We used long term monitoring data to evaluate changes in abundance and species dominance of small-jellyfish (collected with zooplankton net whose bell diameter was less than 5 cm) between 1991 and 2009 in the Jiaozhou...We used long term monitoring data to evaluate changes in abundance and species dominance of small-jellyfish (collected with zooplankton net whose bell diameter was less than 5 cm) between 1991 and 2009 in the Jiaozhou Bay, China. Zooplankton samples were vertically towed with conical plankton net from near-bottom to surface, identified microscopically, and mapped in time-space using Grapher 7.0 and Surfer 8.0. Results show that the abundance of small-jellyfish throughout the bay had been increasing during 2001-2009 on average of 15.2 ind./m 3 , almost 5 times higher than that between 1991 and 2000. The occurrence of peak abundance shifted from spring to summer after 2000, and two peaks appeared in spring and summer, respectively, after 2005. Both the abundance and the frequency of blooms of small-jellyfish increased after 2000 in the bay. In addition, the biodiversity of jellyfish has increased significantly in recent years with a change in dominant species. Several new dominant species appeared after 2000, including Rathkae octopunctata in winter, Phialidium hemisphaericum in spring, summer, and autumn, Phialucium carolinae in spring, and Pleurobrachia globosa in summer and autumn, while some previous dominant species throughout the 1990s (Eirene ceylonensis, Zanclea costata, Lovenella assimilis, and Muggiaea atlantica) were no longer dominant after 2000. The abundance of small-jellyfish was positively correlated with the density of dinoflagellates, and the abundance of zooplankton. We believe that the changes in smalljellyfish abundance and species composition were the result of eutrophication, aquaculture and coastal construction activities around the bay. Concurrently, seawater warming and salinity decrease in recent decades promoted the growth and reproduction of small-jellyfish in the bay.展开更多
The solidification of a binary mixture causes allowed thermosolutal convection. Under certain conditions, the separation of its components gives rise to a preferential movement of migration of solutes. The quantity an...The solidification of a binary mixture causes allowed thermosolutal convection. Under certain conditions, the separation of its components gives rise to a preferential movement of migration of solutes. The quantity and the concentration of the obtained products depend on the mechanisms of sepa＇,ration which depend on different parameters and the applied boundary conditions. In this way, the freezing of H20-NaC1 mixture makes it possible to obtain a liquid phase which is charged in solute and is called brine and a solid phase which is composed of ice being able to become fresh water, and so it can works as a desalination process. In this paper, a series of experiments of seawater freezing on cold surface is carried out at the laboratory under different operating conditions. During these experiments, the role of each parameter （temperature of crystallization, duration of crystallizat on...） which is able to impact the final composition is focused on. After a preliminary series of experiment, the yield is： improved to reach rates of salt and make it possible to regard the water produced as drinkable according to the standards of WHO （World Health Organization）.展开更多
基金Supported by the National Basic Research Program of China (973 Program) (No. 2011CB403601)the Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX2-YW-Q07-01)+2 种基金the External Cooperation Program of Chinese Academy of Sciences (No. GJHZ200808)the National Natural Science Foundation of China (No. 40876083)the Ocean Public Welfare Scientific Research Project, State Oceanic Administration of China (No. 201005014)
文摘We used long term monitoring data to evaluate changes in abundance and species dominance of small-jellyfish (collected with zooplankton net whose bell diameter was less than 5 cm) between 1991 and 2009 in the Jiaozhou Bay, China. Zooplankton samples were vertically towed with conical plankton net from near-bottom to surface, identified microscopically, and mapped in time-space using Grapher 7.0 and Surfer 8.0. Results show that the abundance of small-jellyfish throughout the bay had been increasing during 2001-2009 on average of 15.2 ind./m 3 , almost 5 times higher than that between 1991 and 2000. The occurrence of peak abundance shifted from spring to summer after 2000, and two peaks appeared in spring and summer, respectively, after 2005. Both the abundance and the frequency of blooms of small-jellyfish increased after 2000 in the bay. In addition, the biodiversity of jellyfish has increased significantly in recent years with a change in dominant species. Several new dominant species appeared after 2000, including Rathkae octopunctata in winter, Phialidium hemisphaericum in spring, summer, and autumn, Phialucium carolinae in spring, and Pleurobrachia globosa in summer and autumn, while some previous dominant species throughout the 1990s (Eirene ceylonensis, Zanclea costata, Lovenella assimilis, and Muggiaea atlantica) were no longer dominant after 2000. The abundance of small-jellyfish was positively correlated with the density of dinoflagellates, and the abundance of zooplankton. We believe that the changes in smalljellyfish abundance and species composition were the result of eutrophication, aquaculture and coastal construction activities around the bay. Concurrently, seawater warming and salinity decrease in recent decades promoted the growth and reproduction of small-jellyfish in the bay.
文摘The solidification of a binary mixture causes allowed thermosolutal convection. Under certain conditions, the separation of its components gives rise to a preferential movement of migration of solutes. The quantity and the concentration of the obtained products depend on the mechanisms of sepa＇,ration which depend on different parameters and the applied boundary conditions. In this way, the freezing of H20-NaC1 mixture makes it possible to obtain a liquid phase which is charged in solute and is called brine and a solid phase which is composed of ice being able to become fresh water, and so it can works as a desalination process. In this paper, a series of experiments of seawater freezing on cold surface is carried out at the laboratory under different operating conditions. During these experiments, the role of each parameter （temperature of crystallization, duration of crystallizat on...） which is able to impact the final composition is focused on. After a preliminary series of experiment, the yield is： improved to reach rates of salt and make it possible to regard the water produced as drinkable according to the standards of WHO （World Health Organization）.
