The dynamic oxygen storage capacity (DOSC) and rate (DOSR) over Mn 0.1 Ce 0.9 O x and Mn 0.1 Ce 0.6 Zr 0.3 O x prepared by sol-gel method were investigated. The results show that Ce-based compounds containing Mn oxides with variable valences contribute to the majority of DOSC and DOSR performances at low temperature, and the DOSC and DOSR of Mn-Ce-O can be enhanced by the Zr addition at high temperature. Both materials were characterized by XRD, BET, Raman, TPR, EPR and XPS. XRD and Raman results indicate that Mn 0.1 Ce 0.9 O x and Mn 0.1 Ce 0.6 Zr 0.3 O x are characterized with the fluorite-type cubic structure similar to CeO 2 , and furthermore the thermal stability of M-Ce-O materials is improved by the introduction of some Zr atoms. EPR researches reveal that there are three types of Mn 2+ species: isolated Mn 2+ substituting for Ce 4+ ions in the lattice with a cubic symmetry, ones in defect with a noncubic symmetry and at the surface of samples. From XPS, it can be concluded that Mn 2+ /Mn 3+ redox couples exist on the surface of Mn 0.1 Ce 0.9 O x and Mn 0.1 Ce 0.6 Zr 0.3 O x samples.

No abstract

As the intelligent car-networking represents the new direction of the future vehicular development, automotive security plays an increasingly important role in the whole car industry chain. On condition that the accompanying problems of security are proofed, vehicles will provide more convenience while ensuring safety. Security models can be utilized as tools to rationalize the security of the automotive system and represent it in a structured manner. It is essential to improve the knowledge about security models by comparing them besides proposing new methods. This paper aims to give a comprehensive introduction to the topic of security models for the Intelligent Transport System (ITS). A survey of the current methodologies for security modeling is conducted and a classification scheme is subsequently proposed. Furthermore, the existing framework and methods to build automotive security models are broadly examined according to the features of automotive electronic system. A number of fundamental aspects are defined to compare the presented methods in order to comprehend the automotive security modeling in depth.

No abstract