Culturable thermophilic microorganisms were enriched from samples collected from Lau Basin hydrothermal vents in artificial seawater medium at 45 ℃ and pH 7.0. Microbial diversities of the enriched communities were d...Culturable thermophilic microorganisms were enriched from samples collected from Lau Basin hydrothermal vents in artificial seawater medium at 45 ℃ and pH 7.0. Microbial diversities of the enriched communities were defined by performing a restriction fragment length polymorphism （RFLP） analysis of 16S rRNA gene sequences with enzymes MspI and Hin6 I. A total of 14 phylotypes have been detected by the RFLP patterns identified for 16S rRNA clone libraries of the enrichment. Analysis of sequences showed that at least four bacterial divisions presented in the clones libraries. The phyla Proteobacteria and Firmicutes were the most dominant groups. The majority of the sequences included in this analysis affiliated with Gamma Proteobacteria （71%） and Bacillus （23%）. Scanning electron micrographs revealed that there were abundant rod and coceoidal forms encased in sulphur and sodium chloride precipitate. These results revealed that there were a diversity of moderate thermophilic bacterial populations thrived in Lau Basin hydrothermal vents that were previously not detected by either molecular retrieval or strain purification techniques.展开更多
This study investigated the impact of soil texture and sweetpotato cropping system on soil erosion and nutrient loss in the drought infield of the Three Gorges Reservoir Area of Changjiang River under field conditions...This study investigated the impact of soil texture and sweetpotato cropping system on soil erosion and nutrient loss in the drought infield of the Three Gorges Reservoir Area of Changjiang River under field conditions. A factorial experiment was conducted in the study using five soil textures and two cropping systems. The lost soil during the crop season was recovered by a soil-blocking device and the dry weights for the total lost soil and its nutrient components, such as ammonium nitrogen, effective phosphorus, K^＋ and organic matter were analyzed. We found that soil texture significantly affected the dry weights of the total lost soil, effective phosphorus, K^＋, and organic matter, while sweetpotato cropping systems and interaction between soil texture and sweetpotato cropping system affected the dry weights of the total lost soil, the effective phosphorus and organic matter. Among the five soil textures tested, Da and Huang caused significantly less soil erosion and nutrient loss compared with the other three soil textures; intercropping sweetpotato with corn significantly reduced soil erosion and nutrient loss.展开更多
With the accelerating process of urbanization and industrialization, the peasants for loss of land use fights has become a universal social phenomenon, the problem of landless peasants old-age security community has a...With the accelerating process of urbanization and industrialization, the peasants for loss of land use fights has become a universal social phenomenon, the problem of landless peasants old-age security community has aroused much attention. However, the presence of Hefei landless peasants pension current pension system is not perfect, the shortcomings of the current government policy, peasants lack insurance awareness and so on. This paper argucs that the land should bc constructed by the pension insurance system, improvc the land compensation policy, increase financial input and improve peasants＇ pension fund supervision and management mechanism to ensure the standardization of the system, thereby providing an important guarantee for building a socialist new urbanization.展开更多
基金Project(200805032) supported by Grands from Scientific Research Program of Marine Public Welfare Industry of ChinaProject (DYXM-115-02-2-07) supported by China Ocean Mineral Resources R&D Association (COMRA)
文摘Culturable thermophilic microorganisms were enriched from samples collected from Lau Basin hydrothermal vents in artificial seawater medium at 45 ℃ and pH 7.0. Microbial diversities of the enriched communities were defined by performing a restriction fragment length polymorphism （RFLP） analysis of 16S rRNA gene sequences with enzymes MspI and Hin6 I. A total of 14 phylotypes have been detected by the RFLP patterns identified for 16S rRNA clone libraries of the enrichment. Analysis of sequences showed that at least four bacterial divisions presented in the clones libraries. The phyla Proteobacteria and Firmicutes were the most dominant groups. The majority of the sequences included in this analysis affiliated with Gamma Proteobacteria （71%） and Bacillus （23%）. Scanning electron micrographs revealed that there were abundant rod and coceoidal forms encased in sulphur and sodium chloride precipitate. These results revealed that there were a diversity of moderate thermophilic bacterial populations thrived in Lau Basin hydrothermal vents that were previously not detected by either molecular retrieval or strain purification techniques.
文摘This study investigated the impact of soil texture and sweetpotato cropping system on soil erosion and nutrient loss in the drought infield of the Three Gorges Reservoir Area of Changjiang River under field conditions. A factorial experiment was conducted in the study using five soil textures and two cropping systems. The lost soil during the crop season was recovered by a soil-blocking device and the dry weights for the total lost soil and its nutrient components, such as ammonium nitrogen, effective phosphorus, K^＋ and organic matter were analyzed. We found that soil texture significantly affected the dry weights of the total lost soil, effective phosphorus, K^＋, and organic matter, while sweetpotato cropping systems and interaction between soil texture and sweetpotato cropping system affected the dry weights of the total lost soil, the effective phosphorus and organic matter. Among the five soil textures tested, Da and Huang caused significantly less soil erosion and nutrient loss compared with the other three soil textures; intercropping sweetpotato with corn significantly reduced soil erosion and nutrient loss.
文摘With the accelerating process of urbanization and industrialization, the peasants for loss of land use fights has become a universal social phenomenon, the problem of landless peasants old-age security community has aroused much attention. However, the presence of Hefei landless peasants pension current pension system is not perfect, the shortcomings of the current government policy, peasants lack insurance awareness and so on. This paper argucs that the land should bc constructed by the pension insurance system, improvc the land compensation policy, increase financial input and improve peasants＇ pension fund supervision and management mechanism to ensure the standardization of the system, thereby providing an important guarantee for building a socialist new urbanization.
