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Evolutionary multi-task optimization for parameters extraction of photovoltaic models
摘要： As the demand for solar energy increases dramatically, the optimization and control of photovoltaic systems become increasingly important, accurate and reliable parameter identification of photovoltaic models is always required, which proposes an urgent need for accurate and robust algorithms. To this end, many heuristic algorithms have been proposed to extract the parameters of different photovoltaic models. However, they only extract the parameters of one model in a single run, which is inconsistent with the human ability to solve multiple tasks simultaneously and ignores the useful information derived from different models. Therefore, in this paper an evolutionary multi-task optimization algorithm is proposed to extract the parameters of multiple different photovoltaic models simultaneously. To be specific, the helpful information found by the population is transferred through the cross-task crossover to improve the performance in terms of solution quality and convergence rate of the population. The proposed algorithm is evaluated by extracting the parameters of three different models simultaneously, i.e., single diode, double diode, and photovoltaic module model. Comprehensive results demonstrate that the proposed algorithm has better performance with respect to the accuracy and robustness in comparison with other state-of-the-art algorithms.
关键词： Differential evolution,Parameter extraction,Evolutionary multi-task optimization,Photovoltaic models
更新于2025-09-16 10:30:52
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Copper Tungstate (CuWO4) Nanoflakes Coupled with Cobalt Phosphate (Co-Pi) for Effective Photoelectrochemical Water Splitting
摘要： Photoelectrochemical (PEC) water splitting provides us a green way to convert and utilize solar energy. In this work, Co-Pi was electrochemically deposited onto CuWO4 nanoflakes (NFs) via a cyclic voltammetry (CV) method to enhance the photocatalytic performance of CuWO4 toward PEC water splitting. The results demonstrated that the photocurrent density as well as the charge-transfer efficiency was improved within the entire potential range. Besides, the CuWO4/Co-Pi exhibited an enhanced stability over the bare CuWO4 in the phosphate buffer solution (pH 7) and an extremely high Faradaic efficiency (ca. 96%). Our work reveals that combination of CuWO4 with Co-Pi is a feasible way to further enhance the performance of CuWO4 photoanode toward PEC OER.
关键词： Photoelectrochemical water splitting,oxygen evolution reaction,copper tungstate,electrochemical cocatalyst,cobalt phosphate
更新于2025-09-16 10:30:52
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Functional Transformation of Four-Bladed Rylene Propellers Utilizing Non-Metal and d <sup>8</sup> Metal Core Shifting Strategy: Significant Impact on Photovoltaic Performance and Electrocatalytic Hydrogen Evolution Activity
摘要： Two kinds of four-bladed perylene diimide (PDI) propellers with d8 metal and non-metal cores are efficiently synthesized. The Ni-PDI, Pd-PDI, and Pt-PDI propellers, equipped with d8 metal cores, have two absorption bands at 350-650 nm and 780-1200 nm with deep LUMO levels of -4.40 eV to -4.51 eV. The TTF-PDI, QU-PDI, and PH-PDI propellers with non-metal cores have only one absorption band at 350-650 nm with upshifted LUMO levels. Interestingly, the organic photovoltaic (OPV) results show that reducing the intramolecular charge traps between the blade and core subunits of the PDI propellers can effectively improve the power conversion efficiency (PCE). The device based on the QU-PDI acceptor exhibits a PCE that is up to more than 300 times higher (9.33%) than that of the d8 metal core PDI propellers (Pd-PDI, PCE=0.03%), which is one of the best photovoltaic performances with an excellent fill factor (FF=71.8%) exhibited by PDI-derivative acceptors. Conversely, the electro-catalytic H2 evolution activity of Pt-PDI (current destiny =10.00 mA/cm2 at -0.377 V), which exhibited a record performance for PDI-based catalysts to date, is up to 1000 times greater than that of the non-metal core PDI propellers (QU-PDI, 0.01 mA/cm2 at -0.377 V). Our results indicate that both highly efficient OPV and electrochemical H2 evolution catalysts can be achieved via the rational functionalization of PDI propellers with non-metal and d8 metal cores.
关键词： d8 metal cores,electrocatalytic hydrogen evolution,non-metal cores,organic photovoltaic (OPV),perylene diimide (PDI)
更新于2025-09-16 10:30:52
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Thermodynamics analysis and rapid solidification of laser polished Inconel 718 by selective laser melting
摘要： This paper presents thermodynamics analysis and rapid solidi?cation of laser polishing technology for selective laser melting (SLM) Inconel 718 superalloy. Signi?cant porosity reduction has been examined in the laser polished layer, where the surface porosity is reduced by 65.7% compared with that of the as-fabricated SLM surface. The results show that the temperature in the polished zone is over 1683 K, and the cooling rate is approximately up to 2.46 × 106 K/s. Besides, the polished layer consists of equiaxed grain and columnar grain with average grain size of 10 ± 2.4 μm and 5 ± 1.2 μm, respectively, and tiny cell grains with average size of 3.5 μm in the heat-a?ected zone (HAZ). Moreover, the transmission electron microscope (TEM) results show that the orientation relationship (OR) between the γ matrix and Laves phase is found to be Burgers OR [0 1 1] ‖[0 1 1ˉ 2] Laves on the as-received layer and [1ˉ 1 1] ‖[1 2ˉ 1 3ˉ] Laves on the polished layer.
关键词： Inconel 718 superalloy,Microstructural evolution,Crystallographic orientation,Selective laser melting,Laser polishing
更新于2025-09-16 10:30:52
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Curtailing the Overpotential of Lia??CO2 Batteries with Shapea??Controlled Cu2O as Cathode: Effect of Illuminating the Cathode
摘要： Li-air batteries are circumscribed to lab-scale research due to the uninterrupted formation of discharge products. In the case of Li–CO2 batteries, the increase in overpotential due to Li2CO3 formation results in cell death. In this study, we have synthesized Cu2O crystals having three different types of shapes, i.e., cubic, octahedral, and rhombic, to compare the catalytic activity toward CO2 reactions. The full-cycle and long-term stability test reveals that rhombohedral Cu2O facilitates Li2CO3 decomposition more efficiently than that of cubic and octahedral Cu2O. We have extended the cycle to dig into the photocatalytic activeness of the rhombic Cu2O by illuminating the cell. The repeated cycles to 1 h show maximum overpotential of 1.5 V, which is 0.5 V less than that of the cell without illumination. A postmortem analysis of the cell after dividing the cycles into segments demonstrates interesting results on the role of light and Cu2O during the cell cycle.
关键词： Li-CO2 batteries,Shape evolution,Cu2O cathode catalyst,Illumination effect,Charge overpotential
更新于2025-09-16 10:30:52
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Electric field-assisted synthesis of Pt, carbon quantum dots-coloaded graphene hybrid for hydrogen evolution reaction
摘要： A simple method for preparation of Pt, CQDs-coloaded graphene composite for hydrogen evolution reaction (HER) is established by electrolysis-solvothermal process. Graphene is obtained by electrochemical exfoliation of graphite in cathode, while carbon quantum dots (CQDs) and Pt nanoparticles (NPs) are in-situ generated in the electrolyte simultaneously. CQDs are evolved from propylene carbonate solvent and Pt NPs are derived from reduction of Pt intermediate species generated from anodic dissolution of Pt counter electrode during electrolysis process. Then Pt NPs and CQDs are well dispersed on graphene at subsequent solvothermal process. Work voltage and electrolyte type as the key electrolysis conditions are applied to control the concentration of CQDs and Pt NPs, which decides electrochemically active surface area and HER activity of obtained catalysts. Significantly, the obtained superior catalyst with trace amount of Pt (0.145 wt%), shows markedly enhanced catalytic HER activity with mass activity of 37.5 A mg?1 at ?50 mV in acidic solution, 68.2 times more active than Pt/C. This study provides a universal and promising methodology for synthesizing Pt, CQDs coloaded hybrid with the assistance of electric field as cost-effective catalysts for fuel cells.
关键词： Pt nanoparticles,Carbon quantum dots,Graphene,Hydrogen evolution reaction
更新于2025-09-16 10:30:52
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Rapid Solidification and Non-equilibrium Phase Constitution in Laser Powder Bed Fusion (LPBF) of AlSi10Mg Alloy: Analysis of Nano-precipitates, Eutectic Phases, and Hardness Evolution
摘要： The non-equilibrium phase evolution during laser powder bed fusion (LPBF) of AlSi10Mg alloy is thoroughly characterized and analyzed by means of advanced electron microscopy and analytical simulation of rapid solidification phenomenon. The evolution of microstructural strengthening agents such as inter-cellular eutectic phase and intra-cellular precipitates is presented in correspondence with the local variation of cellular/dendritic solidification patterns within a typical melt pool. The eutectic phase exhibits two different morphologies: lamellar and fibrous. As with the cell size variation, the overall volume fraction of eutectic phase and the lamella spacing is shown to gradually decrease by moving away from the melt-pool boundary (MPB), i.e., through crossing over from a coarse to a fine cellular zone. The eutectic-free regions within the a-Al cells contain a large number density of nano-sized precipitates that are predominantly Si-rich and are either fully or semi-coherent with the Al matrix. The formation of nano-precipitates is linked to the increased (non-equilibrium) solubility limits of a-Al cells due to the rapid solidification effect. For the first time, we identify such nano-precipitates with non-equilibrium crystal structures and morphologies: ‘‘Spheres’’ and ‘‘Ellipsoids’’ with Face Centered Cubic (FCC), and ‘‘Plates’’ and ‘‘Needles’’ with a Diamond Cubic (DC) superlattice structure that emerges from within the Al matrix. The microstructure in the heat-affected zone (HAZ) right underneath the MPB exhibits an absence of cell boundaries and eutectic phases while consisting primarily of large Si-rich and Mg-rich precipitates. Finally, the local variation of nano-hardness across a solidified melt pool is shown to correlate well with the corresponding profile of microstructural refinement, i.e., exhibiting a minimum at the HAZ and a peak at around the melt-pool centerline. The findings here can significantly advance the state of knowledge for the strengthening behavior in an as-built LPBF-processed AlSi10Mg alloy.
关键词： hardness evolution,Laser Powder Bed Fusion,non-equilibrium phase evolution,eutectic phases,nano-precipitates,AlSi10Mg
更新于2025-09-12 10:27:22
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Charge Transfer Engineering via Multiple Heteroatom Doping in Dual Carbon-Coupled Cobalt Phosphides for Highly Efficient Overall Water Splitting
摘要： The exploration of non-noble-metal bifunctional electrocatalysts with high activity and stability for overall water splitting is crucial, but remains challenging for hydrogen fuel production. Herein, tuning of the charge transfer ability and catalytic performance of zeolitic imidazolate framework-derived porous carbon/reduced graphene oxide-coupled CoP composites (CoP@C@rGO) was achieved by incorporating multiple heteroatoms. The combined experimental investigation and density functional theory calculations revealed that the electronic interaction within the composites caused by B, N, and S tri-doped heteroatoms effectively induced interfacial charge transfer, which improved the active site accessibility and reduced the energy barriers of the evolution reaction; water splitting intermediates. From the synergetic effects of the components, the overall water splitting electrolyzer assembled using the newly prepared B,N,S-CoP@C@rGO catalyst required only 1.50 V to drive a current density of 10 mA cm–2, which is superior to the commercial Pt/C and IrO2/C couple (1.56 V).
关键词： hydrogen evolution reaction,oxygen evolution reaction,multiple doping,overall water splitting,charge transfer
更新于2025-09-12 10:27:22
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Operando X-ray diffraction during laser 3D printing
摘要： Laser based additive manufacturing allows to build a designed shape layer-by-layer, offering versatility and flexibility to many metallurgical sectors. The fast cooling rates and repeated heat cycles depending on the laser and scanning parameters are not easily measurable with conventional methods. Thus, advanced predictive computational simulations, required to reduce trial and error lead time, are difficult to validate. A newly developed in operando X-ray diffraction device implemented at a synchrotron beamline, taking advantage of the high brilliance and the fast detectors available, brings the missing link with numerical methods. By performing operando experiments on Ti-6Al-4V with different printing parameters, the temporal evolution of the low and high temperature phases are followed, the heating and cooling rates are measured for the powder and the solid material; and the formation of residual stresses in the b phase is demonstrated. Moreover it is shown that the parameter that has the largest influence on the evolving microstructure is the scanning strategy, introducing a size effect related to the scanning length.
关键词： microstructure evolution,operando X-ray diffraction,scanning strategy,Laser based additive manufacturing,Ti-6Al-4V
更新于2025-09-12 10:27:22
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Wigner-function Evolution and Photon-number Decay of Quantum States in a Laser Cavity with the Kerr Medium
摘要： Using the thermal-entangled state representation theory, we solve the master equation describing a laser cavity with the Kerr medium, and find that the analytical evolution law of the density operator is governed by the infinitive Kraus operator-sum representation. Also, we obtain a new evolution formula of the Wigner function (WF) for any initial state in this cavity by rewriting the WF as a scalar product between two pure states. In term of the new WF formula, the WF evolution of the initial coherent and number states and the decay of photon number are also presented.
关键词： Photon-number decay,Infinitive operator-sum representation,Laser cavity with Kerr medium,Wigner-function evolution,Thermal-entangled state representation
更新于2025-09-12 10:27:22