In this paper,the authors presented a study on the discrimination of handlebar grip samples,to provide effective forensic science service for hit and run traffic cases.50 bicycle handlebar grip samples,49 electric bik...In this paper,the authors presented a study on the discrimination of handlebar grip samples,to provide effective forensic science service for hit and run traffic cases.50 bicycle handlebar grip samples,49 electric bike handlebar grip samples,and 96 motorcycle handlebar grip samples have been randomly collected by the local police in Beijing(China).Fourier transform infrared microspectroscopy(FTIR)was utilized as analytical technology.Then,target absorption selection,data pretreatment,and discrimination of linked samples and unlinked samples were chosen as three steps to improve the discrimination of FTIR spectrums collected from different handlebar grip samples.Principal component analysis and receiver operating characteristic curve were utilized to evaluate different data selection methods and different data pretreatment methods,respectively.It is possible to explore the evidential value of handlebar grip residue evidence through instrumental analysis and statistical treatments.It will provide a universal discrimination method for other forensic science samples as well.展开更多
应用调谐质量阻尼器(tuned mass damper, TMD)改善某摩托车手把振动。建立了用于手把减振研究的整车有限元模型,通过振动台架试验验证发动机激励下所建模型的可行性。提出了一种符合TMD安装方式的嵌入式TMD振动模型,以手把第一阶振动模...应用调谐质量阻尼器(tuned mass damper, TMD)改善某摩托车手把振动。建立了用于手把减振研究的整车有限元模型,通过振动台架试验验证发动机激励下所建模型的可行性。提出了一种符合TMD安装方式的嵌入式TMD振动模型,以手把第一阶振动模态频率为TMD调谐频率,以抑制手把振动加速度响应为目标,结合Den Hartog定点理论和等价质量识别法确定了嵌入式TMD最优减振设计参数值。通过发动机激励下的手把振动响应分析表明:所设计TMD对手把振动有显著抑制效果,其总加权加速度均方根值减小了37.8%。展开更多
基金This work was financially supported by Beijing Nova Programme(Grant Number:Z1511000003150123)China,and Key Program of National Social Science Fund(Grant Number:16AYY015)。
文摘In this paper,the authors presented a study on the discrimination of handlebar grip samples,to provide effective forensic science service for hit and run traffic cases.50 bicycle handlebar grip samples,49 electric bike handlebar grip samples,and 96 motorcycle handlebar grip samples have been randomly collected by the local police in Beijing(China).Fourier transform infrared microspectroscopy(FTIR)was utilized as analytical technology.Then,target absorption selection,data pretreatment,and discrimination of linked samples and unlinked samples were chosen as three steps to improve the discrimination of FTIR spectrums collected from different handlebar grip samples.Principal component analysis and receiver operating characteristic curve were utilized to evaluate different data selection methods and different data pretreatment methods,respectively.It is possible to explore the evidential value of handlebar grip residue evidence through instrumental analysis and statistical treatments.It will provide a universal discrimination method for other forensic science samples as well.
文摘应用调谐质量阻尼器(tuned mass damper, TMD)改善某摩托车手把振动。建立了用于手把减振研究的整车有限元模型,通过振动台架试验验证发动机激励下所建模型的可行性。提出了一种符合TMD安装方式的嵌入式TMD振动模型,以手把第一阶振动模态频率为TMD调谐频率,以抑制手把振动加速度响应为目标,结合Den Hartog定点理论和等价质量识别法确定了嵌入式TMD最优减振设计参数值。通过发动机激励下的手把振动响应分析表明:所设计TMD对手把振动有显著抑制效果,其总加权加速度均方根值减小了37.8%。
