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Direct seawater splitting for hydrogen production:Recent advances in materials synthesis and technological innovation

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Green Energy & Environment 2025年第1期10卷 11-33页

作者： Yilin Zhao Zhipeng Yu Aimin ge Lujia Liu Joaquim Luis Faria Guiyin Xu Meifang zhu State Key Laboratory for Modification of Chemical Fibers and Polymer Materials Center for Advanced Low-dimension MaterialsCollege of Materials Science and EngineeringDonghua UniversityShanghai201620China International Iberian Nanotechnology Laboratory(INL) Avenida Mestre Jose VeigaBraga4715-330Portugal The MacDiarmid Institute for Advanced Materials and Nanotechnology School of Chemical and Physical SciencesVictoria University of WellingtonWellington6012New Zealand LSRE-LCM-Laboratory of Separation and Reaction Engineering-Laboratory of Catalysis and Materials Faculty of EngineeringUniversity of PortoRua Dr.Roberto Frias s/nPorto4200-465Portugal ALiCE-Associate Laboratory in Chemical Engineering Faculty of EngineeringUniversity of PortoRua Dr.Roberto Frias s/nPorto4200-465Portugal

Direct seawater splitting has emerged as a popular and promising research direction for synthesising clean,green,non-polluting,and sustainable hydrogen energy without depending on high-purity water in the face of the world’s shortage of fossil ***,efficient seawater splitting is hindered by slow kinetics caused by the ultra-low conductivity and the presence of bacteria,microorganisms,and stray ions in ***,producing hydrogen on an industrial scale is challenging due to the high production *** present review addresses these challenges from the catalyst point of view,namely,that designing catalysts with high catalytic activity and stability can directly affect the rate and effect of seawater *** the ion transfer perspective,designing membranes can block harmful ions,improving the stability of seawater *** the energy point of view,mixed seawater systems and self-powered systems also provide new and low-energy research systems for seawater ***,ideas and directions for further research on direct seawater splitting in the future are pointed out,with the aim of achieving low-cost and high-efficiency hydrogen production.

关键词： Seawater splitting Catalyst Membranes Mixed seawater systems Self-powered systems

Buried interface bridging for inverted cesium-formamidinium triiodide perovskite solar cells with long operational stability

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Science China Chemistry 2025年第1期68卷 163-173页

作者： Chenhui Zhang Chunjun Liang Fulin Sun Ting zhu Xinghai Huang Yuzhu Guo Xinyu Guo Kunyang ge Dan Li Fangtian You Zhiqun He Key Laboratory of Luminescence and Optical Information Ministry of Education Institute of Optoelectronic TechnologyBeijing Jiaotong University Department of Physics School of Physical Science and Engineering Beijing Jiaotong University

In the field of perovskite solar cells(PSCs), the research on defects in the buried interface has been relatively limited due to its non-exposure; however, this interface significantly impacts the performance enhancement of inverted PSCs. This study employs phenylethylammonium chloride(PEACl) molecules as a buffer layer to modify the buried interface of p-i-n structured PSCs,aiming to enhance the uniformity of self-assembled monolayers(SAMs) and facilitate the uniform nucleation and growth of perovskite films on the substrate. Furthermore, the introduction of the PEACl buffer layer effectively passivates defects at the bottom of the perovskite layer and notably enhances the crystal quality of the perovskite film by mitigating residual stress,thereby reducing nonradiative recombination loss. Following these optimizations, the MA-free PSCs treated with PEACl achieve a power conversion efficiency(PCE) of 24.11%, with significant improvements in storage, thermal stability, and operational stability. Particularly noteworthy is the device's performance in an unencapsulated state, whereas after 1,500 hours of continuous light operation stability testing, it retains 97% of its original efficiency. This study not only enriches the systematic understanding of the characteristics of the buried interface in PSCs but also contributes significantly to advancing the commercial production of perovskite photovoltaic technology.

关键词： defect-induced recombination buried interfaces inverted perovskite solar cells crystallization lattice mismatch

Influence of morphology on high-temperature rheological properties of bitumen modified with styrene-butadiene-styrene(SBS)copolymer

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Frontiers of Structural and Civil Engineering 2021年第3期15卷 806-819页

作者： Jiqing zhu xiaohu LU Swedish National Road and Transport Research Institute(VTI) Linköping SE-58195Sweden Nynas AB Nynäshamn SE-14982Sweden

Different microstructures of the same polymer-modified bitumen(PMB)were obtained by subjecting the bitumen modified with styrene-butadiene-styrene(SBS)copolymer to isothermal annealing at various *** effects of the morphology on the rheological properties of SBS-modified bitumen were investigated within the hightemperature *** PMB microstructures were quantitatively evaluated using image analysis.A dynamic shear rheometer was used to measure the rheological parameters of the PMB samples and perform the multiple stress creep and recovery(MSCR)test.A quantitative basis could be established on which to discuss the relationship between the PMB morphology and *** image analysis indicated that conditioning by isothermal annealing evidently led to a difference in the microstructure of the *** of the thermal history is demonstrated to be a practical way to vary the morphology of the PMB with the same raw materials and *** with the two-phase morphology,the single-phase microstructure tended to have a narrower linear viscoelastic(LVE)region of the *** the LVE region,especially at low frequencies,the homogenous PMB can store more energy when experiencing loadings and is more *** the LVE region,based on the MSCR test results,the homogenous morphology could assist in reaching a higher percentage of strain recovery after the creep period.

关键词： polymer bitumen microstructure rheology viscoelasticity

Dynamic Spectrum Anti-Jamming with Distributed Learning and Transfer Learning

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China Communications 2023年第12期20卷 52-65页

作者： Xinyu zhu Yang Huang Delong Liu Qihui Wu xiaohu ge Yuan Liu Key Laboratory of Dynamic Cognitive System of Electromagnetic Spectrum Space Ministry of Industry and Information TechnologyNanjing University of Aeronautics and AstronauticsNanjing 210016China The 723 Institute of CSSC Yangzhou 225001China School of Electronic Information and Communications Huazhong University of Science and TechnologyWuhan 430074China School of Electronic and Information Engineering South China University of TechnologyGuangzhou 510641China

Physical-layer security issues in wireless systems have attracted great *** this paper,we investigate the spectrum anti-jamming(AJ)problem for data transmissions between *** fast-changing physical-layer jamming attacks in the time/frequency domain,frequency resources have to be configured for devices in advance with unknown jamming patterns(*** time-frequency distribution of the jamming signals)to avoid jamming signals emitted by malicious *** process can be formulated as a Markov decision process and solved by reinforcement learning(RL).Unfortunately,stateof-the-art RL methods may put pressure on the system which has limited computing *** a result,we propose a novel RL,by integrating the asynchronous advantage actor-critic(A3C)approach with the kernel method to learn a flexible frequency pre-configuration ***,in the presence of time-varying jamming patterns,the traditional AJ strategy can not adapt to the dynamic interference *** handle this issue,we design a kernelbased feature transfer learning method to adjust the structure of the policy function *** results reveal that our proposed approach can significantly outperform various baselines,in terms of the average normalized throughput and the convergence speed of policy learning.

关键词： A3C anti-jamming reinforcement learning spectrum transfer learning wireless system

Impacts of practical channel impairments on the downlink spectral efficiency of large-scale distributed antenna systems

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Science China(Information Sciences) 2019年第2期62卷 146-159页

作者： Jiamin LI Dongming WANG Pengcheng zhu xiaohu YOU National Mobile Communications Research Laboratory Southeast University

Channel impairments are major limiting factors in the performance of large-scale antenna systems. In this paper, we analyze the impacts of practical channel impairments caused by pilot contamination,Doppler shift, and phase noise on the downlink spectral efficiency of large-scale distributed antenna systems(L-DASs) with maximum ratio transmission(MRT) and zero-forcing(ZF) beamforming, in which per user power normalization is considered. Using a joint channel model that allows study of the simultaneous impacts of these channel impairments, we derive accurate and tractable closed-form approximations for the ergodic achievable downlink rate, thereby enabling spectral efficiency analysis of L-DASs and an efficient evaluation of the impacts of the channel impairments. It is shown that channel impairments reduce the downlink spectral efficiency and have a significant impact on ZF beamforming. The asymptotic user rate limit is also determined, from which we analyze the asymptotic performance of L-DASs with channel impairments. The analytical results show that MRT and ZF beamforming achieve the same asymptotic performance limit even with channel impairments. It is also found that the use of a large-scale antenna array at the base station sides can weaken the impacts of channel impairments.

关键词： Doppler shift phase noise large-scale distributed antenna systems spectral efficiency pilot contamination

Electrochemical machining of a convex strips structure on a revolving part by using site directed power interruption

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Chinese Journal of Aeronautics 2018年第10期31卷 2049-2056页

作者： Yongcheng ge Zengwei zhu Di zhu Dengyong WANG Nanjing University of Aeronautics and Astronautics Nanjing 210016China Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology Nanjing 210016China

Revolving parts with complex surface structures are widely used in machinery and mechanical equipment. The ECM process provides its adequacy to cut hard materials with different shapes, and its applications are widely increased, due to its outstanding advantages. In this paper, a new method for machining a convex strips structure on a cylinder by using site directed power interruption（SDPI） in the ECM process is presented. A variable correction value of the power-off time was defined and optimized to obtain the ideal interval for better machining accuracy and *** electric field distribution and the simulated convex profiles show that the stray current density can be reduced effectively by using the proposed method. The correction value has an important influence on the machining accuracy. A suitable correction value in the range of 0.6–1.2 s can effectively improve the machining accuracy of the convex strips structure. Experiments were also conducted to verify the proposed method. Results have confirmed that the stray corrosion on the convex strips surface is significantly reduced and the machining accuracy of convex strips structure is remarkably improved by using the proposed method with a suitable correction value in the ECM process. Finally, a convex strip with a height of 2 mm on a thin-wall revolving part was also produced successfully using a correction value of 0.9.

关键词： Convex strips structure Electrochemical machining Revolving part Site directed power interruption Stray corrosion

Chemical composition and petrogenesis of plagioclases in plagioclase-phyric basalts from the Southwest Indian Ridge(51°E)

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Acta Oceanologica Sinica 2020年第7期39卷 42-49页

作者： Jie Li Jihao zhu Fengyou Chu xiaohu Li Zhimin zhu Hao Wang Key Laboratory of Submarine geosciences Ministry of Natural ResourcesHangzhou 310012China Second Institute of Oceanography Ministry of Natural ResourcesHangzhou 310012China

Electron microprobe analysis was conducted on plagioclase from the plagioclase ultraphyric basalts(PUBs)erupted on the Southwest Indian Ridge(SWIR)(51°E)to investigate the geochemical changes in order to better understand the magmatic processes occurring under ultraslow spreading ridges and to provide insights into the thermal and dynamic regimes of the magmatic reservoirs and conduit *** phenocryst cores are generally calcic(An74–82)and are depleted in FeO and *** the phenocryst rims(An67–71)and the plagioclase in the groundmass(An58–63)are more sodic and have higher FeO and MgO contents than the phenocryst *** crystallization temperatures of the phenocryst cores and the calculation of the equilibrium between the phenocrysts and the matrix suggest that the plagioclase cores are unlikely to have crystallized from the host basaltic melt,but are likely to have crystallized from a more calcic *** enrichment in incompatible elements(FeO and MgO),as well as the higher FeO/MgO ratios of the outermost phenocryst rims and the groundmass,are the result of plagioclase-melt disequilibrium diffusion during the short residence time in which the plagioclase *** results indicate that an evolved melt replenishing under the SWIR(51°E)drives the eruption over a short period of time.

关键词： plagioclase–phyric basalt plagioclase phenocrysts magmatic evolution SWIR

Simulation and Experimental Study on Improving Electrochemical Machining Stability of Highly Convex Structures on Casing Surfaces Using Backwater Pressure

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Chinese Journal of Mechanical Engineering 2022年第4期35卷 152-158页

作者： Zhenghui ge Wangwang Chen Yongwei zhu College of Mechanical Engineering Yangzhou UniversityYangzhou 225000China

Casing parts are regarded as key components of *** casing parts are attached to convex structures of diferent shapes,whose heights range from hundreds of microns to tens of *** profling blocky electrodes for electrochemical machining(ECM)of casing parts is a commonly adopted method,especially when highly convex ***,with an increase in the convex structure height,the fow felds of the machining areas become more complex,and short circuits may occur at any *** this study,a method to improve the fow feld characteristics within a machining area by adjusting the backwater pressure is proposed and validated through simulation and experiment *** simulation results demonstrated that the back-pressure method can signifcantly improve the uniformity of the fow feld around the convex structure compared with the extraction and open outlet ***,the back-pressure value was optimized at 0.5 MPa according to the simulation *** experimental results showed that using the optimized back-pressure parameters,the cathode feed-rate increased from 0.6 to 0.7 mm/min,and a 16.1 mm tall convex structure was successfully *** indicates that the back-pressure method is suitable and efective for electrochemical machining of highly convex structures with blocky *** this study,we propose a method to improve the electrochemical machining stability of a convex structure on a casing surface using backwater pressure,which has achieved remarkable results.

关键词： Casing parts Electrochemical machining Convex structures Back-pressure method Blocky electrode

Performance Analysis and Multi-Objective Optimization of Two Organic Rankine Cycles with Different Fluids for Low Grade Waste Heat Recovery

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Journal of Thermal Science 2022年第3期31卷 650-662页

作者： ge Yi HAN Jitian zhu Xiaoxuan School of Energy and Power Engineering Shandong UniversityJi’nan250061China

The basic organic Rankine cycle(BORC)and ORC with an internal heat exchanger(IHORC)are studied with different working fluids under a given heat source condition to analyse the thermodynamic performances and net power *** results demonstrate that the external exergy efficiency of IHORC is lower than that of BORC while the internal exergy efficiency is on the opposite with the same overall exergy efficiencies.A multi-objective optimization model with inlet pressure and temperature of expander as independent parameters and exergy and heat recovery efficiencies as objective functions is solved by NSGA-II(the second non-dominated sorting genetic algorithm).The Pareto optimal solutions are obtained by the optimization *** calculation with the optimum conditions,it is determined that R236ea has the best comprehensive performance with exergy efficiencies being 40.69%and 41.38%,and heat recovery efficiencies being 83.2%and 75.6%in IHORC and BORC,*** evaporators occupy the maximum exergy destruction,which can be reduced by decreasing pinch point temperatures and increasing evaporation pressures.

关键词： ORC working fluids exergy analysis multi-objective optimization exergy destruction