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Mussels have been widely used as bioindicators of coastal contamination, and recent reports have demonstrated that metals are accumulated from both the dissolved phase and from ingested food. In the winter and spring of 1995, we examined the influence of the chemical composition of food (protein content, trace element concentrations and ratios in the diatom Thalassiosira pseudomana) on the assimilation of six trace elements (Ag, Am, Cd, Co, Se and Zn) in the mussel Mytilus edulis (L.). Differences of up to 38% in diatom protein content had no major influence on the assimilation of any trace element or carbon. Protein assimilation in M. edulis examined with a 35S radiotracer was also independent of protein content in the diatoms. Similarly, Se assimilation in mussels was not affected by the different Se concentrations in the diatoms. Cd assimilation increased with increasing Cd concentration, presumably due to higher desorption of Cd under acidic conditions typical of the mussel gut. Zn assimilation was inversely related to Zn concentration in the food particles, implying a partial regulation of this metal in the mussels. There was no evidence of any interaction of Cd and Zn in their assimilation by the mussels. These results suggest that mussels are highly responsive, in an element-specific way, to some components of ingested food (e.g., metal concentration), but other food components (such as the biochemical composition of the algae) have little effect on assimilation.

Based on relevant research on critical influential factors for pricing (CIFP) in urban transportation infrastructure projects (UTIP) product/servicepsilas under public-private partnership (PPP) scheme, a comprehensive theoretical model of UTIP product/service is proposed, which is tested for various types of such projects using structural equation model (SEM) with the data from questionnaire survey and statistical analysis. The results show that: there is clear difference in the loading of CIFP between light rail (subway) and tunnel (bridge) projects product/service. The three most important CIFP in light rail (subway) project are government factors, the public factors and private investor factors while for tunnel (bridge) project are government factor, private investor factors and project & market factors. And there is clear difference in the covariance and error of CIFP between light rail (subway) and tunnel (bridge) project product/service.

In recent years, a large number of PPP infrastructure projects have emerged in China. But various reasons have led to a low success rate of these projects. The aim of this paper is to establish critical success factors model for infrastructure projects under PPP mode and to identify the links between these factors. So this research is of important practical significance to improve the success rate of PPP projects. On the basis of reviewing relevant researches of project critical success factors, this paper proposed forty-five success factors of infrastructure projects under PPP mode and found out twenty-one critical success factors among them through questionnaire survey and statistical analysis. Then the relationship between these twenty-one factors was analyzed by applying system engineering method and an interpretative structural model with six layer of recursive structure was established. The practical study in the last part showed that five factors can affect the realization of other success factors and are of especial importance. And these five factors should be the focus of future research.

The construction of infrastructure projects is significant for urban development. The shortage of funds has become the bottle-neck in the construction and development of Chinese infrastructure projects. Public private partnership is an effective approach to solve this problem. Selection of the private-sector partner plays an important role in PPP model, for his ability and cooperation with the public sector concerns the success or failure of the project directly. First we reviewed the research about selecting cooperators. Based on the relevant research and the specific characteristics of infrastructure projects under PPP model, an index system consists of eighteen indexes coming from four parts, including the ability of financing and financial management, the ability to design, to build, to operate and to manage, the ability of managing safety, health and environment, and other aspects. Then according to the theory of group decision-making and the fuzzy set theory, we transformed the fuzzy linguistic assessment into a non-fuzzy number, and at the same time, we treated the fuzzy number with variable weight according to the requirement of the project so that we can encourage some special factors and avoid the limitation of constant weight comprehensive evaluation approach. At last we applied this new approach to a specific case and the result proved that the method is scientific and feasible.