研究了Al2O3陶瓷从室温至1200℃在干摩擦条件下的高温摩擦磨损行为。结果表明：在600℃以后的摩擦磨损随温度上升而逐渐减小。在1200℃的摩擦系数仅为室温的60%，磨损则降低了两个数量级。表现出良好的高温自润滑特征。在不同温度下，存在三种显著不同的磨损机理。从室温至600℃，主要是磨粒磨损和微断裂，磨损随温度上升而略有增加。在600～1000℃，磨损机理逐渐由脆性断裂过渡到塑性变形和再结晶，在表面形成一个厚度为5～10μm的、类似于纳米材料结构的特殊表面层。随着这种特殊表面层的形成。磨损显著下降。在1200℃，摩擦表面由塑性变形发展到软化状态，出现流体动力润滑，使摩擦磨损进一步降低。

The colloidal stabilization of nano-sized zinc oxide suspensions with maleic anhydride sodium salt copolymer is examined to understand the primary mechanism of dispersion. FTIR spectroscopic data provided evidence in support of hydrogen bonding and chemical interaction in the case of the MA-Na copolymer/ZnO system. The suspension stability was characterized by sedimentation tests and TEM method. The copolymer was found to stabilize the suspension of ZnO nanoparticles through electrosteric repulsion. Influences of factors such as pH and the copolymer concentration on the colloidal stability of aqueous suspension were investigated. The copolymer at high pH of the solution provided more effective degree of sustained particle dispersion. The adsorbed MA-Na copolymer provided a good stabilization under the saturated adsorption amount, while the excess copolymer flocculated the dispersed system.

以硅溶胶、尿素和炭黑为原料，经氨解溶胶-凝胶、碳热还原法合成了纳米Si3N4-SiC复合粉末。通过在硅溶胶中引入Y（NO3）3，合成了Si3N4-SiC-Y2O3超细复合粉末。Y2O3的加入有助于降低Si3N4-SiC的合成温度。采用XPS和XRD分析复合粉末中Y的存在状态表明：一部分Y固溶在Si3N4-SiC中，另有一部分以Y2O3形式存在。Si3N4-SiC-Y2O3复合粉末的烧结性能良好。

The thermal degradation behaviour of polyacrylate and its zinc oxide composites were investigated by differential scanning calorimetry (DSC), thermogravimetry (TG) and Fourier transform infrared spectroscopy (FTIR). Reaction mechanisms of polymer degradation with and without ZnO particles were obtained. Filler-free polyacrylate exhibited one DSC peak, indicating that the polymer was degraded with only one stage of weight loss. Polyacrylate/ZnO composites underwent two minor weight losses as well as the major weight loss. ZnO stabilized or destabilized the polymer molecules according to the temperature region. Two mechanisms were proposed for the change of thermal properties of the nanocomposite. An increase of the stabilization or destabilization effect of ZnO nanoparticles was found in the nanocomposite with a higher content of the inorganic phase. Compared to micron ZnO particles, ZnO nanoparticles exhibited a greater effect due to their high specific area giving more sites for interactions. In addition, kinetics of thermal degradation of filler-free polyacrylate and polyacrylate/ZnO composite were quantitatively obtained by means of non-isothermal weight loss data analysis.

The adsorption of poly(acrylic acid) (PAA) in aqueous suspension onto the surface of TiO2 nanoparticles was investigated. FTIR spectroscopic data provided evidence in support of hydrogen bonding and chemical interaction in the case of the PAA–TiO2 system. Adsorption isotherms demonstrated that part of the PAA initially added to the suspension was adsorbed onto the TiO2 surface, after which there was a gradual attainment of an adsorption plateau. The adsorption density of PAA was found to increase with an increase of PAA molecular weight, while it decreased with an increase of pH. The thickness of the PAA adsorption layer was calculated based on measurements of suspension viscosities in the absence and presence of PAA. It was shown that the thickness of the adsorption layer increased with the increase of pH, PAA molecular weight, and its concentration. The surface charge density, the diffuse charge density, and the zeta potential of TiO2 varied distinctly after PAA adsorption. The shift of pHiep toward a lower pH value was observed in the presence of PAA. PAA was found to stabilize the suspension of TiO2 nanoparticles through electrosteric repulsion. The influence of factors such as PAA molecular weight and its concentration on the colloidal stability of the aqueous suspension was also investigated.