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The distributions of net-phytoplankton and nutrients were studied in Xiangshan Bay in summer, 2012. The results showed that in summer, the higher values of net-phytoplankton cell abundance were distributed in the areas of Tie port, Huangdun port and Xihu Port. Whereas, the lower values were mainly found in the stations located in the outer area of Xiangshan Bay and the area around Liuheng Island. The content of nitrate in the middle of the bay was higher than that both in the bottom and the entrance of the bay. The concentration of nitrate in the bottom water was a little higher than that in the surface water. The distribution trends of the concentration of nitrite, ammonium and phosphate were almost the same. The higher values were discovered in the sea area of Tie port and Huangdun port and the lower were mainly distributed in the area of the outer Xiangshan Bay and the sea area around Liuheng Island. The distribution trends were almost the same no matter in the surface water or in the bottom water. From the bottom to the middle to the entrance of the bay, the values reduced in turn. In summer, in the water of Xiangshan Bay, net-phytoplankton cell abundance and nutrient (N, P) content didn’t have significant correlation. The concentration of the nutrients (Nitrate, Nitrite, Ammonium and Phosphate) was far more than the minimum threshold of the growth of phytoplankton.

The 30 years’ annual variations of major nutrients dissolved inorganic nitrogen(DIN) and dissolved inorganic phosphorus(DIP) in Xiangshan Bay East China Sea between 1982 and 2011 were reported. The results showed that the concentrations of nitrogen and phosphorus nutrients increased year by year, consistent with the trend of nitrogen and phosphorus consumption in our country. Inorganic nitrogen was the main pollutant, then was inorganic phosphorus in Xiangshan harbor. The annual average change of DIN ranged from 0.21 to 0.76 mg∙dm-3 while DIP ranged from 0.018 to 0.054 mg∙dm-3. And the change trend of DIN and DIP was as following: winter > autumn > summer > spring. The DIN and DIP in Xiangshan horbor exceeded the standard limits greatly, the water quality in culture areas exceeded national criteria for sea water Level IV and most water qualities were inferior Level IV.

Using China Southern Ocean’s study data collected from 1989 to 2009 year, this paper analyzed the related characteristics between phytoplankton abundance, Ch1 a concentrations and particulate organic carbon. The average cell abundance of Southern Ocean phytoplankton was 7.38×104 cells/dm3. The dominant species of Southern Ocean phytoplankton were Fragilariopsis kerguelensis, Fragilariopsis curta, Pseudo-nitzschia lineola, Eucampia antarctica, Thalassiosira antarctica and Corethron criophilum and son on. In Prydz Bay of the Southern Ocean, the contribution of phytoplankton cell abundance and phytoplankton carbon toward particulate organic carbon were higher than that in the Northern Gulf Ocean Area. In the upper layer of euphotic zone, the contribution of phytoplankton abundance and phytoplankton carbon toward particulate organic carbon were higher than that in the deep water district. Through analysis of regressive statistics, phytoplankton cell abundance (y) and particulate organic carbon (POC) and chlorophyll a (Chl a) were a remarkable positive correlation.

With the aggravation of high grade highway asphalt pavement destructions, it becomes particularly important to maintain pavement performance and enhance road economic efficiency. The asphalt pavement preventive maintenance technology is an effective technique to extend pavement services and maintain pavement performance. In this paper, we combine the decay model of pavement performance with assets value evaluation idea and establish an analytical method about preventive maintenance technology based on assets evaluation. An example of hot asphalt overlay is also presented, it is found that preventive maintenance techniques can reduce the attenuation of road infrastructure assets value and maintain pavement performance efficiently.