Search

Taking AC power supply system of a mine as research object and combining possible circulation path of AC stray current, a mine AC stray current model was built based on analysis of generation mechanism of mine AC stray current. Distribution laws of AC stray current under different unbalance coefficient of insulation resistance of high voltage or low voltage cable were researched by Matlab/Simulink simulation. The research results show that when insulation resistance of high voltage or low voltage cable is asymmetry, the generated AC stray current mainly distributes in shielding or ground wire and metal net in asymmetry section of insulation resistance. When insulation resistance of the entire cable is asymmetric, AC stray current increases continuously in return path to power grid. With the increase of unbalance coefficient of insulation resistance, effective value of AC stray current flowing through shielding or ground wire, metal net and each ground electrode all increases.

Abstract: The electrochemical behavior of 1,4-dinitrobenzene (1,4-PNB) on the Au electrode was investigated by cyclic voltammetry (CV), in situ FT-IR spectroelectrochemistry, cyclic voltabsorptometry (CVA) and derivative cyclic voltabsorptometry (DCVA) techniques. In aprotic media, 1,4-dinitrobenzene is reversibly reduced in two-step one-electron transfer. A series of IR absorption bands at 1056, 1210, 1341, 1356, 1464 and 1549cm−1, tracing to PNB; PNB − and PNB2− are observed. In the presence of proton donors mixed media, with increasing concentrations of proton donors, hydrogen-bonding and protonation process are found successively. The values of combining proton donors with per PNB2− to form hydrogen-bonding are estimated by using electrochemical parameters. The result of forming aromatic nitroso compound is supported by tracing the change of IR absorption bands at 1149 and 1587cm−1 at high concentration of proton donors. Based on CVA and DCVA techniques, it is clearly distinguished that the mechanisms of electrochemical reduction of PNB are elaborated in different systems. [Copyright &y& Elsevier]