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The Status Quo and Development Trend of High-purity Gold Sputtering Targets 被引量:1
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作者 YANG Anheng XIE Hongchao ZHU Yong 《贵金属》 CAS CSCD 北大核心 2012年第A01期173-176,共4页
This article gives a brief introduction to manufacturers and markets of sputtering targets as well as the manufacturing technology thereof. Then, it analyzes the application of high-purity gold sputtering targets in t... This article gives a brief introduction to manufacturers and markets of sputtering targets as well as the manufacturing technology thereof. Then, it analyzes the application of high-purity gold sputtering targets in the fields of integrated circuit, information storage, flat panel display, etc. Based on the above, the article analyzes the processing development trend for the high-purity gold sputtering targets in aspects of ultra-high purity, manufacturing technology, analysis and testing technologies. 展开更多
关键词 high-purity gold sputtering targets status quo development trend
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Multiple factors influencing high-purity indium electrolytic refining
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作者 Hong-Qiang Fan Fei Li +5 位作者 Hong-Xing Zheng Wu-ji Pan Mei-Zhen Wu Yashar Behnamian Ju-Bo Peng Dong-Hai Lin 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第7期148-160,共13页
The effects of various contaminants in the electrolytic refinement of indium were investigated using a glow discharge mass spectrometer(GDMS).The effects of several factors such as the indium ion(In3+)concentration,th... The effects of various contaminants in the electrolytic refinement of indium were investigated using a glow discharge mass spectrometer(GDMS).The effects of several factors such as the indium ion(In3+)concentration,the sodium chloride(NaCl)concentration,the current density,the gelatin concentration,the pH,and the electrode distance,were examined.Significant variations in impurity levels concerning gelatin concentration were observed.Both the gelatin and In3+concentration were moderately positively correlated with the Pb content.The Sb concentration was associated positively with the NaCl concentration,while the Ti concentration had an adverse correlation with the NaCl concentration.The Bi element content was positively linked to the electrode distance.As the current density increased,Cu,Pb,and Bi impurities initially rose and then eventually declined.Notably,a critical current density of 45 A·m^(-2) was identified in this behavior. 展开更多
关键词 high-purity indium ELECTROLYSIS Multiple factors ELECTROCHEMISTRY Purification
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Polydopamine-modified metal-organic frameworks nanoparticles enhance the corrosion resistance and bioactivity of polycaprolactone coating on high-purity magnesium
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作者 Qingyun Fu Shaojie He +7 位作者 Junjie Yang Ziyu Su Ping Li Xincheng Yu Weihong Jin Shulan Xu Zhentao Yu Dingsheng Zha 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第5期2070-2089,共20页
Biodegradable magnesium(Mg)and its alloys exhibit excellent biocompatibility and mechanical compatibility,demonstrating tremendous potential for applications in orthopedics.However,the rapid degradation rate has limit... Biodegradable magnesium(Mg)and its alloys exhibit excellent biocompatibility and mechanical compatibility,demonstrating tremendous potential for applications in orthopedics.However,the rapid degradation rate has limited their clinical application.Polycaprolactone(PCL)is commonly employed as a polymer coating to impede the rapid degradation of Mg.Unfortunately,its long-term anti-corrosion capability and bioactivity are inadequate.To address these issues,polydopamine(PDA)-modified zeolitic imidazolate framework-8(PZIF-8)bioactive nanoparticles are fabricated and incorporated into the PCL coating.The PZIF-8 particles,featuring catechol motifs,can enhance the compactness of the PCL coating,reduce its defects,and possess biomineralization ability,thereby effectively improving its anti-corrosive and bioactive properties.Moreover,the active substances released from the degradation of the PZIF-8 particles such as Zn^(2+)and PDA are beneficial for osteogenesis.The corrosion tests indicate that the corrosion current density of PCL-treated sample decreases by more than one order of magnitude and the amount of H_(2)released decreases from 0.23±0.12 to 0.08±0.08 ml cm^(-2)after doping with the PZIF-8.Furthermore,the improved corrosion resistance and released PDA and Zn^(2+)from the coating can promote osteogenic differentiation by up-regulating the expression of alkaline phosphatase activity,related osteogenic genes,and proteins.In addition,in vivo implantation experiments in rabbit femur defects further offer strong evidence that the doping of PZIF-8 nanoparticles accelerates bone reconstruction of the PCL coating.In summary,this work implies a new strategy to fabricate a PCL-based coating on Mg-based implants by introducing the PZIF-8 particles for orthopedic applications. 展开更多
关键词 POLYDOPAMINE ZIF-8 high-purity magnesium Polycaprolactone coating ANTICORROSION Bone regeneration
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Enhanced recovery of high-purity Fe powder from iron-rich electrolytic manganese residue by slurry electrolysis
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作者 Wenxing Cao Jiancheng Shu +5 位作者 Jiaming Chen Zihan Li Songshan Zhou Shushu Liao Mengjun Chen Yong Yang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第3期531-538,共8页
Iron-rich electrolytic manganese residue(IREMR)is an industrial waste produced during the processing of electrolytic metal manganese,and it contains certain amounts of Fe and Mn resources and other heavy metals.In thi... Iron-rich electrolytic manganese residue(IREMR)is an industrial waste produced during the processing of electrolytic metal manganese,and it contains certain amounts of Fe and Mn resources and other heavy metals.In this study,the slurry electrolysis technique was used to recover high-purity Fe powder from IREMR.The effects of IREMR and H2SO4 mass ratio,current density,reaction temper-ature,and electrolytic time on the leaching and current efficiencies of Fe were studied.According to the results,high-purity Fe powder can be recovered from the cathode plate,and the slurry electrolyte can be recycled.The leaching efficiency,current efficiency,and purity of Fe reached 92.58%,80.65%,and 98.72wt%,respectively,at a 1:2.5 mass ratio of H2SO4 and IREMR,reaction temperature of 60℃,electric current density of 30 mA/cm^(2),and reaction time of 8 h.In addition,vibrating sample magnetometer(VSM)analysis showed that the coercivity of electrolytic iron powder was 54.5 A/m,which reached the advanced magnetic grade of electrical pure-iron powder(DT4A coercivity standard).The slurry electrolytic method provides fundamental support for the industrial application of Fe resource recovery in IRMER. 展开更多
关键词 iron-rich electrolytic manganese residue slurry electrolysis high-purity iron powder leaching efficiency current efficiency
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Artificial neural network-based method for discriminating Compton scattering events in high-purity germaniumγ-ray spectrometer
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作者 Chun-Di Fan Guo-Qiang Zeng +5 位作者 Hao-Wen Deng Lei Yan Jian Yang Chuan-Hao Hu Song Qing Yang Hou 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第2期64-84,共21页
To detect radioactive substances with low activity levels,an anticoincidence detector and a high-purity germanium(HPGe)detector are typically used simultaneously to suppress Compton scattering background,thereby resul... To detect radioactive substances with low activity levels,an anticoincidence detector and a high-purity germanium(HPGe)detector are typically used simultaneously to suppress Compton scattering background,thereby resulting in an extremely low detection limit and improving the measurement accuracy.However,the complex and expensive hardware required does not facilitate the application or promotion of this method.Thus,a method is proposed in this study to discriminate the digital waveform of pulse signals output using an HPGe detector,whereby Compton scattering background is suppressed and a low minimum detectable activity(MDA)is achieved without using an expensive and complex anticoincidence detector and device.The electric-field-strength and energy-deposition distributions of the detector are simulated to determine the relationship between pulse shape and energy-deposition location,as well as the characteristics of energy-deposition distributions for fulland partial-energy deposition events.This relationship is used to develop a pulse-shape-discrimination algorithm based on an artificial neural network for pulse-feature identification.To accurately determine the relationship between the deposited energy of gamma(γ)rays in the detector and the deposition location,we extract four shape parameters from the pulse signals output by the detector.Machine learning is used to input the four shape parameters into the detector.Subsequently,the pulse signals are identified and classified to discriminate between partial-and full-energy deposition events.Some partial-energy deposition events are removed to suppress Compton scattering.The proposed method effectively decreases the MDA of an HPGeγ-energy dispersive spectrometer.Test results show that the Compton suppression factors for energy spectra obtained from measurements on ^(152)Eu,^(137)Cs,and ^(60)Co radioactive sources are 1.13(344 keV),1.11(662 keV),and 1.08(1332 keV),respectively,and that the corresponding MDAs are 1.4%,5.3%,and 21.6%lower,respectively. 展开更多
关键词 high-purity germaniumγ-ray spectrometer Pulse-shape discrimination Compton scattering Artificial neural network Minimum detectable activity
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Use of various MgO resources for high-purity Mg metal production through molten salt electrolysis and vacuum distillation 被引量:1
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作者 Hyeong-Jun Jeoung Tae-Hyuk Lee +5 位作者 Youngjae Kim Jin-Young Lee Young Min Kim Toru HOkabe Kyung-Woo Yi Jungshin Kang 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第2期562-579,共18页
A green and effective electrolytic process was developed to produce high-purity Mg metal using primary and secondary resources containing Mg O as a feedstock. The electrolysis of various Mg O resources was conducted u... A green and effective electrolytic process was developed to produce high-purity Mg metal using primary and secondary resources containing Mg O as a feedstock. The electrolysis of various Mg O resources was conducted using a Cu cathode in MgF2– LiF – KCl molten salt at 1043 K by applying an average current of 1.44 A for 12.5 h. The electrolysis of calcined North Korean magnesite and seawater Mg O clinker yielded Mg alloys of MgCu2and(Cu) phases with current efficiencies of 89.6–92.4%. The electrolysis of oxidized Mg O-C refractory brick, aged ferronickel slag, and ferronickel slag yielded Mg alloys of MgCu2and(Cu) phases with current efficiencies of 59.3–92.3%. The vacuum distillation of Mg alloys obtained was conducted at 1300 K for 10 h to produce high-purity Mg metal. After vacuum distillation, Mg metal with a purity of above 99.994% was obtained. Therefore, this study demonstrates the feasibility of the production of high-purity Mg metal from various Mg O resources using a novel electrolytic process with a Cu cathode, followed by vacuum distillation. 展开更多
关键词 high-purity magnesium Magnesium oxide resources Electrolytic process Metal cathode Vacuum distillation
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基于“GOLD原则”的金课教学法研究与实践——以离散数学课程为例
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作者 孙丽梅 栾方军 董洁 《计算机教育》 2024年第9期208-212,共5页
针对目前金课教学存在的问题,提出基于“GOLD原则”的金课教学法,从目标(Goal)、选项(Option)、领导(Leading)、展示(Display)4个步骤具体阐述,以离散数学课堂为例介绍基于“GOLD原则”的金课教学法的教学过程,说明教学效果。
关键词 gold原则 金课 教学实践 离散数学
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Minimizing pest aluminum in magnesium for the production of high-purity titanium
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作者 Bo Yang Rui Zheng +2 位作者 Ge Wu Zhi-Min Chang Zhi-Wei Shan 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第11期4189-4196,共8页
It is practically difficult to find titanium sponges with low and stable aluminum impurities on the market even though it is the precondition to prepare high-purity titanium. Analysis indicates that almost all the alu... It is practically difficult to find titanium sponges with low and stable aluminum impurities on the market even though it is the precondition to prepare high-purity titanium. Analysis indicates that almost all the aluminum impurities in the titanium sponge are inherited from the magnesium used to reduce titanium tetrachloride. However, it remains elusive for decades why magnesium produced through the silicothermic reduction method contains a high content of aluminum impurities with large fluctuations. By recourse to thermodynamic calculations and comparative experiments, we demonstrate that fluorite, a material used as a catalyst in the silicothermic reduction method to produce magnesium, is the chief culprit for the pest aluminum and propose a mechanism to rationalize the observed phenomena. Our findings indicate that one practical way to produce qualified magnesium for the production of high-purity titanium is to abandon fluorite during the production of magnesium with the silicothermic reduction method. 展开更多
关键词 high-purity titanium Titanium sponge MAGNESIUM Aluminum impurity Silicothermic reduction
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Production of high-purity Mg metal from dolomite through novel molten salt electrolysis and vacuum distillation
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作者 Hyeong-Jun Jeoung Tae-Hyuk Lee +2 位作者 Jin-Young Lee Kyung-Woo Yi Jungshin Kang 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第4期1308-1320,共13页
In this study,a novel Mg production process for producing high-purity Mg metal from dolomite was developed.When the electrolysis of calcined dolomite was conducted using Cu cathode and C anode in MgF_(2)–LiF molten s... In this study,a novel Mg production process for producing high-purity Mg metal from dolomite was developed.When the electrolysis of calcined dolomite was conducted using Cu cathode and C anode in MgF_(2)–LiF molten salt at 1083–1173 K by applying an average current of 1.42–1.46 A for 9.50–21.0 h,the current efficiency of 66.4–88.6%was obtained.The produced Mg alloys consisted of MgCu_(2)and Cu(Mg)or MgCu_(2)and CuMg_(2)phases,depending on the Mg concentration in the Mg alloy.When the electrolysis of calcined dolomite was conducted in MgF_(2)–LiF–CaF_(2)molten salt at 1083 K,the current efficiency was 40.9–71.4%,owing to undesired reactions such as electroreduction of Ca^(2+)or/and CO_(3)^(2−)ions.Meanwhile,the current efficiency increased from 40.9%to 63.2%by utilizing a Pt anode,because the occurrence of CO_(3)^(2−)ions in the molten salt was prevented.After vacuum distillation of the obtained Mg alloys at 1300 K for 10 h,Mg metal with a purity of 99.9996–99.9998%was produced.Therefore,the feasibility of this novel process for the production of high-purity Mg metal from dolomite was demonstrated. 展开更多
关键词 high-purity magnesium DOLOMITE Magnesium oxide Electrolytic process Copper metal cathode Vacuum distillation
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Characteristics of Gold Mineralization at the Baguiomo Gold Panning Site, Koudougou Region, Burkina Faso, West Africa
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作者 Pascal Ouiya Aziz Fayçal Tarnagda Martial Eric Fozing 《Open Journal of Geology》 CAS 2024年第1期1-18,共18页
The Birimian Baguiomo formations are located in the northern part of the Boromo greenstone belt. In this belt, the volcanic rocks (tholeiitic basalt, calcalkaline basalt, andesite) hosting the gold mineralization are ... The Birimian Baguiomo formations are located in the northern part of the Boromo greenstone belt. In this belt, the volcanic rocks (tholeiitic basalt, calcalkaline basalt, andesite) hosting the gold mineralization are located in the Kwademen-Baguiomo shear zone. This mineralization, located only a few kilometers from the Kwademen gold deposit, is uncharacterized and, together with the latter, could constitute a gold potential capable of being economically exploitable. It is in this sense that this work is carried out with a view to characterizing the gold mineralization of the Baguiomo gold panning site. To carry out this work, we have made direct field measurements, combined with microstructures, and combined all this with data from geochemical rock analysis of the basalts that are the main host formations. Geochemical data show that tholeitic basalts formed from a mantle plume that was emplaced in an oceanic plateau context. Calc-alkaline basalts and andesites are comparable to Paleoproterozoic tholeitic basalts (PTH3), which are slightly enriched in light rare earths. Fertility tests show that these basalts concentrate between 3 and 6 ppb of gold at the time of accretion, which is sufficient for remobilization of this primary gold during the Eburnian orogeny to yield a deposit of around 4 - 5 Moz. Gold mineralization is associated with pyrite crystals when the latter are disseminated in the rock mass, whereas it is associated with hematite in quartz veins concordant with S1 shear deformation. It is mainly the pyrite crystals in the pressure shadows that contain the gold grains, whose development would be synchronous with micro-shear zone reactivation during the first phase of D1<sub>B</sub> deformation. The second phase of D2<sub>B</sub> deformation, which is a crenulation or fracture schistosity, does not significantly affect the shear deformation that controls mineralization. 展开更多
关键词 Kwademen-Baguiomo Shear Zone gold Panning Site gold Mineralization Eburnian Orogeny
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Assessing the Impact of Gold Mining on the Quality of Water Resources in the Commune of Meguet, Burkina Faso
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作者 Issoufou Ouedraogo Samuel Lankoande +3 位作者 Yacouba Konate Boukary Sawadogo Nicolas Kagambega Martin Lompo 《Journal of Water Resource and Protection》 CAS 2024年第4期281-292,共12页
Despite its often illegal nature, artisanal gold mining in Burkina Faso contributes to the economic and social development of the country. However, the rudimentary techniques used in gold panning have a significant im... Despite its often illegal nature, artisanal gold mining in Burkina Faso contributes to the economic and social development of the country. However, the rudimentary techniques used in gold panning have a significant impact on the environment due to inappropriate practices and the use of various chemical substances. This study aims to assess the impact of artisanal gold mining on the quality of water resources in a rural community at Méguet, Burkina Faso. To this end, surface and groundwater samples were collected and analyzed at the BUMIGEB laboratory. Field results show that the waters are slightly alkaline (6.97 < pH < 8.1), weakly mineralized and conductive (124 < EC < 543 μS/cm), with temperatures ranging from 24.6˚C to 31.6˚C. In addition, trace metals (TMEs) analyzed from surface and subsurface waters show very high levels, generally deviating from the levels recommended by WHO guidelines for Burkina Faso. Trace metals contamination of water resources in the commune of Méguet is mainly due to Fe (3.78 - 11.12 mg/kg), Hg (0.03 - 0.29 mg/kg), As (0.01- 6.31 mg/kg) and Pb (0.01 - 3.8 mg/kg). This study can serve as a basis for guiding national environmental policies to protect the water resources of the Méguet mine. 展开更多
关键词 gold Panning Water Quality Trace Metal Méguet Burkina Faso
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Discovery of scheelite in the Zaozigou gold deposit of West Qinling Orogen,Northwest China and its implications for ore genesis
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作者 Meng-xu Guo Jia-jun Liu +2 位作者 De-gao Zhai Guo-ming Weng Rui Zhu 《China Geology》 CAS CSCD 2024年第3期586-588,共3页
1.Objective The West Qinling Orogen extends east-west over 1500 km and is endowed with dozens of large-super large scale gold deposits.The Zaozigou gold deposit has a proven reserve of 134 t with an average grade of 3... 1.Objective The West Qinling Orogen extends east-west over 1500 km and is endowed with dozens of large-super large scale gold deposits.The Zaozigou gold deposit has a proven reserve of 134 t with an average grade of 3.08 g/t thus is one of the largest deposits in the West Qinling Orogen.However,whether the fluid type is metamorphic or magmatichydrothermal and ore-formation processes of the Zaozigou gold deposit are equivocal.Scheelite is a ubiquitous accessory mineral in geologically diverse ore-deposit types and attested to be a strong indicator of ore-forming conditions and oredeposit genesis. 展开更多
关键词 DEPOSIT gold QINLING
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Origin of the Yueguang gold deposit in Xinhua, Hunan Province, South China: insights from fl uid inclusion and hydrogen–oxygen stable isotope analysis
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作者 Hongxin Fan Qiang Wang +2 位作者 Yulong Yang Yao Tang Hao Zou 《Acta Geochimica》 EI CAS CSCD 2024年第2期235-254,共20页
The Yueguang gold deposit is located in Fengjia,Xinhua County,Hunan Province,South China.It represents a recently discovered small-scale gold deposit situated in the southwestern region of the Jiangnan Orogenic Belt,w... The Yueguang gold deposit is located in Fengjia,Xinhua County,Hunan Province,South China.It represents a recently discovered small-scale gold deposit situated in the southwestern region of the Jiangnan Orogenic Belt,west of the Baimashan granitic batholith.In order to discern the characteristics of the ore-formingfluids,the underlying mineralization processes,and establish a foundation for the origin of the Yueguang gold depositfluid inclusion micro-thermometry,as well as quartz hydrogen and oxygen isotope analysis,have been carried out on samples obtained from various stages of mineralization.The hydrothermal miner-alization stages within the Yueguang gold deposit can be categorized into three stages:(i)the barren,pre-ore quartz-pyrite stage(Stage Ⅰ),the quartz-pyrite-gold stage(Stage Ⅱ),and the post-ore quartz-carbonate stage(Stage Ⅲ),with the second stage being the main mineralization stage.Thefluid inclusions identified in samples from the main min-eralization stage can predominantly be described with the NaCl–H_(2)O and CO_(2)–NaCl–H_(2)O systems.These inclusions display homogenization temperatures ranging from 158.8 to 334.9℃,and thefluid salinity ranges from 0.3%to 4.0%(wt.%NaCl equiv.).Laser Raman spectroscopy analysis of individual inclusions further reveals the presence of gas-phases such as CO_(2),CH_(4),and N_(2).Isotopic analysis indicatesδ^(18)Ofluid values ranging from 3.95 to 6.7‰ and δDH_(2)O values ranging from-71.9 to-55.7‰.These results indi-cate that the ore-formingfluid of the Yueguang gold deposit belongs to metamorphic hydrothermalfluids of middle-low temperature and low salinity.In the process of ore formation,gold is transported in the form of Au(HS)2-complexes,with gold deposition being driven byfluid immiscibility.Therefore,the Yueguang gold deposit is categorized as an orogenic gold deposit dominated by metamorphic hydrother-malfluid.It may become a new target for gold exploration in the Baimashan region,central Hunan Province. 展开更多
关键词 Hunan province Yueguang gold deposit Fluid inclusions Hydrogen–oxygen isotopes Laser Raman Fluid immiscibility Orogenic gold deposit
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Structural Pattern Related to Gold Mineralization in the Essakane Area (Northern Burkina Faso, West African Craton)
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作者 Marc Desire Valea Benjamin Sawadogo +3 位作者 Kalidou Traoré Urbain Wenmenga Naba Seta Benjamin Allou 《Open Journal of Geology》 CAS 2024年第9期855-879,共25页
The finite deformation structures recorded in the Essakane area, located in the northeast corner of Burkina Faso, highlight three major compressive deformation phases, successively named D1, D2, and D3. The D1 event p... The finite deformation structures recorded in the Essakane area, located in the northeast corner of Burkina Faso, highlight three major compressive deformation phases, successively named D1, D2, and D3. The D1 event phase, trending NE-SW, is characterised by P1 folds and S1 axial plane schistosity. The D2 phase trending NW-SE is characterised by folds P2, schistosity (S2) and shear (C) planes. And the D3 phase trending NNE-SSW to N-S is characterised by P3 folds, crenulation microfolds and S3 spaced schistosity. It has also been noted that gold mineralizations are mainly hosted in quartz, carbonate, pyrite, and arsenopyrite veins. Structural interpretation indicates that these veins are organized into lenticular bodies that were formed during the first two deformation phases (D1 and D2). This suggests a strong structural control typical of orogenic gold concentrations. 展开更多
关键词 Burkina Faso Essakane Shear Zone Deformation Phases Orogenic gold
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Fast synthesis of gold nanoparticles by cold atmospheric pressure plasma jet in the presence of Au^(+) ions and a capping agent
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作者 Tatiana HABIB José Mauricio A.CAIUT Bruno CAILLIER 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第7期108-115,共8页
Homogeneous gold nanoparticles were synthesized under atmospheric pressure using a nonthermal helium plasma jet in a single-step process.A current power supply was used to generate the plasma discharge rich in diverse... Homogeneous gold nanoparticles were synthesized under atmospheric pressure using a nonthermal helium plasma jet in a single-step process.A current power supply was used to generate the plasma discharge rich in diverse reactive species.These species induce rapid chemical reactions responsible for the reduction of the gold salts upon contact with the liquid solution.In this study,spherical and monodispersed gold nanoparticles were obtained within 5 min of plasma exposure using a solution containing gold(Ⅲ)chloride hydrate(HAuCl_(4))as a precursor and polyvinylpyrrolidone(PVP)as a capping agent to inhibit agglomerations.The formation of these metal nanoparticles was initially perceptible through a visible change in the sample's color,transitioning from light yellow to a red/pink color.This was subsequently corroborated by UVvis spectroscopy,which revealed an optical absorption in the 520-550 nm range for Au NPs,corresponding to the surface plasmon resonance(SPR)band.An investigation into the impact of various parameters,including plasma discharge duration,precursor and capping agent concentrations,was carried out to optimize conditions for the formation of well-separated,spherical gold nanoparticles.Dynamic light scattering(DLS)was used to measure the size of these nanoparticles,transmission electron microscopy(TEM)was used to observe their morphology and X-ray diffraction(XRD)was also employed to determine their crystallographic structure.The results confirm that homogeneous spherical gold nanoparticles with an average diameter of 13 nm can be easily synthesized through a rapid,straightforward,and environmentally friendly approach utilizing a helium atmospheric pressure plasma. 展开更多
关键词 gold nanoparticles NON-THERMAL plasma jet HELIUM DBD
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Multi-Scale Approach for Gold Targeting in Côte d’Ivoire Paleoproterozoic Rocks
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作者 Martial Pohn Koffi Adingra Yao Augustin Koffi +3 位作者 N’guessan Nestor Houssou Zié Ouattara Tokpa Kakeu Lionel-Dimitri Boya Marc Ephrem Allialy 《Open Journal of Geology》 CAS 2024年第2期155-176,共22页
The aim of this study is to contribute to better targeting of gold prospecting areas using geospatial information. To this end, 3 mining sites were selected for the study. They are: the Sénoufo belt (Barrick Gold... The aim of this study is to contribute to better targeting of gold prospecting areas using geospatial information. To this end, 3 mining sites were selected for the study. They are: the Sénoufo belt (Barrick Gold mine), the Yaouré complex (Perseus Mining mine) and the South Fetêkro belt (Bonikro, Hiré and Agbaou mines). For this study, a multi-scale approach was carried out at regional, mine and microscopic levels. At the regional scale, a comparative analysis of 1:200,000 scale geological maps revealed that 3 main lithologies are regularly repeated on and around the various mining sites. These are: undifferentiated volcanics, metagranodiorites and metasiltites dominated by meta-arenites. Most of these lithologies are affected by undifferentiated faults generally oriented NE-SW, N-S, ENE-WSW and WNW-ESE. In addition, gold and manganese occurrences are present on all the sites studied. At the mine scale, radarsat-1 images processing indicate that the main mining sites are generally located near or at the intersection of lineaments-oriented NE-SW or N-S on the one hand and E-W or ENE-WSW or WNW-ESE or again NW-SE on the other. These mines are also located at the interface between zones of high and low lineament density. At the microscopic scale, petrographic studies of undifferentiated volcanic samples from the various sites indicate that they consist of andesites, meta-andesites and tuffs. 展开更多
关键词 gold Targeting Undifferentiated Volcanics Mineral Occurrences LINEAMENTS Côte d’Ivoire
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Tamping the movement of the laser absorption cutoff position using gold foam hohlraum
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作者 张璐 李丽灵 +14 位作者 林稚伟 董云松 景龙飞 郑建华 况龙钰 黎航 郑金华 张继彦 宋天明 张志宇 赵阳 牛高 杨冬 杨家敏 丁永坤 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第5期56-61,共6页
In indirect-driven laser fusion experiments,the movement of the laser absorption layer will distort the radiation uniformity on the capsule.The gold foam has advantages in symmetry control and lowering wall plasma blo... In indirect-driven laser fusion experiments,the movement of the laser absorption layer will distort the radiation uniformity on the capsule.The gold foam has advantages in symmetry control and lowering wall plasma blowoff when used in an inertial confinement fusion(ICF)hohlraum.This work investigates the motion of the laser absorption cutoff position using lowdensity foam gold walls.It is found that the motion of the laser absorption cutoff position can be significantly mitigated through optimal initial low density,tailored to a specific laser shape.For a short square laser pulse,the laser absorption cutoff position remains almost stationary at an initial density of approximately 0.6 g cm^(-3).For a long-shaped laser pulse,the minimal motion of the laser absorption cutoff position is observed at an initial density of about 0.1 g cm^(-3).This approach allows for the adjustment of the symmetry of the hohlraum radiation source.The insights gained from this study serve as a crucial reference for optimizing the hohlraum wall density. 展开更多
关键词 hohlraum symmetry laser absorption plasma blowoff gold foam
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Industrial utilization of arsenic-containing gold dressing tailings as pellet prepared by straight grate process
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作者 LIU Wei GUO Zheng-qi +5 位作者 ZHU De-qing PAN Jian ZHANG Wu-ju WANG Jin ZHANG Ying-qun YIN Fu-xing 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第6期1888-1899,共12页
The utilization of arsenic-containing gold dressing tailings is an urgent issue faced by gold production companies worldwide.The thermodynamic analysis results indicate that ferrous arsenate(FeAsO_(4)),pyrite(FeS_(2))... The utilization of arsenic-containing gold dressing tailings is an urgent issue faced by gold production companies worldwide.The thermodynamic analysis results indicate that ferrous arsenate(FeAsO_(4)),pyrite(FeS_(2))and sodium cyanide(NaCN)in the arsenic-containing gold metallurgical tailings can be effectively removed using straight grate process,and the removal of pyrite and sodium cyanide is basically completed during the preheating stage,while the removal of ferrous arsenate requires the roasting stage.The pellets undergo a transformation from magnetite to hematite during the preheating process,and are solidified through micro-crystalline bonding and high-temperature recrystallization of hematite(Fe_(2)O_(3))during the roasting process.Ultimately,pellets with removal rates of 80.77% for arsenic,88.78% for sulfur,and 99.88% for cyanide are obtained,as well as the iron content is 61.1% and the compressive strength is 3071 N,meeting the requirements for blast furnace burden.This study provides an industrially feasible method for treating arsenic-containing gold smelting tailings,benefiting gold production enterprises. 展开更多
关键词 arsenic-containing gold dressing tailings pelletizing straight grate process recycling
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Land Use and Land Cover Dynamics in the Eseka Alluvial Gold Mining District, Centre Region, Cameroon
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作者 Shu Vejiline Lum-Ndob Fonge Beatrice Ambo +3 位作者 Ambe Godlove Neba Ateh Kevin Ijunghi Enerst Tata Cheo Emmanuel Suh 《Journal of Geographic Information System》 2024年第4期289-305,共17页
Local populations in Cameroon thrive on forest resources and the flow of ecosystem services they provide are pivotal in sustaining national economy, improving people’s lives, safeguarding biodiversity, and mitigating... Local populations in Cameroon thrive on forest resources and the flow of ecosystem services they provide are pivotal in sustaining national economy, improving people’s lives, safeguarding biodiversity, and mitigating the impacts of environmental changes. The exploitation of these resources invariably leads to deforestation and forest degradation. This study was designed to evaluate land use land cover change (LULCC) in the Eseka alluvial gold mining district with the aid of Landsat images. In the investigation of forest cover change, four Landsat satellite images for (1990, 2002, 2015 and 2022) were used. Ground-truthing also helped to identify the activities carried out by the local population and to determine agents, drivers and pressures of land use and land cover change. Four main land cover classes namely: forest, agricultural land, settlement/mining camps and water bodies were selected. Between 1990 and 2022, the proportion of forest decreased from 98% to 34% while those of agricultural land and settlement/mining camps increased from 2% to 60% and 0.54% to 6% respectively. Analysis showed ongoing deforestation with forest cover loss of ~98,263 ha in 32 years giving a cover change percentage of 63.94%. Kappa coefficient for the study period ranged from 0.92 to 0.99. Forest cover loss could be attributed to farming activities, wood extraction and alluvial gold mining activities. Economic motives notably the need to increase household income from a frequent demand for farm and wood products in neighbouring towns and the quest for gold were the main drivers of these activities. Hence, this study assesses the impact of human activities from the mining sector on the forest ecosystem in a bid to inform mitigation policies. 展开更多
关键词 Land Use and Land Cover Changes BIODIVERSITY Alluvial gold Mining DRIVERS Landsat Images Ground-Truthing MITIGATION
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A Single-chain Antibody for One-pot Fabrication of Luminescent Gold Nanoclusters and Rabies Virus Imaging in Cells
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作者 ZHANG Chunxia XI Hualong +4 位作者 SUN Bo WU Yongge JIANG Chunlai YU Xianghui WU Yuqing 《发光学报》 EI CAS CSCD 北大核心 2024年第10期1732-1740,共9页
The fragile antibody leads to a great challenge as a scaffold to fabricate the luminescent metal nanoclusters using one-pot method.This study presents a stable single-chain anti-body(scFv57R-ATS)for the fabrication of... The fragile antibody leads to a great challenge as a scaffold to fabricate the luminescent metal nanoclusters using one-pot method.This study presents a stable single-chain anti-body(scFv57R-ATS)for the fabrication of luminescent gold nanoclusters(AuNCs@scFv57R-ATS)and a quick,sensitive rabies virus detection in living cells.In this paper,AuNCs@scFv57R-ATS was designed to specifically recognize antigen RV in modified HeLa cells,which promoted the demonstration of metal nanocluster fluorescent probes for antigen targeting and therapy. 展开更多
关键词 gold nanoclusters scFv57R-ATS rabies virus
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