Generation Mechanism of Interfacial Layer and Its Effect on Fe-Cr-Ni/Al-Si-Cu-Ni-Mg Composite Performance

Fe-Cr-Ni/Al-Si-Cu-Ni-Mg composite was taken as the experimental material. The chemical composition of interfacial layer was tested. The generation mechanism and influence of interfacial layer on the composite were analyzed. The results indicated that the generation of interfacial layer is sensitive to temperature. Interfacial layer will generate rapidly when temperature reaches 500 ℃ or above. The interfacial layer is mainly composed of Al, Si, Cu, Fe, and Cr, element Ni distributes at the outward of the interfacial layer for the precipitate of Ni later than Si and Cu, and there is almost no diffusion of Ni during the solution treatment. During heat treatment process, unequal quantity changing of metal atom results in disperse or concentrated vacancies or holes near the matrix. The existence of interfacial layer will induce a decrease of compression strength and plasticity at room temperature and an increase of strength at higher temperature comparing with composite without interfacial layer.

Gender Composition and Gender-based Employees＇ Turnover： An Empirical Study among Women and Men in China＇s Organization

With the disappearance of rigid employment contract and the-intenseness of competition of human resources, turnover has become a great obstacle to firm＇s well-runned development. From the point of firm＇s gender composition, the influence of gender composition on gender-based turnover in each level including leading post remains unclear. The paper explores this issue by using statistical methods on the basis of 332 individual sampling data in 65 different enterprises. The results show that proportion of male to female in high and first-line level has significantly positive influence on employee turnover for both male and female. But the proportion of male to female in middle level has significantly negative influence on employee turnover for both male and female. The whole proportion of male to female in organization has positive influence on turnover. The leader＇s gender has negative effect on turnover of male employee. Most of the above correlations are consistent with foreign researches. Referred to our results, enterprise could control turnover and improve the organization efficiency by adjusting the proportion of male to female in different levels when we make decisions on human resources management in order to attract female employees.

Advances in selective catalytic oxidation of ammonia (NH_(3)-SCO): A review of catalyst structure-activity relationship and design principles

NH_(3) in ambient air directly leads to an increase in the aerosol content in the air. These substances lead to the formation of haze to various environmental problems after atmospheric circulation and diffusion. Controlling NH_(3) emissions caused by ammonia escaping from mobile and industrial sources can effectively reduce the NH_(3) content in ambient air. Among the various NH_(3) removal methods, the selective catalytic oxygen method (NH_(3)-SCO) is committed to oxidizing NH_(3) to environmentally harmless H_(2)O and N_(2);therefore, it is the most valuable and ideal ammonia removal method. In this review, the characteristics of loaded and core-shell catalysts in NH_(3)-SCO have been reviewed in the context of catalyst structure-activity relationships, and the H_(2)O resistance and SO2 resistance of the catalysts are discussed in the context of practical application conditions. Then the effects of the valence state of the active center, oxygen species on the catalyst surface, dispersion of the active center and acidic sites on the catalyst performance are discussed comprehensively. Finally, the shortcomings of the existing catalysts are summarized and the catalyst development is discussed based on the existing studies.