The high concentration of Cl − in seawater causes serious corrosion of copper and enormous economic losses. In order to reveal the microscopic mechanism and kinetic process of Cl − in different corrosion inhibition films, the diffusion of Cl − in benzotriazole, mercaptobenzothiazole and methyl benzene three nitrogen thiazole and the interaction between CuO (−1 0 0) and three corrosion inhibition films were researched by using molecular dynamic simulation. The research indicated that corrosion inhibition mechanisms of the three films are not the same. The inhibition of benzotriazole and methyl benzene three nitrogen thiazole is mainly because of direct chemical adsorption. However, the inhibition of mercaptobenzothiazole is because of indirect chemical adsorption. The diffusion coefficient of Cl − in benzotriazole, mercaptobenzothiazole and methyl benzene three nitrogen thiazole is 1·634 × 10 −5 , 1·656 × 10 −5 and 1·627 × 10 −5 cm 2 s −1 , respectively. All of them are relatively low, so the three inhibitors can effectively prevent Cl − diffusing into themselves. Furthermore, pore connectivity is worst for benzotriazole film and the membrane structure is more stable than that of methyl benzene three nitrogen thiazole and mercaptobenzothiazole.

B-site complex ions (Li 1/4 Nb 3/4 ) 4z modification (Bi 1/2 Na 1/2 ) 0?94 Ba 0?06 TiO 3 ceramics with compositions of (Bi 1/2 Na 1/2 ) 0?94 Ba 0?06 Ti 12x (Li 1/4 Nb 3/4 ) x O 3 (x50, 0?01, 0?03 and 0?06) have been synthesised via the conventional solid state reaction. The effect of (Li 1/4 Nb 3/4 ) 4z content and sintering temperature on structures and electrical properties were investigated. It was found that both compositions and sintering temperatures have no significant effect on the crystal structure, and trace (Li 1/4 Nb 3/4 ) 4z addition and sintering temperatures have a great influence on the microstructure. Two obvious dielectric anomaly peaks (T d and T m ) were observed and dielectric constant for all poled specimens displayed significant frequency dispersion at T d and diffusion phase transition at T m . The piezoelectric properties of the ceramics are insensitive to the sintering temperatures, and the composition with x50?03 sintering at 1150uC exhibits favourable piezoelectric properties of d 33 5155 pC N 21 and k p 50?312.