The strain distributions near the interface when the elbow steel fiber is pulled out from the half-mould concrete matrix are directly measured using a combined method of single fiber pull-out test and digital image co...The strain distributions near the interface when the elbow steel fiber is pulled out from the half-mould concrete matrix are directly measured using a combined method of single fiber pull-out test and digital image correlation. Meanwhile, the real-time processes of the bonding, debonding and sliding at the interface are observed. The micro-mechanism of the strain localization in the failure process of interface when debonding occurs and the strengthening mechanism at the imbedded fiber are discussed. The experimental results show that the meso-scale strain localization gives rise to the localization of shear damage near the fiber interface. This strain localization characterized by the debonding process near the interface occurs, develops and moves gradually at an apparently regular interval. At the elbow part of the imbedded fiber, the peak value of the shearing stress occurs. But the primary debonding does not occur at this place because the strength of the shear damage is increased at the local area of the elbow part in the concrete, displaying an apparent reinforced effect at the end of the fiber.展开更多
Functional magnetic resonance imaging （fMRI） is a new tool for brain-computer interface （BCI）. This paper presents an overview to fMRI-BCI. Our attention is mainly put on the methods of signal acquisition, signal ...Functional magnetic resonance imaging （fMRI） is a new tool for brain-computer interface （BCI）. This paper presents an overview to fMRI-BCI. Our attention is mainly put on the methods of signal acquisition, signal preprocessing, and signal analysis of basic fMRI-BCI structure. The available softwares and the applications of fMRI-BCI are briefly introduced. At last, we suggest focusing on some technologies to make fMRI-BCI more perfect.展开更多
基金the National Natural Science Foundation of China(Nos.10972097,11062007)Specialized Research Fund for the Doctoral Programof Higher Education of China(No.20101514120005)the Inner Mongolia Natural Science Foundation of China(No.2010MS0703)
文摘The strain distributions near the interface when the elbow steel fiber is pulled out from the half-mould concrete matrix are directly measured using a combined method of single fiber pull-out test and digital image correlation. Meanwhile, the real-time processes of the bonding, debonding and sliding at the interface are observed. The micro-mechanism of the strain localization in the failure process of interface when debonding occurs and the strengthening mechanism at the imbedded fiber are discussed. The experimental results show that the meso-scale strain localization gives rise to the localization of shear damage near the fiber interface. This strain localization characterized by the debonding process near the interface occurs, develops and moves gradually at an apparently regular interval. At the elbow part of the imbedded fiber, the peak value of the shearing stress occurs. But the primary debonding does not occur at this place because the strength of the shear damage is increased at the local area of the elbow part in the concrete, displaying an apparent reinforced effect at the end of the fiber.
基金supported by the National Natural Science Foundation of China under Grant No. 30570507, 30770590, and 90820006National 863 Program under Grant No: 2008AA02Z408.
文摘Functional magnetic resonance imaging （fMRI） is a new tool for brain-computer interface （BCI）. This paper presents an overview to fMRI-BCI. Our attention is mainly put on the methods of signal acquisition, signal preprocessing, and signal analysis of basic fMRI-BCI structure. The available softwares and the applications of fMRI-BCI are briefly introduced. At last, we suggest focusing on some technologies to make fMRI-BCI more perfect.
