This article establishes a set of indicators and standards for landscape ecological sensitivity analysis of site resources by using the theories and approaches of landscape ecology. It uses landscape diversity index(H...This article establishes a set of indicators and standards for landscape ecological sensitivity analysis of site resources by using the theories and approaches of landscape ecology. It uses landscape diversity index(H), evenness(E), natural degree(N), contrast degree(C) to study spatial structure and landscape heterogeneity of site resources and thus provides a qualitative-quantitative evaluation method for land planning and management of small, medium scale areas. The analysis of Yantian District, Shenzhen of China showed that Wutong Mountain belonged to high landscape ecological sensitivity area, Sanzhoutian Reservoir and Shangping Reservoir were medium landscape sensitivity area and high ecological sensitivity area; Dameisha and Xiaomeisha belonged to medium sensitivity area caused by the decline of natural ecological areas. Shatoujiao, Yantian Pier belonged to low sensitivity area but urban landscape ecological development had reshaped and influenced their landscape ecological roles in a great extent. Suggestions on planning, protection goals and development intensity of each site or district were raised.展开更多
The Olympic Events are a good opportunity to expand the services. It is two-folded： a）The building-up of communication equipments for the Olympic Village and the games venues provides vast opportunity for manufactur...The Olympic Events are a good opportunity to expand the services. It is two-folded： a）The building-up of communication equipments for the Olympic Village and the games venues provides vast opportunity for manufacturers and contractors.展开更多
Extraction of uranium with N-octanoylpyrrolidine (OPOD) in sulfonated kerosene from aqueous nitric acid media has been studied. The dependence of the extraction distribution ratios on the concentrations of aqueous nit...Extraction of uranium with N-octanoylpyrrolidine (OPOD) in sulfonated kerosene from aqueous nitric acid media has been studied. The dependence of the extraction distribution ratios on the concentrations of aqueous nitric acid, extractant, salting-out agent and the temperature was investigated. The constitution of extracted complex was established, and the related thermodynamic functions were calculated.展开更多
Loess deposit in the northeastern Qinghai-Tibetan Plateau offers an excellent record of climate and environment changes in this region. We have conducted multiparameter mineral magnetic analyses of samples of loess de...Loess deposit in the northeastern Qinghai-Tibetan Plateau offers an excellent record of climate and environment changes in this region. We have conducted multiparameter mineral magnetic analyses of samples of loess deposits from the Dongchuan, Lalakou and Panzishan sections. The methods used include magnetic susceptibility, frequency-dependent susceptibility, temperature-dependent susceptibility, isothermal remanent magnetization acquisition, and magnetic hysteresis loops. The results reveal that magnetite is the dominant contributor to magnetic susceptibility. Maghemite and hematite is also present in the loess layers and paleosol horizons. The higher concentration of maghemite in paleosols suggests that the formation of maghemite occurred during in situ pedogenesis, which plays an important role in the enhancement of the magnetic susceptibility. Similar to that in the Chinese Loess Plateau lying to the east of the Liupan Mountains, magnetic granulometry in the studied loess and paleosols is predominantly pseudo-single-domain (PSD). However, the mean grain-size of the ferrimagnetic minerals in loess is evidently coarser (larger PSD and multidomain-like) than in paleosols (mainly PSD). The magnetic susceptibility of loess and paleosols is positively correlated with the content of ultrafine magnetite/maghemite grains, and hence with the intensity of in situ pedogenesis. Therefore, the enhanced magnetic susceptibility in the studied loess-paleosol sequences can be interpreted as being due to climatically induced in situ pedogenesis.展开更多
In order to understand the relationship be- tween the community structure of bacteria in ice core and the past climate and environment, we initiated the study on the microorganisms in the three selected ice samples fr...In order to understand the relationship be- tween the community structure of bacteria in ice core and the past climate and environment, we initiated the study on the microorganisms in the three selected ice samples from the Malan ice core drilled from the Tibetan Plateau. The 16S ribosomal DNA (rDNA) molecules were directly amplified from the melt water samples, and three 16S rDNA clone li- braries were established. Among 94 positive clones, eleven clones with unique restriction pattern were used for partial sequence and compared with eight reported sequences from the same ice core. The phylotypes were divided into 5 groups: alpha, beta, gamma proteobacteria; CFB, and other eubac- teria group. Among them, there were many “typical Malan glacial bacteria” pertaining to psychrophilies and new bacte- ria found in the ice core. At a longer time scale, the concen- tration distribution of “typical Malan glacial bacteria” with depth showed negative correlation with temperature varia- tions and was coincident with dirty layer. It implied the in- fluence of temperature on the microbial record through im- pact on the concentrations of the “typical Malan glacial bac- teria”. In addition, the nutrition contained in ice was another important factor controlling the distribution of microbial population in ice core section. Moreover, the result displayed an apparent layer distribution of bacterial community in the ice core section, which reflected the microbial response to the past climatic and environmental conditions at the time of deposition.展开更多
Microfossil assemblage and pollen zone characteristics in Core B10 recorded the history of environmental changes in the southern Yellow Sea since Wiirm Subinterglaciation. Environmental variations reflected by these g...Microfossil assemblage and pollen zone characteristics in Core B10 recorded the history of environmental changes in the southern Yellow Sea since Wiirm Subinterglaciation. Environmental variations reflected by these glacial and interglacial sediments coincide with general characteristics of paleoenvironmental and sedimentary changes in the Yellow Sea. In the section of 550-520 cm, microfossil foraminifera have low abundance and diversity, and pollens are composed mainly of those of herbaceous vegetation, indicating climate change during Wiirm Subinterglaciation. In the section of 520-140 cm, the changes from a few microfossils to no microfossils reflect the sedimentary environment variation from coastal to terrestrial facies. Paleoclimate reflected by pollen also underwent the changes from conifer-broadleaf mixed forest to grassland, indicating the climate changes from temperate and cool type to warm and dry one. In the section of 140-0 cm, the general microfossil characteristics are the gradual increase in abundance with most species being neritic species, the major pollen being ligneous pollen and the rapid increase in small Hystrichosphaera content, which indicates that the air temperature increased and the sea level gradually rose.展开更多
文摘This article establishes a set of indicators and standards for landscape ecological sensitivity analysis of site resources by using the theories and approaches of landscape ecology. It uses landscape diversity index(H), evenness(E), natural degree(N), contrast degree(C) to study spatial structure and landscape heterogeneity of site resources and thus provides a qualitative-quantitative evaluation method for land planning and management of small, medium scale areas. The analysis of Yantian District, Shenzhen of China showed that Wutong Mountain belonged to high landscape ecological sensitivity area, Sanzhoutian Reservoir and Shangping Reservoir were medium landscape sensitivity area and high ecological sensitivity area; Dameisha and Xiaomeisha belonged to medium sensitivity area caused by the decline of natural ecological areas. Shatoujiao, Yantian Pier belonged to low sensitivity area but urban landscape ecological development had reshaped and influenced their landscape ecological roles in a great extent. Suggestions on planning, protection goals and development intensity of each site or district were raised.
文摘The Olympic Events are a good opportunity to expand the services. It is two-folded： a）The building-up of communication equipments for the Olympic Village and the games venues provides vast opportunity for manufacturers and contractors.
文摘Extraction of uranium with N-octanoylpyrrolidine (OPOD) in sulfonated kerosene from aqueous nitric acid media has been studied. The dependence of the extraction distribution ratios on the concentrations of aqueous nitric acid, extractant, salting-out agent and the temperature was investigated. The constitution of extracted complex was established, and the related thermodynamic functions were calculated.
基金This work was supported by the Chinese Academy of Sciences(Grant Nos.KZCX2-305,KZCX1-10-01 and KZCX2-SW-118).
文摘Loess deposit in the northeastern Qinghai-Tibetan Plateau offers an excellent record of climate and environment changes in this region. We have conducted multiparameter mineral magnetic analyses of samples of loess deposits from the Dongchuan, Lalakou and Panzishan sections. The methods used include magnetic susceptibility, frequency-dependent susceptibility, temperature-dependent susceptibility, isothermal remanent magnetization acquisition, and magnetic hysteresis loops. The results reveal that magnetite is the dominant contributor to magnetic susceptibility. Maghemite and hematite is also present in the loess layers and paleosol horizons. The higher concentration of maghemite in paleosols suggests that the formation of maghemite occurred during in situ pedogenesis, which plays an important role in the enhancement of the magnetic susceptibility. Similar to that in the Chinese Loess Plateau lying to the east of the Liupan Mountains, magnetic granulometry in the studied loess and paleosols is predominantly pseudo-single-domain (PSD). However, the mean grain-size of the ferrimagnetic minerals in loess is evidently coarser (larger PSD and multidomain-like) than in paleosols (mainly PSD). The magnetic susceptibility of loess and paleosols is positively correlated with the content of ultrafine magnetite/maghemite grains, and hence with the intensity of in situ pedogenesis. Therefore, the enhanced magnetic susceptibility in the studied loess-paleosol sequences can be interpreted as being due to climatically induced in situ pedogenesis.
文摘In order to understand the relationship be- tween the community structure of bacteria in ice core and the past climate and environment, we initiated the study on the microorganisms in the three selected ice samples from the Malan ice core drilled from the Tibetan Plateau. The 16S ribosomal DNA (rDNA) molecules were directly amplified from the melt water samples, and three 16S rDNA clone li- braries were established. Among 94 positive clones, eleven clones with unique restriction pattern were used for partial sequence and compared with eight reported sequences from the same ice core. The phylotypes were divided into 5 groups: alpha, beta, gamma proteobacteria; CFB, and other eubac- teria group. Among them, there were many “typical Malan glacial bacteria” pertaining to psychrophilies and new bacte- ria found in the ice core. At a longer time scale, the concen- tration distribution of “typical Malan glacial bacteria” with depth showed negative correlation with temperature varia- tions and was coincident with dirty layer. It implied the in- fluence of temperature on the microbial record through im- pact on the concentrations of the “typical Malan glacial bac- teria”. In addition, the nutrition contained in ice was another important factor controlling the distribution of microbial population in ice core section. Moreover, the result displayed an apparent layer distribution of bacterial community in the ice core section, which reflected the microbial response to the past climatic and environmental conditions at the time of deposition.
文摘Microfossil assemblage and pollen zone characteristics in Core B10 recorded the history of environmental changes in the southern Yellow Sea since Wiirm Subinterglaciation. Environmental variations reflected by these glacial and interglacial sediments coincide with general characteristics of paleoenvironmental and sedimentary changes in the Yellow Sea. In the section of 550-520 cm, microfossil foraminifera have low abundance and diversity, and pollens are composed mainly of those of herbaceous vegetation, indicating climate change during Wiirm Subinterglaciation. In the section of 520-140 cm, the changes from a few microfossils to no microfossils reflect the sedimentary environment variation from coastal to terrestrial facies. Paleoclimate reflected by pollen also underwent the changes from conifer-broadleaf mixed forest to grassland, indicating the climate changes from temperate and cool type to warm and dry one. In the section of 140-0 cm, the general microfossil characteristics are the gradual increase in abundance with most species being neritic species, the major pollen being ligneous pollen and the rapid increase in small Hystrichosphaera content, which indicates that the air temperature increased and the sea level gradually rose.
