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Bandgap characteristics analysis and graded design of a novel metamaterial for flexural wave suppression

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 1-24页

作者： Fan YANG Zhaoyang MA Xingming guo Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Institute of Applied Mathematics and Mechanics School of Mechanics and Engineering ScienceShanghai University Shanghai Institute of Aircraft Mechanics and Control

A novel elastic metamaterial is proposed with the aim of achieving lowfrequency broad bandgaps and bandgap regulation. The band structure of the proposed metamaterial is calculated based on the Floquet-Bloch theorem, and the boundary modes of each bandgap are analyzed to understand the effects of each component of the unit cell on the bandgap formation. It is found that the metamaterials with a low elastic modulus of ligaments can generate flexural wave bandgaps below 300 Hz. Multi-frequency vibrations can be suppressed through the selective manipulation of bandgaps. The dual-graded design of metamaterials that can significantly improve the bandgap width is proposed based on parametric studies. A new way that can regulate the bandgap is revealed by studying the graded elastic modulus in the substrate. The results demonstrate that the nonlinear gradient of the elastic modulus in the substrate offers better bandgap performance. Based on these analyses, the proposed elastic metamaterials can pave the way for multi-frequency vibration control, low-frequency bandgap broadening, and bandgap tuning.

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Asking one mechanism in glial cells during neuroinflammation

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Neural Regeneration Research 2025年第4期20卷 1077-1078页

作者： Xiaoli guo Chikako Harada Takayuki Harada Visual Research Project Tokyo Metropolitan Institute of Medical ScienceTokyoJapan

Multiple sclerosis(MS),which is characterized by inflammatory demyelination in the central nervous system(CNS),is the most common neurological disease in the young adult *** autoimmune encephalomyelitis(EAE),an animal model of MS,is often used in preclinical *** data indicate that in addition to immune cells such as T cells and dendritic cells,CNS resident microglia and astrocytes play important roles in demyelinating neuroinflammation(Healy et al.,2022).In particular,microglia are key immune-competent cells that can respond to environmental *** depletion of transforming growth factor-β-activated kinase 1,a mitogen-associated protein kinase kinase kinase,in microglia is reported to reduce CNS inflammation and diminish axonal and myelin damage *** suggests that elucidating the mechanisms of microglia-specific responses during pathologies may help in the development of treatments that reduce EAE/MS disease severity(Goldmann et al.,2013).

关键词： inflammation clinical

Monogenic gene therapy for glaucoma and optic nerve injury

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Neural Regeneration Research 2025年第3期20卷 815-816页

作者： Chikako Harada Xiaoli guo Takayuki Harada Visual Research Project Tokyo Metropolitan Institute of Medical ScienceTokyoJapan

The prevalence of glaucoma, the second leading cause of global blindness, is increasing due to aging populations. In glaucoma, degeneration of the optic nerve and retinal ganglion cells(RGCs) causes visual field defec... 详细信息

关键词： visual glaucoma degeneration

Acquired sensorineural hearing loss,oxidative stress,and microRNAs

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Neural Regeneration Research 2025年第9期20卷 2513-2519页

作者： Desmond A.Nunez Ru C.guo Division of Otolaryngology–Head&Neck Surgery Department of SurgeryFaculty of MedicineThe University of British ColumbiaVancouverBCCanada Division of Otolaryngology–Head&Neck Surgery Gordon&Leslie Diamond Health Care CentreVancouver General HospitalVancouverBCCanada Faculty of Medicine–The University of British Columbia VancouverBCCanada

Hearing loss is the third leading cause of human ***-related hearing loss,one type of acquired sensorineural hearing loss,is largely responsible for this escalating global health ***-induced,ototoxic,and idiopathic sudden sensorineural are other less common types of acquired hearing *** etiology of these conditions is complex and multi-fa ctorial involving an interplay of genetic and environmental *** stress has recently been proposed as a likely linking cause in most types of acquired sensorineural hearing *** non-coding RNA sequences known as microRNAs(miRNAs)have increasingly been shown to play a role in cellular hypoxia and oxidative stress responses including promoting an apoptotic *** hair cell death is a central histopathological finding in sensorineural hearing *** these cells do not regenerate in humans,it underlies the irreversibility of human age-related hearing *** EMBASE,Ovid MEDLINE,Web of Science Core Collection,and *** databases over the period August 1,2018 to July 31,2023 were searched with"hearing loss,""hypoxamiRs,""hypoxia,""microRNAs,""ischemia,"and"oxidative stress"text words for English language primary study publications or registered clinical *** red clinical trials known to the senior author we re also assessed.A total of 222studies were thus *** excluding duplicates,editorials,retra ctions,secondary research studies,and non-English language articles,39 primary studies and clinical trials underwent full-text *** resulted in 11 animal,in vitro,and/or human subject journal articles and 8 registered clinical trial database entries which form the basis of this narrative *** miR-34a and miR-29b levels increase with age in *** miRNAs were demonstrated in human neuroblastoma and murine cochlear cell lines to target Sirtuin 1/peroxisome proliferato r-activated receptor gamma coactivator-1-alpha(SIRT1/P GC-1α),SIRT

关键词： hearing loss hypoxia microRNAs oxidative stress sensorineural

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汽车空调压缩机关键机构的运动学分析与仿真

制冷与空调 2017年第1期17卷 27-30,21页

作者：罗炎旺郭迎福赵延明童亚凯湖南科技大学

汽车空调SD7V16型压缩机排量的可变化性由其活塞行程的改变实现。根据SD7V16型压缩机关键机构的传动原理建立数学模型,对关键机构进行运动学分析,得到活塞的位移、速度和加速度计算公式,进而求出压缩机排量的几何算法。最后,通过ADAMS... 详细信息

汽车空调SD7V16型压缩机排量的可变化性由其活塞行程的改变实现。根据SD7V16型压缩机关键机构的传动原理建立数学模型,对关键机构进行运动学分析,得到活塞的位移、速度和加速度计算公式,进而求出压缩机排量的几何算法。最后,通过ADAMS仿真得到活塞的位移、速度和加速度以及在600r/min,3 000 r/min和6 000 r/min主轴转速下的变化曲线。研究结果可为深入研究同类压缩机关键机构尺寸公差及尺寸公差的敏感性对压缩机排量的影响奠定基础。

关键词：汽车空调压缩机传动原理运动学分析 ADAMS仿真

矿井掘进工作面及巷道环境噪声预测与控制研究状况

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矿业工程研究 2010年第4期25卷 62-68页

作者：彭佑多郭迎福李新谢伟华 B.S.Dhillon 湖南科技大学机械设备健康维护省重点实验室湖南湘潭411201 Department of Mechanical Engineering of University of Ottawa Canada.ON K1N6N5

源于机器声源的矿井掘进工作面及巷道环境噪声严重影响着矿工的身心健康,并可能掩蔽各种安全警报信号而成为安全事故的重大隐患.简要分析了典型掘进工作面机器噪声和巷道环境噪声特点,重点论述了预测与控制掘进工作面及巷道环境噪声密... 详细信息

源于机器声源的矿井掘进工作面及巷道环境噪声严重影响着矿工的身心健康,并可能掩蔽各种安全警报信号而成为安全事故的重大隐患.简要分析了典型掘进工作面机器噪声和巷道环境噪声特点,重点论述了预测与控制掘进工作面及巷道环境噪声密切相关的凿岩机器噪声辐射机理、噪声源时空特性、矿(煤)岩力学特性对机器噪声影响、巷道声学长空间环境噪声传播与衰减规律及噪声控制等领域的主要研究课题和研究进展,为掘工作面及巷道环境噪声预测与控制提供了一定依据.

关键词：掘进工作面噪声预测控制研究状况

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磁力金属带传动的传动特性分析

中国工程科学 2005年第7期7卷 76-80页

作者：罗善明郭迎福陈安华余以道陈立锋湖南科技大学机械设备健康维护省重点实验室湖南湘潭411201

介绍了磁力金属带传动的工作原理,分析和探讨了其有效拉力、线速度及弹性滑动率等传动性能,并通过实验测定了相关性能参数。结果表明,磁力金属带传动主要是利用磁场吸引力与初拉力的耦合作用来增加摩擦力进而传递运动和动力的,其传动效... 详细信息

介绍了磁力金属带传动的工作原理,分析和探讨了其有效拉力、线速度及弹性滑动率等传动性能,并通过实验测定了相关性能参数。结果表明,磁力金属带传动主要是利用磁场吸引力与初拉力的耦合作用来增加摩擦力进而传递运动和动力的,其传动效率可达95 %～98% ,而弹性滑动率一般在0 1%以下。

关键词：带传动金属带磁场吸引力机电耦合

Multiple Tin Compounds Modified Carbon Fibers to Construct Heterogeneous Interfaces for Corrosion Prevention and Electromagnetic Wave Absorption

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Nano-Micro Letters 2025年第1期17卷 507-527页

作者： Zhiqiang guo Di Lan Zirui Jia Zhenguo Gao Xuetao Shi Mukun He Hua guo Guanglei Wu Pengfei Yin College of Science Sichuan Agricultural UniversityYa’an 625014People’s Republic of China School of Materials Science and Engineering Hubei University of Automotive TechnologyShiyan 442002People’s Republic of China Institute of Materials for Energy and Environment State Key Laboratory of Bio‑Fibers and Eco‑TextilesCollege of Materials Science and EngineeringQingdao UniversityQingdao 266071People’s Republic of China Shaanxi Key Laboratory of Macromolecular Science and Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’anShaanxi 710072People’s Republic of China

Currently,the demand for electromagnetic wave(EMW)absorbing materials with specific functions and capable of withstanding harsh environments is becoming increasingly ***-component interface engineering is considered an effective means to achieve high-efficiency EMW ***,interface modulation engineering has not been fully discussed and has great potential in the field of EMW *** this study,multi-component tin compound fiber composites based on carbon fiber(CF)substrate were prepared by electrospinning,hydrothermal synthesis,and high-temperature thermal *** utilizing the different properties of different substances,rich heterogeneous interfaces are *** effectively promotes charge transfer and enhances interfacial polarization and conduction *** prepared SnS/SnS_(2)/SnO_(2)/CF composites with abundant heterogeneous interfaces have and exhibit excellent EMW absorption properties at a loading of 50 wt%in epoxy *** minimum reflection loss(RL)is−46.74 dB and the maximum effective absorption bandwidth is 5.28 ***,SnS/SnS_(2)/SnO_(2)/CF epoxy composite coatings exhibited long-term corrosion resistance on Q235 steel ***,this study provides an effective strategy for the design of high-efficiency EMW absorbing materials in complex and harsh environments.

关键词： Electrostatic spinning Component regulation Heterogeneous interfaces Electromagnetic wave absorption Corrosion protection

Synergistic effect of bonding heterogeneity and phonon localization in introducing excellent thermoelectric properties in layered heteroanionic NdZnSbO material

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Journal of Energy Chemistry 2025年第1期100卷 259-272页

作者： Da Wan Shuwei Tang Shulin Bai Xiaodong Li Peng Ai Wanrong guo Tuo Zheng College of Materials Science and Engineering Liaoning Technical University Faculty of Chemistry Northeast Normal University

Layered rare-earth metal oxides, harnessing the dual properties of oxides and two-dimensional layered materials, exhibit remarkable thermal stability and quantum confinement effects. Therefore, this work adopts the first-principles calculation combined with the Boltzmann transport theory to predict the thermoelectric properties of NdZnSbO compound. The coexistence of weak interlayer van der Waals interactions, robust intralayer ionic bonding, and partial covalent bonding leads to remarkable bonding heterogeneity, which engenders pronounced phonon scattering and imposes constraints on thermal transport along the out-of-plane direction. The weakened chemical bonds induced by the antibonding states, together with the rattling-like behavior of the Zn atom, culminate in the profound anharmonicity in the layered NdZnSbO compound. The weakening bond and heavy element contribute to the softness of phonon modes, which significantly diminishes the phonon group velocity. The redistribution-dominated four-phonon scattering process spans a large optical gap, which effectively reduces the lattice thermal conductivity. The NdZnSbO compound exhibits direct semiconductor characteristic with a bandgap of 0.73 e V by adopting the Heyd-Scuseria-Ernzerhof(HSE06) functional in combination with spin–orbit coupling(SOC) effect. The multi-valley feature of NdZnSbO compound augur favorably for band degeneracy, thus amplifying the power factor. Consequently, an optimal figure-of-merit(ZT) of 3.40 at 900 K is achieved for the n-type NdZnSbO compound. The present study delves deeply insights into the origins for the low thermal conductivity of NdZnSbO compound and proposes an optimization scheme to enhance overall thermoelectric performance.

关键词： Bond strength (chemical)