Blooms of Phaeocystis globosa have been frequently reported in Chinese coastal waters, causing serious damage to marine ecosystems. To better understand the ecological characteristics of P. globosa in Chinese coastal ...Blooms of Phaeocystis globosa have been frequently reported in Chinese coastal waters, causing serious damage to marine ecosystems. To better understand the ecological characteristics of P. globosa in Chinese coastal waters that facilitate its rapid expansion, the effects of temperature, salinity and irradiance on the growth of P. globosa from the South China Sea were examined in the laboratory. The saturating irradiance for the growth ofP. globosa （Is） was 60 μmol/（m^2·s）, which was lower than those of other harmful algal species （70-114μmol/（m^2·s））. A moderate growth rate of 0.22/d was observed at 2 μmol/（m^2·s） （the minimum irradiance in the experiment）, and photo-inhibition did not occur at 230 μmol/（m^2·s） （the maximum irradiance in the experiment）. Exposed to 42 different combinations of temperatures （10- 31 ℃） and salinities （10-40） under saturating irradiance, P. globosa exhibited its maximum specific growth rate of 0.80/d at the combinations of 24℃ and 35, and 27℃ and 40. The optimum growth rates （〉0.80/d） were observed at temperatures ranging from 24 to 27℃ and salinities from 35 to 40. While P. globosa was able to grow well at temperatures from 20℃ to 31℃ and salinities from 20 to 40, it could not grow at temperatures lower than 15℃ or salinities lower than 15. Factorial analysis revealed that temperature and salinity has similar influences on the growth of this species. This strain ofP. globosa not only prefers higher temperatures and higher salinity, but also possesses a flexible nutrient competing strategy, adapted to lower irradiance. Therefore, the P. globosa population from South China Sea should belong to a new ecotype. There is also a potentially high risk of blooms developing in this area throughout the year.展开更多
For non-catalytic gas-solid reaction, it is desirable to match the mean residence time （MRT） of particles and complete conversion time （tc） in a fluidized bed. In this study, the MRT differences （MRT ratios） bet...For non-catalytic gas-solid reaction, it is desirable to match the mean residence time （MRT） of particles and complete conversion time （tc） in a fluidized bed. In this study, the MRT differences （MRT ratios） between the coarse particles and the fine particles were investigated in a continuous fluidized bed with a side exit by varying the superficial gas velocity, feed composition and particle size ratio, The results show that the MRT ratio increases firstly and then decreases with increasing the gas velocity. By controlling the gas velocity and the feed composi tion of coarse particles, the MRT ratio can be modulated from 1.8 to 10.5 at the gas velocity of 1.0 m-s -1 for the binary mixture with the size ratio of 2.2. The MRT ratio can reach to - 12 at the gas velocity of 1.2 m. s for the particle size ratio of 3.3. The present study has endeavored to obtain fundamental data for an effective plant operation to meet the need of synchronously complete conversion of particles with different sizes during the film diffusion controlling reaction.展开更多
基金Supported by the National Natural Science Foundation of China(NSFC)(Nos.41576159,U1133003)the National High Technology Research and Development Program of China(863 Program)(No.2013AA065805)
文摘Blooms of Phaeocystis globosa have been frequently reported in Chinese coastal waters, causing serious damage to marine ecosystems. To better understand the ecological characteristics of P. globosa in Chinese coastal waters that facilitate its rapid expansion, the effects of temperature, salinity and irradiance on the growth of P. globosa from the South China Sea were examined in the laboratory. The saturating irradiance for the growth ofP. globosa （Is） was 60 μmol/（m^2·s）, which was lower than those of other harmful algal species （70-114μmol/（m^2·s））. A moderate growth rate of 0.22/d was observed at 2 μmol/（m^2·s） （the minimum irradiance in the experiment）, and photo-inhibition did not occur at 230 μmol/（m^2·s） （the maximum irradiance in the experiment）. Exposed to 42 different combinations of temperatures （10- 31 ℃） and salinities （10-40） under saturating irradiance, P. globosa exhibited its maximum specific growth rate of 0.80/d at the combinations of 24℃ and 35, and 27℃ and 40. The optimum growth rates （〉0.80/d） were observed at temperatures ranging from 24 to 27℃ and salinities from 35 to 40. While P. globosa was able to grow well at temperatures from 20℃ to 31℃ and salinities from 20 to 40, it could not grow at temperatures lower than 15℃ or salinities lower than 15. Factorial analysis revealed that temperature and salinity has similar influences on the growth of this species. This strain ofP. globosa not only prefers higher temperatures and higher salinity, but also possesses a flexible nutrient competing strategy, adapted to lower irradiance. Therefore, the P. globosa population from South China Sea should belong to a new ecotype. There is also a potentially high risk of blooms developing in this area throughout the year.
基金Supported by the China National Funds for Distinguished Young Scientists(21325628)National Natural Science Foundation of China(91334108)the State Key Laboratory of Multiphase Complex Systems,Institute of Process Engineering,Chinese Academy of Sciences(MPCS-2012-A-02 and MPCS-2014-A-03)
文摘For non-catalytic gas-solid reaction, it is desirable to match the mean residence time （MRT） of particles and complete conversion time （tc） in a fluidized bed. In this study, the MRT differences （MRT ratios） between the coarse particles and the fine particles were investigated in a continuous fluidized bed with a side exit by varying the superficial gas velocity, feed composition and particle size ratio, The results show that the MRT ratio increases firstly and then decreases with increasing the gas velocity. By controlling the gas velocity and the feed composi tion of coarse particles, the MRT ratio can be modulated from 1.8 to 10.5 at the gas velocity of 1.0 m-s -1 for the binary mixture with the size ratio of 2.2. The MRT ratio can reach to - 12 at the gas velocity of 1.2 m. s for the particle size ratio of 3.3. The present study has endeavored to obtain fundamental data for an effective plant operation to meet the need of synchronously complete conversion of particles with different sizes during the film diffusion controlling reaction.
