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WZ
Verified CAS / Academic Author9 Decoded Studies

Prof. WANG Zhaofeng

North China Branch of State Grid Corporation of China, Beijing 100053, China; Beijing Kedong Electric Power Control System Co., Ltd., Beijing 100192, China

Co-Affiliations:Tianjin University

Research Publications & English Decoded Briefs

Showing 9 publications
Acta Energiae Solaris Sinica2026DOI: 10.19912/j.0254-0096.tynxb.202608_9706

Optimal Control Method for Renewable Energy Generation Based on Power Angle Stability of Sending-End Grid

The increasing penetration of renewable energy in sending-end grids introduces significant power angle and voltage stability challenges due to the stochastic and fluctuating nature of renewable generation. This paper proposes an optimal control method for renewable energy generation to enhance the power angle stability of sending-end grids. First, a model of a renewable energy generation transmission system is established, and the output power of renewable sources is optimized based on sending-end grid stability. Second, the dynamic responses of power angle and voltage under disturbances are analyzed, and a virtual power angle model characterizing the dynamic behavior of renewable energy units is derived. Third, a power angle stability control model based on energy fluctuation is developed to analyze the impact of energy fluctuations on power angle stability. Finally, a multi-objective optimization algorithm based on neural networks is employed to minimize power angle deviation and maximize transient stability margin of the sending-end grid. Simulation results validate the effectiveness of the proposed method. The method demonstrates significant improvements in grid stability, renewable energy utilization, and reduction of system power angle oscillations, thereby effectively enhancing the power angle stability of sending-end grids with high renewable penetration.

Power Automation Equipment2026DOI: 10.16081/j.epae.202605005

Temporal Regulation Domain for New-Type Power Systems: Concept and Methodology

The rapid proliferation of inverter-based renewables in new-type power systems has exposed the inadequacy of conventional point-based regulation capability assessments, which evaluate a single operating point and fail to capture the temporally coupled feasible space required for scheduling and resource allocation. This paper introduces the temporal regulation domain (TRD) as a global construct that maps all feasible system states satisfying intertemporal constraints into an observation space. A compact TRD model is formulated incorporating ramping, state-of-charge, power balance, security, and regulation cost budget constraints. Topological analysis establishes that the TRD is bounded, closed, and monotonically non-decreasing with respect to the cost budget. To overcome the curse of dimensionality in boundary characterization, a prior-constraint-guided deep neural network is developed, embedding monotonicity priors into the loss function. Simulations on a modified IEEE 118-bus system demonstrate that the proposed method efficiently and accurately delineates high-dimensional TRD boundaries. The TRD expands in a stepwise manner with regulation cost investment, exhibiting diminishing marginal returns; identifying the stepwise growth point provides a reliable reference for cost optimization. As renewable penetration increases, the TRD follows a steep-rise, plateau, and sharp-drop pattern, enabling identification of critical penetration thresholds to guide renewable deployment without violating security boundaries.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-026-4244-0

Boosting the Operational Stability of Near-Infrared Perovskite LEDs Utilizing a Zinc Ion-Chelated Hybrid Electron-Transport Layer: The Critical Role of Interfacial Reactions

Near-infrared perovskite light-emitting diodes (NIR-PeLEDs) suffer from poor operational stability, largely due to interfacial reactions at the electron-transport layer (ETL)/perovskite interface. Here, we introduce a zinc ion (Zn2+)-chelated hybrid ETL derived from a Zn2+-chelated polyethylenimine ethoxylated (PEIE) complex, which partially retains the surface properties of ZnO but exhibits significantly reduced oxygen defects and surface-adsorbed hydroxyl groups. This well-modulated surface promotes perovskite crystallization and mitigates interface-induced deprotonation of organic cations during device operation. Consequently, NIR-PeLEDs employing this hybrid ETL achieve a peak external quantum efficiency (EQE) of 20.1%, a high radiance of 652 W sr-1 m-2, and an exceptional T50 lifetime of 270.7 hours at a high current density of 100 mA cm-2, which is over five times that of devices based on conventional ZnO nanocrystal (NC) ETLs. Our results present an effective ETL strategy for operationally stable NIR-PeLEDs and thoroughly reveal the critical role of regulating interfacial reactions in stabilizing buried interfacial contacts. These findings provide valuable insights for advancing perovskite optoelectronic devices that suffer from interface-induced performance degradation.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-026-4359-0

Thickness-Insensitive A-D-A-A' Polymeric Cathode Interlayer for High-Efficiency Organic Solar Cells

Organic solar cells (OSCs) require cathode interlayers (CILs) that combine high charge transport, defect passivation, and thickness insensitivity for scalable manufacturing. Here, we report the synthesis of a novel A-D-A-A'-type polymer, PDPP2F-NDI-N, via the green and efficient direct arylation polymerization (DArP) method. The multiple electron-deficient units in the backbone confer strong electron-withdrawing character, effective work function modulation, enhanced built-in potential, high crystallinity, and ordered molecular packing. PDPP2F-NDI-N exhibits a high electron mobility of 1.01 × 10⁻³ cm² V⁻¹ s⁻¹ and electrical conductivity of 3.13 × 10⁻³ S m⁻¹, facilitating efficient charge extraction and transport. Its interfacial modification capability suppresses interfacial defects and reduces non-radiative recombination losses. In ternary OSCs, PDPP2F-NDI-N achieves a high power conversion efficiency (PCE) of 20.44%, with outstanding thickness insensitivity retaining 92.8% of peak PCE at a 30 nm CIL thickness, and a T80 lifetime exceeding 1700 hours under photo-thermal aging. This work demonstrates that poly(A-D-A-alt-A') backbone design combined with DArP synthesis provides an effective strategy for developing high-performance, thickness-insensitive, and stable polymeric CILs, advancing efficient, stable, and scalable OSC applications.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-3727-0

Multilevel Encapsulation-Engineered Ultra-Stable Flexible Scintillator Films for High-Resolution X-ray Imaging

Lead halide perovskites are promising scintillators for X-ray imaging due to high X-ray absorption efficiency, excellent luminescence, and facile synthesis. However, their ionic nature challenges simultaneous high photoluminescence efficiency and environmental robustness. This work introduces a multilevel encapsulation strategy: CsPbBr3 quantum dots (QDs) are sequentially coated with Cs4PbBr6, SiO2, and polydimethylsiloxane (PDMS). Cs4PbBr6 passivates surface defects, while SiO2 and PDMS provide barriers against moisture, heat, and radiation. The resulting CsPbBr3@Cs4PbBr6/SiO2/PDMS flexible films exhibit a photoluminescence quantum yield (PLQY) of 85%, outstanding mechanical flexibility, and durability under stretching, bending, and compressing. Films retain emission stability under elevated temperatures, prolonged X-ray irradiation, and extended water immersion. X-ray imaging demonstrates spatial resolution of 12 lp/mm, enabling distortion-free imaging of curved objects; superior water resistance allows long-term underwater imaging. This work highlights hierarchical encapsulation in balancing luminescence efficiency and stability, offering a pathway toward practical flexible perovskite scintillators.

Environmental Chemistry2026DOI: 10.7524/j.issn.0254-6108.2024112104

Neurotoxicity of Carboxyl-Modified Polystyrene Microplastics on Zebrafish at Early Developmental Stage

Carboxyl-modified polystyrene microplastics (PS-COOH) are negatively charged particles formed by surface oxidation and functional group modification of polystyrene microplastics (PS), widely used in biomedical and analytical chemistry. However, studies on their neurotoxic effects on aquatic organisms are scarce. This study employed zebrafish (Danio rerio) as a model organism, exposing embryos to environmentally relevant concentrations (0.1, 1, 10, 100 μg·L−1) of PS and PS-COOH. Neurotoxic effects were assessed by measuring tail coiling frequency at 24 hpf and swimming velocity under alternating light/dark cycles at 120 hpf. Results demonstrated that both PS and PS-COOH induced neurotoxicity, with PS-COOH significantly reducing tail coiling frequency and average swimming speed compared to PS (P<0.05). Exposure to 10 μg·L−1 PS-COOH disrupted neurotransmitter homeostasis, altering levels of acetylcholine (ACh), serotonin (5-HT), and γ-aminobutyric acid (GABA). Transgenic zebrafish Tg(huc:EGFP) fluorescence assays revealed that PS-COOH (0.1–100 μg·L−1) caused damage to central neurons. These findings indicate that PS-COOH exposure impairs cholinergic, serotonergic, and GABAergic neurotransmission, induces neuronal damage, and exerts neurotoxic effects on zebrafish larvae. This study provides a theoretical basis for assessing the ecological and health risks of modified microplastics.

Journal of Fuel Chemistry and Technology2026DOI: 10.1016/S1872-5813(25)60618-9

Advances in Catalytic Pyrolysis of Lignin toward Aromatic Hydrocarbon Production

Aromatic hydrocarbons, essential chemical feedstocks for fuels, synthetic fibers, and pharmaceuticals, are predominantly derived from petroleum refining. The catalytic conversion of lignin, a major lignocellulosic component, offers a renewable route to these chemicals. This review systematically examines the influence of pyrolysis methods, catalysts, and reaction conditions on the catalytic pyrolysis of lignin to aromatic hydrocarbons. Key parameters include catalyst acidity and pore structure, which govern selectivity and yield. Reaction temperature, catalyst-to-lignin ratio, and residence time critically affect product distribution. The review outlines catalytic mechanisms, such as deoxygenation, cracking, and aromatization, and highlights the role of zeolite catalysts, particularly HZSM-5, in enhancing monocyclic aromatic hydrocarbon yields. Metal modification (e.g., Fe, Ni, Ga) and pretreatment strategies (e.g., torrefaction) are discussed for improving efficiency. Challenges remain in catalyst deactivation due to coking and the complexity of lignin structure. Future research directions include developing robust catalysts, optimizing reactor designs, and integrating processes for industrial viability. This review provides theoretical and technological guidance for advancing lignin-to-aromatics conversion.

SCIENCE CHINA Materials2025DOI: 10.1007/s40843-025-3335-6

Nickel-Mediated Formation of Stable Frustrated Lewis Pairs in Rare Earth MOFs for Dicyclopentadiene Hydrogenation

Rare earth metal-organic frameworks (RE-MOFs) exhibit limited active site density and insufficient thermal stability, constraining their catalytic utility. This study employs heteroatom doping and defect engineering to synthesize RE-Ni-BTC materials. Nickel incorporation into RE-MOFs alters charge distribution and crystal structure stability, generating atomic-scale defects that induce RE–O frustrated Lewis pairs (FLPs) and a distinct Ni–O4 coordination motif. Nd-Ni-BTC surpasses Ce-Ni-BTC due to enhanced Lewis acid-base properties and superior substrate adsorption/desorption, achieving complete dicyclopentadiene (DCPD) conversion and at least seven recycling cycles under 100 °C, 2 MPa H2, and 10 h. The approach balances catalytic activity and stability without structural degradation, offering a route for defective MOFs in hydrogenation catalysis and catalyst design.

SCIENCE CHINA Materials2025DOI: 10.1007/s40843-025-3593-5

Blended phase separation strategy for seamless integration of ultrathin crystalline channels and charge trapping layers toward multimode neuromorphic optoelectronics

Organic ultrathin crystals, comprising monolayers or a few molecular layers, exhibit outstanding optoelectronic properties and have shown great promise for constructing advanced functional neuromorphic devices. However, scalable growth of high-quality organic ultrathin crystals and their seamless concurrent integration with charge trapping layers for multi-mode neuromorphic devices, that required in future high-density neuromorphic integration, remain challenging. Here, we present a scalable one-step fabrication strategy based on solution shearing, where spontaneous vertical phase separation of a small-molecule/polymer (Ph-BTBT-10/PS) blend enables the simultaneous formation of high-quality ultrathin Ph-BTBT-10 crystals and an electret PS charge-trapping layer. The PS electret layer serves a dual function: it facilitates the formation of ultrathin, highly ordered Ph-BTBT-10 crystals; meanwhile, its gate-tunable electron-trapping capability enables dynamic switching between photo-switching and photo-synaptic modes within a single device. As a photodetector, the device exhibits exceptional performance, including a responsivity of 4.7 × 10^4 A/W, specific detectivity of 2.2 × 10^17 Jones, and photosensitivity of 1.5 × 10^8. Under negative gate bias, light-triggered switching behavior enables logic gate demonstration, while under positive gate modulation, photonic synaptic behavior successfully emulates key biological functions, including excitatory post-synaptic current (EPSC), paired-pulse facilitation (PPF), short-term plasticity (STP) to long-term plasticity (LTP) transition, dynamic learning-forgetting processes, and image processing. Moreover, the system exhibits excellent compatibility with low-voltage flexible substrates and further demonstrates its application in low-consumption flexible neuromorphic devices. This work provides a scalable route toward high-performance, multifunctional neuromorphic optoelectronics based on organic ultrathin crystals, and advances the integration of flexible electronics and brain-inspired computing.