Background:Excessive use of inorganic trace minerals(ITMs)in swine production leads to high fecal mineral excretion and environmental risks,while most studies on organic trace minerals(OTMs)focus on single elements,wi...Background:Excessive use of inorganic trace minerals(ITMs)in swine production leads to high fecal mineral excretion and environmental risks,while most studies on organic trace minerals(OTMs)focus on single elements,with limited data on the synergistic effects and molecular mechanisms of combined OTMs(Fe,Cu,Mn,Zn)in growing-finishing pigs.Methods:This study aimed to investigate the effects of graded levels of micromineral proteinates(combined OTMs)on growth performance,mineral metabolism,and mRNA expression of mineral regulatory proteins.A total of 360 crossbred Duroc×Landrace×Large White pigs(initial body weight 47.1±4.8 kg)were randomly assigned to 6 dietary treatments:basal diet without microminerals(CON),basal diet with ITMs at commercially recommended levels(IT),and basal diets with 15%(OT 15%),25%(OT 25%),35%(OT 35%)commercially recommended levels(CRL)of combined micromineral proteinates.After a 70-day feeding trial,samples were analyzed using ICP-OES,ELISA,and RT-qPCR.Results:Results showed that reduced levels(15-35%CRL)of micromineral proteinates did not significantly affect average daily gain,average daily feed intake,or feed conversion ratio(gain-to-feed ratio)compared to IT(P>0.05),but significantly increased plasma Cu(1.73-1.83μg/mL)and Zn(1.72-1.97μg/mL)concentrations(P<0.05)and elevated activities of Cu/Zn-superoxide dismutase(32.9-35.9 U/L)and manganese superoxide dismutase(20.5-24.1 U/L)compared to CON(P<0.05),with no significant differences from IT(P>0.05).Fecal excretion of Fe,Cu,Mn,and Zn was significantly reduced by 35-50%in OT 15%-OT 35%groups compared to IT(P<0.05).OT 25%group exhibited the highest apparent absorptivity of Fe(38.5%),Cu(27.8%),and Zn(42.4%)(P<0.05),which was associated with significantly regulated mRNA expression of mineral regulatory proteins:upregulated DMT1,FPN1,ZIP4,and MT1A in the duodenum,and modulated HAMP,ATP7B,ZIP14,and ZnT1 in the liver(P<0.05).Conclusion:In conclusion,dietary supplementation with 25%CRL or less of combined micromineral proteinates can fully meet the nutritional needs of growing-finishing pigs,improve mineral absorptivity,and reduce fecal mineral excretion by regulating intestinal and hepatic mineral transport and homeostatic proteins,providing a sustainable alternative to high-dose ITMs.展开更多
Uranyl arsenate minerals,which exhibit low solubility,serve as major sinks for U and As,playing a crucial role in controlling the mobility of U and As in the environment.However,the specific mechanisms underly-ing the...Uranyl arsenate minerals,which exhibit low solubility,serve as major sinks for U and As,playing a crucial role in controlling the mobility of U and As in the environment.However,the specific mechanisms underly-ing the formation of uranyl arsenate minerals have remained largely elusive.Herein,the formation pathway of the non-charged UO_(2)(H_(2)AsO_(4))_(2)·nH_(2)O0 complex was investigated to elucidate the early formation of the UO_(2)(H_(2)AsO_(4))_(2)·nH_(2)O mineral(where n represents the stoichiometric number of H_(2)O),a representative uranyl arsenate mineral.Based on the combination experiments of U(VI)and As(V),our findings underscore the sig-nificant dependence of UO_(2)(H_(2)AsO_(4))_(2)·nH_(2)O0 formation on solution pH(4.0–10.0).Density functional theory(DFT)calculations reveal a two-step reaction involving two distinct pathways(Pathway 1 and Pathway 2)for the formation of UO_(2)(H_(2)AsO_(4))_(2)·nH_(2)O,and the intermediate was confirmed by in situ Raman and fluorescence spec-troscopy.Specifically,the hydroxyl‑connected uranyl(UO_(2)OH^(+))reacts with the protonated arsenate(H_(2)AsO_(4)^(-))species to form the intermediate UO_(2)HAsO4·H_(2)O(Pathway 1)or UO_(2)OH–H2AsO4(Pathway 2)with a U/As ratio of 1:1.Meanwhile,all the transition states also were obtained and the energy barrier suggested that the UO_(2)(H_(2)AsO_(4))_(2)·2H_(2)O0 formed by Pathway 1 is thermodynamically favored over Pathway 2,and may serve as the primary fundamental structural unit or precursor for the early formation of the UO_(2)(H_(2)AsO_(4))_(2)·nH_(2)O mineral phase.Altogether,this study contributes to advancing the understanding of the formation of uranyl arsenate min-erals at the molecular scale and provides a theoretical basis for predicting and regulating uranium and arsenic mobilization in their coexisting environment.展开更多
Mineral fulvic acid(MFA)was used as an eco-friendly pyrite depressant to recover chalcopyrite by flotation with the use of the butyl xanthate as a collector.Flotation experiments showed that MFA produced a stronger in...Mineral fulvic acid(MFA)was used as an eco-friendly pyrite depressant to recover chalcopyrite by flotation with the use of the butyl xanthate as a collector.Flotation experiments showed that MFA produced a stronger inhibition effect on pyrite than on chalcopyrite.The separation of chalcopyrite from pyrite was realized by introducing 150 mg/L MFA at a pulp pH of approximately 8.0.The copper grade,copper recovery,and separation efficiency were 28.03%,84.79%,and 71.66%,respectively.Surface adsorption tests,zeta potential determinations,and localized electrochemical impedance spectroscopy tests showed that more MFA adsorbed on pyrite than on chalcopyrite,which weakened the subsequent interactions between pyrite and the collector.Atomic force microscope imaging further confirmed the adsorption of MFA on pyrite,and X-ray photoelectron spectroscopy results indicated that hydrophilic Fe-based species on the pyrite surfaces increased after exposure of pyrite to MFA,thereby decreasing the floatability of pyrite.展开更多
The Zijinshan ore field located in southwestern Fujian Province,China,is a representative porphyry-epithermal ore system hosting diverse mineralization types(Mao et al.,2013).The ore field comprises of the Zijinshan h...The Zijinshan ore field located in southwestern Fujian Province,China,is a representative porphyry-epithermal ore system hosting diverse mineralization types(Mao et al.,2013).The ore field comprises of the Zijinshan highsulfidation Cu-Au deposit,the Luoboling porphyry Cu-Mo deposit,the transitional style Cu deposit(Longjiangting and Wuziqilong)and the Yueyang low-sulfidation Agpolymetallic deposit(Zhang,2013;Zhang et al.,2003)展开更多
The substantial emissions of greenhouse gases,particularly CO_(2),constitute a primary driver of global warming.CCUS is proposed as an effective mitigation strategy which is often estimated to account for about 15%of ...The substantial emissions of greenhouse gases,particularly CO_(2),constitute a primary driver of global warming.CCUS is proposed as an effective mitigation strategy which is often estimated to account for about 15%of cumulative carbon emission reduction.In-situ CO_(2) mineralization sequestration,compared to conventional geological storage methods such as depleted oil and gas reservoirs,unmineable coal seams,and deep saline aquifers,offers the advantage of permanent immobilization of injected carbon.However,uncertainties persist regarding the characteristics of geochemical interactions under reservoir pore conditions,as well as the kinetic mechanisms of mineralization reactions.Additionally,geochemical reactions may lead to solid particle transport and deposition,potentially causing pore throat occlusion.Pilot projects in Iceland and the United States have demonstrated the feasibility of this technology,but the field remains in the early deployment stage.In this review,the mechanisms of in-situ mineralization have been elucidated,the primary factors influencing the reaction kinetics have been discussed,and the current research status in this field has been summarized.It is emphasized that establishing a reliable system for evaluating storage capacity and understanding the kinetic mechanisms governing CO_(2) conversion into minerals at multi-phase interfaces are key priorities for future work.展开更多
The Jiuyishan granitic complex,located in the Nanling Range,South China,is composed of five granitic plutons(Xuehuading,Jinjiling,Pangxiemu,Shaziling and Xishan).Zircon U-Pb dating of four plutons(Jinjiling,Pangxiemu,...The Jiuyishan granitic complex,located in the Nanling Range,South China,is composed of five granitic plutons(Xuehuading,Jinjiling,Pangxiemu,Shaziling and Xishan).Zircon U-Pb dating of four plutons(Jinjiling,Pangxiemu,Shaziling and Xishan)yielded similar ages of approximately 153 Ma,indicating indistinguishable ages within error.Three plutons except the Shaziling pluton,have consistentε_(Nd)(t)(-7.8 to-5.8)andε_(Hf)(t)(-9.1 to-2.2)values,which are similar to those of the lower crustal granulitic metasedimentary and meta-igneous rocks in South China.Compared to other three plutons,the Shaziling pluton has consistentε_(Nd)(t)(-7.4 to-6.8)andε_(Hf)(t)(-7.5 to-4.7)values and shows similar source,but the Shaziling mafic microgranular enclaves(MMEs)show variableε_(Hf)(t)(-14.2 to 4.8)values,indicating a remarkable mantle magma injection of the Shaziling pluton.Zircon Ce/Sm-Yb/Gd,whole-rock CaO-P_(2)O_(5)and CaO-TiO_(2)linear trends reveal that from the Xishan to the Shaziling and from the Jinjiling to the Pangxiemu granites,they experienced apatite and titanite fractionation,respectively.Zircon Th,U,Nb,Ta,Hf,Ti,Y,P and rare earth element(REE)contents and whole-rock Sr,Ba and Rb contents also show that the Shaziling,Xishan,Jinjiling and Pangxiemu granites followed a discontinuous evolutionary series,but the Pangxiemu granites exhibit highly evolved nature.Four main controlling factors of W-Sn and rare metal mineralization in granitic rocks were discussed,and we found that the mineralization in Jiuyishan granitic complex was mainly controlled by the fractionation degree and crystallization temperature,but were rarely affected by oxygen fugacity and mantle material input.The Pangxiemu granites show particularly higher Rb and Ta contents than the other three plutons,implying that the ore deposits developed in the Jiuyishan Complex were directly related to the most evolved Pangxiemu pluton,with the occurrence of Rb and Ta as the most likely rare metal mineralization in the Jiuyishan District.A crystal mush model is proposed to interpret the petrogenetic and mineralizing processes of the Jiuyishan granitic complex.展开更多
Natural gas hydrates widely accumulate in submarine sediments composed of clay minerals.However,due to the complex physiochemistry and micron-sized particles of clay minerals,their effects on methane hydrate(MH)format...Natural gas hydrates widely accumulate in submarine sediments composed of clay minerals.However,due to the complex physiochemistry and micron-sized particles of clay minerals,their effects on methane hydrate(MH)formation and dissociation are still in controversy.In this study,montmorillonite and illite were separately mixed with quartz sand to investigate their effects on MH formation and dissociation.The microstructure of synthesized samples was observed by cryo-SEM innovatively to understand the effects of montmorillonite and illite on MH phase transition in micron scale.Results show that montmorillonite and illite both show the inhibition on MH formation kinetics and water-to-hydrate conversion,and illite shows a stronger inhibition.The 10 wt%montmorillonite addition significantly retards MH formation rate,and the 20 wt%montmorillonite has a less inhibition on the rate.The increase of illite mass ratio(0-20 wt%)retards the rate of MH formation.As the content of clay minerals increase,the water-to-hydrate conversion decreases.Cryo-SEM images presented that montmorillonite aggregates separate as individual clusters while illite particles pack as face-to-face configuration under the interaction with water.The surface-overlapped illite aggregates would make sediments pack tightly,hinder the contact between gas and water,and result in the more significant inhibition on MH formation kinetics.Under the depressurization method,the addition of clay minerals facilitates MH dissociation rate.Physicochemical properties of clay minerals and MH distribution in the pore space lead to the faster dissociation rate in clay-containing sediments.The results of this study would provide beneficial guides on geological investigations and optimizing strategies of natural gas production in marine hydrate-bearing sediments.展开更多
Carbon dioxide (CO_(2)) mineralization technology has attracted significant attention, due tothe synergistic terminal treatment of CO_(2) and industrial waste. The combined CO_(2) mineralizationprocess with steel ente...Carbon dioxide (CO_(2)) mineralization technology has attracted significant attention, due tothe synergistic terminal treatment of CO_(2) and industrial waste. The combined CO_(2) mineralizationprocess with steel enterprises is a promising route to simultaneously address CO_(2)emissions and SS treatment. Recently, a serial of the relevant work focus on a single type ofsteel slag (SS), and the understanding of CO_(2) absorption by mineralization of various SS isvery lacking.Meanwhile, it is urgent requirement for systematic summary and discussion onhow to make full use of the mineralized products produced after the mineralization of CO_(2)in SS. This review aims to investigate the progress of CO_(2) mineralization using SS, includingthe potential applications of mineralization products, as well as the environmental impactand risk assessment ofmineralization product applications. Currently, the application of SSmineralization products is primarily focused on their use as construction materials with loweconomic value. With usage of the mineralization products for ecological restoration (e.g.sandy soil remediation) was treated as an advanced route, but still remaining challenge infunctional materials preparation, and its technical economy and possible hazards need tobe further explored by long-term experimental tests.展开更多
As a widely used fertilizer,urea significantly promotes the leaching of dissolved organic nitrogen(DON)in soils and aggravates nitrogen contamination in groundwater.Clayminerals are considered the most important facto...As a widely used fertilizer,urea significantly promotes the leaching of dissolved organic nitrogen(DON)in soils and aggravates nitrogen contamination in groundwater.Clayminerals are considered the most important factor in retaining DON.However,the effect of urea on the retention of DON with different molecular weights by clay minerals is unknown.In this study,the retention of both low-molecular weight DON(LMWD)and high-molecular weight DON(HMWD)by clay minerals in the presence of urea was investigated.For this purpose,batch adsorption and soil column leaching experiments,characterization analysis(Fourier transform infrared spectroscopy X-ray diffraction,and X-ray photoelectron spectroscopy),and molecular dynamics simulations were carried out.Urea had a positive effect on the adsorption of LMWD,whereas a competitive effect existed for the adsorption of HMWD.The dominant interactions among DON,urea,and clay minerals included H-bonding,ligand exchange,and cation exchange.The urea was preferentially adsorbed on clay minerals and formed a complex,which provided more adsorption sites to LMWD and only a few to HMWD.The presence of urea increased the retention of LMWD and decreased the retention of HMWD in clay minerals.The retention capacity of LMWD increased by 6.9%–12.8%,while that of HMWD decreased by 6.7%–53.1%.These findings suggest that LMWD tended to be trapped in soils,while HMWD was prone to be leached into groundwater,which can be used to evaluate the leaching of DON from soil to groundwater.展开更多
Polybrominated biphenyl ethers(PBDEs)and polycyclic aromatic hydrocarbons(PAHs)are commonly detected contaminants at e-waste recycling sites.Against the conventional wisdom that PBDEs and PAHs are highly immobile and ...Polybrominated biphenyl ethers(PBDEs)and polycyclic aromatic hydrocarbons(PAHs)are commonly detected contaminants at e-waste recycling sites.Against the conventional wisdom that PBDEs and PAHs are highly immobile and persist primarily in shallowsurface soils,increasing evidence shows that these compounds can leach into the groundwater.Herein,we compare the leachabilities of PBDEs vs.PAHs from contaminated soils collected at an e-waste recycling site in Tianjin,China.Considerable amounts of BDE-209(0.3–2 ng/L)and phenanthrene(42–106 ng/L),the most abundant PBDE and PAH at the site,are detected in the effluents of columns packed with contaminated soils,with the specific concentrations varying with hydrodynamic and solution chemistry conditions.Interestingly,the leaching potential of BDE-209 appears to be closely related to the release of colloidal mineral particles,whereas the leachability of phenanthrene correlates well with the concentration of dissolved organic carbon in the effluent,but showing essentially no correlation with the concentration of mineral particles.The surprisingly different trends of the leachability observed between BDE-209 and phenanthrene is counterintuitive,as PBDEs and PAHs often co-exist at e-waste recycling sites(particularly at the sites wherein incineration is being practiced)and share many similarities in terms of physicochemical properties.One possible explanation is that due to its extremely low solubility,BDE-209 predominantly exists in free-phase(i.e.,as solid(nano)particles),whereas the more soluble phenanthrene is mainly sorbed to soil organic matter.Findings in this study underscore the need to better understand the mobility of highly hydrophobic organic contaminants at contaminated sites for improved risk management.展开更多
This study investigates the mineralogy and mineral-chemistry of a newly discovered Au-Ag-Bi-Te mineralization at the Aydindere Fe-Cu skarn deposit,within the Pontides Tectonic Unit,northeastern Turkey.The mineralizati...This study investigates the mineralogy and mineral-chemistry of a newly discovered Au-Ag-Bi-Te mineralization at the Aydindere Fe-Cu skarn deposit,within the Pontides Tectonic Unit,northeastern Turkey.The mineralization is developed in the skarn zone at the contact between Upper Cretaceous andesite-pyroclastic rocks and a Paleocene–Eocene I-type granitoid.The principal ore minerals of the Aydindere Fe-Cu deposit are oxides(magnetite),sulfides(pyrite-chalcopyritegalena-sphalerite),tellurides/sulfotellurides(tetradymite,hessite),sulfosalts(wittichenite,emplectite,aikinite) and native gold-electrum.Skarn minerals include anhydrous phases(garnet) formed in a prograde stage and hydrous phases(amphibole,epidote,chlorite),which were formed in a retrograde stage in association with quartz,adularia,apatite and late calcite.Sulfides,tellurides and sulfosalts are introduced during the retrograde stage.The Au-Ag-Bi-Te mineralization was detected for the first time within the western ore body of the Aydindere deposit,and occurs in calcite-bearing sulfide bodies that cut magnetite-garnet-amphibole-epidote skarns with magnetite ores of different grade,including massive magnetite.Chlorite geothermometry indicates formation of the Au-Ag-BiTe mineralization at temperatures between 300 and 250 ℃,during the retrograde skarn evolution.Assuming the temperature is ~275 ℃,logfS_(2) =-10.5 to-13,logfO_(2) =-37 to-33,and logf Te2 values range from approximately-12 to-8.5 were estimated.The available mineralogical and geological data(presences of magnetite,oxidized-type tellurides/sulfotellurides,and andraditic garnets,and absence of pyrrhotite and arsenopyrite) suggest that Aydindere is an oxidized Au-bearing skarn deposit.The discovery of Au-Ag-Bi-Te mineralization at Aydindere increases its productivity and requires more detailed exploration in the deposit for precious(Au,Ag) and critical(Bi,Te) metals.展开更多
The precise identification of quartz minerals is crucial in mineralogy and geology due to their widespread occurrence and industrial significance.Traditional methods of quartz identification in thin sections are labor...The precise identification of quartz minerals is crucial in mineralogy and geology due to their widespread occurrence and industrial significance.Traditional methods of quartz identification in thin sections are labor-intensive and require significant expertise,often complicated by the coexistence of other minerals.This study presents a novel approach leveraging deep learning techniques combined with hyperspectral imaging to automate the identification process of quartz minerals.The utilizied four advanced deep learning models—PSPNet,U-Net,FPN,and LinkNet—has significant advancements in efficiency and accuracy.Among these models,PSPNet exhibited superior performance,achieving the highest intersection over union(IoU)scores and demonstrating exceptional reliability in segmenting quartz minerals,even in complex scenarios.The study involved a comprehensive dataset of 120 thin sections,encompassing 2470 hyperspectral images prepared from 20 rock samples.Expert-reviewed masks were used for model training,ensuring robust segmentation results.This automated approach not only expedites the recognition process but also enhances reliability,providing a valuable tool for geologists and advancing the field of mineralogical analysis.展开更多
Hydrogen-based mineral phase transformation(HMPT)technology has demonstrated its effectiveness in separating iron and enriching rare earths from Bayan Obo refractory ores.However,further research is needed to clarify ...Hydrogen-based mineral phase transformation(HMPT)technology has demonstrated its effectiveness in separating iron and enriching rare earths from Bayan Obo refractory ores.However,further research is needed to clarify the phase composition and floatability of rare earths obtained after HMPT owing to the associated phase transformations.This study explored the mineralogical characteristics and separation behavior of rare earths in HMPT-treated iron tailings.Process mineralogy studies conducted via BGRIMM process mineralogy analysis and X-ray diffraction revealed that the main valuable minerals in the tailings included rare-earth oxides(9.15wt%),monazite(5.31wt%),and fluorite(23.52wt%).The study also examined the impact of mineral liberation and gangue mineral intergrowth on flotation performance.Flotation tests achieved a rare-earth oxide(REO)grade of 74.12wt% with a recovery of 34.17% in open-circuit flotation,whereas closed-circuit flotation resulted in a REO grade of 60.27wt% with a recovery of 73%.Transmission electron microscopy and scanning electron microscopy coupled with energy-dispersive spectroscopy revealed that monazite remained stable during the HMPT process,while bastnaesite was transformed into Ce_(7)O_(12)and CeF_(3),leading to increased collector consumption.Nonetheless,the HMPT process did not significantly affect the flotation performance of rare earths.The enrichment of fluorite in the tailings highlighted its further recovery potential.The integration of HMPT with magnetic separation and flotation presents an efficient strategy for recovering rare earths,iron,and fluorite from Bayan Obo ores.展开更多
Gas hydrate(GH)is an unconventional resource estimated at 1000-120,000 trillion m^(3)worldwide.Research on GH is ongoing to determine its geological and flow characteristics for commercial produc-tion.After two large-...Gas hydrate(GH)is an unconventional resource estimated at 1000-120,000 trillion m^(3)worldwide.Research on GH is ongoing to determine its geological and flow characteristics for commercial produc-tion.After two large-scale drilling expeditions to study the GH-bearing zone in the Ulleung Basin,the mineral composition of 488 sediment samples was analyzed using X-ray diffraction(XRD).Because the analysis is costly and dependent on experts,a machine learning model was developed to predict the mineral composition using XRD intensity profiles as input data.However,the model’s performance was limited because of improper preprocessing of the intensity profile.Because preprocessing was applied to each feature,the intensity trend was not preserved even though this factor is the most important when analyzing mineral composition.In this study,the profile was preprocessed for each sample using min-max scaling because relative intensity is critical for mineral analysis.For 49 test data among the 488 data,the convolutional neural network(CNN)model improved the average absolute error and coefficient of determination by 41%and 46%,respectively,than those of CNN model with feature-based pre-processing.This study confirms that combining preprocessing for each sample with CNN is the most efficient approach for analyzing XRD data.The developed model can be used for the compositional analysis of sediment samples from the Ulleung Basin and the Korea Plateau.In addition,the overall procedure can be applied to any XRD data of sediments worldwide.展开更多
Synthetic fertilizers are widely used to address the urgent challenge of ensuring food supplies for a growing world population in the context of climate change. However, their industrial production and use in agricult...Synthetic fertilizers are widely used to address the urgent challenge of ensuring food supplies for a growing world population in the context of climate change. However, their industrial production and use in agriculture have a negative impact on the environment and consequently on human health. While chemical fertilizers may not have to be abandoned in agricultural production systems, limiting their use could help to make agriculture sustainable and resilient to climate change. In Senegal, the level of mineral fertilizers used in market gardening has become alarming in the Niayes area. As a result, microbial biotechnologies have been promoted for biofertilizer production of common bean (Phaseolus vulgaris L.) cultivation. Rhizobial inoculums have thus been used to reduce the rate of chemical nitrogen fertilizers being applied in cropping systems. Several investigations in the laboratory, on experimental stations and in the field have shown a possibility of a significant reduction in the use of nitrogen fertilizers in common bean production. Conventional mineral fertilization use can be reduced from over 120 kg N/ha to 20 kg N/ha. This contributes both to a very significant reduction in the application rate with the same level of yield and to an improvement in the standard of living. In addition, the environmental impact of using chemical fertilizers can be mitigated. This study is a contribution to the promotion of biofertilizers adoption in agricultural systems.展开更多
This study was carried out with the aim of investigating the effect of indigenous microorganism (IMO), effective (EM) and mineral fertilizers (NPK) on the yield and nutritional value of groundnut (Arachis hypogaea) in...This study was carried out with the aim of investigating the effect of indigenous microorganism (IMO), effective (EM) and mineral fertilizers (NPK) on the yield and nutritional value of groundnut (Arachis hypogaea) in Western Cameroon (Baboutcha-Fongam). The study was conducted during two consecutive years, using a completely randomized block design of 8 treatments repeated three times in each subblock. The sub-plots were enriched with 0, 10, 20 and 40 g corresponding to the treatment of EM and IMO respectively and 3.2 g of NPK in 2019. Subsequently, the best dose that resulted in excellent yields was repeated for the rest of the experiment in 2020. The yield parameters and nutritional value of the two varieties of Arachis hypogaea used in the two consecutive years increase with the contribution of the different doses compared to the control. Overall, a significant increase (p A. hypogaea plants fertilized with EM 20 g (2.15 ± 0.24 and 2.01 ± 0.23 t/ha) and plants fertilized with NPK 3.2 g (2.36 ± 0.65 and 2.04 ± 0.17 t/ha) was not significant. On the other hand, there was a significant difference (P ≤ 0.05) between plants fertilized with IMO 10 g (2.65 ± 0.17 and 2.24 ± 0.2 t/ha) and plants fertilized with EM 20 g and plants fertilized with NPK 3.2 g for both varieties during the two years combined. In addition to being local and therefore adapted to environmental conditions, IMOs could be a promising biological means for improving soil fertility in Cameroon.展开更多
Dinosaur discoveries from India have been known since 1844, while dinosaur discoveries from Pakistan have appeared recently since 2000. 3 large and 2 small theropod dinosaurs are known from Pakistan, while 11 large an...Dinosaur discoveries from India have been known since 1844, while dinosaur discoveries from Pakistan have appeared recently since 2000. 3 large and 2 small theropod dinosaurs are known from Pakistan, while 11 large and 4 small theropods are known from India. Pakistani land uncovered many footprints and trackways of Jurassic small and large theropods, Jurassic ankylosaur and Cretaceous hadrosaur ornithischian dinosaurs, while Indian land uncovered a footprint of small and a footprint of large theropod and 1 footprint of stegosaur. Pakistan uncovered a Jurassic bone taxon of ankylosaur ornithischian based on heavily armored synapomorphies. Recently, Pakistan yielded 1 bone taxon and 1 ichno taxon of pterosaurs, while Indian land yielded 1 bone taxon of pterosaur. Pakistani land uncovered 14 bone taxa (and 2 ichno taxa) of herbivorous sauropod dinosaurs, 5 bone taxa (and 2 ichnotaxa) of carnivorous theropod dinosaurs, 1 bone taxon of ankylosaur and 2 (ichnotaxa) of ornithischian (ankylosaur and hadrosaurs) dinosaurs, 1 bone taxon (and 1 ichno taxon) of pterosaurs, 1 plesiosaur, 7 crocodiles, 1 snake, 1 bird, 11 mammals, 3 fishes, 7 invertebrates and 1 plant. This study fills a significant gap in the literature by bringing together paleontological records from an understudied geographical location, enhancing the global understanding of dinosaur paleobiogeography. Pakistan hosts Precambrian to recent sediments igneous and metamorphic rocks. Pakistan is rich in mineral resources/rocks, but it needs more attention for its development to fulfill local requirements and earn foreign exchange.展开更多
Fine debris is an important component of natural debris flows.Previous studies focused primarily on the clay minerals found in the fines,and non-clay minerals were often neglected.The effects of mineralogy of fines on...Fine debris is an important component of natural debris flows.Previous studies focused primarily on the clay minerals found in the fines,and non-clay minerals were often neglected.The effects of mineralogy of fines on debris-mass slurrying and flow behaviors of the resultant slurries are examined herein.The fines(≤0.04 mm)in the<5 mm fraction of the Dongyuege Creek debris-flow deposit is replaced with five other mineral powders with the same maximum particle size.Four types of separate and sequential experiments related to debris slurrying and slurry behaviors are carried out with the prepared clastic materials.The obtained slurrying index ranging from 0.08 to 0.18 shows that non-clay minerals also can function as the fine fractions of debris-flow materials,so long as the requirement of grain size distribution is met.Equidimensional,non-clay minerals making up fines of debris flows can increase the upper solid concentration limits of slurrying(with a maximum of 0.692)and peak values of relative excess water pressure(measured maximum mean peak value is 0.99),leading to higher momentum and higher competence,and thereby more destructive catastrophe.The sediments with platy non-clay mineral-dominated fines have potential for mobilizing into small-to medium-size debris flows with a relatively small competence.Clay minerals in the fines may indeed enhance the liquefaction potential of debris masses by expanding the difference between upper and lower solid concentration limits of slurrying(0.413 and 0.238,respectively,for pure kaolinite),but they significantly suppress the momentum,competence,and destructive power of potential debris flows by lowering upper solid concentration limit of slurrying of debris masses.Alpine catchments rich in non-clay minerals,notably those releasing dolomite into loose sediments,may be more prone to threatening and destructive debris flows.The basin producing clay minerals should be more susceptible to lowmagnitude/high-frequency debris flows with less devastating consequences.展开更多
In this study,Schwertmannite,Akaganéite and ammoniojarosite were biosynthesized by different bacteria and characterized.The results showed that bacteria are critical in mediating the mineral formation process:the...In this study,Schwertmannite,Akaganéite and ammoniojarosite were biosynthesized by different bacteria and characterized.The results showed that bacteria are critical in mediating the mineral formation process:the morphology,crystallinity,grain size and specific surface area of each mineral varied upon different bacteria and culturing conditions.In addition,the formed minerals’elemental composition and group disparity lead to different morphology,crystallinity and subsequent adsorption performance.In particular,adsorption difference existed in iron minerals biosynthesized by different bacteria.The maximal adsorption capacities of Akaganéite,Schwertmannite and ammoniojarosite were 26.6 mg/g,17.5 mg/g and 3.90 mg/g respectively.Cr(VI)adsorption on iron-minerals involves hydrogen bonding,electrostatic interaction,and ligand exchange.The adsorption only occurred on the surface of ammoniojarosite,while for Akaganéite and Schwertmannite,the tunnel structure greatly facilitated the adsorption process and improved adsorption capacity.Thus,the molecular structure is the primary determining factor for adsorption performance.Collectively,the results can provide useful information in selecting suitable bacteria for synthesizing heavy-metal scavenging minerals according to different environmental conditions.展开更多
基金financially supported by the Hainan Province Science and Technology Special Fund(Grant no:ZDYF2024XDNY187).
文摘Background:Excessive use of inorganic trace minerals(ITMs)in swine production leads to high fecal mineral excretion and environmental risks,while most studies on organic trace minerals(OTMs)focus on single elements,with limited data on the synergistic effects and molecular mechanisms of combined OTMs(Fe,Cu,Mn,Zn)in growing-finishing pigs.Methods:This study aimed to investigate the effects of graded levels of micromineral proteinates(combined OTMs)on growth performance,mineral metabolism,and mRNA expression of mineral regulatory proteins.A total of 360 crossbred Duroc×Landrace×Large White pigs(initial body weight 47.1±4.8 kg)were randomly assigned to 6 dietary treatments:basal diet without microminerals(CON),basal diet with ITMs at commercially recommended levels(IT),and basal diets with 15%(OT 15%),25%(OT 25%),35%(OT 35%)commercially recommended levels(CRL)of combined micromineral proteinates.After a 70-day feeding trial,samples were analyzed using ICP-OES,ELISA,and RT-qPCR.Results:Results showed that reduced levels(15-35%CRL)of micromineral proteinates did not significantly affect average daily gain,average daily feed intake,or feed conversion ratio(gain-to-feed ratio)compared to IT(P>0.05),but significantly increased plasma Cu(1.73-1.83μg/mL)and Zn(1.72-1.97μg/mL)concentrations(P<0.05)and elevated activities of Cu/Zn-superoxide dismutase(32.9-35.9 U/L)and manganese superoxide dismutase(20.5-24.1 U/L)compared to CON(P<0.05),with no significant differences from IT(P>0.05).Fecal excretion of Fe,Cu,Mn,and Zn was significantly reduced by 35-50%in OT 15%-OT 35%groups compared to IT(P<0.05).OT 25%group exhibited the highest apparent absorptivity of Fe(38.5%),Cu(27.8%),and Zn(42.4%)(P<0.05),which was associated with significantly regulated mRNA expression of mineral regulatory proteins:upregulated DMT1,FPN1,ZIP4,and MT1A in the duodenum,and modulated HAMP,ATP7B,ZIP14,and ZnT1 in the liver(P<0.05).Conclusion:In conclusion,dietary supplementation with 25%CRL or less of combined micromineral proteinates can fully meet the nutritional needs of growing-finishing pigs,improve mineral absorptivity,and reduce fecal mineral excretion by regulating intestinal and hepatic mineral transport and homeostatic proteins,providing a sustainable alternative to high-dose ITMs.
基金supported by the National Natural Science Foundation of China(Nos.U20A20267 and 22376223)Hunan Provincial Natural Science Foundation(No.2023JJ0065).
文摘Uranyl arsenate minerals,which exhibit low solubility,serve as major sinks for U and As,playing a crucial role in controlling the mobility of U and As in the environment.However,the specific mechanisms underly-ing the formation of uranyl arsenate minerals have remained largely elusive.Herein,the formation pathway of the non-charged UO_(2)(H_(2)AsO_(4))_(2)·nH_(2)O0 complex was investigated to elucidate the early formation of the UO_(2)(H_(2)AsO_(4))_(2)·nH_(2)O mineral(where n represents the stoichiometric number of H_(2)O),a representative uranyl arsenate mineral.Based on the combination experiments of U(VI)and As(V),our findings underscore the sig-nificant dependence of UO_(2)(H_(2)AsO_(4))_(2)·nH_(2)O0 formation on solution pH(4.0–10.0).Density functional theory(DFT)calculations reveal a two-step reaction involving two distinct pathways(Pathway 1 and Pathway 2)for the formation of UO_(2)(H_(2)AsO_(4))_(2)·nH_(2)O,and the intermediate was confirmed by in situ Raman and fluorescence spec-troscopy.Specifically,the hydroxyl‑connected uranyl(UO_(2)OH^(+))reacts with the protonated arsenate(H_(2)AsO_(4)^(-))species to form the intermediate UO_(2)HAsO4·H_(2)O(Pathway 1)or UO_(2)OH–H2AsO4(Pathway 2)with a U/As ratio of 1:1.Meanwhile,all the transition states also were obtained and the energy barrier suggested that the UO_(2)(H_(2)AsO_(4))_(2)·2H_(2)O0 formed by Pathway 1 is thermodynamically favored over Pathway 2,and may serve as the primary fundamental structural unit or precursor for the early formation of the UO_(2)(H_(2)AsO_(4))_(2)·nH_(2)O mineral phase.Altogether,this study contributes to advancing the understanding of the formation of uranyl arsenate min-erals at the molecular scale and provides a theoretical basis for predicting and regulating uranium and arsenic mobilization in their coexisting environment.
基金supported by Fundamental Research Projects of Yunnan Province,China(Nos.202101BE070001-009,202301AU070189).
文摘Mineral fulvic acid(MFA)was used as an eco-friendly pyrite depressant to recover chalcopyrite by flotation with the use of the butyl xanthate as a collector.Flotation experiments showed that MFA produced a stronger inhibition effect on pyrite than on chalcopyrite.The separation of chalcopyrite from pyrite was realized by introducing 150 mg/L MFA at a pulp pH of approximately 8.0.The copper grade,copper recovery,and separation efficiency were 28.03%,84.79%,and 71.66%,respectively.Surface adsorption tests,zeta potential determinations,and localized electrochemical impedance spectroscopy tests showed that more MFA adsorbed on pyrite than on chalcopyrite,which weakened the subsequent interactions between pyrite and the collector.Atomic force microscope imaging further confirmed the adsorption of MFA on pyrite,and X-ray photoelectron spectroscopy results indicated that hydrophilic Fe-based species on the pyrite surfaces increased after exposure of pyrite to MFA,thereby decreasing the floatability of pyrite.
基金financially supported by Zijin Mining Group(No.01612216)the Ministry of Natural Resources,China(No.ZKKJ202426)。
文摘The Zijinshan ore field located in southwestern Fujian Province,China,is a representative porphyry-epithermal ore system hosting diverse mineralization types(Mao et al.,2013).The ore field comprises of the Zijinshan highsulfidation Cu-Au deposit,the Luoboling porphyry Cu-Mo deposit,the transitional style Cu deposit(Longjiangting and Wuziqilong)and the Yueyang low-sulfidation Agpolymetallic deposit(Zhang,2013;Zhang et al.,2003)
基金support from the National Natural Science Foundation of China(51604288)the Beijing Natural Science Foundation(IS23043)+1 种基金the Science Foundation of China University of Petroleum-Beijing(ZX20200133)the Research and Development Fund of China Huaneng Group Clean Energy Technology Research Institute(QNYJJ22-21).
文摘The substantial emissions of greenhouse gases,particularly CO_(2),constitute a primary driver of global warming.CCUS is proposed as an effective mitigation strategy which is often estimated to account for about 15%of cumulative carbon emission reduction.In-situ CO_(2) mineralization sequestration,compared to conventional geological storage methods such as depleted oil and gas reservoirs,unmineable coal seams,and deep saline aquifers,offers the advantage of permanent immobilization of injected carbon.However,uncertainties persist regarding the characteristics of geochemical interactions under reservoir pore conditions,as well as the kinetic mechanisms of mineralization reactions.Additionally,geochemical reactions may lead to solid particle transport and deposition,potentially causing pore throat occlusion.Pilot projects in Iceland and the United States have demonstrated the feasibility of this technology,but the field remains in the early deployment stage.In this review,the mechanisms of in-situ mineralization have been elucidated,the primary factors influencing the reaction kinetics have been discussed,and the current research status in this field has been summarized.It is emphasized that establishing a reliable system for evaluating storage capacity and understanding the kinetic mechanisms governing CO_(2) conversion into minerals at multi-phase interfaces are key priorities for future work.
基金financially supported by the Provincial Natural Science Foundation of Hunan(Nos.2019JJ50831,2023JJ30505 and 2023JJ40541)the China Postdoctoral Science Foundation(Nos.2017M622597 and 2021M690591)+2 种基金the Open Research Fund Program of Fundamental Science on Radioactive Geology and Exploration Technology Laboratory(East China University of Technology)(No.2022RGET04)the National Foreign Expert Project(No.G2022029012L)the National Nature Science Foundation of China(No.41002022)。
文摘The Jiuyishan granitic complex,located in the Nanling Range,South China,is composed of five granitic plutons(Xuehuading,Jinjiling,Pangxiemu,Shaziling and Xishan).Zircon U-Pb dating of four plutons(Jinjiling,Pangxiemu,Shaziling and Xishan)yielded similar ages of approximately 153 Ma,indicating indistinguishable ages within error.Three plutons except the Shaziling pluton,have consistentε_(Nd)(t)(-7.8 to-5.8)andε_(Hf)(t)(-9.1 to-2.2)values,which are similar to those of the lower crustal granulitic metasedimentary and meta-igneous rocks in South China.Compared to other three plutons,the Shaziling pluton has consistentε_(Nd)(t)(-7.4 to-6.8)andε_(Hf)(t)(-7.5 to-4.7)values and shows similar source,but the Shaziling mafic microgranular enclaves(MMEs)show variableε_(Hf)(t)(-14.2 to 4.8)values,indicating a remarkable mantle magma injection of the Shaziling pluton.Zircon Ce/Sm-Yb/Gd,whole-rock CaO-P_(2)O_(5)and CaO-TiO_(2)linear trends reveal that from the Xishan to the Shaziling and from the Jinjiling to the Pangxiemu granites,they experienced apatite and titanite fractionation,respectively.Zircon Th,U,Nb,Ta,Hf,Ti,Y,P and rare earth element(REE)contents and whole-rock Sr,Ba and Rb contents also show that the Shaziling,Xishan,Jinjiling and Pangxiemu granites followed a discontinuous evolutionary series,but the Pangxiemu granites exhibit highly evolved nature.Four main controlling factors of W-Sn and rare metal mineralization in granitic rocks were discussed,and we found that the mineralization in Jiuyishan granitic complex was mainly controlled by the fractionation degree and crystallization temperature,but were rarely affected by oxygen fugacity and mantle material input.The Pangxiemu granites show particularly higher Rb and Ta contents than the other three plutons,implying that the ore deposits developed in the Jiuyishan Complex were directly related to the most evolved Pangxiemu pluton,with the occurrence of Rb and Ta as the most likely rare metal mineralization in the Jiuyishan District.A crystal mush model is proposed to interpret the petrogenetic and mineralizing processes of the Jiuyishan granitic complex.
基金supported by the Key Research Program of the Institute of Geology&Geophysics,CAS(Grant No.IGGCAS-201903).
文摘Natural gas hydrates widely accumulate in submarine sediments composed of clay minerals.However,due to the complex physiochemistry and micron-sized particles of clay minerals,their effects on methane hydrate(MH)formation and dissociation are still in controversy.In this study,montmorillonite and illite were separately mixed with quartz sand to investigate their effects on MH formation and dissociation.The microstructure of synthesized samples was observed by cryo-SEM innovatively to understand the effects of montmorillonite and illite on MH phase transition in micron scale.Results show that montmorillonite and illite both show the inhibition on MH formation kinetics and water-to-hydrate conversion,and illite shows a stronger inhibition.The 10 wt%montmorillonite addition significantly retards MH formation rate,and the 20 wt%montmorillonite has a less inhibition on the rate.The increase of illite mass ratio(0-20 wt%)retards the rate of MH formation.As the content of clay minerals increase,the water-to-hydrate conversion decreases.Cryo-SEM images presented that montmorillonite aggregates separate as individual clusters while illite particles pack as face-to-face configuration under the interaction with water.The surface-overlapped illite aggregates would make sediments pack tightly,hinder the contact between gas and water,and result in the more significant inhibition on MH formation kinetics.Under the depressurization method,the addition of clay minerals facilitates MH dissociation rate.Physicochemical properties of clay minerals and MH distribution in the pore space lead to the faster dissociation rate in clay-containing sediments.The results of this study would provide beneficial guides on geological investigations and optimizing strategies of natural gas production in marine hydrate-bearing sediments.
基金supported by the National Key Research and Development Program(Nos.2023YFC3707101 and 2023YFF0614301)the Tsinghua University Initiative Scientific Research Program(No.2023Z02JMP001)the Linghang Project of School of Environment(No.025108011).
文摘Carbon dioxide (CO_(2)) mineralization technology has attracted significant attention, due tothe synergistic terminal treatment of CO_(2) and industrial waste. The combined CO_(2) mineralizationprocess with steel enterprises is a promising route to simultaneously address CO_(2)emissions and SS treatment. Recently, a serial of the relevant work focus on a single type ofsteel slag (SS), and the understanding of CO_(2) absorption by mineralization of various SS isvery lacking.Meanwhile, it is urgent requirement for systematic summary and discussion onhow to make full use of the mineralized products produced after the mineralization of CO_(2)in SS. This review aims to investigate the progress of CO_(2) mineralization using SS, includingthe potential applications of mineralization products, as well as the environmental impactand risk assessment ofmineralization product applications. Currently, the application of SSmineralization products is primarily focused on their use as construction materials with loweconomic value. With usage of the mineralization products for ecological restoration (e.g.sandy soil remediation) was treated as an advanced route, but still remaining challenge infunctional materials preparation, and its technical economy and possible hazards need tobe further explored by long-term experimental tests.
基金supported by the National Natural Science Foundation of China(No.42107052)Beijing Natural Science Foundation(No.JQ21031).
文摘As a widely used fertilizer,urea significantly promotes the leaching of dissolved organic nitrogen(DON)in soils and aggravates nitrogen contamination in groundwater.Clayminerals are considered the most important factor in retaining DON.However,the effect of urea on the retention of DON with different molecular weights by clay minerals is unknown.In this study,the retention of both low-molecular weight DON(LMWD)and high-molecular weight DON(HMWD)by clay minerals in the presence of urea was investigated.For this purpose,batch adsorption and soil column leaching experiments,characterization analysis(Fourier transform infrared spectroscopy X-ray diffraction,and X-ray photoelectron spectroscopy),and molecular dynamics simulations were carried out.Urea had a positive effect on the adsorption of LMWD,whereas a competitive effect existed for the adsorption of HMWD.The dominant interactions among DON,urea,and clay minerals included H-bonding,ligand exchange,and cation exchange.The urea was preferentially adsorbed on clay minerals and formed a complex,which provided more adsorption sites to LMWD and only a few to HMWD.The presence of urea increased the retention of LMWD and decreased the retention of HMWD in clay minerals.The retention capacity of LMWD increased by 6.9%–12.8%,while that of HMWD decreased by 6.7%–53.1%.These findings suggest that LMWD tended to be trapped in soils,while HMWD was prone to be leached into groundwater,which can be used to evaluate the leaching of DON from soil to groundwater.
基金supported by the National Key Research and Development Program of China(No.2019YFC1804202)the National Natural Science Foundation of China(Nos.22020102004 and 22125603)+1 种基金Tianjin Municipal Science and Technology Bureau(No.21JCZDJC00280)the Fundamental Research Funds for the Central Universities,and the Ministry of Education of China(No.T2017002).
文摘Polybrominated biphenyl ethers(PBDEs)and polycyclic aromatic hydrocarbons(PAHs)are commonly detected contaminants at e-waste recycling sites.Against the conventional wisdom that PBDEs and PAHs are highly immobile and persist primarily in shallowsurface soils,increasing evidence shows that these compounds can leach into the groundwater.Herein,we compare the leachabilities of PBDEs vs.PAHs from contaminated soils collected at an e-waste recycling site in Tianjin,China.Considerable amounts of BDE-209(0.3–2 ng/L)and phenanthrene(42–106 ng/L),the most abundant PBDE and PAH at the site,are detected in the effluents of columns packed with contaminated soils,with the specific concentrations varying with hydrodynamic and solution chemistry conditions.Interestingly,the leaching potential of BDE-209 appears to be closely related to the release of colloidal mineral particles,whereas the leachability of phenanthrene correlates well with the concentration of dissolved organic carbon in the effluent,but showing essentially no correlation with the concentration of mineral particles.The surprisingly different trends of the leachability observed between BDE-209 and phenanthrene is counterintuitive,as PBDEs and PAHs often co-exist at e-waste recycling sites(particularly at the sites wherein incineration is being practiced)and share many similarities in terms of physicochemical properties.One possible explanation is that due to its extremely low solubility,BDE-209 predominantly exists in free-phase(i.e.,as solid(nano)particles),whereas the more soluble phenanthrene is mainly sorbed to soil organic matter.Findings in this study underscore the need to better understand the mobility of highly hydrophobic organic contaminants at contaminated sites for improved risk management.
文摘This study investigates the mineralogy and mineral-chemistry of a newly discovered Au-Ag-Bi-Te mineralization at the Aydindere Fe-Cu skarn deposit,within the Pontides Tectonic Unit,northeastern Turkey.The mineralization is developed in the skarn zone at the contact between Upper Cretaceous andesite-pyroclastic rocks and a Paleocene–Eocene I-type granitoid.The principal ore minerals of the Aydindere Fe-Cu deposit are oxides(magnetite),sulfides(pyrite-chalcopyritegalena-sphalerite),tellurides/sulfotellurides(tetradymite,hessite),sulfosalts(wittichenite,emplectite,aikinite) and native gold-electrum.Skarn minerals include anhydrous phases(garnet) formed in a prograde stage and hydrous phases(amphibole,epidote,chlorite),which were formed in a retrograde stage in association with quartz,adularia,apatite and late calcite.Sulfides,tellurides and sulfosalts are introduced during the retrograde stage.The Au-Ag-Bi-Te mineralization was detected for the first time within the western ore body of the Aydindere deposit,and occurs in calcite-bearing sulfide bodies that cut magnetite-garnet-amphibole-epidote skarns with magnetite ores of different grade,including massive magnetite.Chlorite geothermometry indicates formation of the Au-Ag-BiTe mineralization at temperatures between 300 and 250 ℃,during the retrograde skarn evolution.Assuming the temperature is ~275 ℃,logfS_(2) =-10.5 to-13,logfO_(2) =-37 to-33,and logf Te2 values range from approximately-12 to-8.5 were estimated.The available mineralogical and geological data(presences of magnetite,oxidized-type tellurides/sulfotellurides,and andraditic garnets,and absence of pyrrhotite and arsenopyrite) suggest that Aydindere is an oxidized Au-bearing skarn deposit.The discovery of Au-Ag-Bi-Te mineralization at Aydindere increases its productivity and requires more detailed exploration in the deposit for precious(Au,Ag) and critical(Bi,Te) metals.
文摘The precise identification of quartz minerals is crucial in mineralogy and geology due to their widespread occurrence and industrial significance.Traditional methods of quartz identification in thin sections are labor-intensive and require significant expertise,often complicated by the coexistence of other minerals.This study presents a novel approach leveraging deep learning techniques combined with hyperspectral imaging to automate the identification process of quartz minerals.The utilizied four advanced deep learning models—PSPNet,U-Net,FPN,and LinkNet—has significant advancements in efficiency and accuracy.Among these models,PSPNet exhibited superior performance,achieving the highest intersection over union(IoU)scores and demonstrating exceptional reliability in segmenting quartz minerals,even in complex scenarios.The study involved a comprehensive dataset of 120 thin sections,encompassing 2470 hyperspectral images prepared from 20 rock samples.Expert-reviewed masks were used for model training,ensuring robust segmentation results.This automated approach not only expedites the recognition process but also enhances reliability,providing a valuable tool for geologists and advancing the field of mineralogical analysis.
基金the financial support received from the Key Program of National Natural Science Foundation of China(No.52130406)the National Key R&D Program of China(Nos.2021YFC2901000 and 2022YFC2905800)+1 种基金the General Program of National Natural Science Foundation of China(No.52274253)Natural Science Foundation Innovation Group Project of Hubei Province,China(No.2023AFA044)。
文摘Hydrogen-based mineral phase transformation(HMPT)technology has demonstrated its effectiveness in separating iron and enriching rare earths from Bayan Obo refractory ores.However,further research is needed to clarify the phase composition and floatability of rare earths obtained after HMPT owing to the associated phase transformations.This study explored the mineralogical characteristics and separation behavior of rare earths in HMPT-treated iron tailings.Process mineralogy studies conducted via BGRIMM process mineralogy analysis and X-ray diffraction revealed that the main valuable minerals in the tailings included rare-earth oxides(9.15wt%),monazite(5.31wt%),and fluorite(23.52wt%).The study also examined the impact of mineral liberation and gangue mineral intergrowth on flotation performance.Flotation tests achieved a rare-earth oxide(REO)grade of 74.12wt% with a recovery of 34.17% in open-circuit flotation,whereas closed-circuit flotation resulted in a REO grade of 60.27wt% with a recovery of 73%.Transmission electron microscopy and scanning electron microscopy coupled with energy-dispersive spectroscopy revealed that monazite remained stable during the HMPT process,while bastnaesite was transformed into Ce_(7)O_(12)and CeF_(3),leading to increased collector consumption.Nonetheless,the HMPT process did not significantly affect the flotation performance of rare earths.The enrichment of fluorite in the tailings highlighted its further recovery potential.The integration of HMPT with magnetic separation and flotation presents an efficient strategy for recovering rare earths,iron,and fluorite from Bayan Obo ores.
基金supported by the Gas Hydrate R&D Organization and the Korea Institute of Geoscience and Mineral Resources(KIGAM)(GP2021-010)supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(No.2021R1C1C1004460)Korea Institute of Energy Technology Evaluation and Planning(KETEP)grant funded by the Korean government(MOTIE)(20214000000500,Training Program of CCUS for Green Growth).
文摘Gas hydrate(GH)is an unconventional resource estimated at 1000-120,000 trillion m^(3)worldwide.Research on GH is ongoing to determine its geological and flow characteristics for commercial produc-tion.After two large-scale drilling expeditions to study the GH-bearing zone in the Ulleung Basin,the mineral composition of 488 sediment samples was analyzed using X-ray diffraction(XRD).Because the analysis is costly and dependent on experts,a machine learning model was developed to predict the mineral composition using XRD intensity profiles as input data.However,the model’s performance was limited because of improper preprocessing of the intensity profile.Because preprocessing was applied to each feature,the intensity trend was not preserved even though this factor is the most important when analyzing mineral composition.In this study,the profile was preprocessed for each sample using min-max scaling because relative intensity is critical for mineral analysis.For 49 test data among the 488 data,the convolutional neural network(CNN)model improved the average absolute error and coefficient of determination by 41%and 46%,respectively,than those of CNN model with feature-based pre-processing.This study confirms that combining preprocessing for each sample with CNN is the most efficient approach for analyzing XRD data.The developed model can be used for the compositional analysis of sediment samples from the Ulleung Basin and the Korea Plateau.In addition,the overall procedure can be applied to any XRD data of sediments worldwide.
文摘Synthetic fertilizers are widely used to address the urgent challenge of ensuring food supplies for a growing world population in the context of climate change. However, their industrial production and use in agriculture have a negative impact on the environment and consequently on human health. While chemical fertilizers may not have to be abandoned in agricultural production systems, limiting their use could help to make agriculture sustainable and resilient to climate change. In Senegal, the level of mineral fertilizers used in market gardening has become alarming in the Niayes area. As a result, microbial biotechnologies have been promoted for biofertilizer production of common bean (Phaseolus vulgaris L.) cultivation. Rhizobial inoculums have thus been used to reduce the rate of chemical nitrogen fertilizers being applied in cropping systems. Several investigations in the laboratory, on experimental stations and in the field have shown a possibility of a significant reduction in the use of nitrogen fertilizers in common bean production. Conventional mineral fertilization use can be reduced from over 120 kg N/ha to 20 kg N/ha. This contributes both to a very significant reduction in the application rate with the same level of yield and to an improvement in the standard of living. In addition, the environmental impact of using chemical fertilizers can be mitigated. This study is a contribution to the promotion of biofertilizers adoption in agricultural systems.
文摘This study was carried out with the aim of investigating the effect of indigenous microorganism (IMO), effective (EM) and mineral fertilizers (NPK) on the yield and nutritional value of groundnut (Arachis hypogaea) in Western Cameroon (Baboutcha-Fongam). The study was conducted during two consecutive years, using a completely randomized block design of 8 treatments repeated three times in each subblock. The sub-plots were enriched with 0, 10, 20 and 40 g corresponding to the treatment of EM and IMO respectively and 3.2 g of NPK in 2019. Subsequently, the best dose that resulted in excellent yields was repeated for the rest of the experiment in 2020. The yield parameters and nutritional value of the two varieties of Arachis hypogaea used in the two consecutive years increase with the contribution of the different doses compared to the control. Overall, a significant increase (p A. hypogaea plants fertilized with EM 20 g (2.15 ± 0.24 and 2.01 ± 0.23 t/ha) and plants fertilized with NPK 3.2 g (2.36 ± 0.65 and 2.04 ± 0.17 t/ha) was not significant. On the other hand, there was a significant difference (P ≤ 0.05) between plants fertilized with IMO 10 g (2.65 ± 0.17 and 2.24 ± 0.2 t/ha) and plants fertilized with EM 20 g and plants fertilized with NPK 3.2 g for both varieties during the two years combined. In addition to being local and therefore adapted to environmental conditions, IMOs could be a promising biological means for improving soil fertility in Cameroon.
文摘Dinosaur discoveries from India have been known since 1844, while dinosaur discoveries from Pakistan have appeared recently since 2000. 3 large and 2 small theropod dinosaurs are known from Pakistan, while 11 large and 4 small theropods are known from India. Pakistani land uncovered many footprints and trackways of Jurassic small and large theropods, Jurassic ankylosaur and Cretaceous hadrosaur ornithischian dinosaurs, while Indian land uncovered a footprint of small and a footprint of large theropod and 1 footprint of stegosaur. Pakistan uncovered a Jurassic bone taxon of ankylosaur ornithischian based on heavily armored synapomorphies. Recently, Pakistan yielded 1 bone taxon and 1 ichno taxon of pterosaurs, while Indian land yielded 1 bone taxon of pterosaur. Pakistani land uncovered 14 bone taxa (and 2 ichno taxa) of herbivorous sauropod dinosaurs, 5 bone taxa (and 2 ichnotaxa) of carnivorous theropod dinosaurs, 1 bone taxon of ankylosaur and 2 (ichnotaxa) of ornithischian (ankylosaur and hadrosaurs) dinosaurs, 1 bone taxon (and 1 ichno taxon) of pterosaurs, 1 plesiosaur, 7 crocodiles, 1 snake, 1 bird, 11 mammals, 3 fishes, 7 invertebrates and 1 plant. This study fills a significant gap in the literature by bringing together paleontological records from an understudied geographical location, enhancing the global understanding of dinosaur paleobiogeography. Pakistan hosts Precambrian to recent sediments igneous and metamorphic rocks. Pakistan is rich in mineral resources/rocks, but it needs more attention for its development to fulfill local requirements and earn foreign exchange.
基金supported by the National Natural Science Foundation of China(41931294)the National Natural Science Foundation of China-Yunnan Joint Fund(U1502232,U1033601)。
文摘Fine debris is an important component of natural debris flows.Previous studies focused primarily on the clay minerals found in the fines,and non-clay minerals were often neglected.The effects of mineralogy of fines on debris-mass slurrying and flow behaviors of the resultant slurries are examined herein.The fines(≤0.04 mm)in the<5 mm fraction of the Dongyuege Creek debris-flow deposit is replaced with five other mineral powders with the same maximum particle size.Four types of separate and sequential experiments related to debris slurrying and slurry behaviors are carried out with the prepared clastic materials.The obtained slurrying index ranging from 0.08 to 0.18 shows that non-clay minerals also can function as the fine fractions of debris-flow materials,so long as the requirement of grain size distribution is met.Equidimensional,non-clay minerals making up fines of debris flows can increase the upper solid concentration limits of slurrying(with a maximum of 0.692)and peak values of relative excess water pressure(measured maximum mean peak value is 0.99),leading to higher momentum and higher competence,and thereby more destructive catastrophe.The sediments with platy non-clay mineral-dominated fines have potential for mobilizing into small-to medium-size debris flows with a relatively small competence.Clay minerals in the fines may indeed enhance the liquefaction potential of debris masses by expanding the difference between upper and lower solid concentration limits of slurrying(0.413 and 0.238,respectively,for pure kaolinite),but they significantly suppress the momentum,competence,and destructive power of potential debris flows by lowering upper solid concentration limit of slurrying of debris masses.Alpine catchments rich in non-clay minerals,notably those releasing dolomite into loose sediments,may be more prone to threatening and destructive debris flows.The basin producing clay minerals should be more susceptible to lowmagnitude/high-frequency debris flows with less devastating consequences.
基金Project(42277256)supported by the National Natural Science Foundation of ChinaProjects(HBKT-2021011,HBKT-2021014)supported by the Hunan Province Environmental Protection Research Program,ChinaProject(CDSKY-2023-05)supported by the Scientific Research of Project Hunan Provincial Urban Geological Survey and Monitoring Institute,China。
文摘In this study,Schwertmannite,Akaganéite and ammoniojarosite were biosynthesized by different bacteria and characterized.The results showed that bacteria are critical in mediating the mineral formation process:the morphology,crystallinity,grain size and specific surface area of each mineral varied upon different bacteria and culturing conditions.In addition,the formed minerals’elemental composition and group disparity lead to different morphology,crystallinity and subsequent adsorption performance.In particular,adsorption difference existed in iron minerals biosynthesized by different bacteria.The maximal adsorption capacities of Akaganéite,Schwertmannite and ammoniojarosite were 26.6 mg/g,17.5 mg/g and 3.90 mg/g respectively.Cr(VI)adsorption on iron-minerals involves hydrogen bonding,electrostatic interaction,and ligand exchange.The adsorption only occurred on the surface of ammoniojarosite,while for Akaganéite and Schwertmannite,the tunnel structure greatly facilitated the adsorption process and improved adsorption capacity.Thus,the molecular structure is the primary determining factor for adsorption performance.Collectively,the results can provide useful information in selecting suitable bacteria for synthesizing heavy-metal scavenging minerals according to different environmental conditions.
