The West Kunlun orogenic belt(WKOB) along the northern margin of the Tibetan Plateau is important for understanding the evolution of the Proto-and Paleo-Tethys oceans. Previous investigations have focused on the igneo...The West Kunlun orogenic belt(WKOB) along the northern margin of the Tibetan Plateau is important for understanding the evolution of the Proto-and Paleo-Tethys oceans. Previous investigations have focused on the igneous rocks and ophiolites distributed mostly along the Xinjiang-Tibet road and the China-Pakistan road, and have constructed a preliminary tectonic model for this orogenic belt. However, few studies have focused on the so-called Precambrian basement in this area. As a result, the tectonic affinity of the individual terranes of the WKOB and their detailed evolution process are uncertain. Here we report new field observations, zircon and monazite U-Pb ages of the "Precambrian basement" of the South Kunlun terrane(SKT) and the Tianshuihai terrane(TSHT), two major terranes in the WKOB. Based on new zircon U-Pb age data, the amphibolite-facies metamorphosed volcanosedimentary sequence within SKT was deposited during the late Neoproterozoic to Cambrian(600-500 Ma), and the flysch-affinity Tianshuihai Group, as the basement of the TSHT, was deposited during the late Neoproterozoic rather than Mesoproterozoic. The rock association of the volcano-sedimentary sequence within SKT suggests a large early Paleozoic accretionary wedge formed by the long-term lowangle southward subduction of the Proto-Tethys Ocean between Tarim and TSHT. The amphibolitefacies metamorphism in SKT occurred at ca. 440 Ma. This ca. 440 Ma metamorphism is genetically related to the closure of the Proto-Tethys Ocean between Tarim and the Tianshuihai terrane, which led to the assembly of Tarim to Eastern Gondwana and the final formation of the Gondwana. Since the late Paleozoic to early Mesozoic, the northward subduction of the Paleo-Tethys Ocean along the HongshihuQiaoertianshan belt produced the voluminous early Mesozoic arc-signature granites along the southern part of NKT-TSHT. The Paleo-Tethys ocean between TSHT and Karakorum closed at ca. 200 Ma, as demonstrated by the monazite age of the paragneiss in the Kangxiwa Group. Our study does not favor the existence of a Precambrian basement in SKT.展开更多
Objective： To investigate general self-efficacy levels and to examine the relationship between self-efficacy and achievement motivation in student nurses in China. Methods： A total of 716 student nurses were enrolle...Objective： To investigate general self-efficacy levels and to examine the relationship between self-efficacy and achievement motivation in student nurses in China. Methods： A total of 716 student nurses were enrolled in this study from 7 hospitals in western China. Data were collected using three scales： General Data Scale, Self-Efficacy Scale （SES） and Achievement Motivation Scale （AMS）. There were 566 valid questionnaires. Results： The mean general self-efficacy scores of the student nurses were low. There was a significantly positive relationship between self-efficacy and achievement motivation （ r = 0. 432, P = 0. 000）. Conclusions： Our findings suggested that self-efficacy was related to age and educational levels, rather than gender and place of residence. Nursing managers should take measures to develop the self-efficacy of student nurses; when self-efficacy is developed, the achievement motivation may then be improved. Achievement motivation may also be improved through the improvement of self-efficacy.展开更多
基金funded by the National 305 Project of China (2018A03004-1, 2015BAB05B01-02)the Fundamental Research Fund for Central Universities(B16020127)
文摘The West Kunlun orogenic belt(WKOB) along the northern margin of the Tibetan Plateau is important for understanding the evolution of the Proto-and Paleo-Tethys oceans. Previous investigations have focused on the igneous rocks and ophiolites distributed mostly along the Xinjiang-Tibet road and the China-Pakistan road, and have constructed a preliminary tectonic model for this orogenic belt. However, few studies have focused on the so-called Precambrian basement in this area. As a result, the tectonic affinity of the individual terranes of the WKOB and their detailed evolution process are uncertain. Here we report new field observations, zircon and monazite U-Pb ages of the "Precambrian basement" of the South Kunlun terrane(SKT) and the Tianshuihai terrane(TSHT), two major terranes in the WKOB. Based on new zircon U-Pb age data, the amphibolite-facies metamorphosed volcanosedimentary sequence within SKT was deposited during the late Neoproterozoic to Cambrian(600-500 Ma), and the flysch-affinity Tianshuihai Group, as the basement of the TSHT, was deposited during the late Neoproterozoic rather than Mesoproterozoic. The rock association of the volcano-sedimentary sequence within SKT suggests a large early Paleozoic accretionary wedge formed by the long-term lowangle southward subduction of the Proto-Tethys Ocean between Tarim and TSHT. The amphibolitefacies metamorphism in SKT occurred at ca. 440 Ma. This ca. 440 Ma metamorphism is genetically related to the closure of the Proto-Tethys Ocean between Tarim and the Tianshuihai terrane, which led to the assembly of Tarim to Eastern Gondwana and the final formation of the Gondwana. Since the late Paleozoic to early Mesozoic, the northward subduction of the Paleo-Tethys Ocean along the HongshihuQiaoertianshan belt produced the voluminous early Mesozoic arc-signature granites along the southern part of NKT-TSHT. The Paleo-Tethys ocean between TSHT and Karakorum closed at ca. 200 Ma, as demonstrated by the monazite age of the paragneiss in the Kangxiwa Group. Our study does not favor the existence of a Precambrian basement in SKT.
基金supported by the research fund of Chengdu University of TCM(No.ky2013-124)
文摘Objective： To investigate general self-efficacy levels and to examine the relationship between self-efficacy and achievement motivation in student nurses in China. Methods： A total of 716 student nurses were enrolled in this study from 7 hospitals in western China. Data were collected using three scales： General Data Scale, Self-Efficacy Scale （SES） and Achievement Motivation Scale （AMS）. There were 566 valid questionnaires. Results： The mean general self-efficacy scores of the student nurses were low. There was a significantly positive relationship between self-efficacy and achievement motivation （ r = 0. 432, P = 0. 000）. Conclusions： Our findings suggested that self-efficacy was related to age and educational levels, rather than gender and place of residence. Nursing managers should take measures to develop the self-efficacy of student nurses; when self-efficacy is developed, the achievement motivation may then be improved. Achievement motivation may also be improved through the improvement of self-efficacy.
