This study presents the modeling of a parabolic trough solar collector. The main objective is to show the influences of the parabolic trough sensor effective efficiency （concentrator optical efflciencies of transmiss...This study presents the modeling of a parabolic trough solar collector. The main objective is to show the influences of the parabolic trough sensor effective efficiency （concentrator optical efflciencies of transmission, reflection, geometrical and the receiver absorption coefficient）, of its length, of the mass flow rate on temperatures distributions of the heat fluid and the receiver and on thermal global efficiency （solar conversion efficiency into energy usable）. The atmospheric parameters are those of Senegal in April. A prototype existing in the CERER （Center of Studies and Research on Renewable Energies） （Dakar-Senegal） is given as example of application.展开更多
Dissolved organic matter(DOM) is a group of compounds that have complex chemical structures and multiple interactions with their surrounding materials. More than one trillion tons of DOM are stocked in the world's...Dissolved organic matter(DOM) is a group of compounds that have complex chemical structures and multiple interactions with their surrounding materials. More than one trillion tons of DOM are stocked in the world's aquatic ecosystems. DOM is a very important part of aquatic ecosystem productivity and plays a crucial role in global carbon cycling. DOM has rich environmental behaviors and effects such as influencing the bioavailability of contaminants, serving as an important inducer of reactive oxygen species(ROS), and protecting aquatic organisms from the harm of dangerous ultraviolet radiation. There have been many systematic studies on the composition, structure, and sources of DOM because such studies are much easier to conduct than studies on the environmental behaviors and effects of DOM. Due to many factors, the research systems of DOM's environmental behaviors and effects are still being developed and have become a hotspot of environmental science. This review paper focuses on some critical progress, problems, and trends of DOM's environmental behaviors and effects in aquatic ecosystems, including mutual exchange mechanisms between DOM and particulate organic matter(POM) with influencing factors, photochemical behaviors of DOM especially inducing ROS, binding interactions between DOM and anthropogenic organic contaminants(AOC), interactions between DOM and microorganisms, effects of DOM on pollutants' bioavailability, ecotoxicity, and ecological risks. Hopefully, this paper will contribute to a more systematic understanding of the DOM environmental behaviors and effects and to promoting further relevant studies.展开更多
文摘This study presents the modeling of a parabolic trough solar collector. The main objective is to show the influences of the parabolic trough sensor effective efficiency （concentrator optical efflciencies of transmission, reflection, geometrical and the receiver absorption coefficient）, of its length, of the mass flow rate on temperatures distributions of the heat fluid and the receiver and on thermal global efficiency （solar conversion efficiency into energy usable）. The atmospheric parameters are those of Senegal in April. A prototype existing in the CERER （Center of Studies and Research on Renewable Energies） （Dakar-Senegal） is given as example of application.
基金supported by the National Project for Water Pollution Control in China(Grant No.2012ZX07103-002)the National Natural Science Foundation of China(Grant Nos.4150308341271462&41030529)
文摘Dissolved organic matter(DOM) is a group of compounds that have complex chemical structures and multiple interactions with their surrounding materials. More than one trillion tons of DOM are stocked in the world's aquatic ecosystems. DOM is a very important part of aquatic ecosystem productivity and plays a crucial role in global carbon cycling. DOM has rich environmental behaviors and effects such as influencing the bioavailability of contaminants, serving as an important inducer of reactive oxygen species(ROS), and protecting aquatic organisms from the harm of dangerous ultraviolet radiation. There have been many systematic studies on the composition, structure, and sources of DOM because such studies are much easier to conduct than studies on the environmental behaviors and effects of DOM. Due to many factors, the research systems of DOM's environmental behaviors and effects are still being developed and have become a hotspot of environmental science. This review paper focuses on some critical progress, problems, and trends of DOM's environmental behaviors and effects in aquatic ecosystems, including mutual exchange mechanisms between DOM and particulate organic matter(POM) with influencing factors, photochemical behaviors of DOM especially inducing ROS, binding interactions between DOM and anthropogenic organic contaminants(AOC), interactions between DOM and microorganisms, effects of DOM on pollutants' bioavailability, ecotoxicity, and ecological risks. Hopefully, this paper will contribute to a more systematic understanding of the DOM environmental behaviors and effects and to promoting further relevant studies.
