Based on data from 22 sample plots and applying the Canonical Correspondence Analysis （CCA）, this paper discusses the vegetation-environment relationships between the northern slope of Karlik Mountain and Naomaohu B...Based on data from 22 sample plots and applying the Canonical Correspondence Analysis （CCA）, this paper discusses the vegetation-environment relationships between the northern slope of Karlik Mountain and Naomaohu Ba- sin, which is situated in the easternmost end of the Tianshan Mountains, Xinjiang Uygur Autonomous Region, China. For the zonal vegetation, community diversity of mountain vegetation is higher than that of the desert vegetation due to environmental factors. The CCA ordination diagram revealed that the composition and distribution of vegetation types are mainly determined by altitude, soil pH and soil salt content. With increasing elevation, the soil pH and total salt content decrease but the contents of soil organic matter, soil water, total nitrogen and total phosphorus increase gradu- ally. In the CCA ordination diagrams, the sample plots and main species can be divided into five types according to their adaptations to the environmental factors. Type Ⅰ is composed of desert vegetation distributed on the low moun- tains, hills, plains and deserts below an elevation of 1900 m; type Ⅱ is distributed in the mountain and desert ecotone with an elevation of 1900-2300 m, and includes steppe desert, desert steppe and wetland meadow; type Ⅲ is very sim- ply composed of only salinized meadow; type Ⅳ is distributed above an elevation of 2300 m, containing mountain steppe, meadow steppe, subalpine meadow and alpine meadow; type Ⅴ only contains salinized meadow. The results show that with increasing elevation, species combination changes from the xerophytic shrubs, semi-shrubs and herbs distributed in the low altitude zone with arid climate to the cold-tolerant perennial herbs growing in the high altitudinal zone with cold climate.展开更多
Traumatic spinal cord injury (SCI) usually results in devastating neurologic deficits and disability. In the United States,approximately 12,500 new cases are reported each year, while an estimated 100,000–140,000 new...Traumatic spinal cord injury (SCI) usually results in devastating neurologic deficits and disability. In the United States,approximately 12,500 new cases are reported each year, while an estimated 100,000–140,000 new cases occur every year in China (National Spinal Cord Injury Statistical Center, 2016).Spinal cord injuries are highly disabling and primarily affect young adults, and therefore create great psychological and financial burden on the affected individuals and their families.展开更多
Detailed radiolarian biostratigraphy in the Plio-Pleistocene was analyzed by using samples from IODP Site U1340 that was drilled to a core depth of 604 m in the southern Bering Sea.A total of 227 species belonging to ...Detailed radiolarian biostratigraphy in the Plio-Pleistocene was analyzed by using samples from IODP Site U1340 that was drilled to a core depth of 604 m in the southern Bering Sea.A total of 227 species belonging to 102 genera were identified.Based on the distributions of the radiolarian index species at Site U1340,five radiolarian zones since the Pliocene were established in the southern Bering Sea for the first time,and 25 radiolarian bioevents were recognized.Their ages were estimated on the basis of the age-depth plot that was constructed by the synthetical datum of the effective biostratigraphic and magnetostratigraphic events.The radiolarian zones at Site U1340 were systematically compared with those in its adjacent regions since the late Early Pliocene,which further improved and interpreted the biostratigraphic datum as well as their correlations in the middle-high latitude of the North Pacific.In addition,the comparative results of radiolarian zones show that Botryostrobus aquilonaris Zone emended in this paper is equivalent to the upper part of the same zone defined by Hays,1970,and Druppatractus irregularis-Dorydruppa bensoni Zone as well as Spongodiscus sp.Zone,newly proposed in this paper,are well correlated with Cycladophora sakaii Zone and Stylatractus universus Zone in the subarctic North Pacific,respectively.展开更多
基金Under the auspices of National Natural Science Foundation of China(No.41171157)
文摘Based on data from 22 sample plots and applying the Canonical Correspondence Analysis （CCA）, this paper discusses the vegetation-environment relationships between the northern slope of Karlik Mountain and Naomaohu Ba- sin, which is situated in the easternmost end of the Tianshan Mountains, Xinjiang Uygur Autonomous Region, China. For the zonal vegetation, community diversity of mountain vegetation is higher than that of the desert vegetation due to environmental factors. The CCA ordination diagram revealed that the composition and distribution of vegetation types are mainly determined by altitude, soil pH and soil salt content. With increasing elevation, the soil pH and total salt content decrease but the contents of soil organic matter, soil water, total nitrogen and total phosphorus increase gradu- ally. In the CCA ordination diagrams, the sample plots and main species can be divided into five types according to their adaptations to the environmental factors. Type Ⅰ is composed of desert vegetation distributed on the low moun- tains, hills, plains and deserts below an elevation of 1900 m; type Ⅱ is distributed in the mountain and desert ecotone with an elevation of 1900-2300 m, and includes steppe desert, desert steppe and wetland meadow; type Ⅲ is very sim- ply composed of only salinized meadow; type Ⅳ is distributed above an elevation of 2300 m, containing mountain steppe, meadow steppe, subalpine meadow and alpine meadow; type Ⅴ only contains salinized meadow. The results show that with increasing elevation, species combination changes from the xerophytic shrubs, semi-shrubs and herbs distributed in the low altitude zone with arid climate to the cold-tolerant perennial herbs growing in the high altitudinal zone with cold climate.
基金supported by the key Research Program of the Chinese Academy of Sciences (ZDRW-ZS-2016-2)the"Strategic Priority Research Program of the Chinese Academy of Sciences"(XDA01030000)
文摘Traumatic spinal cord injury (SCI) usually results in devastating neurologic deficits and disability. In the United States,approximately 12,500 new cases are reported each year, while an estimated 100,000–140,000 new cases occur every year in China (National Spinal Cord Injury Statistical Center, 2016).Spinal cord injuries are highly disabling and primarily affect young adults, and therefore create great psychological and financial burden on the affected individuals and their families.
基金supported by the National Natural Science Foundation of China(Grant Nos.41076026,40906030,41276051&41030859)the National Key Basic Research Program of China(Grant No.2013CB956102)+1 种基金the Knowledge Innovation Program of the Chinese Academy of Sciences(Grant No.SQ200808)the Key Technology Research on Investigations of Ocean Drilling Sites(Grant No.2008AA093001)
文摘Detailed radiolarian biostratigraphy in the Plio-Pleistocene was analyzed by using samples from IODP Site U1340 that was drilled to a core depth of 604 m in the southern Bering Sea.A total of 227 species belonging to 102 genera were identified.Based on the distributions of the radiolarian index species at Site U1340,five radiolarian zones since the Pliocene were established in the southern Bering Sea for the first time,and 25 radiolarian bioevents were recognized.Their ages were estimated on the basis of the age-depth plot that was constructed by the synthetical datum of the effective biostratigraphic and magnetostratigraphic events.The radiolarian zones at Site U1340 were systematically compared with those in its adjacent regions since the late Early Pliocene,which further improved and interpreted the biostratigraphic datum as well as their correlations in the middle-high latitude of the North Pacific.In addition,the comparative results of radiolarian zones show that Botryostrobus aquilonaris Zone emended in this paper is equivalent to the upper part of the same zone defined by Hays,1970,and Druppatractus irregularis-Dorydruppa bensoni Zone as well as Spongodiscus sp.Zone,newly proposed in this paper,are well correlated with Cycladophora sakaii Zone and Stylatractus universus Zone in the subarctic North Pacific,respectively.
