A 400-mm-long stalagmite from Tangshan Cave, Nanjing has beenanalyzed by a high-precision TIMS-U series dating method and also determined for oxygen and carbon stable isotopic compositions. The results provided a high...A 400-mm-long stalagmite from Tangshan Cave, Nanjing has beenanalyzed by a high-precision TIMS-U series dating method and also determined for oxygen and carbon stable isotopic compositions. The results provided a high-resolution paleoclimate record for eastern China during a time interval (from 54 000 to 19 000 aBP) of the last glaciation. The continuous record of oxygen-18 variations in the stalagmite, indicating a precipitation history of the East Asian monsoon, shows not only signals of the Heinrich events, but also the Dansgaard-Oeschger cycles which are first found in the last glacial climate record of the East Asian monsoon area. Although the stalagmite-based climatic signals match well with the GRIP ice core record, some differences between the two re-cords can be recognized: (1) The last glacial climate changes in eastern China exhibited a long-term remarkably cooling trend, superimposed on which were four successive Bond’s cycles illus-trated by the δ18O curve. This strong cooling tendency may be an effect of the strong summer mon-soon event during the MIS 3 over the Tibetan Plateau. (2) There exist some phase differences of 1000—2000 years between the cooling events in the stalagmite-based climate signal and the GRIP ice core record. Such differences should be further verified by calibrations of multiple dating meth-ods.展开更多
The analysis of hydrochemical characteristics and influencing factors of surface river on plateau is helpful to study water hydrological cycle and environmental evolution,which can scientifically guide rational develo...The analysis of hydrochemical characteristics and influencing factors of surface river on plateau is helpful to study water hydrological cycle and environmental evolution,which can scientifically guide rational development and utilization of water resources and planning of ecological environment protection.With the expansion and diversification of human activities,the quality of surface rivers will be more directly affected.Therefore,it is of great significance to pay attention to the hydrochemical characteristics of plateau surface rivers and the influence of human activities on their circulation and evolution.In this study,surface water in the Duoqu basin of Jinsha River located in Hengduan mountain region of Eastern Tibet was selected as the representative case.Twenty-three groups of surface water samples were collected to analyze the hydrochemical characteristics and ion sources based on correlation analysis,piper trigram,gibbs model,hydrogen and oxygen isotopic techniques.The results suggest the following:(1)The pH showed slight alkalinity with the value ranged from 7.25 to 8.62.Ca^(2+),Mg^(2+)and HCO_(3)^(–)were the main cations and anions.HCO_(3)^(-)Ca and HCO_(3)^(-)Ca·Mg were the primary hydrochemical types for the surface water of Duoqu River.The correlation analysis showed that TDS had the most significant correlation with Ca^(2+),Mg^(2+)and HCO_(3)^(–).Analysis on hydrogen and oxygen isotopes indicated that the surface rivers were mainly recharged by atmospheric precipitation and glacial melt water in this study area.(2)The surface water had a certain reverse cation alternating adsorption,and surface water ions were mainly derived from rock weathering,mainly controlled by weathering and dissolution of carbonates,and secondly by silicates and sodium rocks.(3)The influence of human activities was weak,while the development of cinnabar minerals had a certain impact on the hydrochemistry characteristics,which was the main factor for causing the increase of SO_(4)^(2–).The densely populated county t展开更多
O-linked N-acetyl-glucosamine glycosylation(O-GlcNAcylation)of intracellular proteins is a dynamic process broadly implicated in age-related disease,yet it remains uncharacterized whether and how O-GlcNAcylation contr...O-linked N-acetyl-glucosamine glycosylation(O-GlcNAcylation)of intracellular proteins is a dynamic process broadly implicated in age-related disease,yet it remains uncharacterized whether and how O-GlcNAcylation contributes to the natural aging process.O-GlcNAc transferase(OGT)and the opposing enzyme O-GlcNAcase(OGA)control this nutrient-sensing protein modification in cells.Here,we show that global O-GlcNAc levels are increased in multiple tissues of aged mice.In aged liver,carbamoyl phosphate synthetase 1(CPS1)is among the most heavilyO-GlcNAcylated proteins.CPS1O-GlcNAcylation is reversed by calorie restriction and is sensitive to genetic and pharmacological manipulations of theO-GlcNAc pathway.High glucose stimulates CPS1O-GlcNAcylation and inhibits CPS1 activity.Liver-specific deletion of OGT potentiates CPS1 activity and renders CPS1 irresponsive to further stimulation by a prolonged fasting.Our results identify CPS1 O-GlcNAcylation as a key nutrient-sensing regulatory step in the urea cycle during aging and dietary restriction,implying a role for mitochondrial O-GlcNAcylation in nutritional regulation of longevity.展开更多
The poor rate capability of battery-type anode is usually the bottleneck of the power-energy outputs of a hybrid alkaline metal ion capacitor.In this work,nitrogen and oxygen co-doped mesoporous carbon spheres with ex...The poor rate capability of battery-type anode is usually the bottleneck of the power-energy outputs of a hybrid alkaline metal ion capacitor.In this work,nitrogen and oxygen co-doped mesoporous carbon spheres with excellent rate performance and cycle stability are used as anode materials of sodium ion capacitors(SICs).The high N and O element doping levels as well as the amorphous and mesoporous structure have enabled prominent capacitive Na ion storage behavior,which in turn match well with the capacitive cathode in the hybrid device.Under optimum conditions,the SIC delivers a high energy density of 103.1 Wh kg^(-1)at a power density of 205.6 W kg^(-1).Even at a high power density of 7520 W kg^(-1),an energy density of 23.5 Wh kg^(-1)is still maintained.Moreover,a robust cycle stability with capacity retention of 84.6%after 2500 cycles at 1 A g^(-1)is maintained.Such excellent electrochemical performances convincingly demonstrate that the all-carbon based SICs with the highly capacitive N and O co-doped mesoporous carbon anode can be promising Na ion-based energy storage devices alternative to their Li ion-based counterparts.展开更多
The society’s urgent demand for environmentally friendly, safe and low-cost energy storage devices has promoted the research of aqueous zinc-ion batteries. However, the uneven deposition of Zn ions on anodes will lea...The society’s urgent demand for environmentally friendly, safe and low-cost energy storage devices has promoted the research of aqueous zinc-ion batteries. However, the uneven deposition of Zn ions on anodes will lead to the growth of the dendrite and reduce the Coulombic efficiency as well as the lifespan of the devices. Herein, we construct an O,N-dual functionalized carbon cloth current collector via a simple hydrothermal strategy, in which the oxygen-containing functional groups and the N heteroatoms can regulate the transmission and deposition of Zn ions, respectively. The proposed synergistic strategy ensures the uniform distribution of Zn ions on the surface of the Zn anode and inhibits the formation of dendrites. The symmetric cell based on the O,N-dual doped carbon cloth presents superior cycling stability(318 h) with a low voltage hysteresis(11.2 mV) at an areal capacity of 1 m Ah cm^(-2)(20% depth of diacharge). Meanwhile, the appreciably low overpotential(16 m V) and high Columbic efficiency(98.2%)also demonstrate that the O,N-dual functionalized carbon cloth can be worked as a promising host for Zn ions deposition.展开更多
基金the National Natural Science Foundation of China (Grant No.49972055). We thank Dr. Hai Cheng at Isotope Laboratory of Geology and Geophysics Department, Minnesota University, USA for his measurement of TIMS-U series dating.
文摘A 400-mm-long stalagmite from Tangshan Cave, Nanjing has beenanalyzed by a high-precision TIMS-U series dating method and also determined for oxygen and carbon stable isotopic compositions. The results provided a high-resolution paleoclimate record for eastern China during a time interval (from 54 000 to 19 000 aBP) of the last glaciation. The continuous record of oxygen-18 variations in the stalagmite, indicating a precipitation history of the East Asian monsoon, shows not only signals of the Heinrich events, but also the Dansgaard-Oeschger cycles which are first found in the last glacial climate record of the East Asian monsoon area. Although the stalagmite-based climatic signals match well with the GRIP ice core record, some differences between the two re-cords can be recognized: (1) The last glacial climate changes in eastern China exhibited a long-term remarkably cooling trend, superimposed on which were four successive Bond’s cycles illus-trated by the δ18O curve. This strong cooling tendency may be an effect of the strong summer mon-soon event during the MIS 3 over the Tibetan Plateau. (2) There exist some phase differences of 1000—2000 years between the cooling events in the stalagmite-based climate signal and the GRIP ice core record. Such differences should be further verified by calibrations of multiple dating meth-ods.
基金financially supported by the Geological Survey Project of China Geological Survey(DD20230077,DD20230456,DD20230424)。
文摘The analysis of hydrochemical characteristics and influencing factors of surface river on plateau is helpful to study water hydrological cycle and environmental evolution,which can scientifically guide rational development and utilization of water resources and planning of ecological environment protection.With the expansion and diversification of human activities,the quality of surface rivers will be more directly affected.Therefore,it is of great significance to pay attention to the hydrochemical characteristics of plateau surface rivers and the influence of human activities on their circulation and evolution.In this study,surface water in the Duoqu basin of Jinsha River located in Hengduan mountain region of Eastern Tibet was selected as the representative case.Twenty-three groups of surface water samples were collected to analyze the hydrochemical characteristics and ion sources based on correlation analysis,piper trigram,gibbs model,hydrogen and oxygen isotopic techniques.The results suggest the following:(1)The pH showed slight alkalinity with the value ranged from 7.25 to 8.62.Ca^(2+),Mg^(2+)and HCO_(3)^(–)were the main cations and anions.HCO_(3)^(-)Ca and HCO_(3)^(-)Ca·Mg were the primary hydrochemical types for the surface water of Duoqu River.The correlation analysis showed that TDS had the most significant correlation with Ca^(2+),Mg^(2+)and HCO_(3)^(–).Analysis on hydrogen and oxygen isotopes indicated that the surface rivers were mainly recharged by atmospheric precipitation and glacial melt water in this study area.(2)The surface water had a certain reverse cation alternating adsorption,and surface water ions were mainly derived from rock weathering,mainly controlled by weathering and dissolution of carbonates,and secondly by silicates and sodium rocks.(3)The influence of human activities was weak,while the development of cinnabar minerals had a certain impact on the hydrochemistry characteristics,which was the main factor for causing the increase of SO_(4)^(2–).The densely populated county t
基金was supported by grants from National Institutes of Health(R01DK089098 and P01DK57751)American Diabetes Association(1-19-IBS-119)+1 种基金X.Y.and a Glenn/AFAR Scholarship for Research in the Biology of Aging to M.-D.LYale School of Medicine and by the Office of The Director,National Institutes of Health(S10OD02365101A1,S10OD019967,and S10OD018034).
文摘O-linked N-acetyl-glucosamine glycosylation(O-GlcNAcylation)of intracellular proteins is a dynamic process broadly implicated in age-related disease,yet it remains uncharacterized whether and how O-GlcNAcylation contributes to the natural aging process.O-GlcNAc transferase(OGT)and the opposing enzyme O-GlcNAcase(OGA)control this nutrient-sensing protein modification in cells.Here,we show that global O-GlcNAc levels are increased in multiple tissues of aged mice.In aged liver,carbamoyl phosphate synthetase 1(CPS1)is among the most heavilyO-GlcNAcylated proteins.CPS1O-GlcNAcylation is reversed by calorie restriction and is sensitive to genetic and pharmacological manipulations of theO-GlcNAc pathway.High glucose stimulates CPS1O-GlcNAcylation and inhibits CPS1 activity.Liver-specific deletion of OGT potentiates CPS1 activity and renders CPS1 irresponsive to further stimulation by a prolonged fasting.Our results identify CPS1 O-GlcNAcylation as a key nutrient-sensing regulatory step in the urea cycle during aging and dietary restriction,implying a role for mitochondrial O-GlcNAcylation in nutritional regulation of longevity.
基金financially supported by the Natural Science Foundation projects(No.2020J01287)Guidance Project(No.2020H0024)of Fujian Provincethe Program for Innovative Research Team in Science and Technology in Fujian Province University。
文摘The poor rate capability of battery-type anode is usually the bottleneck of the power-energy outputs of a hybrid alkaline metal ion capacitor.In this work,nitrogen and oxygen co-doped mesoporous carbon spheres with excellent rate performance and cycle stability are used as anode materials of sodium ion capacitors(SICs).The high N and O element doping levels as well as the amorphous and mesoporous structure have enabled prominent capacitive Na ion storage behavior,which in turn match well with the capacitive cathode in the hybrid device.Under optimum conditions,the SIC delivers a high energy density of 103.1 Wh kg^(-1)at a power density of 205.6 W kg^(-1).Even at a high power density of 7520 W kg^(-1),an energy density of 23.5 Wh kg^(-1)is still maintained.Moreover,a robust cycle stability with capacity retention of 84.6%after 2500 cycles at 1 A g^(-1)is maintained.Such excellent electrochemical performances convincingly demonstrate that the all-carbon based SICs with the highly capacitive N and O co-doped mesoporous carbon anode can be promising Na ion-based energy storage devices alternative to their Li ion-based counterparts.
基金supported by the National Natural Science Foundation of China (21825106, 92061201)the Program for Innovative Research Team (in Science and Technology) in Universities of Henan Province (19IRTSTHN022)Zhengzhou University。
文摘The society’s urgent demand for environmentally friendly, safe and low-cost energy storage devices has promoted the research of aqueous zinc-ion batteries. However, the uneven deposition of Zn ions on anodes will lead to the growth of the dendrite and reduce the Coulombic efficiency as well as the lifespan of the devices. Herein, we construct an O,N-dual functionalized carbon cloth current collector via a simple hydrothermal strategy, in which the oxygen-containing functional groups and the N heteroatoms can regulate the transmission and deposition of Zn ions, respectively. The proposed synergistic strategy ensures the uniform distribution of Zn ions on the surface of the Zn anode and inhibits the formation of dendrites. The symmetric cell based on the O,N-dual doped carbon cloth presents superior cycling stability(318 h) with a low voltage hysteresis(11.2 mV) at an areal capacity of 1 m Ah cm^(-2)(20% depth of diacharge). Meanwhile, the appreciably low overpotential(16 m V) and high Columbic efficiency(98.2%)also demonstrate that the O,N-dual functionalized carbon cloth can be worked as a promising host for Zn ions deposition.
