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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.

关键词： flexural wave bandgap graded design local resonance metamaterial O421+.5

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计算机远程网络通讯技术的应用

电子测试 2016年第9X期27卷 80-,92页

作者：范肖飞成都理工大学信息科学与技术学院四川成都610059

随着现今经济以及科学技术的快速发展,我国的计算机技术也得到了迅速的发展。在日常生活中,信息技术对于人们的生活产生极大的影响,如移动媒体的大范围使用等。从本质上来说,移动媒体属于远程网络通讯技术的一种,利用这种技术,可实现对... 详细信息

随着现今经济以及科学技术的快速发展,我国的计算机技术也得到了迅速的发展。在日常生活中,信息技术对于人们的生活产生极大的影响,如移动媒体的大范围使用等。从本质上来说,移动媒体属于远程网络通讯技术的一种,利用这种技术,可实现对社会上信息的实时共享。本文主要从目前的情况下对计算机远程网络通讯技术的应用进行了深入分析。

关键词：计算机远程网络通讯技术应用

Reconstructing forest and grassland cover changes in China over the past millennium

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Science China Earth Sciences 2025年第1期68卷 94-110页

作者： fanneng HE fan YANG Yafei WANG Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing100101China Key Research Institute of Yellow River Civilization and Sustainable Development Henan UniversityKaifeng475001China University of Chinese Academy of Sciences Beijing100049China

Historical forest and grassland cover changes not only are critical indicators for quantifying ecological and environmental change processes but also serve as fundamental data for long-term climate change simulations and terrestrial ecosystem carbon emission ***,because of limitations in historical data,quantitative estimations and spatially gridded reconstructions of these changes remain challenging,necessitating further methodological *** study focused on China's present-day land area over the past millennium,objectively capturing the characteristics and drivers of forest and grassland cover *** this basis,using the forest transition theory and the space-for-time substitution method,we depicted the historical deforestation process as an inverted“S”curve and developed a model to reconstruct historical forest area changes based on the functional relationship between the forest area and population size ***,a gridded forest allocation model was established on the basis of deforestation *** the grassland cover,we implemented regionspecific methods,such as the cropland area deduction method and the habitat constraint method,to quantitatively reconstruct historical ***,we obtained provincial forest and grassland area changes over the past millennium and mapped 10-km-resolution gridded data of forest and grassland *** results indicated the following.(1)The methods developed using population data as a proxy objectively reproduced the spatiotemporal evolution of forest and grassland cover in China over the past *** feasible methods offer a novel pathway for the quantitative reconstruction of historical forest and grassland cover changes.(2)The data indicated that China's forest area generally decreased over the past millennium,characterized by a“decrease-then-increase”*** forest area experienced three distinct phases:a slow decline(AD 1000–1650),a rapid decline(AD 16

关键词： Land use and land cover change Forest Grassland Quantitative reconstruction Gridded reconstruction China historical period

Dynamic behaviors of graphene platelets-reinforced metal foam piezoelectric beams with velocity feedback control

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 63-80页

作者： Jie CHEN Xinyue ZHANG Mingyang fan School of Mathematics Statistics and Mechanics Beijing University of Technology College of Mechanical & Energy Engineering Beijing University of Technology

Graphene platelets(GPLs)-reinforced metal foam structures enhance the mechanical properties while maintaining the lightweight characteristics of metal foams. Further bonding piezoelectric actuator and sensor layers on the surfaces of GPLs-reinforced metal foam beams enables active vibration control, greatly expanding their applications in the aerospace industry. For the first time, this paper investigates the vibration characteristics and active vibration control of GPLs-reinforced metal foam beams with surfacebonded piezoelectric layers. The constant velocity feedback scheme is used to design the closed-loop controller including piezoelectric actuators and sensors. The effects of the GPLs on the linear and nonlinear free vibrations of the beams are numerically *** Newmark-β method combined with Newton's iteration technique is used to calculate the nonlinear responses of the beams under different load forms including harmonic loads,impact loads, and moving loads. Additionally, special attention is given to the vibration reduction performance of the velocity feedback control on the responses of the beam.

关键词： active vibration control metal foam nonlinear free vibration O341 piezoelectric material velocity feedback control

Sarcopenic obesity in liver disease: Handling both sides of the penny

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Portal Hypertension & Cirrhosis 2022年第1期1卷 42-56页

作者： Yangyang Hui Binxin Cui Xiaoyu Wang Mingyu Sun Yifan Li Wanting Yang Gaoyue Guo Lihong Mao Zihan Yu xiaofei fan Chao Sun Department of Gastroenterology and Hepatology Tianjin Medical University General HospitalTianjinChina Department of Gastroenterology Tianjin Medical University General Hospital Airport HospitalTianjinChina

Skeletal muscle and fat tissue show distinct pathophysiological roles and pivotal *** culmination of muscle wasting and fat accumulation represents an opposite terminal of each ***,this situation has been designated as sarcopenic ***,sarcopenic obesity still lacks a unanimous definition,diagnostic criteria,and generalized modalities for assessment in the context of versatile liver ***,the underpinning mechanisms by which a combination of abnormal skeletal muscle and fat tissue leads to the progression of liver disease and impairs health‐related consequences are still ***,the interplay between skeletal muscle and fat,and the driving factors that shift different body compositions are not well ***,in this review,we discuss skeletal muscle and fat components,with the purpose of conceptualization,as well as interpret their roles in liver *** focus on the definitions,diagnostic criteria,and currently available measurements for sarcopenic obesity in the *** comprehensively discuss recent data and evidence regarding the potential role of sarcopenic obesity in the development and progression of numerous liver diseases and associated conditions,including nonalcoholic fatty liver disease,chronic viral hepatitis,cirrhosis,and liver ***,explicit information related to the pathogenesis of sarcopenic obesity from basic research is also provided in this narrative ***,we discuss,from the clinical perspective of view,how to manage sarcopenic obesity using nutritional,physical,and pharmacological methods.

关键词： hepatocellular carcinoma liver cirrhosis NAFLD pathogenesis sarcopenic obesity

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黄芩素的简便合成

中国医药工业杂志 2014年第10期45卷 916-918页

作者：景临林范小飞马慧萍樊鹏程贾正平兰州军区兰州总医院药剂科甘肃兰州730050 兰州大学药学院甘肃兰州730000

白杨素通过5,7-双甲基化保护羟基得5,7-二甲氧基黄酮,与N-溴代丁二酰亚胺(NBS)进行选择性溴代得5,7-二甲氧基-8-溴黄酮,以DMF为溶剂、溴化亚铜为催化剂,于120℃与甲醇钠反应4 h制得5,7,8-三甲氧基黄酮,最后经去甲基化和Wessely-Moser重... 详细信息

白杨素通过5,7-双甲基化保护羟基得5,7-二甲氧基黄酮,与N-溴代丁二酰亚胺(NBS)进行选择性溴代得5,7-二甲氧基-8-溴黄酮,以DMF为溶剂、溴化亚铜为催化剂,于120℃与甲醇钠反应4 h制得5,7,8-三甲氧基黄酮,最后经去甲基化和Wessely-Moser重排反应得黄芩素,总收率约56%。

关键词：白杨素黄芩素醇解反应合成

Effects of carbon content on the microstructure and tensile properties of a low-density steel

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 391-401页

作者： Yongxuan Shang Mingyu fan Shuyong Jiang Zhongwu Zhang Key Laboratory of Superlight Materials and Surface Technology Ministry of EducationCollege of Materials Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150001China State Key Laboratory of Metal Material for Marine Equipment and Application Iron&Steel Research Institute of Ansteel Group CorporationAnshan 114009China

Carbon can change the phase components of low-density steels and influence the mechanical *** this study,a new method to control the carbon content and avoid the formation ofδ-ferrite by decarburization treatment was *** microstructural changes and mechanical characteristics with carbon content induced by decarburization were systematically ***-Jaoul(C-J)analysis was employed to examine the work hardening characteristics during the tensile *** decarburization by heat treatments,the carbon content within the austenite phase decreased,while Mn and Al were almost unchanged;this made the steel with full austenite transform into the austenite and ferrite dual ***,(Ti,V)C carbides existed in both matrix phase and the mole fraction almost the *** addition,the formation of other carbides *** loss induced a decrease in strength due to the weakening of the carbon solid *** the steel with the single austinite,the deformation mode of austenite was the dislocation planar glide,resulting in the formation of *** the dual-phase steel,the deformation occurred by the dislocation planar glide of austenite first,with the increase in strain,the cross slip of ferrite took place,forming dislocation cells in *** the late stage of deformation,the work hardening of austinite increased rapidly,while that of ferrite increased slightly.

关键词： low-density steels carbon content decarburization strengthening mechanisms work hardening behavior

Automatic and Rapid Throughflow-Based Optimal Design Method for Multi-Stage Axial-Flow Compressors

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Journal of Thermal Science 2025年第1期34卷 77-91页

作者： LEI fan ZHANG Xiawen JU Yaping ZHANG Chuhua Department of Fluid Machinery and Engineering School of Energy and Power EngineeringXi'an Jiaotong UniversityXi'an 710049China State Key Laboratory for Strength and Vibration of Mechanical Structures Xi'an Jiaotong UniversityXi'an 710049China Production and Environmental Department China Huaneng Group.Co.Ltd.Beijing 100031China

Throughflow design has the advantages of less time consumption and large optimization space,and thus is the corner stone of advanced design system of multi-stage axial-flow *** majority of relevant studies were limited to the throughflow inverse designs,and quite few works have been till now devoted to the throughflow optimal *** this work,an automatic and rapid throughflow-based optimal design method is proposed for axial-flow compressors in which a throughflow inverse design solver is embedded in optimal genetic algorithm to improve the design efficiency of axial-flow *** types of design parameters in the throughflow inverse design of axial-flow compressors,i.e.,swirl and shroud curve,are simultaneously used to optimize both the blade shape and flow *** proposed method is validated by the redesign optimization of the benchmark axial-flow compressor NASA Stage 35,and the CFD predictions show that the throughflow-based optimization leads to 1.18% efficiency benefit at design *** proposed method is then utilized to the two-dimensional throughflow optimal design of a large-scale 6.5-stage axial-flow industrial *** optimal design results are confirmed by CFD predictions,indicating that the proposed method can effectively improve the design adiabatic efficiency of the compressors by 1.09% within a few minutes on desk-top *** throughflow design implications are also obtained for advanced axial-flow industrial *** work could enhance the capability of throughflow design method and has engineering application value to explore the throughflow optimization space of multi-stage axial-flow compressors.

关键词： multi-stage axial-flow compressor throughflow design empirical correlations genetic algorithm aerodynamic optimization

国医大师王晞星运用升清降浊法治疗代谢性疾病经验

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中华中医药杂志 2024年第11期39卷 5900-5904页

作者：凡晓菲刘然王晞星山西省中医药研究院太原030012

代谢性疾病是由于糖、脂类、蛋白质、嘌呤、微量元素等物质与能量在新陈代谢的过程中出现了障碍。王晞星教授认为代谢性疾病的关键病机是脾胃升清降浊功能失常,其从升阳益气、升阳除湿、升阳散火三方面恢复脾胃升清降浊功能,选用补中益... 详细信息

代谢性疾病是由于糖、脂类、蛋白质、嘌呤、微量元素等物质与能量在新陈代谢的过程中出现了障碍。王晞星教授认为代谢性疾病的关键病机是脾胃升清降浊功能失常,其从升阳益气、升阳除湿、升阳散火三方面恢复脾胃升清降浊功能,选用补中益气汤、升阳益胃汤、补脾胃泻阴火升阳汤为基础方治疗,临床效果良好。“升”与“降”在人体的运用中相辅相成,升降相因,有升则有降,有降则有升,“升”与“降”既对立又统一。文章总结了王教授的临床经验,王教授在运用升清降浊之法时,升清与降浊并用,配伍风药以胜湿。清阳升则人体脏腑得以濡养,浊阴降则糟粕垃圾排出体外,人体新陈代谢维持相对平衡的状态从而阴平阳秘。

关键词：代谢性疾病升清降浊法名医经验升阳益气升阳除湿升阳散火