7Han B G, Ou J P. Embedded piezoresistive cement-based stress/strain sensor [ J ]. Sensors and Actuators A, 2007, 138(2) : 294-298.
8Li H, Xiao H G, Ou J P. Effect of compressive strain on electrical resistivity of carbon black-filled cement-based composites [ J ]. Cement and Concrete Composites, 2006, 28 (9) : 824-828.
9Sun M Q, Liu Q P, Li Z Q, et al. A study of piezoelectric properties of carbon fiber reinforced concrete and plain cement paste during dynamic loading [ J ]. Cement and Concrete Research, 2000, 30 (10) : 1593-1595.
10Iijima S. Helical microtubules of graphitic carbon [ J ]. Nature, 1991, 354: 56-58.