检索结果-南通市图书馆

Chinese Journal of Aeronautics 2020年第2期33卷 598-608页

作者： jian WANG Fengtong ZHAO Yundong SHA Song gu Department of Aircraft Maintenance Engineering Chengdu Aeronautic PolytechnicChengdu 610100China Liaoning Key Laboratory of Advanced Test Technology for Aeronautical Propulsion System Shenyang Aerospace UniversityShenyang 110136China

Rapid alternating stress is formed in structure subjected to harsh thermal-acoustic loads,which will affect fatigue performance and reduce fatigue life ***,fatigue experiment of superalloy thin-walled structure was carried out to obtain fatigue damage location and failure time of the experiment specimen,and S-iN curves of superalloy thin-walled structure at 723 K were ***,dynamic response simulation of superalloy thin-walled structure under the same load as experiment was implemented,and fatigue life was estimated based on the fatigue life prediction model which mainly included:improved rain-flow counting method,Morrow average stress model and Miner linear cumulative damage ***,comparisons between simulation solutions and experimental results achieved a consistency,which verified the validity of the Fatigue Life Prediction Model(FLPM).Moreover,taking a rectangle plate as the analysis object,the distributions of Fain-low circulation blocks and damage levels of the structure were discussed ***,current research indicates that in pre-buckling the structure is in softened area and fatigue life decreases with the increase of temperature;in post-buckling the structure is in hardened area and fatigue life increases with the increase of temperature within a certain range.

关键词： Experimental verification Fatigue life Improved rain-flow counting method Rain-flow cycle matrix Rain-flow damage matrix Thermal-acoustic load Thin-walled structures

A review on conventional and nonconventional machining of SiC particle-reinforced aluminium matrix composites

在线全文

学校读者我要写书评

暂无评论

Advances in Manufacturing 2020年第3期8卷 279-315页

作者： Ji-Peng Chen Lin gu guo-jian He School of Mechanical and Electronic Engineering Nanjing Forestry UniversityNanjing 210037People’s Republic of China Department of Mechanical Engineering Polytechnic University of MilanPiazza Leonardo da Vinci 32Milan 20133Italy State Key Laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240People’s Republic of China

Among the various types of metal matrix composites,SiC particle-reinforced aluminum matrix composites(SiCp/Al)are finding increasing applications in many industrial fields such as aerospace,automotive,and ***,SiCp/Al composites are considered as difficult-to-cut materials due to the hard ceramic reinforcement,which causes severe machinability degradation by increasing cutting tool wear,cutting force,*** improve the machinability of SiCp/Al composites,many techniques including conventional and nonconventional machining processes have been *** purpose of this study is to evaluate the machining performance of SiCp/Al composites using conventional machining,i.e.,turning,milling,drilling,and grinding,and using nonconventional machining,namely electrical discharge machining(EDM),powder mixed EDM,wire EDM,electrochemical machining,and newly developed high-efficiency machining technologies,e.g.,blasting erosion arc *** research not only presents an overview of the machining aspects of SiCp/Al composites using various processing technologies but also establishes optimization parameters as reference of industry applications.

关键词： SiCp/Al Machining Conventional Wear mechanism Nonconventional Performance

Tunable chiroptical application by encapsulating achiral lanthanide complexes into chiral MOF thin films

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2022年第2期15卷 1102-1108页

作者： Rui Zhai Yihong Xiao Zhigang gu jian Zhang State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China College of Chemistry and Materials Science Fujian Normal UniversityFuzhou 350007China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108China University of Chinese Academy of Sciences Beijing 100049China

Chiral metal-organic frameworks(chirMOFs)have been widely considered on enantioselective adsorption/separation,asymmetric catalysis,biological and nonlinear optical ***,chirMOFs are facing a great challenge in development of chiroptical thin films with circularly polarized luminescence(CPL)***,we first report CPL thin films by encapsulating achiral lanthanide complexes Ln(acac)_(3)(Ln=Eu_(a)Tb_(b)Gd_(c))into the pores of surface-coordinated chirMOF thin films(SURchirMOF)[Zn_(2)(cam)_(2)dabco]_(n) with layer by layer(Ibl)encapsulation *** to the unique combination of chiral porous MOF and adjustable luminescent complexes in the host-guest thin films,the obtained Ln(acac)_(3)@SURchirMOF possess strong and tunable CPL property with high dissymmetry *** compared CPL and fluorescent lifetime results show that the advantage of this preparation strategy can effectively achieve energy transfer from Ln(acac)_(3) to SURchirMOF,resulting in an excellent CPL *** study not only provides a novel strategy to develop new types of chiral thin films but also offers an efficient approach for tunable chiroptical applications.

关键词： metal-organic frameworks lanthanide complexes thin films encapsulation chiral optical application

Suppressing nonlinear aeroelastic response of laminated composite panels in supersonic airflows using a nonlinear energy sink

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

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

在线全文

学校读者我要写书评

暂无评论

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

Unveiling Dynamic System Strategies for Multisensory Processing: From Neuronal Fixed-Criterion Integration to Population Bayesian Inference

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research 2023年第2期2022卷 81-100页

作者： Jiawei Zhang yong gu Aihua Chen Yuguo Yu State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science Shanghai Artificial Intelligence LaboratoryResearch Institute of Intelligent and Complex Systems and Institute of Science and Technology for Brain-Inspired IntelligenceHuman Phenome InstituteShanghai 200433China Key Laboratory of Primate Neurobiology Institute of NeuroscienceCAS Center for Excellence in Brain Science and Intelligence TechnologyChinese Academy of SciencesShanghaiChina Key Laboratory of Brain Functional Genomics(Ministry of Education) East China Normal University3663 Zhongshan Road N.Shanghai 200062China

Multisensory processing is of vital importance for survival in the external *** circuits can both integrate and separate visual and vestibular senses to infer self-motion and the motion of other ***,it is largely debated how multisensory brain regions process such multisensory information and whether they follow the Bayesian strategy in this process.

关键词： Integration Fixed Criterion

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

高压泡沫涨裂破岩特性试验研究

岩土工程学报 2025年第1期47卷 125-134页

作者：刘送永崔松顾聪聪中国矿业大学机电工程学院江苏徐州221116 中国矿业大学智能采矿装备技术全国重点实验室江苏徐州221116 安徽理工大学机电工程学院安徽淮南232001

针对钻爆法和机械法在岩石破碎工程中的弊端,基于泡沫的高黏性和可压缩性,提出了高压泡沫涨裂破岩技术。首先设计高压泡沫涨裂破岩装置,理论分析高压泡沫瞬间释放冲击岩石涨裂孔过程,搭建高压泡沫涨裂力测试装置并开展涨裂力影响试验,... 详细信息

针对钻爆法和机械法在岩石破碎工程中的弊端,基于泡沫的高黏性和可压缩性,提出了高压泡沫涨裂破岩技术。首先设计高压泡沫涨裂破岩装置,理论分析高压泡沫瞬间释放冲击岩石涨裂孔过程,搭建高压泡沫涨裂力测试装置并开展涨裂力影响试验,建立高压泡沫涨裂破岩试验系统,探讨不同空气体积分数时的泡沫涨裂特性,揭示高压泡沫涨裂破岩机理。研究表明:高压泡沫释放时,能够在涨裂孔内产生比泡沫初始压力更高的涨裂力,但涨裂力随泡沫空气体积分数增加而先增大后减小,高压泡沫涨裂破岩经历了裂纹初生、裂纹扩展、涨裂抛掷、涨裂结束4个阶段,破岩重量随泡沫空气体积分数的增加而先增大后减小,当空气体积分数为60%时,由高压泡沫冲击涨裂孔产生的压应力波在岩石上表面反射形成的拉应力造成岩石破坏形式为涨裂坑,空气体积分数为70%~90%时,泡沫涨裂形式为大块岩石分离,这主要是由孔底直角处应力集中效应造成。

关键词：高压泡沫涨裂破岩裂纹扩展涨裂力

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

Sensitivity of Sample for Simulation-Based Reliability Analysis Methods

在线全文

学校读者我要写书评

暂无评论

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

基于度量学习理论的马田系统改进及其应用研究

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

管理工程学报 2025年第2期39卷 221-233页

作者：常志朋顾玉萍陈闻鹤安徽工业大学商学院安徽工业大学复杂系统多学科管理与控制安徽普通高校重点实验室安徽财经大学管理科学与工程学院南京理工大学经济管理学院

为提升马田系统的识别性能,本文利用度量学习理论对其进行改进。一是将传统协方差马氏距离改进为以度量矩阵为参变量的马氏距离函数,然后利用简单直接的KISSME度量学习算法估计一个最能反映数据间内在关系的度量矩阵,该度量矩阵可以使... 详细信息

为提升马田系统的识别性能,本文利用度量学习理论对其进行改进。一是将传统协方差马氏距离改进为以度量矩阵为参变量的马氏距离函数,然后利用简单直接的KISSME度量学习算法估计一个最能反映数据间内在关系的度量矩阵,该度量矩阵可以使同类样本更紧凑、非同类样本更分离,这有助于提升马田系统的识别性能。二是基于拉近同类样本、推远非同类样本的思想,定义一个新的特征子集评估函数代替田口方法中的信噪比,这有助于筛选出可以提高马田系统识别性能的特征。改进后的马田系统仍然保持了原理简单、易于操作的优势。本文选取6个UCI数据集进行验证,得出改进后的马田系统在Accuracy、Specificity、G-means和降维率等方面均明显优于传统马田系统的结论。最后,本文通过返贫识别验证了改进后马田系统的可行性和有效性。

关键词：马田系统度量学习 KISSME 返贫识别

同方期刊数据库