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Inverse design of mechanical metamaterial achieving a prescribedconstitutive curve

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Theoretical & Applied Mechanics Letters 2024年第1期14卷 16-22页

作者： Zongliang Du Tanghuai Bian Xiaoqiang Ren Yibo Jia Shan Tang Tianchen Cui Xu Guo State Key Laboratory of structural Analysis Optimization and CAE Software for Industrial EquipmentDepartment of Engineering MechanicsDalian University of TechnologyDalian 116023China Ningbo Institute of Dalian University of Technology Ningbo 315016China

Besides exhibiting excellent capabilities such as energy absorption,phase-transforming metamaterials offer a vast design space for achieving nonlinear constitutive *** is facilitated by switching between different patterns under ***,the related inverse design problem is quite challenging,due to the lack of appropriate mathematical formulation and the convergence issue in the post-buckling analysis of intermediate *** this work,periodic unit cells are explicitly described by the moving morphable voids method and effectively analyzed by eliminating the degrees of freedom in void ***,by exploring the Pareto frontiers between error and cost,an inverse design formulation is proposed for unit *** formulation aims to achieve a prescribed constitutive curve and is validated through numerical examples and experimental *** design approach presented here can be extended to the inverse design of other types of mechanical metamaterials with prescribed nonlinear effective properties.

关键词： Metamaterial Pattern-transformation Constitutive curve Inverse design

Pacemaker post transcatheter aortic valve replacement:A multifactorial risk?

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World Journal of Cardiology 2024年第4期16卷 168-172页

作者： Stephane Noble Karim Bendjelid department of Medicine Structural Heart UnitUniversity Hospital of GenevaGeneva 1211Switzerland department of Acute Medicine Geneva University HospitalsGeneva 1211Switzerland

Pacemaker post-transcatheter aortic valve replacement is related to multifactorial *** et al brought to the body of evidence electrocardiogram and clinical ***,procedural characteristics have at least as much impact on the final need for a permanent pacemaker and potentially on the pacing *** this regard,long-term follow-up and understanding of the impact of long-term stimulation is of utmost importance.

关键词： Transcatheter aortic valve replacement Permanent pacemaker implantation Conduction abnormalities Right bundle branch block Left bundle branch block

Data-driven modeling on anisotropic mechanical behavior of brain tissue with internal pressure

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Defence Technology（防务技术） 2024年第3期33卷 55-65页

作者： Zhiyuan Tang Yu Wang Khalil I.Elkhodary Zefeng Yu Shan Tang Dan Peng State Key Laboratory of structural Analysis Optimization and CAE Software for Industrial EquipmentDalian University of Technology116023DalianPR China The department of Mechanical Engineering The American University in CairoNew Cairo11835Egypt department of Neurology The Second Hospital of Dalian Medical UniversityDalian116023PR China

Brain tissue is one of the softest parts of the human body,composed of white matter and grey *** mechanical behavior of the brain tissue plays an essential role in regulating brain morphology and brain ***,traumatic brain injury(TBI)and various brain diseases are also greatly influenced by the brain's mechanical *** white matter or grey matter,brain tissue contains multiscale structures composed of neurons,glial cells,fibers,blood vessels,etc.,each with different mechanical *** such,brain tissue exhibits complex mechanical behavior,usually with strong nonlinearity,heterogeneity,and directional *** a constitutive law for multiscale brain tissue using traditional function-based approaches can be very ***,this paper proposes a data-driven approach to establish the desired mechanical model of brain *** focus on blood vessels with internal pressure embedded in a white or grey matter matrix material to demonstrate our *** matrix is described by an isotropic or anisotropic nonlinear elastic model.A representative unit cell(RUC)with blood vessels is built,which is used to generate the stress-strain data under different internal blood pressure and various proportional displacement loading *** generated stress-strain data is then used to train a mechanical law using artificial neural networks to predict the macroscopic mechanical response of brain tissue under different internal ***,the trained material model is implemented into finite element software to predict the mechanical behavior of a whole brain under intracranial pressure and distributed body *** with a direct numerical simulation that employs a reference material model,our proposed approach greatly reduces the computational cost and improves modeling *** predictions made by our trained model demonstrate sufficient ***,we find that the level of internal blood pressur

关键词： Data driven Constitutive law Anisotropy Brain tissue Internal pressure

An artificial neural network based deep collocation method for the solution of transient linear and nonlinear partial differential equations

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Frontiers of structural and Civil Engineering 2024年第8期18卷 1296-1310页

作者： Abhishek MISHRA Cosmin ANITESCU Pattabhi Ramaiah BUDARAPU Sundararajan NATARAJAN Pandu Rang VUNDAVILLI Timon RABCZUK School of Mechanical Sciences Indian Institute of TechnologyBhubaneswar 752050India Institute of structural Mechanics Bauhaus University of WeimarWeimar 99423Germany department of Mechanical Engineering Indian Institute of Technology MadrasChennai 600036India

A combined deep machine learning(DML)and collocation based approach to solve the partial differential equations using artificial neural networks is *** developed method is applied to solve problems governed by the Sine–Gordon equation(SGE),the scalar wave equation and *** methods are studied:one is a space-time formulation and the other is a semi-discrete method based on an implicit Runge–Kutta(RK)time *** methodology is implemented using the Tensorflow framework and it is tested on several numerical *** on the results,the relative normalized error was observed to be less than 5%in all cases.

关键词： collocation method artificial neural networks deep machine learning Sine-Gordon equation transient wave equation dynamic scalar and elasto-dynamic equation Runge-Kutta method

Possibility and stabilizing effect of Mo clusters in the Ni-based single-crystal superalloy

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Communications in Theoretical Physics 2024年第8期76卷 187-192页

作者： Yiqun Du Huixin Jin Rongkai Kang Boya Zhang Han Wang Jianxin Zhang Key Laboratory for Liquid-Solid structural Evolution and Processing of Materials(Ministry of Education) School of Materials Science and EngineeringShandong UniversityJinan 250061China department of Materials Science and Technology Tokyo University of ScienceTokyo 1258585Japan

Nickel-based single-crystal superalloys are crucial materials for the preparation of aero-engine turbine blades. Many solute elements are added to superalloys for strengthening. However, the relationship between the clustering behavior of solute atoms and the properties of nickel-based single-crystal superalloys is still unclear. Herein, we conduct first-principles calculations onγ phases with Mo-Mo and Mo-Mo-Ru clusters to reveal the possibility and stabilizing mechanism of solute clusters. Introducing Mo lowers the total energy, binding energy, and formation energy of the γ phase due to the replacement of weak Ni-Ni interaction with strong Mo-Ni bonding. Note that the γ phase containing the Mo-Mo cluster is more stable than that containing a Mo single atom, possibly owing to a wide affecting range. The Ru atom added to the γ phase can further boost system stability, and it tends to form a Mo-Mo-Ru cluster. The stabilizing impact of the Mo-Mo-Ru cluster is demonstrated to be the replacement of weak Ni-Mo interaction by the strong Ru-Mo interaction, which may be derived from the enhanced d-orbital hybridization.

关键词： density functional theory superalloys solute cluster

Catalytic Asymmetric Diastereodivergent Synthesis of 2-Alkenylindoles Bearing both Axial and Central Chirality

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Precision Chemistry 2024年第5期2卷 208-220页

作者： Shuang Yang Jia-Bo Huang Da-Hua Wang Ning-Yi Wang Yu-Yu Chen Xin-Yan Ke Hao Chen Shao-Fei Ni Yu-Chen Zhang Feng Shi Research Center of Chiral functional Heterocycles School of Chemistry and Materials ScienceJiangsu Normal UniversityXuzhou 221116China department of Chemistry Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong ProvinceShantou UniversityShantou 515063China department of Otolaryngology Xuzhou First People’s HospitalAffiliated Xuzhou Municipal Hospital of Xuzhou Medical UniversityXuzhou 221002China School of Petrochemical Engineering Changzhou UniversityChangzhou 213164China

The catalytic asymmetric diastereodivergent synthesis of axially chiral 2-alkenylindoles was established via chiral phosphoric acid-catalyzed addition reactions of C3-unsubstituted 2-alkenylindoles with o-hydroxybenzyl alcohols under different reaction *** this strategy,two series of 2-alkenylindoles bearing both axial and central chirality were synthesized in a diastereodivergent fashion with moderate to high yields and good stereoselectivities(up to 99%yield,95:5 er,>95:5 dr).Moreover,theoretical calculations were performed on the key transition states leading to different stereoisomers,which provided an in-depth understanding of the origin of the observed stereoselectivity and diastereodivergence of the products under different reaction *** importantly,these 2-alkenylindoles were utilized in asymmetric catalysis as chiral organocatalysts and in medicinal chemistry for evaluation of their cytotoxicity,which demonstrated their potential *** study has not only established the catalytic atroposelective synthesis of axially chiral 2-alkenylindoles,but also provided an efficient strategy for catalytic asymmetric diastereodivergent construction of indole-based scaffolds bearing both axial and central chirality.

关键词： 2-Alkenylindole Axial chirality Central chirality Diastereodivergent synthesis Chiral phosphoric acid

Recent Advances in Asymmetric structural Composites for Excellent Electromagnetic Interference Shielding: A Review

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Chinese Journal of Polymer Science 2024年第6期42卷 693-710页

作者： Ying Zhou Bai Xue Lan Xie Chang-Mei Wu Qiang Zheng department of Polymer Materials and Engineering College of Materials and Metallurgy Guizhou University National Engineering Research Center for Compounding and Modification of Polymer Materials National and Local Joint Engineering Research Center for Functional Polymer Membrane Materials and Membrane Processes State Key Laboratory of Public Big Data Guizhou University department of Polymer Science and Engineering Zhejiang University

Since electromagnetic pollution is detrimental to human health and the environment, numerous efforts have been successively made to achieve excellent electromagnetic interference shielding effectiveness(EMI SE) via designing the hierarchical structures for electromagnetic interference(EMI) shielding polymer composites. Among the plentiful structures, the asymmetric structures are currently a hot spot, principally categorizing into multi-layered, porous, fibrous, and segregated asymmetric structures, which endows the high EMI shielding performance for polymer composites incorporated with magnetic, conductive, and/or dielectric micro/nano-fillers, due to the “absorption-reflection-reabsorption” shielding mechanism. Therefore, this review provides the retrospection and summary of the efforts with respect to abundant asymmetric structures and multifunctional micro/nano-fillers for enhancing EMI shielding properties, which is conducive to the booming development of polymeric EMI shielding materials for the promising prospect in modern electronics and 5-generation(5G) technology.

关键词： Asymmetric structure Microano functional filler Polymer composite Electromagnetic interference shielding

Cryogenic transmission electron microscopy on beam-sensitive materials and quantum science

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Chinese Physics B 2024年第8期33卷 9-29页

作者：王刚林君浩 department of Physics and Shenzhen Key Laboratory of Advanced Quantum functional Materials and Devices Southern University of Science and TechnologyShenzhen 518055China Quantum Science Center of Guangdong–Hong Kong–Macao Greater Bay Area(Guangdong) Shenzhen 518045China

Transmission electron microscopy(TEM)offers unparalleled atomic-resolution imaging of complex materials and heterogeneous ***,high-energy imaging electrons can induce structural damage,posing a challenge for electron-beam-sensitive *** TEM(Cryo-TEM)has revolutionized structural biology,enabling the visualization of biomolecules in their near-native states at unprecedented *** low electron dose imaging and stable cryogenic environment in Cryo-TEM are now being harnessed for the investigation of electron-beam-sensitive materials and low-temperature quantum ***,we present a systematic review of the interaction mechanisms between imaging electrons and atomic structures,illustrating the electron beam-induced damage and the mitigating role of *** review then explores the advancements in low-dose Cryo-TEM imaging for elucidating the structures of organic-based ***,we showcase the application of Cryo-TEM in the study of strongly correlated quantum materials,including the detection of charge order and novel topological spin ***,we discuss the future prospects of Cryo-TEM,emphasizing its transformative potential in unraveling the complexities of materials and phenomena across diverse scientific disciplines.

关键词： cryogenic TEM low dose imaging quantum materials

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揭示鱼鳞降低冰黏附力的奥秘

Science China Materials 2024年第6期67卷 2016-2022页

作者：王锋刘思琪肖森波 Bjørn Skallerud 张志良何健英 department of structural Engineering Norwegian University of Science and Technology(NTNU)Trondheim 7491Norway Suzhou Laboratory Suzhou 215000China

近几十年来,大量的研究文献表明,研究人员一直在探究静态表面特性(包括自由能、韧性和弹性)对疏冰性的影响.然而,对于动态表面特性在辅助除冰方面的理解非常有限.在本工作中,我们重点研究了北三文鱼表皮的冰黏附强度,并且观察到了有趣... 详细信息

近几十年来,大量的研究文献表明,研究人员一直在探究静态表面特性(包括自由能、韧性和弹性)对疏冰性的影响.然而,对于动态表面特性在辅助除冰方面的理解非常有限.在本工作中,我们重点研究了北三文鱼表皮的冰黏附强度,并且观察到了有趣的各向异性的冰黏附行为.与顺着鱼鳞生长方向的冰黏附强度(353±95 kPa)相比,逆着鱼鳞生长方向的冰黏附强度(141±47 kPa)降低了60%.我们发现,鱼鳞在受到剪切力的过程中,会发生独特的结构演变,从而导致界面连续断裂,有利于降低冰的黏附性.研究发现,鱼鳞的张开和剥离能力(描述了鳞片在外力下与其下部鳞片和黏结物分离的趋势)可以调控冰的脱落.通过提高鱼鳞的张开和剥离能力,可以在鱼鳞上实现更低的冰黏附强度(66±15 kPa)和更为容易的除冰过程.由于鱼鳞具有出色的机械鲁棒性,这一发现为设计坚硬耐用的防覆冰表面提供了新的视角.

关键词： fish scale ice adhesion dynamic behaviors sequential rupture anti-icing