The galvanic coupling formed in origin potential flotation systems of sulfide minerals can be divided （into） three types: sulfide mineral-sulfide mineral-water system; sulfide mineral-steel ball-water system; and su...The galvanic coupling formed in origin potential flotation systems of sulfide minerals can be divided （into） three types: sulfide mineral-sulfide mineral-water system; sulfide mineral-steel ball-water system; and sulfide mineral-sulfide mineral-collector system. In this paper, taking lead, zinc, iron sulfide mineral systems for examples, several models of galvanic coupling were proposed and the effects of galvanic coupling on flotation were discussed. A galvanic contact between galena （or sphalerite） and pyrite contributes to decreasing the content of zinc in lead concentrate, and enhances remarkably the absorption of collector on the galena surface. During grinding, due to galvanic interactions between minerals and steel medium, Fe（OH）3 formed covers on the cathodic mineral surface, affecting its floatability.展开更多
"Golden triangle"area bordered on Yunnan-Guizhou-Guangxi was one of the most important Carlin-type gold deposits concentration areas.Deep understanding of Carlin-type gold deposits in Guizhou and Guangxi Pro..."Golden triangle"area bordered on Yunnan-Guizhou-Guangxi was one of the most important Carlin-type gold deposits concentration areas.Deep understanding of Carlin-type gold deposits in Guizhou and Guangxi Province had reached through several decades studies,but geological environment was very complex in the southeastern Yunnan,and Carlin-type gold deposits produced in the southeastern Yunnan were different from that of America,few studies were taken there.Based on a large number of field work,studies on the geological characteristics combining with geochemistry characteristics were taken,and analysis the genesis of Laozhaiwan gold deposit.The types of alteration in Laozhaiwan gold deposit were mainly silicification and pyritization,and Gold grade was high when silicification and pyritization were both occurred.It could be caculated that fluid density(g/cm3)varied from 0.7 to 4.9,salinity varied from 0.76%to 0.95%and ore-forming pressure(Pa)varied from 1.81×105 to 49.96×105 according to fluid inclusion test results,showed that Laozhaiwan gold deposit was hypabyssal hydrothermal deposit in low temperature and low salinity.According to composition of fluid inclusion analysis,combining with H-O isotope,made theδD-δ18O figure,showed that the fluid of the deposit rooted in formation water and mixed with meteoric waters later.展开更多
Forced dissociation of selectin-ligand complex is crucial to such biological processes as leukocyte recruitment,thrombosis formation,as well as tumor metastasis<sup>[</sup>1].Although several assays and te...Forced dissociation of selectin-ligand complex is crucial to such biological processes as leukocyte recruitment,thrombosis formation,as well as tumor metastasis<sup>[</sup>1].Although several assays and techniques,e.g.,dynamic force spectroscopy（DFS）,have been applied to probe the complex at single-bond level,the discrepancies in the loading rate dependence of bond rupture force were found in the assays,presumably due to the different pathways in energy landscape and binding kinetics of molecular complexes<sup>[2]</sup>.However,the underlying mechanisms remain unclear.Here an optical trap（OT）assay was used to quantify the bond rupture at r<sub>f</sub>≤20 pN/s展开更多
Gossypium hirsutum,the most widely planted cotton species,its evolution has long been an unsolved puzzle because of its hybrid origin from D-genome and A-genome species.To better understand the genetic component of co...Gossypium hirsutum,the most widely planted cotton species,its evolution has long been an unsolved puzzle because of its hybrid origin from D-genome and A-genome species.To better understand the genetic component of cotton,Huang et al.recently sequenced and assembled the first A1-genome G.herbaceum,and updated the A2-genome G.arboreum and(AD)1-genome G.hirsutum.On the basis of the three reference genomes,they resolved existing controversial concepts and provided novel evolutionary insights surrounding the A-genome.展开更多
Hot-filament chemical vapor deposition ( HFCVD) is a promising method for commercial production of diamond films. Filament performance in heat transfer and hydrogen decomposition in reactive environment was investigat...Hot-filament chemical vapor deposition ( HFCVD) is a promising method for commercial production of diamond films. Filament performance in heat transfer and hydrogen decomposition in reactive environment was investigated. Power consumption by the filament in vacuum, helium and 2% CH4/H2 was experimentally determined in temperature range 1300℃-2200℃. Filament heat transfer mechanism in C-H reactive environment was calculated and analyzed. The result shows that due to surface carburization and slight carbon deposition, radiation in stead of hydrogen dissociation, becomes the largest contributor to power consumption. Filament-surface dissociation of H2 was observed at temperatures below 1873K, demonstrating the feasibility of diamond growth at low filament temperatures. The effective activation energies of hydrogen dissociation on several clean refractory flaments were derived from power consumption data in literatures. They are all lower than that of thermal dissociation of hydrogen revealing the nature of catalytic dissociation of hydrogen on filament surface. Observation of substrate temperature suggested a weaker role of atomic hydrogen recombination in heating substrates in C-H environment than in pure hydrogen.展开更多
文摘The galvanic coupling formed in origin potential flotation systems of sulfide minerals can be divided （into） three types: sulfide mineral-sulfide mineral-water system; sulfide mineral-steel ball-water system; and sulfide mineral-sulfide mineral-collector system. In this paper, taking lead, zinc, iron sulfide mineral systems for examples, several models of galvanic coupling were proposed and the effects of galvanic coupling on flotation were discussed. A galvanic contact between galena （or sphalerite） and pyrite contributes to decreasing the content of zinc in lead concentrate, and enhances remarkably the absorption of collector on the galena surface. During grinding, due to galvanic interactions between minerals and steel medium, Fe（OH）3 formed covers on the cathodic mineral surface, affecting its floatability.
基金financially supported by the Program of National Natural Science Foundation of China(No.41372093No.40930423+2 种基金No.41171302)the work item of China Geological Survey(No.12120113036200)higher education quality engineering project of chalcography excellent textbook Construction(No.XJC1105)
文摘"Golden triangle"area bordered on Yunnan-Guizhou-Guangxi was one of the most important Carlin-type gold deposits concentration areas.Deep understanding of Carlin-type gold deposits in Guizhou and Guangxi Province had reached through several decades studies,but geological environment was very complex in the southeastern Yunnan,and Carlin-type gold deposits produced in the southeastern Yunnan were different from that of America,few studies were taken there.Based on a large number of field work,studies on the geological characteristics combining with geochemistry characteristics were taken,and analysis the genesis of Laozhaiwan gold deposit.The types of alteration in Laozhaiwan gold deposit were mainly silicification and pyritization,and Gold grade was high when silicification and pyritization were both occurred.It could be caculated that fluid density(g/cm3)varied from 0.7 to 4.9,salinity varied from 0.76%to 0.95%and ore-forming pressure(Pa)varied from 1.81×105 to 49.96×105 according to fluid inclusion test results,showed that Laozhaiwan gold deposit was hypabyssal hydrothermal deposit in low temperature and low salinity.According to composition of fluid inclusion analysis,combining with H-O isotope,made theδD-δ18O figure,showed that the fluid of the deposit rooted in formation water and mixed with meteoric waters later.
基金supported by National Natural Science Foundation of China grants 10902117, 31230027,30730032,and 10332060
文摘Forced dissociation of selectin-ligand complex is crucial to such biological processes as leukocyte recruitment,thrombosis formation,as well as tumor metastasis<sup>[</sup>1].Although several assays and techniques,e.g.,dynamic force spectroscopy（DFS）,have been applied to probe the complex at single-bond level,the discrepancies in the loading rate dependence of bond rupture force were found in the assays,presumably due to the different pathways in energy landscape and binding kinetics of molecular complexes<sup>[2]</sup>.However,the underlying mechanisms remain unclear.Here an optical trap（OT）assay was used to quantify the bond rupture at r<sub>f</sub>≤20 pN/s
文摘Gossypium hirsutum,the most widely planted cotton species,its evolution has long been an unsolved puzzle because of its hybrid origin from D-genome and A-genome species.To better understand the genetic component of cotton,Huang et al.recently sequenced and assembled the first A1-genome G.herbaceum,and updated the A2-genome G.arboreum and(AD)1-genome G.hirsutum.On the basis of the three reference genomes,they resolved existing controversial concepts and provided novel evolutionary insights surrounding the A-genome.
基金Supported by the National Natural Science Foundation of China under contract No.59976038.
文摘Hot-filament chemical vapor deposition ( HFCVD) is a promising method for commercial production of diamond films. Filament performance in heat transfer and hydrogen decomposition in reactive environment was investigated. Power consumption by the filament in vacuum, helium and 2% CH4/H2 was experimentally determined in temperature range 1300℃-2200℃. Filament heat transfer mechanism in C-H reactive environment was calculated and analyzed. The result shows that due to surface carburization and slight carbon deposition, radiation in stead of hydrogen dissociation, becomes the largest contributor to power consumption. Filament-surface dissociation of H2 was observed at temperatures below 1873K, demonstrating the feasibility of diamond growth at low filament temperatures. The effective activation energies of hydrogen dissociation on several clean refractory flaments were derived from power consumption data in literatures. They are all lower than that of thermal dissociation of hydrogen revealing the nature of catalytic dissociation of hydrogen on filament surface. Observation of substrate temperature suggested a weaker role of atomic hydrogen recombination in heating substrates in C-H environment than in pure hydrogen.
