Nitrobenzene is an important raw material and product, which presents a heavy threat to the ecosystem. The potential impacts of nitrobenzene on sediment oxygen demand （SOD） were studied in lake sediment simulating r...Nitrobenzene is an important raw material and product, which presents a heavy threat to the ecosystem. The potential impacts of nitrobenzene on sediment oxygen demand （SOD） were studied in lake sediment simulating reactors receiving relatively low inputs of nitrobenzene. Oxygen microprofiles were measured in these sediment reactors using microelectrodes. After an initial microprofile measurement as a control, nitrobenzene was added to the overlying water resulting in concentrations of 0, 50, 100, and 150 μg/L. Microprofiles were measured on day 1, 2, 4 and 7 following the addition of nitrobenzene. SODs were determined from the microprofiles using a reaction-diffusion model. Results showed that the SODs increased relative to the initial values measured in the pre-treatment period in reactors exposed to all nitrobenzene concentrations on day 1. However, the values decreased gradually on the following days, which eventually resulted in a 50% loss in SODs after 7 days of exposure to nitrobenzene in all reactors. In addition, the inhibition effect of nitrobenzene on SOD exhibited a weak relationship with its concentration. The microscopic observation and count of algae in the sediment showed that the exposure to nitrobenzene did not change the composition of algae greatly, however, it decreased the number of dominant algae species sharply after 7 days of exposure. These results suggested that nitrobenzene could significantly alter SOD in lakes, which could ultimately affect the pollutant recovery in aquatic-sediment systems.展开更多
This paper examines the effectiveness of redistribution policies under budget constraint considering government spending for the productivity improvement and effective demand. It shows that an asset-based redistributi...This paper examines the effectiveness of redistribution policies under budget constraint considering government spending for the productivity improvement and effective demand. It shows that an asset-based redistribution policy is not always effective under effective demand and budget constraint. However, the increase of effective demand because of an income-based redistribution improves employment, labor productivity, and wage rates because of increased government spending for productivity improvement as the results of saving rate from profit income show. A distinctive feature of this paper is considering effective demand with political aspects. Workers＇ demands on unemployment compensation depend on the demand and supply condition in the goods market. The model implicitly assumes that labor is strong enough to affect political institutions and social security system is prepared enough to affect goods market. Therefore, the model built in this research is applicable to Europe in the real world.展开更多
基金supported by the China Postdoctoral Science Foundation Funded Project (No. 20080430046, 200801093)
文摘Nitrobenzene is an important raw material and product, which presents a heavy threat to the ecosystem. The potential impacts of nitrobenzene on sediment oxygen demand （SOD） were studied in lake sediment simulating reactors receiving relatively low inputs of nitrobenzene. Oxygen microprofiles were measured in these sediment reactors using microelectrodes. After an initial microprofile measurement as a control, nitrobenzene was added to the overlying water resulting in concentrations of 0, 50, 100, and 150 μg/L. Microprofiles were measured on day 1, 2, 4 and 7 following the addition of nitrobenzene. SODs were determined from the microprofiles using a reaction-diffusion model. Results showed that the SODs increased relative to the initial values measured in the pre-treatment period in reactors exposed to all nitrobenzene concentrations on day 1. However, the values decreased gradually on the following days, which eventually resulted in a 50% loss in SODs after 7 days of exposure to nitrobenzene in all reactors. In addition, the inhibition effect of nitrobenzene on SOD exhibited a weak relationship with its concentration. The microscopic observation and count of algae in the sediment showed that the exposure to nitrobenzene did not change the composition of algae greatly, however, it decreased the number of dominant algae species sharply after 7 days of exposure. These results suggested that nitrobenzene could significantly alter SOD in lakes, which could ultimately affect the pollutant recovery in aquatic-sediment systems.
文摘This paper examines the effectiveness of redistribution policies under budget constraint considering government spending for the productivity improvement and effective demand. It shows that an asset-based redistribution policy is not always effective under effective demand and budget constraint. However, the increase of effective demand because of an income-based redistribution improves employment, labor productivity, and wage rates because of increased government spending for productivity improvement as the results of saving rate from profit income show. A distinctive feature of this paper is considering effective demand with political aspects. Workers＇ demands on unemployment compensation depend on the demand and supply condition in the goods market. The model implicitly assumes that labor is strong enough to affect political institutions and social security system is prepared enough to affect goods market. Therefore, the model built in this research is applicable to Europe in the real world.
