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Chinese Journal of Aeronautics 2021年第2期34卷 376-385页

作者： jian ZHOU Minglong XU Zhichun YANG Yingsong gu State Key Laboratory for Strength and Vibration of Mechanical Structures School of Aerospace EngineeringXi'an Jiaotong UniversityXi'an 710049China School of Aeronautics Northwestern Polyteclmical UniversityXi'an 710072China

This paper proposes using a Nonlinear Energy Sink(NES) to suppress the nonlinear aeroelastic response of laminated composite panels in supersonic airflows. Relevant aeroelastic equations are established using Hamilton’s principle and a finite element approach, drawing upon Von Karman’s large deflection theory and first order piston theory. The idea of the NES suppression region is proposed and the effects of NES parameters on the NES suppression region are studied in detail. The results show that the nonlinear aeroelastic responses of the panel can be completely suppressed by the Transient Resonance Capture(TRC);the appropriate NES parameter values can increase the critical dynamic pressure for flutter and suppress the nonlinear aeroelastic response effectively. Increasing the mass ratio of the NES can improve the NES suppression region;the nonlinear stiffness coefficient and damping of the NES within a specific range can suppress the nonlinear aeroelastic response. The most effective installation position for a NES is in a specific region behind the center-line of the panel in the direction of the airflow.

关键词： Aeroelasticity Laminated composite panel Nonlinear dynamics Nonlinear energy sink Panel flutter Passive suppression

On PID control for synchronization of complex dynamical network with delayed nodes

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Science China(Technological Sciences) 2019年第8期62卷 1412-1422页

作者： gu HaiBo Lv JinHu lin ZongLi Key Laboratory of Systems and Control Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 China School of Mathematical Sciences University of Chinese Academy of Sciences Beijing 100049 China School of Automation Science and Electrical Engineering State Key Laboratory of Software Development Environment and Beijing Advanced Innovation Center for Big Data and Brain Machine Intelligence Beihang University Beijing 100083 China Charles L. Brown Department of Electrical and Computer Engineering University of Virginia Charlottesville VA 22904-4743 USA

Over the past two decades, synchronization, as an interesting collective behavior of complex dynamical networks, has been attracting much attention. To reveal and analyze the inherent mechanism of synchronization in complex dynamical networks with time delays in nodes, this paper attempts to use PD and PI control protocols to achieve synchronization. Based on a classical network model, we investigate the PD and PI control for synchronization of complex dynamical networks with delayed nodes and obtain some sufficient conditions. By using Lyapunov functions and appropriate state transformations, we prove that global synchronization can be achieved via the above control protocols. Finally, some simulation examples are illustrated to validate the effectiveness of the proposed theoretical results.

关键词： synchronization PID control complex dynamical network networked control system delayed node

On a Criterion of Universal Spectra

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Acta Mathematica Sinica,English Series 2013年第7期29卷 1323-1328页

作者： jian lin LI College of Mathematics and Information Science Shaanxi Normal University

For positive integers N1,N2,...,Nn, let L = Z^n ＋ A and A =- N1Z x -…… x NnZ ＋ F be two rational periodic sets, where A ∩ （1/N1）Z x ... x （1/Nn）Z and F ∩ Z^n are finite sets with （A- A）∩Z^n = {0} and （F... 详细信息

For positive integers N1,N2,...,Nn, let L = Z^n ＋ A and A =- N1Z x -…… x NnZ ＋ F be two rational periodic sets, where A ∩ （1/N1）Z x ... x （1/Nn）Z and F ∩ Z^n are finite sets with （A- A）∩Z^n = lin and （F- F）N （N1Z x.. x NnZ） = lin. In this note, we shall determine conditions under which the tiling set L has universal spectrum A. We first obtain a criterion of universal spectra. This criterion combined with the properties of compatible pair yields many necessary and sufficient conditions for A to be a universal spectrum for L. We then show that, under some mild additional conditions, the conjecture of Lagarias and Szab5 is true. The results here extend the corresponding results of Lagarias, Szabo and Wang.

关键词： Spectral set periodic set tiling universal spectrum

Tau in Alzheimer’s Disease:Pathological Alterations and an Attractive Therapeutic Target

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Current Medical Science 2020年第6期40卷 1009-1021页

作者： jian-lan gu Fei LIU Department of Biochemistry and Molecular Biology School of MedicineNantong UniversityNantong 226001China Key Laboratory of Neuroregeneration and Ministry of Education of jiangsu Co-innovation Center of NeuroregenerationNantong 226001China Department of Neurochemistry Inge Grundke-Iqbal Research FloorNew York State Institute for Basic Research in Developmental DisabilitiesStaten IslandNY 10314USA

Alzheimer’s disease(AD)is an age-related neurodegenerative disease with two major hallmarks:extracellular amyloid plaques made of amyloid-β(Aβ)and intracellular neurofibrillary tangles(NFTs)of abnormally hyperphosphorylated *** number of NFTs correlates positively with the severity of dementia in AD ***,there is still no efficient therapy available for AD treatment and prevention so far.A deeper understanding of AD pathogenesis has identified novel strategies for the generation of specific therapies over the past few *** studies have suggested that the prion-like seeding and spreading of tau pathology in the brain may be a key driver of *** protein is considered as a promising candidate target for the development of therapeutic interventions due to its considerable pathological role in a variety of neurodegenerative *** tau hyperphosphorylation plays a detrimental pathological role,eventually leading to *** the present review,we describe the recent research progresses in the pathological mechanisms of tau protein in AD and briefly discuss tau-based therapeutic strategies.

关键词： Alzheimer’s disease tau protein hyperphosphorylation propagation of tau pathology

The Luminescence Properties of M' type of YTaO_4∶Eu

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Chemical Research in Chinese Universities 1999年第3期15卷 226-231页

作者： LI Bo gu Zhen-nan DONG Yi lin jian-hua SU Mian-zeng Chemistry Department State key Laboratory of Rare Earth Materials Chemistry and ApplicationsPeking UniversityBejing 100871P.R.China

A series of Eu 3+ doped of Mtype of yttrium orthotantalate Y 1-x Eu x TaO 4( x =0-0.30) was sythesized. The influence of activator concentration on luminescence properties was studied in detail. The strong evidence from excitation spectra, emission spectra and diffusive reflection spectra of this system shows that there is energy transfer from TaO 3- 4 to Eu 3+ via the charge transfer and spectral overlap.

关键词： Tantalate Rare earth Luminescence

Distance Sets Relating to Orthogonal Exponentials

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Acta Mathematica Sinica,English Series 2011年第12期27卷 2409-2414页

作者： jian lin LI College of Mathematics and Information Science Shaanxi Normal University Xi＇an 710062 P. R. China

The aim of this paper is to investigate the size properties of a planar set whose distance set has some prescribed arithmetic combinatorics. Such research is motivated by the conjecture that the disk has no more than 3 orthogonal exponentials. By proving a shifted version of ErdSs-Solymosi＇s theorem on the distance sets, we give some grounds on the conjecture. The results obtained here extend the corresponding results of Iosevich and Jaming in a simple manner.

关键词： Distance sets orthogonal exponentials convex sets algebraic number and transcendental number

自由活塞斯特林发电机气体静压轴承的承载特性

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轴承 2025年第1期 31-38页

作者：杨明卓牟健林明嫱洪国同中国科学院理化技术研究所中国科学院空间功热转换技术重点实验室北京100190 中国科学院大学北京100049

气体静压轴承结合间隙密封技术作为自由活塞斯特林发电机的关键技术之一,可使动力活塞在高频往复运动中实现无接触支承,提高发电机的可靠性和使用寿命。为研究自由活塞斯特林发电机气体静压轴承的承载特性,基于轴向流动假设建立了理论模... 详细信息

气体静压轴承结合间隙密封技术作为自由活塞斯特林发电机的关键技术之一,可使动力活塞在高频往复运动中实现无接触支承,提高发电机的可靠性和使用寿命。为研究自由活塞斯特林发电机气体静压轴承的承载特性,基于轴向流动假设建立了理论模型,通过模型计算了不同条件下气体轴承提供的承载力,设计并搭建了一种气体轴承承载力测试装置,测试了气体轴承在不同供气压力、节流孔直径及数量下的承载力。理论模型与试验结果均表明:承载力与供气压力、节流孔数、节流孔径呈正相关;承载力随活塞与气缸间隙的减小而增大。在间隙一定的条件下,偏心率越大,承载力越大;仿真分析与试验结果具有较好的一致性,说明这种测试方法是可行的。

关键词：滑动轴承气体静压轴承发电机节流孔承载力数值模型

On the correction of the boundary deficiency in SPH for the frictional contact simulation

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Science China(Technological Sciences) 2014年第1期57卷 86-100页

作者： WANG jian HUA Hui gu ChongShi National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety Hohai University College of Water Conservancy and Hydropower Engineering Hohai University

Smoothed particle hydrodynamics(SPH)is a mesh-free method which is powerful for large deformation computation of ***,the algorithm for the simulation of frictional contact which is common in geotechnical engineering is still quite immature due to the boundary *** this study,the cause of boundary deficiency in the SPH simulation for frictional contact is ***,based on mathematical derivation,the method to correct boundary deficiency related to frictional contact is discussed theoretically,where the frictional contact algorithm is established by dividing the computational domain into several subdomains according to the existing contact boundaries and by using contact forces as bridges of these subdomains to fulfil problem solving,and the value of correction coefficient is obtained by comparing the SPH outcome of the contact particles with that calculated through Newton’s second law of *** the same time,from the perspective of numerical computation,an optimized value for the correction coefficient is proposed,and a thorough investigation is performed on the cubic spline kernel function and quintic spline kernel function,whose correction coefficients are found to be 2.0 and[2.0,2.16],***,numerical tests are carried out to verify the proposed *** outcome of the study is helpful to providing theoretical support for the research of frictional contact simulation within the framework of SPH.

关键词： smoothed particle hydrodynamics (SPH) frictional contact boundary deficiency correction

Degrees of freedom for energy storage material

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Carbon Energy 2022年第4期4卷 633-644页

作者： Yue Gong lin gu Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijingChina CAS Key Laboratory of Standardization and Measurement for Nanotechnology CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijingChina School of Physical Science University of Chinese Academy of SciencesBeijingChina Songshan Lake Materials Laboratory DongguanChina

Building a bridge between properties and structures has always been the key focus of any materials ***,energy storage materials,especially lithium-ion batteries,are crucial both in daily life and for the research ***,there is an urgent need to discover the functionality origin of battery performances to improve and design better material *** originates from local symmetry and *** symmetry can be described by four fundamental degrees of freedom:lattice,charge,orbital,and *** the basis of this,detailed descriptions of the battery's properties in terms of lattice,charge,orbital,and spin are presented from the perspective of frontier transmission electron microscopy in this ***,frontier in situ methods are introduced to record the dynamic structural evolution process during the battery *** discussion from the perspectives of both materials and characterizations is provided at the end of this review.

关键词： charge in situ lattice orbital spin transmission electron microscopy

Sensitivity of Sample for Simulation-Based Reliability Analysis Methods

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Computer Modeling in Engineering & Sciences 2021年第1期126卷 331-357页

作者： Xiukai Yuan jian gu Shaolong Liu School of Aerospace and Engineering Xiamen UniversityXiamen361005China Institute for Risk and Reliability Leibniz Universitat HannoverHannoverGermany

In structural reliability analysis,simulation methods are widely *** statistical characteristics of failure probability estimate of these methods have been well *** this study,the sensitivities of the failure probability estimate and its statistical characteristics with regard to sample,called‘contribution indexes’,are proposed to measure the contribution of *** contribution indexes in four widely simulation methods,i.e.,Monte Carlo simulation(MCS),importance sampling(IS),line sampling(LS)and subset simulation(SS)are derived and *** proposed contribution indexes of sample can provide valuable information understanding the methods deeply,and enlighten potential improvement of *** is found that the main differences between these investigated methods lie in the contribution indexes of the safety samples,which are the main factors to the efficiency of the ***,numerical examples are used to validate these findings.

关键词： Reliability analysis Monte Carlo simulation importance sampling line sampling subset simulation