The cationic plugging agent of water base drilling fluid was prepared by emulsion polymerization with styrene (St), butyl acrylate (BA) and cationic polymerizable monomer. The structure characteristics of the plugging agent were analyzed by infrared spectrum. The result of soaking test with clay ball showed that cationic plugging agent emulsion with a mass fraction of 5.0% was equivalent in inhibiting clay hydration property of saturated brine. The effect of cationic plugging agent on the properties of CaCl2 free phase drilling fluid was evaluated. The results showed that the high temperature and high pressure filtration (120~130 ℃) could be controlled at about 10 mL for the non phase drilling fluid with CaCl2 content of 25.0% when the cationic plugging agent is 2.0%.

B a _{0. 6} S r _{0. 4} Co _{0. 9} N b _{0. 1} O _3 --δ (BSCN) perovskitetype oxide was prepared by the solid state reaction. The high temperature chemical compatibility between BSCN0.6 and G d _{0. 1} C e _{0. 9} O _{1. 9 -5}(GDC) were analyzed by XRD. XRD patterns indicate that a week solid solution between BSCN0.6 and GDC takes place after the BSCN0.6GDC composite material was calcined at high temperature. However, this solid solution does not show a negative effect on the performance of the cathode. The mixture of BSCN0.6 and GDC in a weight ratio of 70∶30 was used as SOFC composite cathode and the electrical property, thermal expansion behavior and electrochemical performance were investigated. The electrical conductivity was found to decrease with increasing GDC content|however, the thermal expansion coefficients (TEC) of BSCN0.630%GDC composite cathode decreased, which enhances the thermal match between the cathode and GDC electrolyte. With BSCN0.630%GDC as the electrode, the polarization resistance of a symmetrical cell BSCN0.630%GDC//GDC is only 0.047～0.012 Ω•cm2 in 700～800 ℃. Therefore, BSCN0.630%GDC composite material is a promising ITSOFC cathode.

As compared with stainless steel 304 (SS304), polarization curves and electrochemical impedance spectroscopy (EIS) of high nitrogen stainless steel (HNSS) were measured under simulated PEM fuel cell environment. The experimental results show that the natural corrosion current density and the passivation current density of HNSS is 21.7% and 24.5% lower than SS304 respectively, and this illustrates HNSS has better corrosion resistance than SS304；the value of the charge transmission resistance of HNSS is 2.43×103 times larger than SS304, and the dispersion index of HNSS (N=0.899 4) is closer to 1 than SS304 (N=0.844 5), and this indicates that the passive film of HNSS is thicker and smoother than SS304.