Plasmonic gold nanoflowers(AuNFs)exhibit considerable potential in wound repair therapy due to their excellent photothermal conversion capability,high surface area,and multi-enzyme activities.However,the intrinsic pro...Plasmonic gold nanoflowers(AuNFs)exhibit considerable potential in wound repair therapy due to their excellent photothermal conversion capability,high surface area,and multi-enzyme activities.However,the intrinsic pro-oxidative properties of AuNFs limit their therapeutic efficacy in diabetic wound treatment.To overcome this limitation,a near-infrared plasmonic Au@CDCe nanohybrid system that can enhance antioxidative performance through the synergistic effects of localized surface plasmon resonance-induced photothermal effect and hot electrons is developed.Specifically,AuNFs serve as near-infrared plasmonic exciters,generating hot electrons that are efficiently transferred to cerium-doped carbon dots(CDCe).Combined with mild photothermal effects,these processes synergistically enhance hydroxyl radical scavenging activity,as well as superoxide dismutase-and catalase-mimicking activities.In vitro experiments demonstrate that Au@CDCe effectively protects cells from oxidative damage,and promotes cell proliferation and migration.In vivo evaluations confirm its ability to modulate the immune microenvironment and accelerate diabetic wound healing.This work establishes a new paradigm for modulating the oxidative stress microenvironment through antioxidant gold-based plasmonic nanozymes and provides novel insights into tuning of prooxidant nanozyme into plasmon-enhanced antioxidant nanozyme.展开更多
“Are you dead?”It's not a morbid joke-it's the literal translation of the name of Chinese app Sileme,which went viral around the country in early January.However,amid public controversy over its unsettling c...“Are you dead?”It's not a morbid joke-it's the literal translation of the name of Chinese app Sileme,which went viral around the country in early January.However,amid public controversy over its unsettling connotations,the development team rebranded the app as Demumu on January 14,be-fore it was removed from the app stores of Apple and Android on January 15.展开更多
The Linglong gold ore field is situated in the northwestern region of the Jiaodong gold province,China,with over 1000 tons of gold resources.Although the metallogenic mechanism and fluid sources of the Linglong gold d...The Linglong gold ore field is situated in the northwestern region of the Jiaodong gold province,China,with over 1000 tons of gold resources.Although the metallogenic mechanism and fluid sources of the Linglong gold deposit have been the subject of extensive discussion and analyzed by numerous scholars,a definitive conclusion remains elusive.The Jiuqu Au deposit is a significant metallogenic area in the eastern part of the Linglong gold ore field,characterized as a quartz vein-type gold deposit.Gold mineralization in the Jiuqu gold deposit is classified into four stages,primarily occurring within the Late Jurassic Linglong granite and Early Cretaceous Guojialing granodiorite.Pyrite,the primary gold-bearing mineral at the Jiuqu Gold Mine,has been present throughout the metallogenic period,is rich in a variety of trace elements and is closely related to the formation of gold ore.This study focused on evaluating pyrite from the essential metallogenic stages(Stages Ⅰ-Ⅲ)of the Jiuqu gold deposit using scanning electron microscopy(SEM),electron microprobe analysis(EMPA),laser ablation inductively coupled plasma mass spectrometry(LA-ICP-MS) and laser ablation multi-collector inductively coupled plasma mass spectrometry(LA-MC-ICP-MS) sulfur isotope analysis and detection.The work aimed to reconstruct the origin of metallogenic materials and the evolution of ore-forming fluids and to restrict the genesis of the deposit.Pyrite exhibits discernible alterations in both shape and crystal structure as it progresses through its ore-forming stages.The aforementioned stages can be delineated as follows:type 1 pyrite(PyⅠ),developed in the initial ore stage,is characterized by coarse-to-medium-grained euhedral pyrite in Stage Ⅰ;type 2 pyrite(PyⅡ),developed in the second ore stage,appears during the middle stage of mineralization and is characterized by subhedral or anhedral pyrite;type 3 pyrite(PyⅢ),developed in the third ore stage,primarily occurred in the late-middle stages of mineralization.It is fragmented and coexists with various metal sulfides,including chalcopyrite,sphalerite and galena.The in situ major and elemental compositions of pyrites at Jiuqu indicate that Au,in the form of visible gold,exists in pyrites with low Au and Ag contents throughout all stages.PyⅠ had lower Pb,Bi,Co and Ni contents than those of PyⅡ.PyⅢ displayed decreased Pb,Bi,Co and Ni levels compared with PyⅡ.The δ34S values of the PyⅠ,PyⅡ and PyⅢ pyrite stages ranged from 7.19% to 8.71%,6.24% to 7.68% and 7.66% to 8.07%,respectively.According to the structural and geochemical analysis of pyrite,the ore-forming fluid of the Jiuqu gold deposit was derived from a magmatic-hydrothermal formation created by enriched lithospheric mantle-derived magma,mixing S from Precambrian metamorphic rocks.Previous studies on the H-O isotopes of quartz in the region's ores have indicated the presence of primary magma water.Additionally,studies concerning the C-O isotopes of carbonate minerals in ores have suggested that C may have originated from the mantle.Fluid migration and water-rock interaction resulted in sulfide and gold precipitation.In the Late Meosozoic,lithospheric thinning of eastern North China Craton led to up welling of astheno spheric mantle and partial melting of lithospheric mantle in the Jiaodong area.Under tectonic changes,magmatic-hydro thermal fluid migrated upward along fault structures to form a gold province.展开更多
The microscopy and scanning electronic microscopy （SEM） were used to study the gold occurrence of Jiaojia gold mine, Shandong province. The results show that the gold-bearing minerals are composed of pyrite, chalcop...The microscopy and scanning electronic microscopy （SEM） were used to study the gold occurrence of Jiaojia gold mine, Shandong province. The results show that the gold-bearing minerals are composed of pyrite, chalcopyrite, gangue, sphalerite and galena. 77.12% of gold minerals are the sulphides and 22.88% are the gangues. The gold occurrence is composed of 60.28% fissure gold, 21.63% inclusion gold and 18.09% crystal fractured gold. The morphology of gold mineral is composed of sphere, triangle, rectangle, strip and erose. The Jiaojia gold mineral owns large grain size range from 3-5 μm to 100 μm. 1.5% of gold grains is more than 0.104 mm, 5.26% is 0.074-0.104 mm, 23.31% is 0.043-0.074 mm, 3.76% is 0.043-0.037 mm and 64.29% is less than 0.037 mm. The occurrence of gold mineral is composed of native gold, electrum, native silver, iron-bearing native silver, goldcuprid and acanthite. Electrum is the most important mineral, accounting for 71.56%. The average quality is 641.26‰ for gold and silver mineral.展开更多
Despite the high amount of scientific work dedicated to the gold nanoparticles in catalysis, most of the research has been performed utilising supported nanoparticles obtained by traditional impreg‐nation of gold sal...Despite the high amount of scientific work dedicated to the gold nanoparticles in catalysis, most of the research has been performed utilising supported nanoparticles obtained by traditional impreg‐nation of gold salts onto a support, co‐precipitation or deposition‐precipitation methods which do not benefit from the recent advances in nanotechnologies. Only more recently, gold catalyst scien‐tists have been exploiting the potential of preforming the metal nanoparticles in a colloidal suspen‐sion before immobilisation with great results in terms of catalytic activity and the morphology con‐trol of mono‐and bimetallic catalysts. On the other hand, the last decade has seen the emergence of more advanced control in gold metal nanoparticle synthesis, resulting in a variety of anisotropic gold nanoparticles with easily accessible new morphologies that offer control over the coordination of surface atoms and the optical properties of the nanoparticles （tunable plasmon band） with im‐mense relevance for catalysis. Such morphologies include nanorods, nanostars, nanoflowers, den‐dritic nanostructures or polyhedral nanoparticles to mention a few. In addition to highlighting newly developed methods and properties of anisotropic gold nanoparticles, in this review we ex‐amine the emerging literature that clearly indicates the often superior catalytic performance and amazing potential of these nanoparticles to transform the field of heterogeneous catalysis by gold by offering potentially higher catalytic performance, control over exposed active sites, robustness and tunability for thermal‐, electro‐and photocatalysis.展开更多
In the Fatira(Abu Zawal)mine area,located in the northern Eastern Desert of Egypt,fieldwork and mineralogical analysis,integrated with machine learning techniques applied to Landsat-8 OLI,ASTER,and Sentinel-2 multi-sp...In the Fatira(Abu Zawal)mine area,located in the northern Eastern Desert of Egypt,fieldwork and mineralogical analysis,integrated with machine learning techniques applied to Landsat-8 OLI,ASTER,and Sentinel-2 multi-spectral imagery(MSI)data delineate gold-sulfide mineralization in altered rocks.Gold(Au)anomalies in hydrothermal breccias and quartz veins are associated with NE-oriented felsite dykes and silicified granitic rocks.Two main alteration types are identified:a pyrite-sericite-quartz and a sulfide-chlorite-carbonate assemblage,locally with dispersed free-milling Au specks.Dimensionality reduction techniques,including principal component analysis(PCA)and independent component analysis(ICA),enabled mapping of alteration types.Sentinel-2 PC125 composite images offered efficient lithological differentiation,while supervised classifications,i.e.,the support vector machine(SVM)of Landsat-8 yielded an accuracy of 88.55%and a Kappa value of 0.86.ASTER mineral indices contributed to map hydrothermal alteration mineral phases,including sericite,muscovite,kaolinite,and iron oxides.Results indicate that post-magmatic epigenetic hydrothermal activity significantly contributed to the Au-sulfide mineralization in the Fatira area,distinguishing it from the more prevalent orogenic gold deposits in the region.展开更多
Based on the properties of antimony(Sb)and arsenic(As),a method was proposed to enhance gold recovery during iron matte smelting.The impact of Sb and As on gold enhancement capture was investigated using an exclusion ...Based on the properties of antimony(Sb)and arsenic(As),a method was proposed to enhance gold recovery during iron matte smelting.The impact of Sb and As on gold enhancement capture was investigated using an exclusion method.The results demonstrated that both Sb and As significantly improved the gold recovery rate.As the Sb or As content increased,the gold recovery rate increased.The enhancement effect of Sb was better than that of As,and the optimal results were achieved through the synergistic effects of Sb and As.Under optimized conditions,the gold recovery rate reached 97.12%,whereas the gold content in the slag decreased to 1.70 g/t.Sb captured and aggregated free gold as an Au-Sb alloy,whereas As-Fe alloy also captured free gold.The growth of the gold-captured phase size enhanced the settling velocity,thereby promoting gold recovery.展开更多
The world-class Jiaodong gold province in the North China Craton hosts over 5000 t of Au resource and is characterized by abundant visible gold mineralization.However,the critical processes controlling the formation o...The world-class Jiaodong gold province in the North China Craton hosts over 5000 t of Au resource and is characterized by abundant visible gold mineralization.However,the critical processes controlling the formation of visible gold in this province remain poorly understood.To solve this problem,integrated microtextural,trace elemental,and sulfur isotopic analyses of pyrite from the high-grade Linglong gold deposit in the Jiaodong gold province were conducted in this study.Two distinct pyrite types were identified within auriferous quartz-sulfide veins:(1)Py1 aggregates in quartz-pyrite veins(hydrothermal stageⅡ),and(2)euhedral to subhedral,coarse-grained Py2 crystals in quartz-polymetallic sulfide veins(hydrothermal stageⅢ).Microtextural and elemental analyses revealed that visible gold predominantly occurs as intergranular particles between primary pyrite crystals within Py1 aggregates.The Py1 exhibits complex microtextures with abundant mineral inclusions of polymetallic sulfides and has low concentrations of Au(median:0.032 ppm)with a narrowδ^(34)S range(4.86‰-6.75‰),indicative of rapid crystallization under unstable,disequilibrium conditions.By contrast,the Py2 is texturally homogeneous and contains higher Au concentrations(median:0.304 ppm)with progressively increasingδ^(34)S values(5.25‰-10.14‰)over time,suggesting slow crystal growth under more stable,near-equilibrium conditions.Based on the microtextural and geochemical information,it is proposed that fluid boiling occurred only during the hydrothermal stage Ⅱ,which resulted in the unstable physicochemical environment and rapid deposition of gold.During the boiling processes,gold colloids likely occurred and promoted the formation of visible gold.展开更多
Cyanide is the most widely used reagent in gold production processes. However, cyanide is highly toxic and poses safety haz-ards during transportation and use. Therefore, it is necessary to develop gold leaching reage...Cyanide is the most widely used reagent in gold production processes. However, cyanide is highly toxic and poses safety haz-ards during transportation and use. Therefore, it is necessary to develop gold leaching reagents that can replace cyanide. This paper intro-duces a method for synthesizing a gold leaching reagent. Sodium cyanate is used as the main raw material, with sodium hydroxide and so-dium ferrocyanide used as additives. The gold leaching reagent can be obtained under the conditions of a mass ratio of sodium cyanate,sodium hydroxide, and sodium ferrocyanide of 15:3:1, synthesis temperature of 600℃, and synthesis time of 1 h. This reagent has a goodrecovery effect on gold concentrate and gold-containing electronic waste. The gold leaching rate of roasted desulfurized gold concentratecan reach 87.56%. For the extraction experiments of three types of gold-containing electronic waste, the gold leaching rate can reach over90% after 2 h. Furthermore, the reagent exhibits good selectivity towards gold. Component analysis indicates that the effective compon-ent in the reagent could be sodium isocyanate.展开更多
Gold Cross,a Thai company specializing in herbal oils,has long combined Thailand’s traditional medicine with modern technology to deliver highquality health products.Invited by the China-ASEAN Expo(CAEXPO),the head o...Gold Cross,a Thai company specializing in herbal oils,has long combined Thailand’s traditional medicine with modern technology to deliver highquality health products.Invited by the China-ASEAN Expo(CAEXPO),the head of Gold Cross arrived at the exhibition hall with a mix of anticipation and slight anxiety and the company’s signature product in tow—Gold Cross yellow oil.Made with a unique Golden Cross traditional formula and infused with natural herbal extracts,the oil relieves muscle aches,insect bites,and dizziness.In Thailand,it is a household name and widely regarded as an all-purpose herbal remedy.At the expo booth,a Chinese buyer was pleasantly surprised after trying it.展开更多
The Jiaodong gold deposits are currently the most important gold resources（with Au reserves of〉4000 t） in China,and the leading gold-producing country globally（with Au production of ～428 t in2013）.Jiaodong is al...The Jiaodong gold deposits are currently the most important gold resources（with Au reserves of〉4000 t） in China,and the leading gold-producing country globally（with Au production of ～428 t in2013）.Jiaodong is also considered as perhaps the only world-class to giant gold accumulation on the planet where relatively young gold ores（ca.130-120 Ma） were deposited in rocks that are 2 Ga older.The Xincheng world-class high-grade gold deposit,with a proven reserve of 〉200 t gold,is one of the largest deposits in the giant gold province of the Jiaodong Peninsula.It is located in the northwestern part of the jiaobei Uplift,and hosted by ca.132-123 Ma Xincheng quartz monzonites and monzogranites.Ore zones are structurally controlled by the NE-trending and NW-dipping Jiaojia Fault and subsidiary faults,and are mainly restricted to the footwall of the fault.The dominant disseminated- and stockworkstyle ores are associated with strong sericitization,silicification,sulfidation and K-feldspathization,and minor carbonate wallrock alteration halos.The four mineralization stages are pyrite-quartz-sericite（stage 1）,quartz-pyrite（stage 2）,quartz-polysulfide（stage 3） and quartz-carbonate（stage 4）.Gold occurs dominantly as electrum,with lesser amounts of sulfide-hosted native gold and rare native silver and argentite,normally associated with pyrite,chalcopyrite,galena and sphalerite：the latter with proven resources of about 105 t Ag,713 t Cu,and 5100 t S.There are three types of ore-related fluid inclusions：type 1 aqueous-carbonate（H2O-CO2）,type 2aqueous（liquid H2O＋vapor H2O）,and type 3 CO2（liquid CO2 and vapor CO2） inclusions.Homogenization temperatures range from 221 to 304℃ for type 1 inclusions,with salinities of 2.4-13.3 wt.%NaCl eq.,and bulk densities of 0.858-1.022 g/cm～3.The δ～（34）S（CDT） values of hydrothermal sulfides are 4.3-10.6‰and δ～（18）O values of hydrothermal quartz have a median value of 13.0‰.δD values of fluid inclusions in hydrothermal quartz have a median value of-75‰.Calculated δ～（18）Owater has a median value of 5.2‰.The timing of gold mineralization at the Xincheng gold deposit is younger than 123±1 Ma,and likely between 120.9 and 119.9 Ma.A minerals system genetic model for the probable epizonal orogenic Xincheng deposit suggests an initial medium temperature,CO2-rich,and low salinity H2O-CO2 deeply sourced metamorphic ore fluid associated with dehydration and decarbonization of subducting Paleo-Pacific lithosphere.The Jiaojia Fault constrained the migration of ore-forming fluids and metals at the brittle-ductile transition.Fluid immiscibility,caused by episodic pressure drops,led to significant high-grade gold deposition in the giant Xincheng gold deposit.展开更多
It is quite evident that it is not anomalous metal transport,nor unique depositional conditions,nor any single factor at the deposit scale,that dictates whether a mineral deposit becomes a giant or not.A hierarchical ...It is quite evident that it is not anomalous metal transport,nor unique depositional conditions,nor any single factor at the deposit scale,that dictates whether a mineral deposit becomes a giant or not.A hierarchical approach thus is required to progressively examine controlling parameters at successively decreasing scales in the total mineral system to understand the location of giant gold deposits in non-arc environments.For giant orogenic,intrusion-related gold systems（IRGS） and Carlin-type gold deposits and iron oxide-copper-gold（IOCG） deposits,there are common factors among all of these at the lithospheric to crustal scale.All are sited in giant gold provinces controlled by complex fundamental fault or shear zones that follow craton margins or,in the case of most Phanerozoic orogenic giants,define the primary suture zones between tectonic terranes.Giant provinces of IRGS,IOCG,and Carlin-type deposits require melting of metasomatized lithosphere beneath craton margins with ascent of hybrid lamprophyric to granitic magmas and associated heat flux to generate the giant province.The IRGS and IOCG deposits require direct exsolution of volatile-rich magmatic-hydrothermal fluids,whereas the association of such melts with Carlin-type ores is more indirect and enigmatic.Giant orogenic gold provinces show no direct relationship to such magmatism.forming from metamorphic fluids,but show an indirect relationship to lamprophyres that reflect the mantle connectivity of controlling first-order structures.In contrast to their province scale similarities,the different giant gold deposit styles show contrasting critical controls at the district to deposit scale.For orogenic gold deposits,the giants appear to have formed by conjunction of a greater number of parameters to those that control smaller deposits,with resultant geometrical and lithostratigraphic complexity as a guide to their location.There are few giant IRGS due to their inferior fluid-flux systems relative to orogenic gold deposits,and those few giants are essentially preservational exceptions.Many Carlin-type deposits are giants due to the exceptional conjunction of both structural and lithological parameters that caused reactive and permeable rocks,enriched in syngenetic gold,to be located below an impermeable cap along antiformal ＂trends＂.Hydrocarbons probably played an important role in concentrating metal.The supergiant Post-Betze deposit has additional ore zones in strain heterogeneities surrounding the pre-gold Goldstrike stock.All unequivocal IOCG deposits are giant or near-giant deposits in terms of gold-equivalent resources,partly due to economic factors for this relatively poorly understood,low Cu-Au grade deposit type.The supergiant Olympic Dam deposit,the most shallowly formed deposit among the larger IOCGs,probably owes its origin to eruption of volatile-rich hybrid magma at surface,with formation of a large maar and intense and widespread brecciation,alteration and Cu-Au-U deposition in a huge rock volume.展开更多
The Neoarchaean Kaigoorlie Gold Field contains the giant Golden Mile and world-class Mt Charlotte deposits,which have been the subject of much research for over 100 years.The Golden Mile deposit is a complex array of ...The Neoarchaean Kaigoorlie Gold Field contains the giant Golden Mile and world-class Mt Charlotte deposits,which have been the subject of much research for over 100 years.The Golden Mile deposit is a complex array of ductile to brittle vein and breccia lodes that are predominantly hosted in the highlyfractionated Golden Mile Dolerite sill.The Fimiston lodes comprise an array of narrow lodes that evolved broadly syn- to late-formation of the regional D2 NW-trending foliation.The lodes are characterized by pyrite veinlets and disseminations,quartz veinlets and breccias,and banded quartz-carbonate veins with sericite,carbonate,and pyrite-dominated alteration.Bonanza Green-Leader,or Oroya-style,lodes,with grades in excess of 1000 g/t Au,are similar to the Fimiston-style lodes,but are characterized by abundant visible gold,native tellurium and more abundant telluride minerals within roscoelitebearing alteration zones.The arguably structurally younger Mt Charlotte-style lodes are characterized by a pipe-shaped,coarse-grained quartz,carbonate and scheelite vein-stockwork with distinct verticallyzoned,carbonate-sericite-albite-pyrite ± pyrrhotite dominant alteration assemblages around veins within Unit 8 of the Golden Mile dolerite and porphyry dykes.The network of steep- and gently-dipping extension and shear fracture-fill veins are associated with NE-trending fault se ts that cross cut the regional NW-trend.The deposit area is intruded by swarms of porphyry dykes,including syn-volcanic mafic dykes,early and volumetrically most significant c.2.67 Ga feldspar-phyric porphyry dykes,as well as later c.2.66-2.65 Ga calc-alkaline hornblende-phyric dykes associated with younger c.2.65-2.64 Ga lamprophyre dykes.All post-volcanic dykes have similar orientations to the Fimiston lodes.The feldspar dykes are clearly overprinted by all styles of mineralization,although the relationship between hornblende-phyric and lamprophyre dykes and gold mineralization is more ambiguous.Most agree that gold mineralization was post-peak regional metamorphism of host rocks,although its relative structural timing is controversial.Direct timing constraints on gold mineralization indicate that Fimiston- and Mt Charlotte-style mineralization formed within a relative short period of time around 2.64 Ga,and,as such,support a model of progressive deformation of a Theologically heterogeneous rock package late in the structural history.Fluid characteristics,combined with the structural,metamorphic and absolute timing,support description of gold mineralization at the Golden Mile as orogenic and mesozonal,and this allows direct correlation with orogenic gold deposits worldwide,which classically formed during accretion along convergent margins throughout Earth history.展开更多
Gold ores in the Jiaozhou region of China are characterized by their abundant reserves,low grade,fine dissemination,and chal-lenges in upgrading.Froth flotation,with xanthate as the collector,is a commonly employed me...Gold ores in the Jiaozhou region of China are characterized by their abundant reserves,low grade,fine dissemination,and chal-lenges in upgrading.Froth flotation,with xanthate as the collector,is a commonly employed method for enriching auriferous pyrite from these ores.This study aimed to develop a more efficient flotation process by utilizing cavitation nanobubbles for a low-grade gold ore.Batch flotation tests demonstrated that nanobubbles significantly enhanced the flotation performance of auriferous pyrite,as evidenced by improved concentrate S and Au grades and their recoveries.The mechanisms underlying this enhancement were explored by investigat-ing surface nanobubble(SNB)formation,bulk nanobubble(BNB)attachment to hydrophobic pyrite surfaces,and nanobubble-induced agglomeration using atomic force microscopy(AFM)and focused beam reflectance measurement(FBRM).The results revealed that nan-obubble coverage on the pyrite surface is a critical factor influencing surface hydrophobicity and agglomeration.SNBs exhibited higher coverage on pyrite surfaces with increased surface hydrophobicity,flow rate,and cavitation time.Similarly,BNB attachment on pyrite surfaces was significantly increased with surface hydrophobicity and cavitation time.Enhanced surface hydrophobicity,along with higher flow rates and cavitation times,promoted pyrite particle agglomeration owing to the increased nanobubble coverage,ultimately leading to improved flotation performance.展开更多
One of the major challenges in the application of microbially induced carbonate precipitation(MICP)is achieving"bacteria freedom",as it necessitates a substantial volume of bacterial solutions.Nevertheless,b...One of the major challenges in the application of microbially induced carbonate precipitation(MICP)is achieving"bacteria freedom",as it necessitates a substantial volume of bacterial solutions.Nevertheless,both insitu bacterial cultivation and transportation of bacterial solutions have proven to be inefficient.In this study,we suggested the utilization of bacteria in the form of dry powder,enabling easy on-site activation and achieving a relatively high urease activity.We conducted MICP curing experiments on gold mine tailings(GMT)using steel slag(SS)as an additive.The results showed that the average unconfined compressive strength(UCS)values of the tailings treated with MICP and MICP+SS reached 0.51 and 0.71 MPa,respectively.In addition,the average leaching reduction rates of Cu,Pb,Cr,Zn,and T-CN in GMT after MICP treatment reached 98.54%,100%,70.94%,59.25%,and 98.02%,respectively,and the average reduction rates after MICP+SS treatment reached 98.77%,100%,88.03%,72.59%,and 98.63%,respectively.SEM,XRD,FT-IR analyses,and ultra-deep field microscopy results confirmed that the MICP treatment produced calcite-based calcium carbonate that filled the inter-tailing pores and cemented them together,and the hydration mechanism was the main reason for the increased curing efficiency of SS.Our research findings demonstrate that bacterial powder can efficiently achieve the objectives of heavy metal removal and tailing solidification.This approach can substantially de-crease the expenses associated with bacterial cultivation and solution transportation,thereby playing a crucial role in advancing the practical implementation of MICP.展开更多
A new gold self-relay catalytic annulation/nucleophilic substitution cascade of 1,3-enyne acetates with cyclic ether acetals is reported,enabling highly diastereoselective access to cyclic etherified cyclopentenones w...A new gold self-relay catalytic annulation/nucleophilic substitution cascade of 1,3-enyne acetates with cyclic ether acetals is reported,enabling highly diastereoselective access to cyclic etherified cyclopentenones with cyclic quaternary centers in moderate to good yields and>19∶1 dr.This catalysis enables the direct construction of two types of carboncyclic skeletons by adjusting the olefin types of 1,3-enyne acetates.When 1,3-enyne acetates bearing a cyclic alkene unit were used,5~6 fused bicarbocyclic products were diastereoselectively synthesized,whereas the reaction of acyclic 1,3-enyne acetates resulted in five-memebered carbocyclic framework.Notably,cyclic ether acetals are commonly used as protecting groups in traditional multistep organic syntheses,and in this reaction,such reagents serve as electrophilic cyclic ether precursors,achieving new uses for old reagents.The current method demonstrates good functional group compatibility,a broad substrate scope and high diastereoselectivity,providing a new synthetic strategy toward functionalized cyclopentenones.展开更多
基金supported by the National Natural Science Foundation of China(No.32401110)Hainan Provincial Science and Technology Special Fund(No.ZDYF2025SHFZ020)+3 种基金Hainan Provincial Natural Science Foundation of China(No.525RC703)Scientific Research Project of Hainan University Collaborative Innovation Center(No.XTCX2022STC12)part of a project RENOVATE that has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement(No.101227121)Wellcome Trust-Translational Partnership Award,UCL Regenerative Medicines TIN Pilot Dara Fund(No.214046/Z/18/Z).
文摘Plasmonic gold nanoflowers(AuNFs)exhibit considerable potential in wound repair therapy due to their excellent photothermal conversion capability,high surface area,and multi-enzyme activities.However,the intrinsic pro-oxidative properties of AuNFs limit their therapeutic efficacy in diabetic wound treatment.To overcome this limitation,a near-infrared plasmonic Au@CDCe nanohybrid system that can enhance antioxidative performance through the synergistic effects of localized surface plasmon resonance-induced photothermal effect and hot electrons is developed.Specifically,AuNFs serve as near-infrared plasmonic exciters,generating hot electrons that are efficiently transferred to cerium-doped carbon dots(CDCe).Combined with mild photothermal effects,these processes synergistically enhance hydroxyl radical scavenging activity,as well as superoxide dismutase-and catalase-mimicking activities.In vitro experiments demonstrate that Au@CDCe effectively protects cells from oxidative damage,and promotes cell proliferation and migration.In vivo evaluations confirm its ability to modulate the immune microenvironment and accelerate diabetic wound healing.This work establishes a new paradigm for modulating the oxidative stress microenvironment through antioxidant gold-based plasmonic nanozymes and provides novel insights into tuning of prooxidant nanozyme into plasmon-enhanced antioxidant nanozyme.
文摘“Are you dead?”It's not a morbid joke-it's the literal translation of the name of Chinese app Sileme,which went viral around the country in early January.However,amid public controversy over its unsettling connotations,the development team rebranded the app as Demumu on January 14,be-fore it was removed from the app stores of Apple and Android on January 15.
基金supported by the National Natural Science Foundation of China(42273063)the Young Elite Scientists Sponsorship(YESS)Program of the China Association for Science and Technology(YESS20220661)+1 种基金Fundamental Research Funds for Central Universities(FRF-IDRY-23-004)the Natural Science Foundation of Shandong Province,China(ZR2022QD050).
文摘The Linglong gold ore field is situated in the northwestern region of the Jiaodong gold province,China,with over 1000 tons of gold resources.Although the metallogenic mechanism and fluid sources of the Linglong gold deposit have been the subject of extensive discussion and analyzed by numerous scholars,a definitive conclusion remains elusive.The Jiuqu Au deposit is a significant metallogenic area in the eastern part of the Linglong gold ore field,characterized as a quartz vein-type gold deposit.Gold mineralization in the Jiuqu gold deposit is classified into four stages,primarily occurring within the Late Jurassic Linglong granite and Early Cretaceous Guojialing granodiorite.Pyrite,the primary gold-bearing mineral at the Jiuqu Gold Mine,has been present throughout the metallogenic period,is rich in a variety of trace elements and is closely related to the formation of gold ore.This study focused on evaluating pyrite from the essential metallogenic stages(Stages Ⅰ-Ⅲ)of the Jiuqu gold deposit using scanning electron microscopy(SEM),electron microprobe analysis(EMPA),laser ablation inductively coupled plasma mass spectrometry(LA-ICP-MS) and laser ablation multi-collector inductively coupled plasma mass spectrometry(LA-MC-ICP-MS) sulfur isotope analysis and detection.The work aimed to reconstruct the origin of metallogenic materials and the evolution of ore-forming fluids and to restrict the genesis of the deposit.Pyrite exhibits discernible alterations in both shape and crystal structure as it progresses through its ore-forming stages.The aforementioned stages can be delineated as follows:type 1 pyrite(PyⅠ),developed in the initial ore stage,is characterized by coarse-to-medium-grained euhedral pyrite in Stage Ⅰ;type 2 pyrite(PyⅡ),developed in the second ore stage,appears during the middle stage of mineralization and is characterized by subhedral or anhedral pyrite;type 3 pyrite(PyⅢ),developed in the third ore stage,primarily occurred in the late-middle stages of mineralization.It is fragmented and coexists with various metal sulfides,including chalcopyrite,sphalerite and galena.The in situ major and elemental compositions of pyrites at Jiuqu indicate that Au,in the form of visible gold,exists in pyrites with low Au and Ag contents throughout all stages.PyⅠ had lower Pb,Bi,Co and Ni contents than those of PyⅡ.PyⅢ displayed decreased Pb,Bi,Co and Ni levels compared with PyⅡ.The δ34S values of the PyⅠ,PyⅡ and PyⅢ pyrite stages ranged from 7.19% to 8.71%,6.24% to 7.68% and 7.66% to 8.07%,respectively.According to the structural and geochemical analysis of pyrite,the ore-forming fluid of the Jiuqu gold deposit was derived from a magmatic-hydrothermal formation created by enriched lithospheric mantle-derived magma,mixing S from Precambrian metamorphic rocks.Previous studies on the H-O isotopes of quartz in the region's ores have indicated the presence of primary magma water.Additionally,studies concerning the C-O isotopes of carbonate minerals in ores have suggested that C may have originated from the mantle.Fluid migration and water-rock interaction resulted in sulfide and gold precipitation.In the Late Meosozoic,lithospheric thinning of eastern North China Craton led to up welling of astheno spheric mantle and partial melting of lithospheric mantle in the Jiaodong area.Under tectonic changes,magmatic-hydro thermal fluid migrated upward along fault structures to form a gold province.
基金Project(50874030)supported by the National Natural Science Foundation of ChinaProject(2009AA06Z104)supported by the National High-Tech Research and Development Program of ChinaProject(2008BAB34B01)supported by the National Support Program of China during the 11th Five-Year Plan Period
文摘The microscopy and scanning electronic microscopy （SEM） were used to study the gold occurrence of Jiaojia gold mine, Shandong province. The results show that the gold-bearing minerals are composed of pyrite, chalcopyrite, gangue, sphalerite and galena. 77.12% of gold minerals are the sulphides and 22.88% are the gangues. The gold occurrence is composed of 60.28% fissure gold, 21.63% inclusion gold and 18.09% crystal fractured gold. The morphology of gold mineral is composed of sphere, triangle, rectangle, strip and erose. The Jiaojia gold mineral owns large grain size range from 3-5 μm to 100 μm. 1.5% of gold grains is more than 0.104 mm, 5.26% is 0.074-0.104 mm, 23.31% is 0.043-0.074 mm, 3.76% is 0.043-0.037 mm and 64.29% is less than 0.037 mm. The occurrence of gold mineral is composed of native gold, electrum, native silver, iron-bearing native silver, goldcuprid and acanthite. Electrum is the most important mineral, accounting for 71.56%. The average quality is 641.26‰ for gold and silver mineral.
基金supported by the Project from Institute of Chemical and Engineering Sciences (ICES), Singapore (ICES/15-1G4B01)~~
文摘Despite the high amount of scientific work dedicated to the gold nanoparticles in catalysis, most of the research has been performed utilising supported nanoparticles obtained by traditional impreg‐nation of gold salts onto a support, co‐precipitation or deposition‐precipitation methods which do not benefit from the recent advances in nanotechnologies. Only more recently, gold catalyst scien‐tists have been exploiting the potential of preforming the metal nanoparticles in a colloidal suspen‐sion before immobilisation with great results in terms of catalytic activity and the morphology con‐trol of mono‐and bimetallic catalysts. On the other hand, the last decade has seen the emergence of more advanced control in gold metal nanoparticle synthesis, resulting in a variety of anisotropic gold nanoparticles with easily accessible new morphologies that offer control over the coordination of surface atoms and the optical properties of the nanoparticles （tunable plasmon band） with im‐mense relevance for catalysis. Such morphologies include nanorods, nanostars, nanoflowers, den‐dritic nanostructures or polyhedral nanoparticles to mention a few. In addition to highlighting newly developed methods and properties of anisotropic gold nanoparticles, in this review we ex‐amine the emerging literature that clearly indicates the often superior catalytic performance and amazing potential of these nanoparticles to transform the field of heterogeneous catalysis by gold by offering potentially higher catalytic performance, control over exposed active sites, robustness and tunability for thermal‐, electro‐and photocatalysis.
基金the National Science Foundation of China (Grant No. NSFC: 92162213)the Geology Department Faculty of Science of Al-Azhar University (Assiut Branch)+2 种基金the China Scholarship CouncilChang'an UniversityIstanbul Technical University's Scientific Research Project (BAP Project ID: 45396, code: FHD-2024-45396)
文摘In the Fatira(Abu Zawal)mine area,located in the northern Eastern Desert of Egypt,fieldwork and mineralogical analysis,integrated with machine learning techniques applied to Landsat-8 OLI,ASTER,and Sentinel-2 multi-spectral imagery(MSI)data delineate gold-sulfide mineralization in altered rocks.Gold(Au)anomalies in hydrothermal breccias and quartz veins are associated with NE-oriented felsite dykes and silicified granitic rocks.Two main alteration types are identified:a pyrite-sericite-quartz and a sulfide-chlorite-carbonate assemblage,locally with dispersed free-milling Au specks.Dimensionality reduction techniques,including principal component analysis(PCA)and independent component analysis(ICA),enabled mapping of alteration types.Sentinel-2 PC125 composite images offered efficient lithological differentiation,while supervised classifications,i.e.,the support vector machine(SVM)of Landsat-8 yielded an accuracy of 88.55%and a Kappa value of 0.86.ASTER mineral indices contributed to map hydrothermal alteration mineral phases,including sericite,muscovite,kaolinite,and iron oxides.Results indicate that post-magmatic epigenetic hydrothermal activity significantly contributed to the Au-sulfide mineralization in the Fatira area,distinguishing it from the more prevalent orogenic gold deposits in the region.
基金financially supported from the National Natural Science Foundation of China(No.52274358)the Natural Science Foundation of Hunan Province,China(No.2020JJ4718)+2 种基金the Major Science and Technology Projects of Gansu Province,China(No.22ZD6GC017)the Young Scientists Fund of National Natural Science Foundation of China(No.51404296)the National Key Research and Development Program of China(No.2018YFC1901604).
文摘Based on the properties of antimony(Sb)and arsenic(As),a method was proposed to enhance gold recovery during iron matte smelting.The impact of Sb and As on gold enhancement capture was investigated using an exclusion method.The results demonstrated that both Sb and As significantly improved the gold recovery rate.As the Sb or As content increased,the gold recovery rate increased.The enhancement effect of Sb was better than that of As,and the optimal results were achieved through the synergistic effects of Sb and As.Under optimized conditions,the gold recovery rate reached 97.12%,whereas the gold content in the slag decreased to 1.70 g/t.Sb captured and aggregated free gold as an Au-Sb alloy,whereas As-Fe alloy also captured free gold.The growth of the gold-captured phase size enhanced the settling velocity,thereby promoting gold recovery.
基金supported by the National Natural Science Foundation of China(Grant Nos.42302106 and 42102089)National Foundation for Guiding Local Science and Technology Development(Guizhou[2024]043)Innovation and Development Fund of Science and Technology of Institute of Geochemistry,Chinese Academy of Sciences(Grant No.2025-1).
文摘The world-class Jiaodong gold province in the North China Craton hosts over 5000 t of Au resource and is characterized by abundant visible gold mineralization.However,the critical processes controlling the formation of visible gold in this province remain poorly understood.To solve this problem,integrated microtextural,trace elemental,and sulfur isotopic analyses of pyrite from the high-grade Linglong gold deposit in the Jiaodong gold province were conducted in this study.Two distinct pyrite types were identified within auriferous quartz-sulfide veins:(1)Py1 aggregates in quartz-pyrite veins(hydrothermal stageⅡ),and(2)euhedral to subhedral,coarse-grained Py2 crystals in quartz-polymetallic sulfide veins(hydrothermal stageⅢ).Microtextural and elemental analyses revealed that visible gold predominantly occurs as intergranular particles between primary pyrite crystals within Py1 aggregates.The Py1 exhibits complex microtextures with abundant mineral inclusions of polymetallic sulfides and has low concentrations of Au(median:0.032 ppm)with a narrowδ^(34)S range(4.86‰-6.75‰),indicative of rapid crystallization under unstable,disequilibrium conditions.By contrast,the Py2 is texturally homogeneous and contains higher Au concentrations(median:0.304 ppm)with progressively increasingδ^(34)S values(5.25‰-10.14‰)over time,suggesting slow crystal growth under more stable,near-equilibrium conditions.Based on the microtextural and geochemical information,it is proposed that fluid boiling occurred only during the hydrothermal stage Ⅱ,which resulted in the unstable physicochemical environment and rapid deposition of gold.During the boiling processes,gold colloids likely occurred and promoted the formation of visible gold.
基金financially supported by the National Natural Science Foundation of China (No.51974016)。
文摘Cyanide is the most widely used reagent in gold production processes. However, cyanide is highly toxic and poses safety haz-ards during transportation and use. Therefore, it is necessary to develop gold leaching reagents that can replace cyanide. This paper intro-duces a method for synthesizing a gold leaching reagent. Sodium cyanate is used as the main raw material, with sodium hydroxide and so-dium ferrocyanide used as additives. The gold leaching reagent can be obtained under the conditions of a mass ratio of sodium cyanate,sodium hydroxide, and sodium ferrocyanide of 15:3:1, synthesis temperature of 600℃, and synthesis time of 1 h. This reagent has a goodrecovery effect on gold concentrate and gold-containing electronic waste. The gold leaching rate of roasted desulfurized gold concentratecan reach 87.56%. For the extraction experiments of three types of gold-containing electronic waste, the gold leaching rate can reach over90% after 2 h. Furthermore, the reagent exhibits good selectivity towards gold. Component analysis indicates that the effective compon-ent in the reagent could be sodium isocyanate.
文摘Gold Cross,a Thai company specializing in herbal oils,has long combined Thailand’s traditional medicine with modern technology to deliver highquality health products.Invited by the China-ASEAN Expo(CAEXPO),the head of Gold Cross arrived at the exhibition hall with a mix of anticipation and slight anxiety and the company’s signature product in tow—Gold Cross yellow oil.Made with a unique Golden Cross traditional formula and infused with natural herbal extracts,the oil relieves muscle aches,insect bites,and dizziness.In Thailand,it is a household name and widely regarded as an all-purpose herbal remedy.At the expo booth,a Chinese buyer was pleasantly surprised after trying it.
基金financially supported by the National Natural Science Foundation of China(Grant No.41230311)the National Science and Technology Support Program(Grant No.2011BAB04B09)+1 种基金the Geological Investigation Work Project of China Geological Survey(Grant No.12120114034901)111 Project of China(Grant No.B07011)
文摘The Jiaodong gold deposits are currently the most important gold resources（with Au reserves of〉4000 t） in China,and the leading gold-producing country globally（with Au production of ～428 t in2013）.Jiaodong is also considered as perhaps the only world-class to giant gold accumulation on the planet where relatively young gold ores（ca.130-120 Ma） were deposited in rocks that are 2 Ga older.The Xincheng world-class high-grade gold deposit,with a proven reserve of 〉200 t gold,is one of the largest deposits in the giant gold province of the Jiaodong Peninsula.It is located in the northwestern part of the jiaobei Uplift,and hosted by ca.132-123 Ma Xincheng quartz monzonites and monzogranites.Ore zones are structurally controlled by the NE-trending and NW-dipping Jiaojia Fault and subsidiary faults,and are mainly restricted to the footwall of the fault.The dominant disseminated- and stockworkstyle ores are associated with strong sericitization,silicification,sulfidation and K-feldspathization,and minor carbonate wallrock alteration halos.The four mineralization stages are pyrite-quartz-sericite（stage 1）,quartz-pyrite（stage 2）,quartz-polysulfide（stage 3） and quartz-carbonate（stage 4）.Gold occurs dominantly as electrum,with lesser amounts of sulfide-hosted native gold and rare native silver and argentite,normally associated with pyrite,chalcopyrite,galena and sphalerite：the latter with proven resources of about 105 t Ag,713 t Cu,and 5100 t S.There are three types of ore-related fluid inclusions：type 1 aqueous-carbonate（H2O-CO2）,type 2aqueous（liquid H2O＋vapor H2O）,and type 3 CO2（liquid CO2 and vapor CO2） inclusions.Homogenization temperatures range from 221 to 304℃ for type 1 inclusions,with salinities of 2.4-13.3 wt.%NaCl eq.,and bulk densities of 0.858-1.022 g/cm～3.The δ～（34）S（CDT） values of hydrothermal sulfides are 4.3-10.6‰and δ～（18）O values of hydrothermal quartz have a median value of 13.0‰.δD values of fluid inclusions in hydrothermal quartz have a median value of-75‰.Calculated δ～（18）Owater has a median value of 5.2‰.The timing of gold mineralization at the Xincheng gold deposit is younger than 123±1 Ma,and likely between 120.9 and 119.9 Ma.A minerals system genetic model for the probable epizonal orogenic Xincheng deposit suggests an initial medium temperature,CO2-rich,and low salinity H2O-CO2 deeply sourced metamorphic ore fluid associated with dehydration and decarbonization of subducting Paleo-Pacific lithosphere.The Jiaojia Fault constrained the migration of ore-forming fluids and metals at the brittle-ductile transition.Fluid immiscibility,caused by episodic pressure drops,led to significant high-grade gold deposition in the giant Xincheng gold deposit.
基金funded by Talent Award under the 1000 Plan Project from the Chinese Government
文摘It is quite evident that it is not anomalous metal transport,nor unique depositional conditions,nor any single factor at the deposit scale,that dictates whether a mineral deposit becomes a giant or not.A hierarchical approach thus is required to progressively examine controlling parameters at successively decreasing scales in the total mineral system to understand the location of giant gold deposits in non-arc environments.For giant orogenic,intrusion-related gold systems（IRGS） and Carlin-type gold deposits and iron oxide-copper-gold（IOCG） deposits,there are common factors among all of these at the lithospheric to crustal scale.All are sited in giant gold provinces controlled by complex fundamental fault or shear zones that follow craton margins or,in the case of most Phanerozoic orogenic giants,define the primary suture zones between tectonic terranes.Giant provinces of IRGS,IOCG,and Carlin-type deposits require melting of metasomatized lithosphere beneath craton margins with ascent of hybrid lamprophyric to granitic magmas and associated heat flux to generate the giant province.The IRGS and IOCG deposits require direct exsolution of volatile-rich magmatic-hydrothermal fluids,whereas the association of such melts with Carlin-type ores is more indirect and enigmatic.Giant orogenic gold provinces show no direct relationship to such magmatism.forming from metamorphic fluids,but show an indirect relationship to lamprophyres that reflect the mantle connectivity of controlling first-order structures.In contrast to their province scale similarities,the different giant gold deposit styles show contrasting critical controls at the district to deposit scale.For orogenic gold deposits,the giants appear to have formed by conjunction of a greater number of parameters to those that control smaller deposits,with resultant geometrical and lithostratigraphic complexity as a guide to their location.There are few giant IRGS due to their inferior fluid-flux systems relative to orogenic gold deposits,and those few giants are essentially preservational exceptions.Many Carlin-type deposits are giants due to the exceptional conjunction of both structural and lithological parameters that caused reactive and permeable rocks,enriched in syngenetic gold,to be located below an impermeable cap along antiformal ＂trends＂.Hydrocarbons probably played an important role in concentrating metal.The supergiant Post-Betze deposit has additional ore zones in strain heterogeneities surrounding the pre-gold Goldstrike stock.All unequivocal IOCG deposits are giant or near-giant deposits in terms of gold-equivalent resources,partly due to economic factors for this relatively poorly understood,low Cu-Au grade deposit type.The supergiant Olympic Dam deposit,the most shallowly formed deposit among the larger IOCGs,probably owes its origin to eruption of volatile-rich hybrid magma at surface,with formation of a large maar and intense and widespread brecciation,alteration and Cu-Au-U deposition in a huge rock volume.
基金carried out by NMV on the eastern Goldfields Province of the Yilgarn Craton was as an ARC Linkage-and AMIRA P680-funded postdoctoral research fellow at the Centre for Global Metallogeny,now the Centre for Exploration Targeting,at the University of Western Australia(UWA)
文摘The Neoarchaean Kaigoorlie Gold Field contains the giant Golden Mile and world-class Mt Charlotte deposits,which have been the subject of much research for over 100 years.The Golden Mile deposit is a complex array of ductile to brittle vein and breccia lodes that are predominantly hosted in the highlyfractionated Golden Mile Dolerite sill.The Fimiston lodes comprise an array of narrow lodes that evolved broadly syn- to late-formation of the regional D2 NW-trending foliation.The lodes are characterized by pyrite veinlets and disseminations,quartz veinlets and breccias,and banded quartz-carbonate veins with sericite,carbonate,and pyrite-dominated alteration.Bonanza Green-Leader,or Oroya-style,lodes,with grades in excess of 1000 g/t Au,are similar to the Fimiston-style lodes,but are characterized by abundant visible gold,native tellurium and more abundant telluride minerals within roscoelitebearing alteration zones.The arguably structurally younger Mt Charlotte-style lodes are characterized by a pipe-shaped,coarse-grained quartz,carbonate and scheelite vein-stockwork with distinct verticallyzoned,carbonate-sericite-albite-pyrite ± pyrrhotite dominant alteration assemblages around veins within Unit 8 of the Golden Mile dolerite and porphyry dykes.The network of steep- and gently-dipping extension and shear fracture-fill veins are associated with NE-trending fault se ts that cross cut the regional NW-trend.The deposit area is intruded by swarms of porphyry dykes,including syn-volcanic mafic dykes,early and volumetrically most significant c.2.67 Ga feldspar-phyric porphyry dykes,as well as later c.2.66-2.65 Ga calc-alkaline hornblende-phyric dykes associated with younger c.2.65-2.64 Ga lamprophyre dykes.All post-volcanic dykes have similar orientations to the Fimiston lodes.The feldspar dykes are clearly overprinted by all styles of mineralization,although the relationship between hornblende-phyric and lamprophyre dykes and gold mineralization is more ambiguous.Most agree that gold mineralization was post-peak regional metamorphism of host rocks,although its relative structural timing is controversial.Direct timing constraints on gold mineralization indicate that Fimiston- and Mt Charlotte-style mineralization formed within a relative short period of time around 2.64 Ga,and,as such,support a model of progressive deformation of a Theologically heterogeneous rock package late in the structural history.Fluid characteristics,combined with the structural,metamorphic and absolute timing,support description of gold mineralization at the Golden Mile as orogenic and mesozonal,and this allows direct correlation with orogenic gold deposits worldwide,which classically formed during accretion along convergent margins throughout Earth history.
基金support from the National Natural Science Foundation of China(No.52204274)the Shandong Provincial Natural Science Foundation,China(No.ZR2021QE122)+1 种基金Shandong Provincial Department of Science and Technology Key Project,China(No.2023TZXD021)Shandong Provincial Department of Science and Technology,China(No.ZTYJY-KY-2033-11).
文摘Gold ores in the Jiaozhou region of China are characterized by their abundant reserves,low grade,fine dissemination,and chal-lenges in upgrading.Froth flotation,with xanthate as the collector,is a commonly employed method for enriching auriferous pyrite from these ores.This study aimed to develop a more efficient flotation process by utilizing cavitation nanobubbles for a low-grade gold ore.Batch flotation tests demonstrated that nanobubbles significantly enhanced the flotation performance of auriferous pyrite,as evidenced by improved concentrate S and Au grades and their recoveries.The mechanisms underlying this enhancement were explored by investigat-ing surface nanobubble(SNB)formation,bulk nanobubble(BNB)attachment to hydrophobic pyrite surfaces,and nanobubble-induced agglomeration using atomic force microscopy(AFM)and focused beam reflectance measurement(FBRM).The results revealed that nan-obubble coverage on the pyrite surface is a critical factor influencing surface hydrophobicity and agglomeration.SNBs exhibited higher coverage on pyrite surfaces with increased surface hydrophobicity,flow rate,and cavitation time.Similarly,BNB attachment on pyrite surfaces was significantly increased with surface hydrophobicity and cavitation time.Enhanced surface hydrophobicity,along with higher flow rates and cavitation times,promoted pyrite particle agglomeration owing to the increased nanobubble coverage,ultimately leading to improved flotation performance.
基金supported by the Ordos City Science and Technology Major Project(2021ZD14-16)the National Key Research and Development Program(2018YFC1802904)the Discipline Signature Achievements of the Shanghai Polytechnic University(A10GY23G004-14).
文摘One of the major challenges in the application of microbially induced carbonate precipitation(MICP)is achieving"bacteria freedom",as it necessitates a substantial volume of bacterial solutions.Nevertheless,both insitu bacterial cultivation and transportation of bacterial solutions have proven to be inefficient.In this study,we suggested the utilization of bacteria in the form of dry powder,enabling easy on-site activation and achieving a relatively high urease activity.We conducted MICP curing experiments on gold mine tailings(GMT)using steel slag(SS)as an additive.The results showed that the average unconfined compressive strength(UCS)values of the tailings treated with MICP and MICP+SS reached 0.51 and 0.71 MPa,respectively.In addition,the average leaching reduction rates of Cu,Pb,Cr,Zn,and T-CN in GMT after MICP treatment reached 98.54%,100%,70.94%,59.25%,and 98.02%,respectively,and the average reduction rates after MICP+SS treatment reached 98.77%,100%,88.03%,72.59%,and 98.63%,respectively.SEM,XRD,FT-IR analyses,and ultra-deep field microscopy results confirmed that the MICP treatment produced calcite-based calcium carbonate that filled the inter-tailing pores and cemented them together,and the hydration mechanism was the main reason for the increased curing efficiency of SS.Our research findings demonstrate that bacterial powder can efficiently achieve the objectives of heavy metal removal and tailing solidification.This approach can substantially de-crease the expenses associated with bacterial cultivation and solution transportation,thereby playing a crucial role in advancing the practical implementation of MICP.
文摘A new gold self-relay catalytic annulation/nucleophilic substitution cascade of 1,3-enyne acetates with cyclic ether acetals is reported,enabling highly diastereoselective access to cyclic etherified cyclopentenones with cyclic quaternary centers in moderate to good yields and>19∶1 dr.This catalysis enables the direct construction of two types of carboncyclic skeletons by adjusting the olefin types of 1,3-enyne acetates.When 1,3-enyne acetates bearing a cyclic alkene unit were used,5~6 fused bicarbocyclic products were diastereoselectively synthesized,whereas the reaction of acyclic 1,3-enyne acetates resulted in five-memebered carbocyclic framework.Notably,cyclic ether acetals are commonly used as protecting groups in traditional multistep organic syntheses,and in this reaction,such reagents serve as electrophilic cyclic ether precursors,achieving new uses for old reagents.The current method demonstrates good functional group compatibility,a broad substrate scope and high diastereoselectivity,providing a new synthetic strategy toward functionalized cyclopentenones.
