Interactive effects of increased temperature, elevated pCO2 and different nitrogen sources on the coccolithophore Gephyrocapsaoceanica.

As a widespread phytoplankton species, the coccolithophore Gephyrocapsaoceanica has a significant impact on the global biogeochemical cycle through calcium carbonate precipitation and photosynthesis. As global change continues, marine phytoplankton will experience alterations in multiple parameters, including temperature, pH, CO2, and nitrogen sources, and the interactive effects of these variables should be examined to understand how marine organisms will respond to global change. Here, we show that the specific growth rate of G. oceanica is reduced by elevated CO2 (1000 μatm) in [Formula: see text]-grown cells, while it is increased by high CO2 in [Formula: see text]-grown ones. This difference was related to intracellular metabolic regulation, with decreased cellular particulate organic carbon and particulate organic nitrogen (PON) content in the [Formula: see text] and high CO2 condition compared to the low CO2 condition. In contrast, no significant difference was found between the high and low CO2 levels in [Formula: see text] cultures (p > 0.05). The temperature increase from 20°C to 25°C increased the PON production rate, and the enhancement was more prominent in [Formula: see text] cultures. Enhanced or inhibited particulate inorganic carbon production rate in cells supplied with [Formula: see text] relative to [Formula: see text] was observed, depending on the temperature and CO2 condition. These results suggest that a greater disruption of the organic carbon pump can be expected in response to the combined effects of increased [Formula: see text]/[Formula: see text] ratio, temperature, and CO2 level in the oceans of the future. Additional experiments conducted under nutrient limitation conditions are needed before we can extrapolate our findings to the global oceans

Pathways and fates of heavy metal mixtures in the Xiamen MEEE

In IDL-1113

Release of heavy metals from polluted sediment in the MEEE enclosures

In IDL-1113

Distribution of heavy metals in Xiamen seawater and in the MEEE enclosures

In IDL-1113

Photogenerated cathodic protection of stainless steel by liquid-phase-deposited sodium polyacrylate/TiO2 hybrid films

Sodium polyacrylate/TiO2 hybrid films that served as photoanodes for cathodic protection application were prepared by liquid phase deposition. Under white-light illumination, the open-circuit potential of the hybrid films coupled with SUS304 stainless steel could shift to a more negative value and offer an effective photogenerated cathodic protection for stainless steel. Moreover, the hybrid films also exhibited stronger photocurrents in both the ultraviolet-light and visible-light regions compared to that of control TiO2 films. In summary, the addition of sodium polyacrylate could greatly improve the photogenerated cathodic protection properties of the liquid-phase-deposited TiO2 films. (C) 2012 Elsevier Ltd. All rights reserved

In situ measurement of the transport processes of corrosive species through a mortar layer by FTIR-MIR

National Natural Science Foundation of China [50731004, 21021002]; National High Key Technology R&D Program of China [2007BAB27B04]Fourier Transform Infrared Spectroscopy with Multiple Internal Reflection mode (FTIR-MIR) has been applied for the first time to in situ follow the transport process of corrosive species through a mortar layer and their accumulation at the internal reflection element (IRE)/mortar interface. The kinetic processes of H(2)O and SO(4)(2-) transport through the mortar specimens with different curing time were studied. The results indicated that H(2)O and SO(4)(2-) presented different transport behavior through the mortar layer. Adding Na(2)SO(4) into distilled water resulted in a slower transport rate of H(2)O. And the curing time of mortar had a significant effect on its permeability. The in situ FTIR-MIR measurement was proved to be able to provide reliable information on the interface and the transport process through mortar. (C) 2011 Elsevier Ltd. All rights reserved

Photogenerated cathodic protection of stainless steel by liquid-phase-deposited sodium polyacrylate/TiO2 hybrid films

Sodium polyacrylate/TiO2 hybrid films that served as photoanodes for cathodic protection application were prepared by liquid phase deposition. Under white-light illumination, the open-circuit potential of the hybrid films coupled with SUS304 stainless steel could shift to a more negative value and offer an effective photogenerated cathodic protection for stainless steel. Moreover, the hybrid films also exhibited stronger photocurrents in both the ultraviolet-light and visible-light regions compared to that of control TiO2 films. In summary, the addition of sodium polyacrylate could greatly improve the photogenerated cathodic protection properties of the liquid-phase-deposited TiO2 films. (C) 2012 Elsevier Ltd. All rights reserved

CORRELATION BETWEEN COMPOSITION OF REINFORCING STEEL SURFACE FILM AND STEEL CORROSION BEHAVIOR IN SIMULATED CONCRETE PORE SOLUTIONS

National Natural Science Foundation of China [21073151, 50731004]; National High Technology Research and Development Program of China [2009AA03Z327]It is well known that reinforcing steel in concrete can be protected from corrosion by forming a compact passive film on its surface in a concrete pore solution with high alkalinity. The corrosion behavior of the steel is related to its passivation and depassivation. The pH value and the Cl(-) concentration in a concrete pore solution are of the most important parameters affecting the passivity of reinforcing steel in concrete. In the present work, XPS analysis, linear polarization and potentiodynamic anodic polarization tests were used to study the relationship between the electro-chemical corrosion behavior of reinforcing steel immersed in a simulated concrete pore solution and the chemical composition of the steel surface film. The results showed that with the increase of the Cl(-) concentration or the decrease of the pH value in the solution, the corrosion potential of the steel shifted negatively and its corrosion current density rose, and the Fe(2+) content of the steel surface film increased and the Fe(3+) content decreased. The steel was in an active state in the solution with Cl(-) concentration higher than 0.6 mol/L or pH lower than 11.31, and the addition of 0.24 mol/L NaNO(2) to the solution could protect steel from corrosion