A strain of Thiobacillus Denitrificans (TD) isolated from the soil was selected to reduce the corrosion caused by Sulfate Reducing Bacteria (SRB). The optimal pH was determined as 7.0 for the growth of TD. The growth environment of TD was found to be similar to that of SRB. Thus they can be cultured together. When they were grown together, it was observed that TD reduced the corrosion caused by SRB, being attributed to that TD might consume corrosive sulfides produced by SRB and restrict the SRB biofilms from accumulation. Scanning probe microscopy observations ex-situ demonstrated that the topography of mixture biofilm formed in the mixed culture of TD and SRB was more compact than that for SRB along. Therefore, the process of charge transfer is baffled, leading to a decrease of the corrosion caused by SRB.

UV-visible absorption and fluorescence properties of 14 nano-size star-like compounds, being composed of oligothienylene units bridged by silicon atoms, have been studied in dioxane solution. The absorption and emission maximum wavelengths are found to be dependent on the oligothienylene units. High fluorescence quantum yields and longer lifetimes are observed for the star-like compounds containing bithienylene units, being related to the σ-π interaction and the star-like structure.

Electrochemical polymerization of ring-substituted dimethylaniline was performed in aqueous acid solutions to obtain soluble conducting polyaniline. The conductivity values of polydimethylanilines obtained were in the range of 10-1- 10-7Scm-1 depending on the preparation conditions. The molar masses of the oxidation products were in the order of 10.3 gregardless of the monomer structure. These conductive oligomers were easily soluble in polar organic solvents. Soluble conducting oligomers were also obtained by chemical polymerization with iron (Ⅲ) species.

Electropolymerization of aniline-2,5-disulfonic acid in aqueous solutions results in formation of a water-soluble self-doped polymer. E€ects of synthesis conditions were investigated on conductivity and molecular-weight distribution of the polymer. The polymer shows solubility in water high up to 109 mg cm-3. The conductivity of the polymer, with best value of about 0.34 S cm-1, is independent on pH up to at least pH 9.

UV-visible absorption and fluorescence properties of three series of s-pconjugated polymers (copolymers of alternative oligothienylene and oligosilylene units) have been studied in dioxane solution. The energies of the absorption maximum, fluorescence maximum, and the 0-0 transition are found to be linearly dependent on the reciprocal of the number of thiophene rings in the repeating unit of the polymer chain, but almost independent of the silicon atom number. The s-p-conjugation in the polymers results in red shift in the absorption and fluorescence maxima, higher fluorescence quantum yields, and longer fluorescence lifetimes of the polymers, with respect to their corresponding analogous a-oligothiophenes.