analysis revealed predominantly amorphous carbon with locally ordered domains. In symmetric supercapacitor cells, PEWax_AC exhibited higher capacitance at low rates and superior rate capability at high scan rates and current densities, along with reduced charge-transfer resistance. Specifically, PEWax_AC delivered a specific capacitance of 22.9 F/g at 5 mV/s and exhibited a rate retention of 18.6% from 0.1 to 7.0 A/g. These findings demonstrate that plastic pyrolysis wax is a viable and scalable carbon precursor for high-performance supercapacitor electrodes. Full article

In this investigation, the nonlinear dust-acoustic waves in the lunar terminator region are studied in a three-component complex plasma comprising Boltzmann-distributed electrons and ions and inertial, cold, negatively charged dust grains. The fluid model is reduced, via the reductive perturbation technique, to a planar Korteweg–de Vries (KdV) equation that governs the evolution of small-amplitude dust-acoustic structures in this environment. Hirota’s direct method is then employed to derive exact multiple-soliton solutions, which allow us to examine the parameter dependence of dust-acoustic solitons and to characterize their overtaking collisions. The analysis shows that the soliton polarity and amplitude are controlled by the equilibrium electron–ion density ratio and the electron-to-ion temperature ratio, and that multi-soliton interactions remain elastic, with only finite phase shifts after collision. In the second part of the study, the planar integer KdV model is generalized to a time-fractional KdV (FKdV) equation to incorporate nonlocal temporal memory effects in the dust-acoustic dynamics. This FKdV equation is analyzed using two analytical approximation schemes: the Tantawy technique, recently proposed as a direct and rapidly convergent approach to fractional evolution equations, and the new iterative method, a widely used high-accuracy scheme in the fractional literature. For both methods, higher-order approximations are constructed, and their absolute and global maximum residual errors are quantified. The results demonstrate that the Tantawy technique provides compact approximations with superior accuracy and stability compared with the new iterative method for the present FKdV-soliton problem. The combined integer- and fractional-analytic framework provides a physically transparent framework for understanding how nonlinearity, dispersion, and fractional memory jointly shape dust-acoustic solitary structures in the electrostatically complex lunar terminator plasma, which is of paramount interest for future lunar missions like Luna-25 and Luna-27. Full article

The efficient removal of low-concentration antibiotics from wastewater is a persistent challenge. In this work, we enhance the performance of a W-BiVO₄ photoanode by modifying it with CoNi-based metal–organic framework nanosheets (CoNi-MOF), constructing a W-BiVO₄@CoNi-MOFN composite. This integration markedly improves the separation and migration of photogenerated charge carriers. Consequently, the modified photoanode delivers a substantially higher photocurrent density of 3.92 mA cm⁻² at 1.23 V_RHE, representing a 2.3-fold enhancement over the pristine W-BiVO₄ (1.74 mA cm⁻²). Furthermore, the photoelectrocatalytic (PEC) system employing the W-BiVO₄@CoNi-MOFN photoanode demonstrates significantly superior degradation efficiency for low-concentration tetracycline compared to the system based on unmodified W-BiVO₄. The performance enhancement is attributed to a dual mechanism. First, the CoNi-MOF modification optimizes the PEC performance of W-BiVO₄, facilitating the generation of photogenerated holes and active oxidants. Second, the composite photoanode exhibits enhanced tetracycline adsorption via π–π stacking and hydrogen bonding, thereby promoting degradation kinetics. The photoanode also shows excellent reusability. Total organic carbon (TOC) analysis and biotoxicity tests confirm effective mineralization and reduced environmental toxicity. Furthermore, the system demonstrates promising concurrent cathodic hydrogen evolution. This work highlights the potential of the W-BiVO₄@CoNi-MOFN-based PEC system for integrated wastewater treatment and hydrogen production. Full article

The electrochemical CO₂ reduction reaction (CO₂RR) offers a sustainable route for converting greenhouse gases into high-value fuels; however, its efficiency has long been constrained by the thermodynamic stability of CO₂ molecules and the competing hydrogen evolution reaction. Using density functional theory (DFT) calculations, this work systematically investigates the catalytic performance of Ni₅ and alloy Ni₄Cu clusters anchored on divacancy graphene (DVG) for CO₂RR. The results demonstrate that the introduction of Cu atoms significantly enhances the interfacial binding energy between the cluster and the support (shifting from −6.2 eV to −7.5 eV). Charge density difference analysis combined with Bader charge analysis further reveals that interfacial charge transfer and the formation of Ni–C bonds serve as the electronic origin of this improved stability. Free energy calculations show that, compared to Ni₅/DVG, Ni₄Cu/DVG substantially reduces the energy barrier of the rate-determining step for formic acid (HCOOH) formation from 1.18 eV to 0.26 eV, thereby significantly optimizing the reaction kinetics. Crystal orbital Hamilton population (COHP) analysis demonstrates that Cu doping modulates metal–oxygen bond strength in the key *OCHO intermediate (ICOHP: Ni-O bonds at −0.697 eV/−0.976 eV vs. Cu-O bonds at −0.408 eV/−0.492 eV), optimizing the adsorption–desorption balance and steering selectivity toward HCOOH. This work elucidates the atomic-scale electronic and bonding mechanisms underlying Ni–Cu synergistic effects, providing theoretical guidance for designing efficient non-noble metal CO₂RR electrocatalysts. Full article

Under China’s “Dual Carbon” goals, the electric vehicle (EV) industry has expanded rapidly, while the imbalance between supply and demand in public charging infrastructure (PCI) has emerged as a critical bottleneck. Accordingly, a structural assessment of PCI demand potential is essential for improving planning effectiveness. Focusing on the seven municipal districts of Qingdao, this study developed a dual-dimensional framework integrating physical space and population activity. Five core factors were incorporated: road network accessibility, road network betweenness, POI functional mixing density, population distribution density, and nighttime light intensity. By integrating Spatial Design Network Analysis (sDNA), Kernel Density Estimation (KDE), and the entropy weighting method, we conducted a structural assessment of PCI demand potential and derived spatial demand tiers and hierarchy. The results indicate that: (1) road network betweenness had the highest weight (0.396), acting as the dominant driver of structural demand potential, followed by POI functional mixing density (0.271), whereas nighttime light intensity (0.151) and population distribution density (0.143) functioned as baseline supportive indicators; (2) spatial demand was classified into five levels (Levels 1–5), with Level 1 hotspots exhibiting a radial spatial structure characterized by “one primary core, four secondary cores, three corridors, and multiple nodes”; and (3) while the existing PCI distribution exhibited overall gradient consistency with the structurally derived demand tiers, quantitative deviation results indicated localized mismatches, including under-allocation in high-demand areas and over-allocation in selected lower-demand pockets. The proposed dual-dimensional framework facilitates the identification of structural demand gradients for PCI by explicitly incorporating traffic-flow potential, functional aggregation, and population concentration. These findings provide planning-oriented diagnostic support for PCI configuration and contribute to the sustainable transformation of urban transportation systems in megacities. Full article

Antibiotics are extensively used in intensive livestock farming for disease prevention, resulting in the discharge of antibiotic-contaminated wastewater into aquatic environments. Addressing this issue, electrocatalytic oxidation has emerged as a promising alternative to conventional chemical oxidation due to its cost-effectiveness and minimal secondary pollution. Central to this technology is the development of catalytic electrodes with high specific surface area and superior electrocatalytic activity. In this work, an Fe₃O₄-modified activated carbon fiber electrode (Fe₃O₄@ACF) was fabricated via a co-precipitation method. The Fe₃O₄@ACF electrode exhibited a hierarchical porous structure with a specific surface area of 940.2 m²/g, and demonstrated significantly enhanced oxygen reduction reaction activity with a current density of 21.8 mA·cm⁻² at –3.25 V vs. Ag/AgCl, which is 2.3 times higher than that of pristine ACF. EIS analysis revealed a low charge transfer resistance of 7.18 Ω, indicating improved electron transfer kinetics. In electro-Fenton degradation of tetracycline, the electrode achieved 82% removal within 120 min with a first-order rate constant of 0.01335 min⁻¹, and maintained over 94% of its initial activity after ten cycles. This study offers a viable and sustainable strategy for the efficient treatment of antibiotic-containing medical wastewater. Full article

Shaped charge is widely used in petroleum drilling, yet the inherent parametric uncertainty of oil shale introduces significant uncertainties that affect perforation outcomes. The complex coupling of oil shale constitutive parameters under extreme strains poses challenges for uncertainty quantification. A coupled algorithm integrating an improved material point method (MPM) and polynomial chaos expansion (PCE) is presented, and polynomial chaos expansion (PCE) is used to systematically analyze the uncertainty and sensitivity of shaped charge jet penetration depth. Mechanical parameters from oil shale samples at Checun Coal Mine well No. 1 were tested to define key parameter ranges and establish a reliable uncertainty space. A benchmark simulation of a single isolated shaped charge jet validated the algorithm, and Sobol’ global sensitivity analysis identified internal friction angle, density, and Poisson’s ratio as strongly sensitive parameters, while tensile strength, Young’s modulus, and cohesion showed weak sensitivity, supporting surrogate model dimensionality reduction. Composite detonation models of three and five charges further revealed the effects of multi-projectile blast wave coupling on jet dynamics, providing new theoretical insights into cluster effects under high-energy, high-pressure, and extreme-strain conditions. Sensitivity and uncertainty analyses based on surrogate models emphasized the critical influence of internal friction angle alongside Poisson’s ratio and density. A reliable numerical framework is established for multi-physics coupled simulations of geomechanical responses under complex multi-source explosive loading. Full article

Additive engineering has become a critical strategy for optimizing the morphology and performance of bulk heterojunction (BHJ) organic solar cells (OSCs), while volatile solid additives have been widely employed to control nanoscale phase separation during film formation. Concerns regarding reproducibility, residual solvent effects, and long-term stability have stimulated increasing interest in non-volatile solid additives. In recent years, solid additive engineering has emerged as a promising approach for modulating molecular packing, regulating phase separation, enhancing charge transport, and improving device stability. However, a systematic analysis of its material design principles and performance impact remains limited. This review summarizes recent progress in solid additive engineering for OSCs, categorizing reported additives into non-volatile, volatile and nanomaterials. The effects of these additives on key photovoltaic parameters, including open-circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF), and power conversion efficiency (PCE), are comparatively analyzed based on the reported data. Particular emphasis is placed on morphology and structural performance relationships and stability enhancement mechanisms. Finally, current challenges, including the lack of universal molecular design rules and limited mechanistic understanding of additive host interactions, are discussed, and future research directions are proposed. This review aims to provide a comprehensive perspective on the material-level role of solid additives and to guide the rational design of next-generation high-performance and stable organic solar cells. Full article

The rapid diffusion of electric vehicles (EVs) is expected to reshape electricity demand patterns, particularly in urban areas where charging infrastructure and mobility transitions are expanding rapidly. While the existing literature has mainly focused on the optimal location of charging infrastructure and on the direct technical implications of EV charging for electricity systems, relatively limited attention has been devoted to the broader relationship between the spatial distribution of public charging infrastructure and residential electricity demand. This study investigates the relationship between public charging infrastructure density and residential electricity consumption across Italian municipalities. Using a dataset covering 40 provincial capitals and applying spatial econometric techniques, the analysis explores both local associations and potential spatial spillover patterns across neighboring municipalities. In particular, Ordinary Least Squares (OLS), Spatial Autoregressive (SAR), and Spatial Durbin Models (SDM) are estimated in order to account for spatial interdependencies in the data. The results reveal a positive and statistically significant association between the density of public charging infrastructure and residential electricity consumption at the municipal level. The preferred Spatial Durbin specification also indicates the presence of spatial spillover patterns, suggesting that charging infrastructure density in neighboring municipalities is positively associated with residential electricity consumption locally. These patterns may reflect regional diffusion dynamics related to electric vehicle adoption, infrastructure visibility, and geographically interconnected urban development processes. Given the cross-sectional nature of the dataset, the results should be interpreted as associative rather than causal relationships. Nevertheless, the findings provide useful insights into how the spatial expansion of charging infrastructure is linked to evolving electricity demand patterns in urban contexts. Overall, the results highlight the importance of considering spatial interdependencies when planning charging infrastructure deployment and electricity network adaptation in the context of the transition toward sustainable electric mobility. Full article

To develop high-performance iridium phosphorescent complexes, we designed and synthesized a series of iridium phosphorescent complexes (G-1, G-2, B-1, B-2, R-1, R-2) using 3-hydroxy-2-methyl-4-pyrone (maltol, short for mal) and 3-hydroxy-2-ethyl-4-pyrone (ethyl maltol, short for emal) as auxiliary ligands, in combination with 2-phenylpyridine (ppy), 2-(2,4-difluorophenyl)pyridine (dfppy), and 1-phenylisoquinoline (piq) as cyclometalating ligands. We systematically investigated their crystal structures, photophysical behavior, electrochemical properties, and electroluminescent performance. The results revealed that the combination of a pyranone auxiliary ligand with the highly conjugated piq ligand leads to the formation of R-1 and R-2, which possess high molecular symmetry and display favorable photophysical performance. These complexes exhibit solution-phase phosphorescence quantum yields of 64% and 55%, and electroluminescent devices incorporating them reach a maximum external quantum efficiency of 13.4%, with brightness exceeding 13,000 cd/m² and minimal efficiency roll-off. In contrast, complexes incorporating pyridine-based cyclometalating ligands (ppy, dfppy)—G-1, G-2, B-1, and B-2—display weak emission in solution but show enhanced solid-state emission through π–π stacking, with a maximum quantum yield of 25.8%. Density functional theory calculations and electrochemical analysis indicate that the presence of both the pyranone auxiliary ligand and the piq ligand results in optimized frontier orbital energy alignment, enhanced metal-to-ligand charge transfer, and reduced non-radiative transitions, thereby improving emission efficiency. This study provides a theoretical framework and molecular design strategy for the application of pyranone auxiliary ligands in high-performance iridium phosphorescent materials. Full article

Based on density functional theory, the structural, mechanical, and photoelectric properties of the perovskite material Cs₂SeCl₆ were systematically studied under pressures ranging from 0 to 50 GPa. Analysis of structural parameters indicates that the lattice constant, unit cell volume, and bond length decrease progressively with increasing pressure. Notably, the material maintains structural stability across the entire pressure range. Electronic property calculations show that Cs₂SeCl₆ retains an indirect band gap under pressure, with the band gap value monotonically decreasing as pressure increases. The orbital contributions remain almost unchanged at different pressures. The conduction band is mainly composed of Cl-p and Se-p orbitals, while the valence band is dominated by Cl-p orbitals. The analysis of the effective mass indicates that the transport capability of charge carriers is enhanced under compression. Mechanical stability and ductility were evaluated by calculating the elastic constants and derived mechanical moduli, confirming that the material remains mechanically stable under high pressure. Optical properties were investigated by computing the dielectric function, reflectivity, refractive index, optical absorption coefficient, and extinction coefficient. Collectively, the findings of this work demonstrate that the pressurized Cs₂SeCl₆ exhibits excellent structural robustness, improved charge transport, and promising photoelectric performance, making it a strong candidate for applications in solar cells and other photoelectronic devices. Full article

Ionic polymer–metal composites consist of an ion-conducting polymer–gel membrane sandwiched between two flexible electrodes, representing a class of soft electroactive materials capable of large deformation under low voltage. The gel membrane, swollen with solvent, facilitates ion migration under an electric field, enabling actuation. Tailoring the interfacial architecture between the electrode and the polymer–gel membrane is pivotal for advancing high-performance IPMC actuators. This study presents a comparative investigation of three core–shell nanocomposite electrodes, fabricated via in situ polymerization, for IPMC applications. Among these, the polyaniline-coated multi-walled carbon nanotube composite exhibits a deliberately designed hierarchical structure, with a specific surface area of 32.345 m²·g⁻¹ and a conductive doped polyaniline shell, as confirmed through XPS analysis. This optimized interface enables superior charge storage and transport, endowing the corresponding electrode with a specific capacitance of 40.28 mF·cm⁻² at 100 mV·s⁻¹—3.2 times greater than that of conventional silver-based electrodes—along with a reduced sheet resistance. When integrated with a Nafion ion–gel membrane, the PANI@MWCNT electrode achieves a 67% increase in force density and a larger displacement output compared to standard devices, directly correlated with its enhanced electrical and electrochemical properties. This work highlights the critical role of core–shell interfacial engineering in governing electromechanical performance at the electrode–gel interface and offers a practical design strategy for developing high-performance, cost-effective IPMC actuators for soft robotics, flexible electronics, and related applications. Full article

We report a rare family of pyridine-coordinated iodobismuthate(III) salts supported by alkyltriphenylphosphonium and tetraphenylphosphonium cations. Reactions of BiI₃ with Ph₃PR⁺I⁻ (R = Me, Et, ⁿPr, ⁿBu, Ph) in neat pyridine, followed by crystallization, yield structurally tunable bismuth-halide-pyridine anions dictated by reagent stoichiometry. Combination of BiI₃ and Ph₃PR⁺I⁻ in 2:1 ratio produced [Ph₃PR]₂[BiI₅Py], 1 (R = Me, Et, ⁿPr, Ph), while combination in 1:1 ratio resulted in three compounds: [Ph₃PR][cis-BiI₄Py₂], 2 (R = ⁿPr, Ph), [Ph₃PR][trans-BiI₄Py₂], 3 (R = Me, Et, Ph), and [Ph₃PR]₂[transoid-Bi₂I₈Py₂], 4 (R = Me, Et, ⁿPr, ⁿBu, Ph). In many cases, the compounds were isolated as Py or Et₂O solvates, and in some cases, multiple degrees of solvation or polymorphism were encountered. Hirshfeld analysis of 1–4 showed the major anion–cation/anion/solvent interactions to be H⋯I, H⋯H, and C⋯H. Diffuse reflectance measurements of representative compounds, all of which were yellow-orange to red-orange, revealed bandgaps in the range of 1.9–2.2 eV, where density-of-states KS-DFT calculations attribute the absorption to metal-centered charge transfer within the anionic unit. NLMO and QTAIM analyses further indicate predominantly ionic Bi(III)–I/pyridine bonding with robust inner-sphere coordination that is insensitive to anion speciation. Full article