Abstract

Fluorinated Multi-walled carbon nanotubes (F-MWCNTs) are chemically modified successfully by cobalt 2, 9, 16, 23tetraaminophthalocyanine and cobalt 1, 8, 15, 22-tetraaminophthalocyanine respectively. Their structures are characterized by IR, SEM, XPS and XRD. Important in this context is that the covalent linkages between F-MWCNTs and cobalt phthalocyanines are corroborated by monitoring the diagnostic signature of the nitrogen atoms as part of the formed -NH-bonds in them by XPS. The electrocatalytic activity of the two kinds of modified F-MWCNTs to Li/SOCl 2 battery is evaluated by adding them into the electrolyte of the battery. It is found that the modified F-MWCNTs can dramatically improve the discharge voltage and lengthen the discharge time of the battery, and finally make the capacity of the battery increase by 97.5% and 103.3% than that of the battery in the absence of them. The excellent electrocatalytic performance of the modified F-MWCNTs may be owing to the fine synergistic effect between the cobalt phthalocyanines and the MWCNTs in them. A reasonable catalytic mechanism of the modified F-MWCNTs to the battery is proposed according to the CV results.

The indirect method of using a passing vehicle to identify modal properties of a girder bridge has become attractive recently. Compared to the direct method, which requires a lot of sensors installed directly on the bridge itself, the indirect method only requires a single sensor installed on the vehicle to indirectly measure the response of the bridge. However, it is difficult to eliminate the adverse effect of road surface roughness. An indirect approach based on blind source separation is proposed for the first time in this study to identify the bridge element stiffness where two movable vehicles are used. Two identical vehicles stay at rest at the designated measurement points and their vertical accelerations are collected. After one measurement, the two vehicles move to other designated measurement points and the accelerations are collected again. The same procedure is repeated until the two vehicles have moved over all the designated measurement points. Then the blind source separation technique is employed to extract the fundamental mode shape of the bridge and the improved direct stiffness method is adopted to estimate the bridge element stiffness based on the collected data, which are used to monitor the health of the bridge structure and to maintain structure safety and natural symmetry. The proposed method only requires the output response of the vehicle due to the involvement of the blind separation technique. In addition, the proposed method can overcome the adverse effect of road surface roughness because the vehicles only move between two measurements and they stay at rest during one measurement. Numerical simulation was conducted to validate the proposed method, and the effect of various factors such as bridge damping ratio and measurement noise was investigated. Field measurement on Min-Xie bridge in Chongqing city was also carried out to further investigate the feasibility of the proposed method and showed that it can perform well in extracting the fundamental mode shape and evaluating bridge element stiffness.