Hydrothermal ore deposits at convergent plate boundaries represent extraordinary metal enrichment in the continental crust. They are generally associated with felsic magmatism in extensional settings at high thermal g...Hydrothermal ore deposits at convergent plate boundaries represent extraordinary metal enrichment in the continental crust. They are generally associated with felsic magmatism in extensional settings at high thermal gradients. Although their formation is common during accretionary orogeny, more and more ore deposits have been discovered recently in the collisional orogens of China. Because collisional orogeny was operated in a compressional regime at low thermal gradients, it is not favorable for mobilization of ore-forming elements and thus for the production of hydrothermal ore deposits. Nevertheless, continental collision is generally preceded by oceanic subduction, which enables the preliminary enrichment of ore-forming elements in the mantle wedge due to chemical metasomatism by subducting slab-derived fluids. This gave rise to metal pre-enriched domains in the overriding lithosphere, which may be reactivated by extensional tectonism for hydrothermal mineralization either immediately during accretionary orogeny or at a later time during and after collisional orogeny. It is these tectonic processes that have resulted in the progressive enrichment of ore-forming elements through the geochemical differentiation of the subducting oceanic crust, the metasomatic mantle domains and the mafic juvenile crust, respectively, at different depths. Finally, the reactivation of metal pre-enriched domains by continental rifting in the orogenic lithosphere is the key to the metallogenesis of collisional orogens.展开更多
Nitrogen atom doping has been found to enhance the electrochemical performance of porous carbon(PC).In this study,hollow tubular nitrogen-doped porous carbon(N/PC)was synthesized using polyvinylpyrrolidone as the car...Nitrogen atom doping has been found to enhance the electrochemical performance of porous carbon(PC).In this study,hollow tubular nitrogen-doped porous carbon(N/PC)was synthesized using polyvinylpyrrolidone as the carbon–nitrogen source and fibrous brucite as the template through carbonization.The effects of nitrogen and argon protective atmospheres on the nitrogen content,the specific surface area(SSA),and electrochemical properties of N/PC were investigated.The results showed that compared with N/FBC-Ar,N/FBC-N2 prepared in nitrogen protective atmosphere had a higher nitrogen content and a larger proportion of pyrrolic nitrogen(N-5)and pyridinic nitrogen(N-6).N/FBC-N2 displayed a specific capacitance(C)of 194.1 F·g^(−1)at 1 A·g^(−1),greater than that of N/FBC-Ar(174.3 F·g^(−1)).This work reveals that the nitrogen doping with a higher nitrogen content in nitrogen protective atmosphere is more favorable.Furthermore,a larger proportion of pyrrolic nitrogen and pyridinic nitrogen in the doped nitrogen atoms significantly enhances the electrochemical performance.展开更多
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences (XDB18020303)the National Key Basic Research Progam of China (2015CB856100)
文摘Hydrothermal ore deposits at convergent plate boundaries represent extraordinary metal enrichment in the continental crust. They are generally associated with felsic magmatism in extensional settings at high thermal gradients. Although their formation is common during accretionary orogeny, more and more ore deposits have been discovered recently in the collisional orogens of China. Because collisional orogeny was operated in a compressional regime at low thermal gradients, it is not favorable for mobilization of ore-forming elements and thus for the production of hydrothermal ore deposits. Nevertheless, continental collision is generally preceded by oceanic subduction, which enables the preliminary enrichment of ore-forming elements in the mantle wedge due to chemical metasomatism by subducting slab-derived fluids. This gave rise to metal pre-enriched domains in the overriding lithosphere, which may be reactivated by extensional tectonism for hydrothermal mineralization either immediately during accretionary orogeny or at a later time during and after collisional orogeny. It is these tectonic processes that have resulted in the progressive enrichment of ore-forming elements through the geochemical differentiation of the subducting oceanic crust, the metasomatic mantle domains and the mafic juvenile crust, respectively, at different depths. Finally, the reactivation of metal pre-enriched domains by continental rifting in the orogenic lithosphere is the key to the metallogenesis of collisional orogens.
基金the National Natural Science Foundation of China(Grant Nos.51774016 and 52074015)Clinical Medicine Plus X-Young Scholars Project,Peking University(2022-33+3 种基金2023-45)the Fundamental Research Funds for the Central Universities(China)the Fundamental Research Funds for the Central Universities(2019XKQYMS76)the Central University Basic Research Business Fund(2023QN1038).
文摘Nitrogen atom doping has been found to enhance the electrochemical performance of porous carbon(PC).In this study,hollow tubular nitrogen-doped porous carbon(N/PC)was synthesized using polyvinylpyrrolidone as the carbon–nitrogen source and fibrous brucite as the template through carbonization.The effects of nitrogen and argon protective atmospheres on the nitrogen content,the specific surface area(SSA),and electrochemical properties of N/PC were investigated.The results showed that compared with N/FBC-Ar,N/FBC-N2 prepared in nitrogen protective atmosphere had a higher nitrogen content and a larger proportion of pyrrolic nitrogen(N-5)and pyridinic nitrogen(N-6).N/FBC-N2 displayed a specific capacitance(C)of 194.1 F·g^(−1)at 1 A·g^(−1),greater than that of N/FBC-Ar(174.3 F·g^(−1)).This work reveals that the nitrogen doping with a higher nitrogen content in nitrogen protective atmosphere is more favorable.Furthermore,a larger proportion of pyrrolic nitrogen and pyridinic nitrogen in the doped nitrogen atoms significantly enhances the electrochemical performance.
