This study introduces space, transportation, and money into an economic growth model. Growth theory neglects the importance of transportation on economic growth and transportation economics fails to properly explain h...This study introduces space, transportation, and money into an economic growth model. Growth theory neglects the importance of transportation on economic growth and transportation economics fails to properly explain how changes in transportation conditions (such as technological improvement, infrastructure investment, and oil prices) affect long-term economic growth. By proposing a growth model with transportations, we try to explain effects of transportation on economic growth. Our model describes dynamic interactions among capital accumulation, travel time, housing, residential distribution, amenity, and endogenous time distribution among work, travel, and leisure. The study examines effects of inflation policy, transportation conditions, and other conditions on long-term economic growth and economic geography. The paper demonstrates a way to integrating some important models in the literature in economic growth theory, urban economics, and transportation research so that the significance of transportation systems upon economies can be properly analyzed.展开更多
Increasing attention has been paid to phosphate-accumulating organisms （PAOs） for their important role in biological phosphorus removal. In this study, microbial communities of PAOs cultivated under different carbon...Increasing attention has been paid to phosphate-accumulating organisms （PAOs） for their important role in biological phosphorus removal. In this study, microbial communities of PAOs cultivated under different carbon sources （sewage, glucose, and sodium acetate） were investigated and compared through culture-dependent and culture-independent methods, respectively. The results obtained using denaturing gradient gel electrophoresis （DGGE） of polymerase chain reaction-amplified 16S rDNA fragments revealed that the diversity of bacteria in a sewage-fed reactor （1#） was much higher than in a glucose-fed one （2#） and a sodium acetate-fed one （3#）; there were common PAOs in three reactors fed by different carbon sources. Five strains were separated from three systems by using a phosphaterich medium; they were from common bacteria isolated and three isolates could not be found in DGGE profile at all. Two isolates had good phosphorus removal ability. When the microbial diversity was studied, the molecular biological method was better than the culture-dependent one. When phosphorus removal characteristics were investigated, culture-dependent approach was more effective. Thus a combination of two methods is necessary to have a comprehensive view of PAOs.展开更多
文摘This study introduces space, transportation, and money into an economic growth model. Growth theory neglects the importance of transportation on economic growth and transportation economics fails to properly explain how changes in transportation conditions (such as technological improvement, infrastructure investment, and oil prices) affect long-term economic growth. By proposing a growth model with transportations, we try to explain effects of transportation on economic growth. Our model describes dynamic interactions among capital accumulation, travel time, housing, residential distribution, amenity, and endogenous time distribution among work, travel, and leisure. The study examines effects of inflation policy, transportation conditions, and other conditions on long-term economic growth and economic geography. The paper demonstrates a way to integrating some important models in the literature in economic growth theory, urban economics, and transportation research so that the significance of transportation systems upon economies can be properly analyzed.
基金Project supported by the Young Teacher Foundation of Donghua University(No.113-10-0044065)Key(keygrant)Project of Chinese Ministry of Education(No.107046)Program for New Century Excellent Talents in University(NCET)
文摘Increasing attention has been paid to phosphate-accumulating organisms （PAOs） for their important role in biological phosphorus removal. In this study, microbial communities of PAOs cultivated under different carbon sources （sewage, glucose, and sodium acetate） were investigated and compared through culture-dependent and culture-independent methods, respectively. The results obtained using denaturing gradient gel electrophoresis （DGGE） of polymerase chain reaction-amplified 16S rDNA fragments revealed that the diversity of bacteria in a sewage-fed reactor （1#） was much higher than in a glucose-fed one （2#） and a sodium acetate-fed one （3#）; there were common PAOs in three reactors fed by different carbon sources. Five strains were separated from three systems by using a phosphaterich medium; they were from common bacteria isolated and three isolates could not be found in DGGE profile at all. Two isolates had good phosphorus removal ability. When the microbial diversity was studied, the molecular biological method was better than the culture-dependent one. When phosphorus removal characteristics were investigated, culture-dependent approach was more effective. Thus a combination of two methods is necessary to have a comprehensive view of PAOs.
