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Cross-section design of the flow channels in membrane electrode assembly electrolyzer for CO_(2) reduction reaction through numerical simulations

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Chinese Chemical Letters 2025年第1期36卷 332-337页

作者： Lili Zhang Hui Gao Gong Zhang Yuning Dong Kai Huang Zifan Pang Tuo Wang Chunlei Pei Peng Zhang Jinlong Gong Key Laboratory for green Chemical technology of Ministry of Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China Collaborative Innovation Center of Chemical Science and Engineering(Tianjin) Tianjin 300072China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China National Industry-Education Platform of Energy Storage Tianjin UniversityTianjin 300350China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhou 350207China

Membrane electrode assembly(MEA)is widely considered to be the most promising type of electrolyzer for the practical application of electrochemical CO_(2) reduction reaction(CO_(2)RR).In MEAs,a square-shaped cross-section in the flow channel is normally adopted,the configuration optimization of which could potentially enhance the performance of the *** paper describes the numerical simulation study on the impact of the flow-channel cross-section shapes in the MEA electrolyzer for CO_(2)*** results show that wide flow channels with low heights are beneficial to the CO_(2)RR by providing a uniform flow field of CO_(2),especially at high current ***,the larger the electrolyzer,the more significant the effect *** study provides a theoretical basis for the design of high-performance MEA electrolyzers for CO_(2)RR.

关键词： Electrochemical reduction of CO_(2) Membrane electrode assembly Mass transfer Gas diffusion electrode Computational fluid dynamics

End-To-End Encryption Enabled Lightweight Mutual Authentication Scheme for Resource Constrained IoT Network

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Computers, Materials & Continua 2025年第2期82卷 3223-3249页

作者： Shafi Ullah Haidawati Muhammad Nasir Kushsairy Kadir Akbar Khan Ahsanullah Memon Shanila Azhar Ilyas Khan Muhammad Ashraf Department of Computer Engineering Balochistan University of Information TechnologyEngineering and Management SciencesQuetta87300Pakistan Computer Engineering section Malaysian Institute of technology Universiti Kuala LumpurKuala Lumpur50250Malaysia Electrical Engineering section Universiti Kuala LumpurBritish Malaysian InstituteSalengor53100Malaysia Electrical Engineering Department Mehran UniversityKhairpur-Mirs76062Pakistan Department of Mathematics College of Science Al-ZulfiMajmaah UniversityAl-Majmaah11952Saudi Arabia

Machine-to-machine (M2M) communication networks consist of resource-constrained autonomous devices, also known as autonomous Internet of things (IoTs) or machine-type communication devices (MTCDs) which act as a backbone for Industrial IoT, smart cities, and other autonomous systems. Due to the limited computing and memory capacity, these devices cannot maintain strong security if conventional security methods are applied such as heavy encryption. This article proposed a novel lightweight mutual authentication scheme including elliptic curve cryptography (ECC) driven end-to-end encryption through curve25519 such as (i): efficient end-to-end encrypted communication with pre-calculation strategy using curve25519;and (ii): elliptic curve Diffie-Hellman (ECDH) based mutual authentication technique through a novel lightweight hash function. The proposed scheme attempts to efficiently counter all known perception layer security threats. Moreover, the pre-calculated key generation strategy resulted in cost-effective encryption with 192-bit curve security. It showed comparative efficiency in key strength, and curve strength compared with similar authentication schemes in terms of computational and memory cost, communication performance and encryption robustness.

关键词： Mutual authentication lightweight end-to-end encryption elliptic curve cryptography industrial internet of things curve25519 machine-to-machine communication

Synthesis of energetic materials by microfluidics

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Defence technology(防务技术) 2025年第2期44卷 306-319页

作者： Shuo Liu Chuanyu Zhang Yanlan Wang Xueyong Wei School of Mechanical Engineering Xi'an Jiaotong UniversityXi'an 710049China School of Instrument Science and technology Xi'an Jiaotong UniversityXi'an 710049China Science and technology on Applied Physical Chemistry Laboratory Xi'an 710061China

Energetic materials,characterized by their capacity to store and release substantial energy,hold pivotal significance in some fields,particularly in defense ***,with its ability to manipulate fluids and facilitate droplet formation at the microscale,enables precise control of chemical *** scholarly endeavors have increasingly harnessed microfluidic reactors in the realm of energetic materials,yielding morphologically controllable particles with enhanced uniformity and explosive ***,crucial insights into microfluidic-based methodologies are dispersed across various publications,necessitating a systematic ***,this review addresses this gap by concentrating on the synthesis of energetic materials through ***,the methods based on micro-mixing and droplets in the previous papers are summarized and the strategies to control the critical parameters within chemical reactions are discussed in ***,the comparison in terms of advantages and disadvantages is *** demonstrated in the last section regarding perspectives,challenges such as clogging,dead zones,and suboptimal production yields are non-ignoble in the promising fields and they might be addressed by integrating sound,optics,or electrical energy to meet heightened *** comprehensive overview aims to consolidate and analyze the diverse array of microfluidic approaches in energetic material synthesis,offering valuable insights for future research directions.

关键词： Microfluidic technology Energetic materials synthesis Micro-mixing Micro-droplets

Dynamic stress intensity factor K_(III) and dynamic crack propagation characteristics of anisotropic materials

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Applied Mathematics and Mechanics(English Edition) 2008年第9期29卷 1119-1129页

作者：高鑫王汉功康兴无 section 501 Xi'an Institute of High Technology section 501 Xi’an Institute of High Technology

Based on the mechanics of anisotropic materials, the dynamic propagation problem of a mode Ⅲ crack in an infinite anisotropic body is investigated. Stress, strain and displacement around the crack tip are expressed as an analytical complex function, which can be represented in power series. Constant coefficients of series are determined by boundary conditions. Expressions of dynamic stress intensity factors for a mode Ⅲ crack are obtained. Components of dynamic stress, dynamic strain and dynamic displacement around the crack tip are derived. Crack propagation characteristics are represented by the mechanical properties of the anisotropic materials, i.e., crack propagation velocity M and the parameter ~. The faster the crack velocity is, the greater the maximums of stress components and dynamic displacement components around the crack tip are. In particular, the parameter α affects stress and dynamic displacement around the crack tip.

关键词： dynamic fracture stress intensity factor crack propagation anisotropy

Machine learning for online control of particle accelerators

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Science China(Physics,Mechanics & Astronomy) 2025年第2期68卷 94-104页

作者： Xiaolong Chen Zhijun Wang Yuan He Hong Zhao Chunguang Su Shuhui Liu Weilong Chen Xiaoying Zhao Xin Qi Kunxiang Sun Chao Jin Yimeng Chu Hongwei Zhao Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and technology Lanzhou UniversityLanzhou 730000China School of Nuclear Science and technology University of Chinese Academy of SciencesBeijing 100049China Advanced Energy Science and Technonlogy Guangdong Laboratory Huizhou 516000China Department of Physics Xiamen UniversityXiamen 361005China

Particle accelerators play a critical role in modern scientific ***,existing manual beam control methods heavily rely on experienced operators,leading to significant time consumption and potential challenges in managing next-generation accelerators characterized by higher beam current and stronger nonlinear *** this paper,we establish a dynamical foundation for designing the online adaptive controller of accelerators using machine *** provides a guarantee for dynamic controllability for a class of scientific instruments whose dynamics are described by spatial-temporal equations of motion but only part variables along the instruments under steady states are *** necessity of using historical time series of beam diagnostic data is *** strategies involve also employing a well-established virtual beamline of accelerators,by which various beam calibration scenarios that actual accelerators may encounter are *** the reinforcement learning algorithm is adopted to train the controller with the interaction to the virtual ***,the controller is seamlessly transitioned to real ion accelerators,enabling efficient online adaptive control and ***,the controller demonstrates significant robustness,effectively managing beams with diverse charge mass ratios without requiring *** a controller allows us to achieve the global control within the entire superconducting section of the China Accelerator Facility for Superheavy Elements.

关键词： nonlinear complex system adaptive control machine learning particle accelerator simulation to reality

Investigations of inelastic cross sections of H_(2)O molecule by He^(2+) and C^(6+) projectiles with energy range around the Bragg peak

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Nuclear Science and Techniques 2025年第2期36卷 141-154页

作者： Guo-Zhuang Li Cheng-Ye Sun Rui Cheng Yan-Shi Zhang Liang-Wen Chen Sheng Zhang Xin-Xia Li Lei Yang School of Nuclear Science and technology University of South ChinaHengyang 421001China Advanced Energy Science and technology Guangdong Laboratory Huizhou 516000China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China Interdisciplinary Center for Fundamental and Frontier Sciences Nanjing University of Science and TechnologyJiangyin 214443China Center for Basic Teaching and Experiment Nanjing University of Science and TechnologyJiangyin 214443China School of Nuclear Science and technology University of Chinese Academy of SciencesBeijing 100049China

Inelastic collisions are the dominant cause of energy loss in *** the energy range around the Bragg peak,single ionization(SI)and single-electron capture(SC)are the primary inelastic collisions that lead to energy *** study employs the classical trajectory Monte Carlo method to study the SI and SC processes of H_(2)O molecules using He^(2+) and C^(6+) projectiles in the energy range of 10 keV/u to 10 MeV/*** total cross sections,single differential cross sections,impact parameter dependence of SI and SC,and fragmentation cross sections were *** illustrate that the cross section for SI is the highest when the projectile energy is close to the Bragg peak *** the projectile energy is below the Bragg peak energy,the ionized electrons in the forward direction dominate,and the removal of electrons can be associated with large impact *** the projectile energy increases,the emission angle of the electrons gradually transitions from small angles(60°~120°)to large angles(60°~120°),and the removal of electrons is associated with small impact *** energy distributions of the ionized electron are similar when the projectile energy is equal to,below or above the Bragg peak *** fragmentation cross sections after SI and SC in the energy range around the Bragg peak were also estimated.

关键词： Classical trajectory Monte Carlo Heavy ion-water molecule collision Inelastic cross sections

Fatigue Strength Analysis of Dissimilar Aluminum Alloy TIG Welds

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Journal of Wuhan University of technology(Materials Science) 2025年第1期40卷 265-274页

作者： LIAO Xiangyun WANG Ruijie LIU Guoshou ZHAO Pinglin Faculty of Mechanical and Electrical Engineering Kunming University of Science and TechnologyKunming 650500China Faculty of Civil Engineering and Mechanics Kunming University of Science and TechnologyKunming 650500China

The constant amplitude loading fatigue tests were carried out on the 6061/7075 aluminum alloy TIG fillet welded lap specimens in this study,and the weld seam cross-section hardness was *** experimental results show that most specimens mainly failed at the 7075 side weld toes even though the base material tensile strength of 7075 is higher than that of *** maximum stress-strain concentration in the two finite element models is located at the 7075 side weld toe,which is basically consistent with the actual fracture *** weld zone on the 7075 side experiences severe material softening,with a large ***,the Vickers hardness value on the 6061 side negligibly changes and fluctuates around 70 *** obvious defects are found on the fatigue fracture,but a large number of secondary cracks *** germinate from the weld toe and propagate in the direction of the plate *** reinforcement has a serious impact on fatigue *** life will decrease exponentially as the weld reinforcement increases under low *** is found that the notch stress method can give a better fatigue life prediction for TIG weldments,and the errors of the predicted results are within the range of two factors,while the prediction accuracy decreases under low *** equivalent structural stress method can also be used for fatigue life prediction of TIG weldments,but the errors of prediction results are within the range of three factors,and the accuracy decreases under high stress.

关键词： TIG welding notch stress method equivalent structural stress method fatigue life finite element analysis

Process optimization study on the carbonylation of methyl acetate

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Chinese Journal of Chemical Engineering 2018年第9期26卷 1937-1942页

作者： Baohe Wang Baomin Ge Jing Zhu Lina Wang Key Laboratory for green Chemical technology of Ministry of Education Research and Development Center of Petrochemical Technology Tianjin University

Acetic anhydride is the important organic chemical raw material, and is used widely in chemical industry,pharmaceutical industry, dyes, spices and other fields. In this paper, the process of carbonylation of methyl acetate in rhodium iodine catalyst system was studied, and the suitable reaction conditions were *** the same time, the kinetic model was established. The optimum reaction conditions were as follows： the reaction pressure was 5 MPa, the hydrogen content was 8%, the amount of iodomethane was 15%, the amount of lithium iodide was 3%, the reaction temperature was 150 ℃ and the reaction time is 3 h. Under the above reaction conditions, the selectivity of the reaction is close to 100% and the conversion is as high as 92%. The macroscopic kinetic model of the reaction was established in the temperature range of 120 ℃–150 ℃. The reaction is an irreversible reaction without the formation of by-products and the dynamic equation is also given in the Conclusions section.

关键词： Carbonylation Rhodium iodine catalyst Reaction conditions Kinetics

Implicit Function Theorem and Its Application to a Ulam's Problem for Exact Differential Equations

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Acta Mathematica Sinica,English Series 2010年第11期26卷 2085-2092页

作者： Soon-Mo JUNG Mathematics section College of Science and TechnologyHong-Ik University

We prove a global version of the implicit function theorem under a special condition and apply this result to the proof of a modified Hyers-Ulam-Rassias stability of exact differential equations of the form, g（x, y）... 详细信息

关键词： Implicit function theorem Ulam's problem Hyers-Ulam-Rassias stability exact differ-ential equation potential function