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Highly efficient pH-universal hydrogen evolution reaction catalyzed by rapidly reconstructed bimetallic cobalt-molybdenum alloy cuboids arrays

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Nano Research 2024年第8期17卷 6977-6983页

作者： Daolian Liu Zihao Wang Yan Zhang Haiqing zhou yong Zhang Dongyang Li Fang Yu Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Key Laboratory for Matter Microstructure and Function of Hunan ProvinceDepartment of Physics and Synergetic Innovation Center for Quantum Effects and ApplicationsHunan Normal UniversityChangsha 410081China State Key Laboratory of Marine Resource Utilization in South China Sea and Department of Materials Science and EngineeringHainan UniversityHaikou 570228China Institute of Interdisciplinary Studies Hunan Normal UniversityChangsha 410081China

Given the inherent potential of seawater,industrial wastewater,and residential water as inherent feedstocks for hydrogen production through water electrolysis,there is a critical demand for the exploration of robust and stable hydrogen-evolving catalysts that can operate effectively across a diverse range of pH ***,the pursuit of hydrogen-evolving electrocatalysts that demonstrate both good stability and high efficiency over a wide pH range remains a formidable *** we report the rational design and synthesis of an outstanding nanoporous hybrid electrocatalyst consisting of intermetallic cobalt-molybdenum alloy particles anchoring on MoO2 cuboid arrays,which demands very low overpotentials of 72,123 and 134 mV to deliver a current density of−100 mA·cm^(−2)for hydrogen evolution reaction under alkaline,neutral and acidic conditions,*** catalytic activities are superior to most non-precious-metal-based catalysts documented in the literatures,and are even comparable to noble metal *** particular,this alloy electrocatalyst exhibits excellent stability at 50 or 300 mA·cm^(−2)without obvious activity degradation,which is further supported by the undetectable changes in the surface chemical valence states on the basis of in-situ X-ray photoelectron spectroscopic *** study provides an innovative strategy for the design and synthesis of effective non-noble intermetallic catalysts for pH-universal hydrogen evolution over a wide pH range.

关键词： electrocatalyst hydrogen evolution reaction pH-universal non-noble water splitting

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Pillar[5]arene based artificial light-harvesting supramolecular polymer for efficient and recyclable photocatalytic applications

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Chinese Chemical Letters 2024年第9期35卷 179-182页

作者： Lei zhou Youjun zhou Lizhen Fang Yiqiao Bai Yujia Meng Liang Li Jie Yang yong Yao School of Chemical and Environmental Engineering Shanghai Institute of TechnologyShanghai 201418China School of Chemistry and Chemical Engineering Nantong City Key Laboratory of Life-Organic ChemistryNantong UniversityNantong 226019China College of Science Nanjing Forestry UniversityNanjing 210037China

Photosynthesis is the process through which living plants utilize photosynthetic pigments,such as chlorophyll,to convert CO_(2)and water into organic compounds and release O_(2)under visible *** this study,we have successfully constructed a fluorescent supramolecular polymer(P5Py_(2)/Zn/Gen)n by employing orthogonal pillar[5]arene-based molecular recognition and metal ion *** the supramolecular polymer,the guest molecule Gen unit acts as a light-harvesting moiety,as the ACQ effect is inhibited by host-guest interactions,while the(Py)_(2)/Zn center serves as a catalytic *** employing this orthogonal self-assembly strategy,we have enhanced the stability of both the donor and acceptor in catalyzing the reduction of p-nitrophenol to ***,this photocatalyst can be reused at least 5 times without significant conversion *** findings provide a pathway for constructing a recyclable artificial LHS that mimics the entire photosynthesis process.

关键词： Pillararenes Light-harvest Supramolecular polymer Photosynthesis Orthogonal self-assembly

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Screening current in ultra-high-field non-insulated superconducting magnets

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Science China(Technological Sciences) 2024年第7期67卷 2255-2273页

作者： zhou BenZhe WANG Lei CHEN yong WANG QiuLiang WANG KangShuai ZHANG ZiLi LIU JianHua University of Chinese Academy of Sciences Beijing 100049China Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190China

Screening current is recognized as one of the critical elements limiting the progression of superconducting magnets toward achieving higher magnetic fields. Currently, most non-insulated(NI) superconducting magnets consider the magnet as insulated when addressing the issue of screening current. However, the bypass current in the NI magnet can modify the actual history of magnetization, so the screening current in NI magnet will be different from that in the insulated magnet. This paper presents a novel method based on the homogenized T-A formulation(T is the current vector potential, and A is the magnetic vector potential), which enables real-time simulation of both the bypass current behavior and the implications of screening current in NI superconducting magnets, even when these magnets contain tens of thousands of turns. We have developed a 32 T NI hybrid superconducting magnet and validated the effectiveness of this method through experiments. Employing this efficacious method,we conducted a comprehensive calculation of screening current in NI magnets, comparing them with insulated magnets in terms of screening current-induced stress(SCIS), screening current-induced field(SCIF), and losses. The results indicate that in the NI insert coils, the sequential excitation of background coils and insert coils induces a reverse screening current, resulting in slightly lower SCIF and SCIS compared to those in the insulated magnets. The method and results can contribute to the enhancement of magnet design and provide valuable insights for the development of ultra-high fields(UHF) NI magnets.

关键词： ultra-high-field superconducting magnet screening current REBCO coil NI coil stress loss

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Effect of Types and Orders of Electromagnetic Field Finite Element Meshes on Power Communication Harmonic Parameters Calculation Results of Tubular Hydrogenerators

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China Communications 2024年第10期21卷 288-300页

作者： Fan Zhennan Chen Jie zhou Zhiting Yang yong Key Laboratory of Fluid and Power Machinery Ministry of EducationXihua UniversityChengdu 610039China State Key Laboratory of Power Transmission Equipment&System Security and New Technology Chongqing UniversityChongqing 400044China KeyDongfang Electric Machinery Co. Ltd Research and Test CenterDeyang 618000China

In generator design field,waveform total harmonic distortion(THD)and telephone harmonic factor(THF)are parameters commonly used to measure the impact of generator no-load voltage harmonics on the power communication *** hydrogenerators are considered the optimal generator for exploiting low-head,high-flow hydro resources,and they have seen increasingly widespread application in China's power systems recent ***,owing to the compact and constrained internal space of such generators,their internal magnetic-field harmonics are ***,accurate calculation of their THD and THF is crucial during the analysis and design stages to ensure the quality of power *** in the electromagnetic field finite element modeling analysis of such generators,the type and order of the finite element meshes may have a significant impact on the THD and THF calculation results,which warrants in-depth *** address this,this study takes a real 34 MW large tubular hydrogenerator as an example,and establishes its electromagnetic field finite element model under no-load *** types of meshes,five mesh densities,and two mesh orders are analyzed to reveal the effect of electromagnetic field finite element mesh types and orders on the calculation results of THD and THF for such generators.

关键词： calculation results electromagnetic field finite element meshes power communication harmonic parameters tubular hydrogenerator types and orders

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Multi-Objective Optimization of Aluminum Alloy Electric Bus Frame Connectors for Enhanced Durability

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 735-755页

作者： Wenjun zhou Mingzhi Yang Qian Peng yong Peng Kui Wang Qiang Xiao Key Laboratory of Traffic Safety on Track Ministry of EducationSchool of Traffic&Transportation EngineeringCentral South UniversityChangsha410018China School of Mechanical and Automotive Engineering Xiamen University of TechnologyXiamen361024China

The widespread adoption of aluminumalloy electric buses,known for their energy efficiency and eco-friendliness,faces a challenge due to the aluminum frame’s susceptibility to deformation compared to *** issue is further exacerbated by the stringent requirements imposed by the flammability and explosiveness of batteries,necessitating robust frame *** study aims to optimize the connectors of aluminum alloy bus frames,emphasizing durability,energy efficiency,and *** research delves into Multi-Objective Coordinated Optimization(MCO)techniques for lightweight design in aluminum alloy bus body *** goal is to enhance lightweighting,reinforce energy absorption,and improve deformation resistance in connector *** typical aluminum alloy connectors were selected and a design optimization platform was built for their MCO using a variety of software and ***,through three-point bending experiments and finite element analysis on three types of connector components,we identified optimized design parameters based on deformation ***,employing Optimal Latin hypercube design(OLHD),parametric modeling,and neural network approximation,we developed high-precision approximate models for the design parameters of each connector component,targeting energy absorption,mass,and logarithmic ***,utilizing the Archive-based Micro Genetic Algorithm(AMGA),Multi-Objective Particle Swarm Optimization(MOPSO),and Non-dominated SortingGenetic Algorithm(NSGA2),we explored optimized design solutions for these joint ***,we simulated joint assembly buckling during bus rollover crash scenarios to verify and analyze the optimized solutions in three-point bending *** joint component showcased a remarkable 30%–40%mass reduction while boosting energy *** design optimization method exhibits high efficiency and *** contemporary automation technology,the design optimiza

关键词： Aluminum connectors three-point bending simulation parametric design model multi-objective collaborative optimization

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Synthesis of Planar-Chiral[2.2]Paracyclophane-Based Oxazole-Pyrimidine Ligands and Application in Nickel-Catalyzed 1,2-Reduction ofα,β-Unsaturated Ketones

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Chinese Journal of Chemistry 2024年第7期42卷 705-710页

作者： Juan Wang Qing-Xian Xie Xiang Li Chang-Bin Yu yong-Gui zhou School of Chemistry Dalian University of Technology2 Linggong RoadDalianLiaoning 116024China State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalianLiaoning 116023China

The planar-chiral ligands have been widely applied as a class of unique and significant ligands in asymmetric *** them,chiral[2.2]paracycyclophane has emerged as a privileged type of planar-chiral framework and has been utilized as an important toolbox due to their structural ***,we design and synthesize[2.2]paracyclophane-derived oxazole-pyrimidine ligands(abberviated as PYMCOX).These N,N-ligands with stable properties,rigid structure and large steric hindrance performed successfully in nickel-catalyzed asymmetric 1,2-reduction ofα,β-unsaturated ketones,affording the chiral allylic alcohols with up to 99%yield and 99%***,this reduction reaction could be conducted on gram-scale without loss of activity and enantioselectivity,and the chiral ligand could be conveniently recovered with high yield.

关键词： Oxazole-pyrimidine ligands Planar chirality Nickel Hydroboration Asymmetric synthesis

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A contradictory phenomenon of thicken pericardium and cardiac compression without inferior vena cava dilation:sign of IVC escape

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Journal of Geriatric Cardiology 2024年第5期21卷 583-587页

作者： Tie-Nan CHEN shuang ZHAO Shuai QIAO yong-yong HAN Qing LIU Chang-Le LIU Guang-Ping LI Tong LIU Hua-Ying FU Department of Cardiovascular Surgery Second Hospital of Tianjin Medical UniversityTianjinChina Department of Cardiology Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular DiseaseTianjin Institute of Cardi-ologyThe Second Hospital of Tianjin Medical UniversityTianjinChina Department of Oncology Second Hospital of Tianjin Medical UniversityTianjinPeople's Republic of China

A 77-year-old female presented with shortness of breath and tightness of chest was *** past medical history included hypertension and she has been taking nifedipine *** years before,she was diagnosed with pericardial effusion(Figure 1)and had pericardiocentesis *** physical examination,her blood pressure was 151/100 mm-Hg and her pulse rate was 91 beats/min.

关键词： admitted cardiac thick

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On capped Higgs positivity cone

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中国科学技术大学学报 2024年第7期54卷 44-54,43,I0003页

作者： Dong-Yu Hong Zhuo-Hui Wang shuang.yong.zhou Interdisciplinary Center for Theoretical Study University of Science and Technology of ChinaHefei 230026China Peng Huanwu Center for Fundamental Theory Hefei 230026China

The Wilson coefficients of the standard model effective field theory are subject to a series of positivity *** has been shown that while the positivity part of the ultraviolet(UV)partial wave unitarity leads to the Wilson coefficients living in a convex cone,further including the nonpositivity part caps the cone from *** Higgs scattering,a capped positivity cone was obtained using a simplified,linear unitarity condition without utilizing the full internal symmetries of Higgs ***,we further implement stronger nonlinear unitarity conditions from the UV,which generically gives rise to better *** show that,for the Higgs case in particular,while the nonlinear unitarity conditions per se do not enhance the bounds,the fuller use of the internal symmetries do shrink the capped positivity cone significantly.

关键词： positivity bounds standard model effective field theory(SMEFT) Higgs

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Time-Domain Higher-Order Boundary Element Method for Simulating High Forward-Speed Ship Motions in Waves

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China Ocean Engineering 2024年第5期38卷 904-914页

作者： zhou Xiao-guo CHENG yong PAN Su-yong School of Naval Architecture and Ocean Engineering Jiangsu University of Science and Technology

The hydrodynamic performance of a high forward-speed ship in obliquely propagating waves is numerically examined to assess both free motions and wave field in comparison with a low forward-speed ship. This numerical model is based on the time-domain potential flow theory and higher-order boundary element method, where an analytical expression is completely expanded to determine the base-unsteady coupling flow imposed on the moving condition of the ship. The ship in the numerical model may possess different advancing speeds, i.e. stationary, low speed, and high speed. The role of the water depth, wave height, wave period, and incident wave angle is analyzed by means of the accurate numerical model. It is found that the resonant motions of the high forward-speed ship are triggered by comparison with the stationary one. More specifically, a higher forward speed generates a V-shaped wave region with a larger elevation, which induces stronger resonant motions corresponding to larger wave periods. The shoaling effect is adverse to the motion of the low-speed ship, but is beneficial to the resonant motion of the high-speed *** waves obliquely propagate toward the ship, the V-shaped wave region would be broken due to the coupling effect between roll and pitch motions. It is also demonstrated that the maximum heave motion occurs in beam seas for stationary cases but occurs in head waves for high speeds. However, the variation of the pitch motion with period is hardly affected by wave incident angles.

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Deep learning methods for roping defect analysis in aluminum alloy sheets: prediction and grading

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Advances in Manufacturing 2024年第3期12卷 576-590页

作者： Yuan-Zhe Hu Ru-Xue Liu Jia-Peng He Guo-Wei zhou Da-yong Li State Key Laboratory of Mechanical Systems and Vibration Shanghai Jiao Tong UniversityShanghai200240People’s Republic of China School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240People’s Republic of China

Roping is a severe band-like surface defect that occurs in deformed aluminum alloy *** roping prediction and rating are essential for industrial ***,the authors introduced an artificial neural network(ANN)model to efficiently forecast roping behavior across the thickness of large regions with texture *** this study,the previously proposed ANN model for roping prediction is briefly reviewed,and a few-shot learning(FSL)-based method is developed for roping grading with limited *** consider the directionality of the roping patterns,the roping dataset constructed from experimental observations is transformed into the frequency domain for more compact characterization.A transfer-based FSL method is further presented for grade roping with manifold mixup regularization and the Sinkhorn mapping algorithm.A new component-focused representation is also implemented for data-processing,exploiting the close correlation between roping and power distribution in the frequency *** ultimate FSL method achieved an optimal accuracy of 95.65%in roping classification with only five training samples per class,outperforming four typical FSL *** FSL approach can be applied to grade the roping morphologies predicted by the ANN ***,the combination of prediction and grading using deep learning provides a new paradigm for roping analysis and control.

关键词： Roping Artificial neural network(ANN) Aluminum alloys Few-shot classification Surface morphology

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