The gold deposits of Triassic period in the northwestern Guangxi are all located in the marine, fine -grained ,fragmental rock series containing organic matter ,i.e .the distribution districts of black rock series . T...The gold deposits of Triassic period in the northwestern Guangxi are all located in the marine, fine -grained ,fragmental rock series containing organic matter ,i.e .the distribution districts of black rock series . The fine-grained gold deposits occur in organic matter -bearing C, D,E,or D,E divisions of the classical Bouma sequences. The evolution degree of organic matters through oil window stage reached the over -mature degree. Both the bio-sources of the organic matters and the distribution of gold in the organic matters disclose the close association between gold , living beings and organic matters . The thermal evolution of organic matters led to the gold to be activized . migrated and enriched , and finally formed gold deposits in the fault belt and crushed zone of black rock series .展开更多
Jinlongshan gold orebelt, a newly discovered one in sedimentary rock region in southern Qinling Mountains, is mainly located in upper Devonian and lower Carboniferous calcareous siltstone and argillic silty limestone ...Jinlongshan gold orebelt, a newly discovered one in sedimentary rock region in southern Qinling Mountains, is mainly located in upper Devonian and lower Carboniferous calcareous siltstone and argillic silty limestone of later Paleozoic era. Typical disseminated gold mineralization occurred in calcareous siltstone, which is major host rock and mainly composed of silt (SiO2 mostly varies from 38% to 73%) and calcite (CaO mostly varies from 10% to 25%). Pyrite created by living beings in Nanyangshan formation may be poor in gold. Faults and favorable layers jointly control disseminated gold mineralization. The significance of this opinion is very great for gold exploration.展开更多
The grain boundaries（GBs） in continuous films or domains of MoS2 are vital to its optical and electrical properties. Almost all previous approaches for GBs visualization are based on microscopy and spectroscopy and ...The grain boundaries（GBs） in continuous films or domains of MoS2 are vital to its optical and electrical properties. Almost all previous approaches for GBs visualization are based on microscopy and spectroscopy and only effective for domains with less than several micrometers in size. Here we report a simple method for the visualization of large GBs in MoS2 surface by optical microscope. Gold was deposited on the MoS2 grown by chemical vapor deposition,and then the GBs could be observed by optical microscope.Upon gold deposition on MoS2, the entire GBs of large-area MoS2 were clearly visualized using this method. To verify the result, the GBs were also characterized via scanning electron microscopy, transmission electron microscopy and atomic force microscopy. It showed the small particles of gold were clustered together on GBs, which had a larger binding energy than the inner regions. The method is universal and allows for the nondestructive identification of the GBs in any two dimensional materials with large area.展开更多
基金The paper is supported by the National Natural Science Foundation of China
文摘The gold deposits of Triassic period in the northwestern Guangxi are all located in the marine, fine -grained ,fragmental rock series containing organic matter ,i.e .the distribution districts of black rock series . The fine-grained gold deposits occur in organic matter -bearing C, D,E,or D,E divisions of the classical Bouma sequences. The evolution degree of organic matters through oil window stage reached the over -mature degree. Both the bio-sources of the organic matters and the distribution of gold in the organic matters disclose the close association between gold , living beings and organic matters . The thermal evolution of organic matters led to the gold to be activized . migrated and enriched , and finally formed gold deposits in the fault belt and crushed zone of black rock series .
文摘Jinlongshan gold orebelt, a newly discovered one in sedimentary rock region in southern Qinling Mountains, is mainly located in upper Devonian and lower Carboniferous calcareous siltstone and argillic silty limestone of later Paleozoic era. Typical disseminated gold mineralization occurred in calcareous siltstone, which is major host rock and mainly composed of silt (SiO2 mostly varies from 38% to 73%) and calcite (CaO mostly varies from 10% to 25%). Pyrite created by living beings in Nanyangshan formation may be poor in gold. Faults and favorable layers jointly control disseminated gold mineralization. The significance of this opinion is very great for gold exploration.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB12010000)the National Natural Science Foundation of China (21573253)
文摘The grain boundaries（GBs） in continuous films or domains of MoS2 are vital to its optical and electrical properties. Almost all previous approaches for GBs visualization are based on microscopy and spectroscopy and only effective for domains with less than several micrometers in size. Here we report a simple method for the visualization of large GBs in MoS2 surface by optical microscope. Gold was deposited on the MoS2 grown by chemical vapor deposition,and then the GBs could be observed by optical microscope.Upon gold deposition on MoS2, the entire GBs of large-area MoS2 were clearly visualized using this method. To verify the result, the GBs were also characterized via scanning electron microscopy, transmission electron microscopy and atomic force microscopy. It showed the small particles of gold were clustered together on GBs, which had a larger binding energy than the inner regions. The method is universal and allows for the nondestructive identification of the GBs in any two dimensional materials with large area.
