The Changkeng gold-silver deposits consist of a sediment-hosted, disseminated gold deposit and a replacement-type silver deposit. The mineralizations of gold and silver are zoned and closely related to the silicificat...The Changkeng gold-silver deposits consist of a sediment-hosted, disseminated gold deposit and a replacement-type silver deposit. The mineralizations of gold and silver are zoned and closely related to the silicification of carbonate and clastic rocks, so that siliceous ores dominate in the deposit. The mineralizing temperature ranges mainly from 300 to 170℃, and K+, Na+, Ca2+, Mg2+, and Cl- are the major ions in the ore-forming fluid. Calculations of distribution of metal complexes show that gold is mainly transported by hydrosulphide complexes, but chloride complexes of silver, iron, lead, and zinc, which are transformed into hydroxyl and hydrosulphide complexes under neutral to weak-alkaline circumstances in the late stage, predominate in the ore-forming solutions. Water-rock interaction is confirmed to be the effective mechanism for the formation of silver ores by computer modelling of reaction of hydrothermal solution with carbonate rocks. The solubility analyses demonstrate that the precipitation of gold and silver-bearing minerals taking place under weak-acid conditions and near-neutral to weak-alkaline conditions, respectively, is the main or favourable factor for the ore zonation and separation between gold and silver.展开更多
Two encouraging results were reportedby the end of 1988.Firstry,a new pro-cess for extraction of RE elements froman ion-adsorption type RE mineral;se-condly,serial production of hi-puritySc has been effective.There ar...Two encouraging results were reportedby the end of 1988.Firstry,a new pro-cess for extraction of RE elements froman ion-adsorption type RE mineral;se-condly,serial production of hi-puritySc has been effective.There are several varieties of ion-adsorption type RE minerals occur inSouth China.They differ in RE contents,展开更多
Protein nanocages are ideal templates for the bio-inspired fabrication of nanomaterials due to several advantageous properties. During the mineralization of nanoparticles （NPs） inside protein nanocages, most studies...Protein nanocages are ideal templates for the bio-inspired fabrication of nanomaterials due to several advantageous properties. During the mineralization of nanoparticles （NPs） inside protein nanocages, most studies have employed a common strategy： seed formation inside protein nanocages followed by seeded NP growth. However, the seed formation step is restricted to gentle reaction conditions to avoid damage to the protein nanocages, which may greatly limit the spectrum of seed materials used for NP growth. We put forward a simple route to circumvent such a limitation： encapsulation of a preformed NP as the seed via self-assembly, followed by the growth of an outer metal layer. Using such a method, we succeeded in mineralizing size-tunable Au NPs and Au@Ag core-shell NPs （〈10 nm in diameter） with narrow size distributions inside the virus-based NPs of simian virus 40. The present route enables the utilization of NPs synthesized under any conditions as the starting seeds for nanomaterial growth inside protein nanocages. Therefore, it potentially leads to novel bioinorganic chimeric nanomaterials with tailorable components and structures.展开更多
基金This project was financially supported by Research Funds of Gold Resources and Doctoral Training Funds sponsored by Chinese Academy of Sciences
文摘The Changkeng gold-silver deposits consist of a sediment-hosted, disseminated gold deposit and a replacement-type silver deposit. The mineralizations of gold and silver are zoned and closely related to the silicification of carbonate and clastic rocks, so that siliceous ores dominate in the deposit. The mineralizing temperature ranges mainly from 300 to 170℃, and K+, Na+, Ca2+, Mg2+, and Cl- are the major ions in the ore-forming fluid. Calculations of distribution of metal complexes show that gold is mainly transported by hydrosulphide complexes, but chloride complexes of silver, iron, lead, and zinc, which are transformed into hydroxyl and hydrosulphide complexes under neutral to weak-alkaline circumstances in the late stage, predominate in the ore-forming solutions. Water-rock interaction is confirmed to be the effective mechanism for the formation of silver ores by computer modelling of reaction of hydrothermal solution with carbonate rocks. The solubility analyses demonstrate that the precipitation of gold and silver-bearing minerals taking place under weak-acid conditions and near-neutral to weak-alkaline conditions, respectively, is the main or favourable factor for the ore zonation and separation between gold and silver.
文摘Two encouraging results were reportedby the end of 1988.Firstry,a new pro-cess for extraction of RE elements froman ion-adsorption type RE mineral;se-condly,serial production of hi-puritySc has been effective.There are several varieties of ion-adsorption type RE minerals occur inSouth China.They differ in RE contents,
基金Acknowledgements We greatly appreciate the financial support from the the National Natural Science Foundation of China （Nos. 31271076, 31470931 and 91527302） and the Key Research Program of the Chinese Academy of Sciences （No. KGZD-EW-T02-3）. We are grateful to Dr. D. Gao, B. C. Xu, P. Zhang and A. N. Du at the Center for Instrumental Analysis and Metrology, Wuhan Institute of Virology, CAS for assistance with TEM imaging and Dr. Kun Zhou at Suzhou Institute of Nano-Tech and Nano-Bionics, CAS for help with EDS analysis.
文摘Protein nanocages are ideal templates for the bio-inspired fabrication of nanomaterials due to several advantageous properties. During the mineralization of nanoparticles （NPs） inside protein nanocages, most studies have employed a common strategy： seed formation inside protein nanocages followed by seeded NP growth. However, the seed formation step is restricted to gentle reaction conditions to avoid damage to the protein nanocages, which may greatly limit the spectrum of seed materials used for NP growth. We put forward a simple route to circumvent such a limitation： encapsulation of a preformed NP as the seed via self-assembly, followed by the growth of an outer metal layer. Using such a method, we succeeded in mineralizing size-tunable Au NPs and Au@Ag core-shell NPs （〈10 nm in diameter） with narrow size distributions inside the virus-based NPs of simian virus 40. The present route enables the utilization of NPs synthesized under any conditions as the starting seeds for nanomaterial growth inside protein nanocages. Therefore, it potentially leads to novel bioinorganic chimeric nanomaterials with tailorable components and structures.
