A tillage method of combining ridge with no-tillage (RNT) was employed in lowland rice-based cropping system to study the long-term effects of RNT on soil profile pattern, soil water stable aggregate distribution, nut...A tillage method of combining ridge with no-tillage (RNT) was employed in lowland rice-based cropping system to study the long-term effects of RNT on soil profile pattern, soil water stable aggregate distribution, nutrients stratification and yields of rice and post-rice crops. After flooded paddy field (FPF) was practiced with RNT for a long time, soil profile changed from G to A-P-G, and horizon G was shifted to a deeper position in the profile. Also the proportion of macroaggregate (> 2 mm) increased, whereas the proportion of silt and clay (< 0.053 mm) decreased under RNT, indicating a better soil structure that will prevent erosion. RNT helped to control leaching and significantly improved total N, P, K and organic matter in soil. The highest crop yields were found under RNT system every year, and total crop yields were higher under conventional paddy-upland rotation tillage (CR) than under FPF, except in 2003 and 2006 when serious drought occurred. RNT was proven to be a better tillage method for lowland rice-based cropping system.展开更多
More than just a drink, tea embodies social, cultural, economic and political meanings through time and across cultures. There is an essential tie between media and this meaning-making process. Media often create and ...More than just a drink, tea embodies social, cultural, economic and political meanings through time and across cultures. There is an essential tie between media and this meaning-making process. Media often create and carry the visions of health, nature, tranquility, and prosperity offered by tea. This mediated imaginary seems to persist even in the face of vast human inequalities and suffering and irreversible negative environmental impacts through the current practice of tea production under global conglomerates. Through textual analysis of media narratives of Teavana, a well-known tea brand, this project explores how media＇s mythic narratives potentially naturalize and celebrate the current production practice and the conspicuous consumption of tea, and silence the human suffering and environmental destruction endured, in order to gratify the very practice and consumption promoted by media.展开更多
Cubic shaped CaCO3 particles with mean size of 30-40nm were prepared by intermittent carbonation process without any additives. It was found that the flow rate of CO2 has no distinct influence on the particle size in ...Cubic shaped CaCO3 particles with mean size of 30-40nm were prepared by intermittent carbonation process without any additives. It was found that the flow rate of CO2 has no distinct influence on the particle size in the range of 30 120ml·min^-1 under conditions of 13℃ and stirring rate of 680r·min^-1. A further increase of flow rate makes the particles larger. When CO2 flow rate is 70ml·min^-1, a high agitation rate is in favor of the reduction of the crystal size in the range of 70-680 r·min^-1. When flow rate is 120 ml·min^-1, the particles prepared at agitation rates of 680r·min^-1 and 280r·min^-1 have similar sizes, while products prepared at 90r·min^-1 have larger size.展开更多
基金Project supported by the National Natural Science Foundation of China (No.40501033)the National Key Technologies R&D Program for the 11th Five-Year Plan of China (No.2007BAD87B10)
文摘A tillage method of combining ridge with no-tillage (RNT) was employed in lowland rice-based cropping system to study the long-term effects of RNT on soil profile pattern, soil water stable aggregate distribution, nutrients stratification and yields of rice and post-rice crops. After flooded paddy field (FPF) was practiced with RNT for a long time, soil profile changed from G to A-P-G, and horizon G was shifted to a deeper position in the profile. Also the proportion of macroaggregate (> 2 mm) increased, whereas the proportion of silt and clay (< 0.053 mm) decreased under RNT, indicating a better soil structure that will prevent erosion. RNT helped to control leaching and significantly improved total N, P, K and organic matter in soil. The highest crop yields were found under RNT system every year, and total crop yields were higher under conventional paddy-upland rotation tillage (CR) than under FPF, except in 2003 and 2006 when serious drought occurred. RNT was proven to be a better tillage method for lowland rice-based cropping system.
文摘More than just a drink, tea embodies social, cultural, economic and political meanings through time and across cultures. There is an essential tie between media and this meaning-making process. Media often create and carry the visions of health, nature, tranquility, and prosperity offered by tea. This mediated imaginary seems to persist even in the face of vast human inequalities and suffering and irreversible negative environmental impacts through the current practice of tea production under global conglomerates. Through textual analysis of media narratives of Teavana, a well-known tea brand, this project explores how media＇s mythic narratives potentially naturalize and celebrate the current production practice and the conspicuous consumption of tea, and silence the human suffering and environmental destruction endured, in order to gratify the very practice and consumption promoted by media.
文摘Cubic shaped CaCO3 particles with mean size of 30-40nm were prepared by intermittent carbonation process without any additives. It was found that the flow rate of CO2 has no distinct influence on the particle size in the range of 30 120ml·min^-1 under conditions of 13℃ and stirring rate of 680r·min^-1. A further increase of flow rate makes the particles larger. When CO2 flow rate is 70ml·min^-1, a high agitation rate is in favor of the reduction of the crystal size in the range of 70-680 r·min^-1. When flow rate is 120 ml·min^-1, the particles prepared at agitation rates of 680r·min^-1 and 280r·min^-1 have similar sizes, while products prepared at 90r·min^-1 have larger size.
