Research on Operational Modal Parameter Identification of Mechanical Structures Based on Blind Source Separation

随着国家机械制造工业的迅速发展，各类工程机械设备广泛地应用于日常生活、生产和建设过程中，机械结构的运行安全越来越受到国家的重视。模态分析是机械结构设计、状态监测和性能评估的重要基础，对机械结构的安全运行起到至关重要的作用。有别于传统的频域模态分析方法，工作模态分析仅利用时域输出信号，能够真实反映机械结构运行过程中的性能指标，因此准确可靠地提取机械结构工作状态下的模态参数具有十分重要的意义。 论文在总结传统模态分析方法的基础上，将盲源分离技术应用于机械结构在环境激励下的工作模态参数提取方法研究。提出了基于盲源分离技术的复模态系统模态参数提取方法和欠定系统的模态参数提取方法。论文的主要工作包括以...With the rapid development of machinery manufacturing industry, all kinds of engineering machinery and equipments are widely used in the process of daily life, production and construction. The operational safety of mechanical structures has been paid more and more attention to. Modal analysis is an important basis of mechanical structure design, status monitoring, performance assessment, which pla...学位：工学博士院系专业：物理与机电工程学院_精密仪器及机械学号：1992008015048

机械结构模态参数时域识别方法原理及展望

分析了传统模态分析方法在大型机械结构模态识别中的弊端,指出利用基于响应信号的时域信号进行大型机械结构的模态参数识别已日益成为一种趋势。对时域模态参数识别的主要方法进行了论述,分析了各类方法的识别原理及优缺点,在此基础上总结了目前时域识别方法存在的问题,并对今后的研究工作进行了展望。国家自然科学基金资助项目(编号:50855002

On the Influences of Cultural Tradition on the Process of the Nationwide Fitness Programs in China

文化传统与全民健身进程存在着非常密切的关系,我国是有着深厚文化传统的国家,在目前全民健身计划推行十余年的关键发展期,必须关注文化传统在这一进程中的深刻影响。通过研究发现,影响全民健身进程主要包括三个层面:物质层面、制度层面、意识层面;文化传统对全民健身进程的影响,也主要表现在对这三个主要层面产生作用,并最终影响到全民健身进程的快慢、突破口、发展模式、完成质量和项目特点等。There are very close relationship between the nationwide fitness programs process and the cultural tradition,because China is the country with a long history of cultural tradition.At present the Whole-Peop1e Health-Building Plan is on the key phase after carrying out it for more than ten years.Therefore,we must pay close attention to the deep influences of the cultural tradition in this process.Through the research,we find three aspects mainly restraining the nationwide fitness programs process: material aspect,system aspect,and consciousness aspect.The impacts of the cultural tradition on nationwide fitness programs process display on these three main aspects,and at last influence the speed,breach,development mode,quality and project characteristics of the nationwide fitness programs process

Assessing ecological risks of heavy metals to marine organisms in the Jiulongjiang Estuary by species sensitivity distribution

采用物种敏感性分布法(SSd)构建常见重金属元素对海洋生物的SSd曲线,结合九龙江口水体5、8、11月份21个站位重金属调查数据,计算了九龙江口7种重金属(AS,Cd,Cr,Cu,Hg,Pb,zn)不同暴露浓度对海洋生物的潜在影响比例(PAf),并分析了在相应站位重金属复合污染生态风险(MSPAf)。结果表明,7种重金属中AS的生态风险最大(即PAf值最高);时间尺度上,5月份总的MSPAf较其他月份稍高;空间尺度上,西溪至海门岛(1~7号站位)污染较严重,其中又以位于西溪和玉枕洲的2号和5号站位的MSPAf为最。In the present work,a species sensitivity distribution( SSD) method was used to assess the ecological risk of common heavy metals to marine organisms.The ecological risk was characterized by potentially affected fraction( PAF) of species in relation to concentration of the toxic materials.According to the investigation data obtained at 21 stations in the Jiulongjiang Estuary in May,August and November,the PAFs of seven heavy metals( As,Cd,Cr,Cu,Hg, Pb,and Zn) to marine organisms were calculated.The results showed that As had the highest PAF among the seven heavy metals at each station of the Jiulongjiang Estuary.Spatially,the multi-substance PAF( msPAF) in May was higher than in other months.Temporally,the msPAF of the Stations 1-7( from the Xixi Stream to the Haimen Isle of the Jiulongjiang Estuary) suffered from heavier pollution.In particular,the pollution status of the Station 2 and Station 5 was the most serious among all the investigated stations.海洋公益性行业科研经费专项(201105015); 国家海洋局青年海洋科学基金项目(2011143); 国家自然科学基金项目(31101902); 福建省自然科学基金项目(2012J05074); 国家海洋局第三海洋研究所基本科研业务费专项(海三科2011006)资