New whole-rock major and trace elements, and zircon U Pb and Hf-Nd isotope compositions are reported for the Karamay dikes, enclaves, and host granites in the West Junggar, NW China. Zircon U -Pb dating of the l（aram...New whole-rock major and trace elements, and zircon U Pb and Hf-Nd isotope compositions are reported for the Karamay dikes, enclaves, and host granites in the West Junggar, NW China. Zircon U -Pb dating of the l（aramay pluton yields an age of 300.7 ~ 2.3 Ma for the enclave and 300.0 ~ 2.6 Ma for the host granite, which was intruded by dike with an age of 298 Ma. The host granites exhibit relatively low SiO2 contents and A/CNK and Ga/Al ratios, low initial 87Sr/86Sr ratios （0.703421 0.703526） and positive eHf（t） （5.5--14.1） and eNd（t） （7.3--8.1） values with a young model age, suggesting that they are I-type granites and were mainly derived from a juvenile lower crustal source. The enclaves and dikes belong to an andesitic calc-alkaline series and have high MgO concentrations at low silica content and positive eHf（t） （7.6--13.2, 14.2--14.9） and εNd（t） （6.8-8.3, ~6.9） values. They are enriched in LILEs （Rb, Ba and U） and LREE and depleted in HFSEs （Nb and Ta） with insignificant negative Eu anomalies, indicating that the melts were derived from an enriched lithospheric mantle modified by subducted oceanic crust-derived melts and minor fluids, followed by fractional crystallization. The Karamay host granites and enclaves are of mixed origin and are most probably formed by the interaction between the lower crust-and lithospheric mantle-derived magmas, and were intruded by the unmixed dikes subsequently. The upwelling mantle through a slab window in an island arc environment might have triggered partial melting of the lithospheric mantle and its subsequent interaction with the granitic magma, further suggesting that the ridge subduction played an important role in the crustal growth of West lun^gar.展开更多
Background.Increasing evidence from human studies has revealed the adverse impact of ambient fine particles(PM_(2.5))on health outcomes related to metabolic disorders and distant organs.Whether exposure to ambient PM_...Background.Increasing evidence from human studies has revealed the adverse impact of ambient fine particles(PM_(2.5))on health outcomes related to metabolic disorders and distant organs.Whether exposure to ambient PM_(2.5)leads to kidney impairment remains unclear.The rapid air quality improvement driven by the clean air actions in China since 2013 provides an opportunity for a quasiexperiment to investigate the beneficial effect of PM_(2.5)reduction on kidney function.Methods.Based on two repeated nationwide surveys of the same population of 5115 adults in 2011 and 2015,we conducted a difference-indifference study.Variations in long-term exposure to ambient PM_(2.5)were associated with changes in kidney function biomarkers,including estimated glomerular filtration rate by serum creatinine(GFRscr)or cystatin C(GFRcys),blood urea nitrogen(BUN),and uric acid(UA).Results.For a 10μg/m^(3)reduction in PM_(2.5),a significant improvement was observed for multiple kidney functional biomarkers,including GFRscr,BUN and UA,with a change of 0.42(95%confidence interval[CI]:0.06,0.78)mL/min/1.73m^(2),-0.38(-0.64,-0.12)mg/dL,and-0.06(-0.12,-0.00)mg/dL,respectively.A lower socioeconomic status,indicated by rural residence or low educational level,enhanced the adverse effect of PM_(2.5)on kidney function.Conclusions.These results support a significant nephrotoxicity of PM_(2.5)based on multiple serum biomarkers and indicate a beneficial effect of improved air quality on kidney function.展开更多
This paper studies the elastic deformation field in lattice-mismatched Ge-Si core-shell nanowires(NWs).Infinite wires with a cylindrical cross section under the assumption of translational symmetry are considered.The ...This paper studies the elastic deformation field in lattice-mismatched Ge-Si core-shell nanowires(NWs).Infinite wires with a cylindrical cross section under the assumption of translational symmetry are considered.The strain distributions are found by minimizing the elastic energy per unit cell using finite element method.This paper finds that the trace of the strain is discontinuous with a simple,almost piecewise variation between core and shell,whereas the individual components of the strain can exhibit complex variations.The simulation results are prerequisite of strained band structure calculation,and pave a way for further investigation of strain effect on the related transport property simulation.展开更多
基金financially supported by the National Science and Technology Major Project(No. 2011ZX05008-001)the National Natural Science Foundation of China(No.40739906)the Chinese State 973 Project(No. 2011CB201100)
文摘New whole-rock major and trace elements, and zircon U Pb and Hf-Nd isotope compositions are reported for the Karamay dikes, enclaves, and host granites in the West Junggar, NW China. Zircon U -Pb dating of the l（aramay pluton yields an age of 300.7 ~ 2.3 Ma for the enclave and 300.0 ~ 2.6 Ma for the host granite, which was intruded by dike with an age of 298 Ma. The host granites exhibit relatively low SiO2 contents and A/CNK and Ga/Al ratios, low initial 87Sr/86Sr ratios （0.703421 0.703526） and positive eHf（t） （5.5--14.1） and eNd（t） （7.3--8.1） values with a young model age, suggesting that they are I-type granites and were mainly derived from a juvenile lower crustal source. The enclaves and dikes belong to an andesitic calc-alkaline series and have high MgO concentrations at low silica content and positive eHf（t） （7.6--13.2, 14.2--14.9） and εNd（t） （6.8-8.3, ~6.9） values. They are enriched in LILEs （Rb, Ba and U） and LREE and depleted in HFSEs （Nb and Ta） with insignificant negative Eu anomalies, indicating that the melts were derived from an enriched lithospheric mantle modified by subducted oceanic crust-derived melts and minor fluids, followed by fractional crystallization. The Karamay host granites and enclaves are of mixed origin and are most probably formed by the interaction between the lower crust-and lithospheric mantle-derived magmas, and were intruded by the unmixed dikes subsequently. The upwelling mantle through a slab window in an island arc environment might have triggered partial melting of the lithospheric mantle and its subsequent interaction with the granitic magma, further suggesting that the ridge subduction played an important role in the crustal growth of West lun^gar.
基金the National Natural Science Foundation of China(4217050142)PKU-Baidu Fund(2020BD031)+2 种基金Energy Foundation(G-2107-33169 and R-2109-33379)the Funda-mental Research Funds for the Central Universities(BMU2021YJ042)CAMS Innovation Fund for Medical Sciences(2017-I2M-1-004).
文摘Background.Increasing evidence from human studies has revealed the adverse impact of ambient fine particles(PM_(2.5))on health outcomes related to metabolic disorders and distant organs.Whether exposure to ambient PM_(2.5)leads to kidney impairment remains unclear.The rapid air quality improvement driven by the clean air actions in China since 2013 provides an opportunity for a quasiexperiment to investigate the beneficial effect of PM_(2.5)reduction on kidney function.Methods.Based on two repeated nationwide surveys of the same population of 5115 adults in 2011 and 2015,we conducted a difference-indifference study.Variations in long-term exposure to ambient PM_(2.5)were associated with changes in kidney function biomarkers,including estimated glomerular filtration rate by serum creatinine(GFRscr)or cystatin C(GFRcys),blood urea nitrogen(BUN),and uric acid(UA).Results.For a 10μg/m^(3)reduction in PM_(2.5),a significant improvement was observed for multiple kidney functional biomarkers,including GFRscr,BUN and UA,with a change of 0.42(95%confidence interval[CI]:0.06,0.78)mL/min/1.73m^(2),-0.38(-0.64,-0.12)mg/dL,and-0.06(-0.12,-0.00)mg/dL,respectively.A lower socioeconomic status,indicated by rural residence or low educational level,enhanced the adverse effect of PM_(2.5)on kidney function.Conclusions.These results support a significant nephrotoxicity of PM_(2.5)based on multiple serum biomarkers and indicate a beneficial effect of improved air quality on kidney function.
文摘This paper studies the elastic deformation field in lattice-mismatched Ge-Si core-shell nanowires(NWs).Infinite wires with a cylindrical cross section under the assumption of translational symmetry are considered.The strain distributions are found by minimizing the elastic energy per unit cell using finite element method.This paper finds that the trace of the strain is discontinuous with a simple,almost piecewise variation between core and shell,whereas the individual components of the strain can exhibit complex variations.The simulation results are prerequisite of strained band structure calculation,and pave a way for further investigation of strain effect on the related transport property simulation.
