Fossil plants from the carbonaceous shale of upper part of the Lower Carboniferous Jiujialu Formation in Lindai bauxite deposit fill a gap regarding the distribution of Early Carboniferous flora in Central Guizhou Pro...Fossil plants from the carbonaceous shale of upper part of the Lower Carboniferous Jiujialu Formation in Lindai bauxite deposit fill a gap regarding the distribution of Early Carboniferous flora in Central Guizhou Province.Here the Lindai plant assemblage is systematically described,and its composition and geological age are discussed.Research demonstrates that 9 species in 6 genera of the fossil plants are discovered in this study,and they belong to lycopsids,sphenopsids and ferns,respectively.Based on the analysis of the floral composition,the geological age of the Lindai plant assemblage belongs to the Early Carboniferous Viséan.The discovery of Lindai plant assemblage not only provides a new fossil evidence to restrict the age of bauxite deposits in Lower Carboniferous Jiujialu Formation of Central Guizhou Province,but also has great significance to further research the palaeoecological setting and floral evolution during the Early Carboniferous.展开更多
Karst sinkholes with natural negative landform provide favorable conditions for the pumped storage reservoir construction for less excavation work.However,the construction of the reservoir would plug the natural karst...Karst sinkholes with natural negative landform provide favorable conditions for the pumped storage reservoir construction for less excavation work.However,the construction of the reservoir would plug the natural karst channels for water and air,which would cause remarkable air pressure in karst channels when the groundwater level fluctuates.A large laboratory simulation test was carried out to study the air pressure variation of a reservoir built on the karst sinkhole.The air pressure in the karst channel and inside the model was monitored during the groundwater rising and falling process.Result showed that the variation of air pressure in the karst channel and the surrounding rock exhibited a high degree of similarity.The air pressure increased rapidly at the initial stage of water level rising,followed by a slight decrease,then the air pressure increased sharply when the water level approached the top of the karst cave.The initial peak of air pressure and the final peak of air pressure were defined,and both air pressure peaks were linearly increasing with the water level rising rate.The negative air pressure was also analyzed during the drainage process,which was linearly correlated with the water level falling rate.The causes of air pressure variation in karst channels of a pumped storage reservoir built on the karst sinkhole were discussed.The initial rapid increase,then slight decrease and final sudden increase of air pressure were controlled by the combined effects of air compression in karst channel and air seepage into the surrounding rock.For the drainage process,the instant negative air pressure and gradual recovering of air pressure were controlled by the combined effects of negative air pressure induced by water level falling and air supply from surrounding rock.This work could provide valuable reference for the reservoir construction in karst area.展开更多
In the northwestern margin of the Youjiang basin(NWYB)in SW China,many Carlin-like gold deposits are highly antimony(Sb)-rich,and many vein-type Sb deposits contain much Au.These deposits have similar ages,host rocks,...In the northwestern margin of the Youjiang basin(NWYB)in SW China,many Carlin-like gold deposits are highly antimony(Sb)-rich,and many vein-type Sb deposits contain much Au.These deposits have similar ages,host rocks,ore-forming temperatures,ore-related alterations and ore mineral assemblages,but the Au and Sb metallogenic relations and their ore-forming process remain enigmatic.Here we investigate the large Qinglong Sb deposit in the NWYB,which has extensive sub-economic Au mineralization,and present a new metallogenic model based on in-situ trace elements(EPMA and LA-ICP-MS)and sulfur isotopes(NanoSIMS and fs-LA-MC-ICPMS)of the ore sulfides.At Qinglong,economic Sb ores contain coarse-grained stibnite,jasperoid quartz and fluorite,whilst the sub-economic Au–Sb ores comprise dominantly veined quartz,arsenian pyrite and fine-grained stibnite.Three generations of ore-related pyrite(Py1,Py2 and Py3)and two generations of stibnite(Stb1 and Stb2)are identified based on their texture,chemistry,and sulfur isotopes.The pre-ore Py1 is characterized by the lower ore element(Au,As,Sb,Cu and Ag)contents(mostly below the LA-ICP-MS detection limit)and Co/Ni ratios(average 0.31)than the ore-stage pyrites(Py2 and Py3),implying a sedimentary/diagenetic origin.The Py2 and Py3 have elevated ore element abundance(maximum As=6500 ppm,Au=22 ppm,Sb=6300 ppm,Cu=951 ppm,Ag=77 ppm)and Co/Ni ratios(average 1.84),and have positive As vs.Au–Sb–Cu–Ag correlations.Early-ore Stb1 has lower As(0.12–0.30 wt.%)than late-ore Stb2(0.91–1.20 wt.%).These features show that the progressive As enrichment in ore sulfides is accompanied by increasing Au,Sb,Cu and Ag with the hydrothermal evolution,thereby making As a good proxy for Au.As-rich,As-poor and As-free zones are identified via NanoSIMS mapping of the Au-bearing pyrite.The As-rich zones in the Qinglong Au-bearing pyrites(Py2 and Py3)and ore stibnites(Stb1 and Stb2)have narrowδ^(34)SH_(2)S ranges(-8.9‰to +4.1‰,average-3.1‰)and-2.9‰to +6.9‰,average + 1.3‰),respectively,indicating that the Au-rich and Sb-rich fluids may have had the same sulfur source.Published in-situ sulfur isotopic data of pyrite As-rich zones from other Carlin-like Au deposits(Shuiyindong,Taipingdong,Nayang,Getang and Lianhuashan)in the NWYB have similar ore-fluidδSH_(2)S values(-4.5‰to +6.7‰,average-0.6‰)to those of Qinglong.Therefore,we infer that the sulfur of both Au and Sb mineralization was derived from the same magmatic-related source(0±5‰)in the NWYB.Moreover,the core of pyrites(Py1)has variable S isotope fractionation(-18.9‰to +18.1‰,mostly +3‰to +12‰),suggesting that the higher-^(34)S H_(2)S was produced by bacterial sulfate reduction(BSR).The hydrothermal pyrite(Py2 and Py3)δ^(34)S values gradually decrease with increasing As concentrations,and ultimately,within the restricted range(-5‰to +5‰)in As-rich zones.This variation implies that the As-rich pyrite was formed through ongoing interactions of the magmatic-hydrothermal fluid with pre-existing sedimentary pyrites,causing the progressive decreasing δ^(34)S values with As content increase,Hence,the fluid/mineral interaction may have generated the observed variation in δ^(34)S and As contents.Overall,comparing the Au and Sb deposits in the NWYB,we favor a magmatic-related source for the Au–Sb–As-rich fluids,but the Au-and Sb-ore fluids were likely evolved at separate stages in the ore-forming system.展开更多
Mining-induced surface deformation disrupts ecological balance and impedes economic progress.This study employs SBAS-InSAR with 107-view of ascending and descending SAR data from Sentinel-1,spanning February 2017 to S...Mining-induced surface deformation disrupts ecological balance and impedes economic progress.This study employs SBAS-InSAR with 107-view of ascending and descending SAR data from Sentinel-1,spanning February 2017 to September 2020,to monitor surface deformation in the Fa’er Coal Mine,Guizhou Province.Analysis on the surface deformation time series reveals the relationship between underground mining and surface shifts.Considering geological conditions,mining activities,duration,and ranges,the study determines surface movement parameters for the coal mine.It asserts that mining depth significantly influences surface movement parameters in mountainous mining areas.Increasing mining depth elevates the strike movement angle on the deeper side of the burial depth by 22.84°,while decreasing by 7.74°on the shallower side.Uphill movement angles decrease by 4.06°,while downhill movement angles increase by 15.71°.This emphasizes the technology's suitability for local mining design,which lays the groundwork for resource development,disaster prevention,and ecological protection in analogous contexts.展开更多
Carbon dioxide(CO_(2))emissions from aquatic ecosystems are an important component of the karst carbon cycle process and also a key indicator for assessing the effect of karst carbon sinks.This paper reviewed the CO_(...Carbon dioxide(CO_(2))emissions from aquatic ecosystems are an important component of the karst carbon cycle process and also a key indicator for assessing the effect of karst carbon sinks.This paper reviewed the CO_(2)partial pressure(pCO_(2))and its diffusion flux(FCO_(2))in karst surface aquatic ecosystems,mainly rivers,lakes,and reservoirs,and their influencing factors summarized the methods for monitoring CO_(2)emissions in karst aquatic ecosystems and discussed their adaptation conditions in karst areas.The pCO_(2)and FCO_(2)decreased in the order of rivers>reservoirs>lakes,and the values in karst lakes were eventually significantly lower than those in global lakes.The pCO_(2)and FCO_(2)of karst aquatic ecosystems had patterns of variation with diurnal,seasonal,water depth and hydrological cycles,and spatial and temporal hetero-geneity.The sources of CO_(2)in karst waters are influenced by both internal and external sources,and the key spatial and temporal factors affecting the CO_(2)emissions from karst rivers,lakes,and reservoirs were determined in terms of physicochemical indicators,biological factors,and bio-genic elements;additionally,the process of human activity interference on CO_(2)emissions was discussed.Finally,a conceptual model illustrating the impacts of urban devel-opment,agriculture,mining,and dam construction on the CO_(2)emissions at the karst surface aquatic ecosystem is presented.Meanwhile,based on the disadvantages existing in current research,we proposed several important research fields related to CO_(2)emissions from karst surface aquatic ecosystems.展开更多
Humic acid(HA),a principal constituent of natural organic matter(NOM),manifests ubiquitously across diverse ecosystems and can significantly influence the environmental behaviors of Cd(II)in aquatic systems.Previous s...Humic acid(HA),a principal constituent of natural organic matter(NOM),manifests ubiquitously across diverse ecosystems and can significantly influence the environmental behaviors of Cd(II)in aquatic systems.Previous studies on NOM-Cd(II)interactions have primarily focused on the immobilization of Cd(II)solids,but little is known about the colloidal stability of organically complexed Cd(II)particles in the environment.In this study,we investigated the formation of HA-Cd(II)colloids and quantified their aggregation,stability,and transport behaviors in a saturated porous media representative of typical subsurface conditions.Results from batch experiments indicated that the relative quantity of HA-Cd(II)colloids increased with increasing C/Cd molar ratio and that the carboxyl functional groups of HA dominated the stability of HA-Cd(II)colloids.The results of correlation analysis between particle size,critical aggregation concentration(CCC),and zeta potential indicated that both Derjaguin-Landau-Verwey-Overbeek(DLVO)and non-DLVO interactions contributed to the enhanced colloidal stability of HA-Cd(II)colloids.Column results further confirmed that the stable HA-Cd(II)colloid can transport fast in a saturated media composed of clean sand.Together,this study provides newknowledge of the colloidal behaviors of NOM-Cd(II)nanoparticles,which is important for better understanding the ultimate cycling of Cd(II)in aquatic systems.展开更多
Dissolved organic matter(DOM)can be removed or transformed by photochemical and biological processes,producing the negative effect of transforming organic carbon into inorganic carbon,which plays a vital role in the k...Dissolved organic matter(DOM)can be removed or transformed by photochemical and biological processes,producing the negative effect of transforming organic carbon into inorganic carbon,which plays a vital role in the karst carbon cycle.However,acid mine drainage(AMD)will affect this process,so the degradation of DOM in karst river water(KRW)needs to be studied in this context.In this study,to reveal the evolution processes of DOM under photochemical and biological conditions in AMD-impacted KRW,AMD and KRW were mixed in different ratios under conditions of visible light irradiation(VL),biodegradation(BD),ultraviolet irradiation(UV)and ultraviolet irradiation+biodegradation(UV+BD).The average DOC concentrations in samples after mixing AMD and KRW in different proportions decreased significantly(by 23%)in UV+BD,which was 1.2–1.4 times higher than under the other conditions and would lead to a significant release of inorganic carbon.Further analysis of the fluorescence parameters via parallel factor analysis(PARAFAC)revealed that the DOM fluorescence components in AMD comprised mainly protein-like substances derived from autochthonous components,while the DOM fluorescence components in KRW were mainly humic-like substances with both autochthonous and allochthonous sources.Therefore,AMD could promote both the photochemical and biological degradation of DOM in karst receiving streams,resulting in the conversion of DOC to inorganic carbon.The results showed that the synergistic effects of UV+BD and AMD accelerated the degradation of DOM and the release of inorganic carbon in KRW,thus affecting the stability of the karst carbon cycle.展开更多
To investigate the stress response characteristics and shear stress transfer mechanism of BFRP(basalt fiber reinforced plastics)anchors under rainfall conditions and to explore the reinforcement effect of BFRP anchors...To investigate the stress response characteristics and shear stress transfer mechanism of BFRP(basalt fiber reinforced plastics)anchors under rainfall conditions and to explore the reinforcement effect of BFRP anchors,a comparative indoor physical model test was conducted in this study using loess mudstone slope as a typical case,and multi-attribute response data,such as slope displacement,BFRP anchor strain and axial force,were obtained.Based on the variation law of slope displacement,it can be concluded that the deformation displacement of the slope on the side reinforced by BFRP anchors is smaller than that of slopes reinforced with steel anchors;the bearing capacity of BFRP anchor is given priority in time,and the anchoring effect of BFRP anchor at the top of the slope is given priority,and the axial force value of anchor is characterized by a surface amplification effect in space;the axial force is higher around the anchor head and tends to decay as a negative exponential function as the anchor extends in the direction of the interior of the slope;the shear stress of BFRP anchor and anchorage body are unevenly distributed along the axial direction,with the maximum value occurring in the free section near the slope surface and decreases as the BFRP anchor extends towards the interior of the slope.These results can provide a theoretical basis for the optimal design of BFRP anchors.展开更多
This study addresses the limitations of Transformer models in image feature extraction,particularly their lack of inductive bias for visual structures.Compared to Convolutional Neural Networks(CNNs),the Transformers a...This study addresses the limitations of Transformer models in image feature extraction,particularly their lack of inductive bias for visual structures.Compared to Convolutional Neural Networks(CNNs),the Transformers are more sensitive to different hyperparameters of optimizers,which leads to a lack of stability and slow convergence.To tackle these challenges,we propose the Convolution-based Efficient Transformer Image Feature Extraction Network(CEFormer)as an enhancement of the Transformer architecture.Our model incorporates E-Attention,depthwise separable convolution,and dilated convolution to introduce crucial inductive biases,such as translation invariance,locality,and scale invariance,into the Transformer framework.Additionally,we implement a lightweight convolution module to process the input images,resulting in faster convergence and improved stability.This results in an efficient convolution combined Transformer image feature extraction network.Experimental results on the ImageNet1k Top-1 dataset demonstrate that the proposed network achieves better accuracy while maintaining high computational speed.It achieves up to 85.0%accuracy across various model sizes on image classification,outperforming various baseline models.When integrated into the Mask Region-ConvolutionalNeuralNetwork(R-CNN)framework as a backbone network,CEFormer outperforms other models and achieves the highest mean Average Precision(mAP)scores.This research presents a significant advancement in Transformer-based image feature extraction,balancing performance and computational efficiency.展开更多
Ultra-low emission(ULE)technology retrofits significantly impact the particulate-bound mercury(Hg)emissions from coal-fired power plants(CFPPs);however,the distribution and bioavailability of Hg in size-fractioned par...Ultra-low emission(ULE)technology retrofits significantly impact the particulate-bound mercury(Hg)emissions from coal-fired power plants(CFPPs);however,the distribution and bioavailability of Hg in size-fractioned particulate matter(PM)around the ULE-retrofitted CF-PPs are less understood.Here,total Hg and its chemical speciation in TSP(total suspended particles),PM_(10)(aerodynamic particle diameter≤10μm)and PM_(2.5)(aerodynamic particle diameter≤2.5μm)around a ULE-retrofitted CFPP in Guizhou Province were quantified.Atmospheric PM_(2.5)concentration was higher around this ULE-retrofitted CFPP than that in the intra-regional urban cities,and it had higher mass Hg concentration than other sizefractioned PM.Total Hg concentrations in PM had multifarious sources including CFPP,vehicle exhaust and biomass combustion,while they were significantly higher in autumn and winter than those in other seasons(P<0.05).Regardless of particulate size,atmospheric PM-bound Hg had lower residual fractions(<21%)while higher HCl-soluble fractions(>40%).Mass concentrations of exchangeable,HCl-soluble,elemental,and residual Hg in PM_(2.5)were higher than those in other size-fractioned PM,and were markedly elevated in autumn and winter(P<0.05).In PM_(2.5),HCl-soluble Hg presented a significantly positive relationship with elemental Hg(P<0.05),while residual Hg showed the significantly positive relationships with HCl-soluble Hg and elemental Hg(P<0.01).Overall,these results suggested that atmospheric PM-bound Hg around the ULE-retrofitted CFPP tends to accumulate in finer PM,and has higher bioavailable fractions,while has potential transformation between chemical speciation.展开更多
Algal-derived organic matter(AOM)regulates methylmercury(MeHg)fate in aquatic ecosystems,whereas its role in MeHg production and bioaccumulation in Hg-contaminated paddies is unclear.Pot and microcosm experiments were...Algal-derived organic matter(AOM)regulates methylmercury(MeHg)fate in aquatic ecosystems,whereas its role in MeHg production and bioaccumulation in Hg-contaminated paddies is unclear.Pot and microcosm experiments were thus performed to understand the response characteristics of MeHg concentrations in soil and rice in different rice-growing periods to algal decomposition.Compared to the control,algal decomposition significantly increased soil water-soluble cysteine concentrations during the rice-tillering and grain-filling periods(P<0.05).It also significantly lowered the molecular weight of soil-dissolved organic matter(SDOM)during the rice-tillering period(P<0.05)and SDOM humification/aromaticity during the grain-filling period.Compared to the control,AOM input increased the abundance of potential Hg and non-Hg methylators in soil.Furthermore,it also greatly increased soil MeHg concentrations by 25.6%-80.2%and 12.6%-66.1%during the rice-tillering and grain-filling periods,with an average of 42.25%and 38.42%,respectively,which were significantly related to the elevated cysteine in soil and the decrease in SDOM molecular weight(P<0.01).In the early stage(within 10 days of microcosm experiments),the MeHg concentrations in decayed algal particles showed a great decrease(P<0.01),suggesting a potential MeHg source in soil.Ultimately,algal decomposition greatly increased the MeHg concentrations and bioaccumulation factors in rice grains,by 72.30%and 16.77%,respectively.Overall,algal decomposition in Hg-contaminated paddies is a non-negligible factor promoting MeHg accumulation in soil-rice systems.展开更多
The Zunyi manganese deposits, which formed during the Middle to Late Permian period and are located in northern Guizhou and adjacent areas, are the core area of a series of large-medium scale manganese enrichment mine...The Zunyi manganese deposits, which formed during the Middle to Late Permian period and are located in northern Guizhou and adjacent areas, are the core area of a series of large-medium scale manganese enrichment minerogenesis in the southern margin and interior of the Yangtze platform, Southern China. This study reports the universal enrichment of rare earth elements(REEs) in Zunyi manganese deposits and examines the enrichment characteristics, metallogenic environment and genesis of REEs. The manganese ore bodies present stratiform or stratoid in shape, hosted in the silicon–mud–limestones of the Late Permian Maokou Formation. The manganese ores generally present lamellar, massive, banded and brecciated structures, and mainly consist of rhodochrosite, ropperite, tetalite, capillitite, as well as contains paragenetic gangue minerals including pyrite, chalcopyrite, rutile, barite, tuffaceous clay rock, etc. The manganese ores have higher ΣREE contents range from 158 to 1138.9 ppm(average 509.54 ppm). In addition, the ΣREE contents of tuffaceous clay rock in ore beds vary from 1032.2 to 1824.5 ppm(average 1396.42 ppm). The REEs from manganese deposits are characterized by La, Ce, Nd and Y enriched, and existing in the form of independent minerals(e.g., monazite and xenotime), indicating Zunyi manganese deposits enriched in light rare earth elements(LREE). The Ceanom ratios(average-0.13) and lithofacies and paleogeography characteristics indicate that Zunyi manganese deposits were formed in a weak oxidation-reduction environment. The(La/Yb)ch, Y/Ho,(La/Nd)N,(Dy/Yb)N, Ce/Ce* and Eu/Eu* values of samples from the Zunyi manganese deposits are 5.53–56.92, 18–39, 1.42–3.15, 0.55–2.20, 0.21–1.76 and 0.48–0.86, respectively, indicating a hydrothermal origin for the manganese mineralization and REEs enrichment. The δ13 CV-PDB(-0.54 to-18.1‰) and δ18 OSMOW(21.6 to 26.0‰) characteristics of manganese ores reveal a mixed source of magmatic and organic matter. Moreover, the manganese ore, tuffaceous clay rock and Emeishan basalt have extremely similar REE fractionation characteristic, suggesting REEs enrichment and manganese mineralization have been mainly origin from hydrothermal fluids.展开更多
The widespread organic pollutants in wastewater are one of the global environmental problems.Advanced oxidation processes(AOPs)are widely used because of their characteristics of high efficiency and strong oxidation.H...The widespread organic pollutants in wastewater are one of the global environmental problems.Advanced oxidation processes(AOPs)are widely used because of their characteristics of high efficiency and strong oxidation.However,AOPs may have some defects,such as incomplete mineralization of organic pollutants and the generation of toxic by-products during the degradation process,thus it is essential to seek efficient and green wastewater treatment technologies.Coupling different AOPs or other processes is beneficial for the mineralization of pollutants and reduces ecological risks to the environment.It is worth noting that carbonaceous materials(CMs)have received widespread attention and application in the degradation of organic pollutants in water by advanced oxidation coupling processes(C-AOPs)due to their excellent physicochemical properties in recent years.However,the behaviors and mechanisms of C-AOPs based on CMs on the degradation of organic pollutants are still unknown.Therefore,it is essential to comprehensively summarize the recent research progress.In this review,the applications of different CMs in C-AOPs were reviewed first.Secondly,the synergistic mechanisms of the C-AOPs based on different CMs were discussed.Then,toxic intermediates were explored and important toxicity assessment methods were proposed.Finally,the application potential of the C-AOPs in the future and the challenges were proposed.This review provides an important reference for the application and optimization of the C-AOPs in organic wastewater treatment in the future.展开更多
The emission of air pollutants from various industries is a major contributor to environmental pollution.The removal of these pollutants before they are discharged into the environment has become an important means of...The emission of air pollutants from various industries is a major contributor to environmental pollution.The removal of these pollutants before they are discharged into the environment has become an important means of controlling air pollution.Biochar has attracted increasing attention because of its low cost,high porosity,large specific surface area,abundant surface functional groups,and high removal capacity.The physicochemical properties of biochar are greatly affected by feedstock types,preparation,and modification conditions.For this reason,the capacity and propensity of biochar for removing air pollutants are rather variable.To understand the existing research status and grasp the latest research progress,a systematic review on the removal of different air pollutants by biochar is highly needed.Based on the recent research,this paper systematically analyzes and summarizes the preparation and modification methods of biochar commonly used for the removal of six air pollutants(SO_(2),H_(2)S,CO_(2),Hg0,VOCs,and NH_(3)),as well as the removal performance and mechanisms.Then,the potential influencing factors(preparation parameters,physicochemical characteristics of biochar,and removal conditions)are discussed.Finally,the regeneration of biochar,suggestions,and future perspectives are proposed.展开更多
Humus is often used as an organic modifier to reduce the bioaccumulation of heavy metals in plants, but the effects of different humus components from different sources on the fate of mercury(Hg) in paddy fields are s...Humus is often used as an organic modifier to reduce the bioaccumulation of heavy metals in plants, but the effects of different humus components from different sources on the fate of mercury(Hg) in paddy fields are still unclear. Here, fulvic acid(FA) and humic acid(HA) extracted from composted straw(CS), composted cow dung(CCD), peat soil(PM) and lignite coal(LC) were used to understand their effects on the methylation and bioaccumulation of Hg in paddy soil by pot experiments. Amendments of both FA and HA largely increased the abundance of Hg-methylating microbes and low-molecular-weight organic matters(e.g, cysteine) in paddy soil. They were also found to change the aromaticity, molecular size and Chromophoric DOM concentration of DOM, and resulted in heterogeneous effects on migration and transformation of Hg. All the FA-amended treatments increased the mobility and methylation of Hg in soil and its absorption in roots. Nevertheless, FA from different sources have heterogeneous effects on transport of Hg between rice tissues. FA-CCD and FA-PM promoted the translocation of Me Hg from roots to rice grains by 32.95% and 41.12%, while FA-CS and FA-LC significantly inhibited the translocation of inorganic Hg(IHg) by 52.65% and 66.06% and of Me Hg by 46.65% and 36.23%, respectively. In contrast, all HA-amended treatments reduced the mobility of soil Hg, but promoted Hg methylation in soil. Among which, HA-CCD and HA-PM promoted the translocation of Me Hg in rice tissues by 88.95% and 64.10%, while its accumulation in rice grains by 28.43% and 28.69%, respectively. In general, the application of some FA and HA as organic modifiers to reduce Hg bioaccumulation in rice is not feasible.展开更多
Kimberlite,which is the primary host rock for diamonds,originates from the deepest sources of all the mantle-derived magmas(Giuliani et al.,2023;Foley et al.,2019).This feature provides a vital perspective to explore ...Kimberlite,which is the primary host rock for diamonds,originates from the deepest sources of all the mantle-derived magmas(Giuliani et al.,2023;Foley et al.,2019).This feature provides a vital perspective to explore Earth's internal structure and evolution.The first primary diamond deposit discovered in China was the East No.1 kimberlite pluton(D1)in Maping(26°56′08″N,108°17′07″E),located on the southeastern margin of the Yangtze Craton(Figure 1).展开更多
At the sediment-water interfaces,filamentous cable bacteria transport electrons from sulfide oxidation along their filaments towards oxygen or nitrate as electron acceptors.These multicellular bacteria belonging to th...At the sediment-water interfaces,filamentous cable bacteria transport electrons from sulfide oxidation along their filaments towards oxygen or nitrate as electron acceptors.These multicellular bacteria belonging to the family Desulfobulbaceae thus form a biogeobattery that mediates redox processes between multiple elements.Cable bacteria were first reported in 2012.In the past years,cable bacteria have been found to be widely distributed across the globe.Their potential in shaping the surface water environments has been extensively studied but is not fully elucidated.In this review,the biogeochemical characteristics,conduction mechanisms,and geographical distribution of cable bacteria,as well as their ecological effects,are systematically reviewed and discussed.Novel insights for understanding and applying the role of cable bacteria in aquatic ecology are summarized.展开更多
Antibiotic pollution has become a global eco-environmental issue.To reduce sulfonamide antibiotics in water and improve resource utilization of solid wastes,phosphogypsummodified biochar composite(PMBC)was prepared vi...Antibiotic pollution has become a global eco-environmental issue.To reduce sulfonamide antibiotics in water and improve resource utilization of solid wastes,phosphogypsummodified biochar composite(PMBC)was prepared via facile one-step from distillers grains,wood chips,and phosphogypsum.The physicochemical properties of PMBCwere characterized by scanning electron microscope(SEM),Fourier transform infrared spectroscopy(FTIR),Zeta potential,X-ray diffraction(XRD),etc.The influencing factors,adsorption behaviors,and mechanisms of sulfadiazine(SD)and sulfamethazine(SMT)onto PMBC were studied by batch and fixed bed column adsorption experiments.The results showed that the removal rates of SD and SMT increased with the increase of phosphogypsum proportion,while decreased with the increase of solution pH.The maximum adsorption capacities of modified distillers grain and wood chips biochars for SD were 2.98 and 4.18 mg/g,and for SMT were 4.40 and 8.91mg/g,respectively,which was 9.0–22.3 times that of pristine biochar.Fixed bed column results demonstrated that PMBC had good adsorption capacities for SD and SMT.When the solution flow rate was 2.0 mL/min and the dosage of PMBC was 5.0 g,the removal rates of SD and SMT by modified wood chips biochar were both higher than 50%in 4 hr.The main mechanisms of SD and SMT removal by PMBC are hydrogen bonding,π-πdonor-acceptor,electrostatic interaction,and hydrophobic interaction.This study provides an effective method for the removal of antibiotics in water and the resource utilization of phosphogypsum.展开更多
The Ediacaran-Cambrian(E-C) succession in South China records remarkable oceanic,biological and geochemical variations,but it was not well defined geochronologically,which hinders the interpretation of the spatio-temp...The Ediacaran-Cambrian(E-C) succession in South China records remarkable oceanic,biological and geochemical variations,but it was not well defined geochronologically,which hinders the interpretation of the spatio-temporal seawater chemical architecture during the time E-C interval.This study presents two Re-Os isochron ages of 520.2±6.1 and 561.7±8.5 Ma for the barite-rich black shales from the top Liuchapo and Doushantuo formations respectively in Tianzhu County,Guizhou Province.In combination with existing age data,the two new Re-Os isochron ages suggest that the Liuchapo Formation was deposited between 550 and 520 Ma.Moreover,like the polymetallic Ni-MoPGE layers of shelf margin(or platform) facies and V-rich horizons of transitional(or shelf slope) to deep-water facies,the barite deposits were likely formed due to differential mineralization.The timing offset likely resulted from differential elemental concentration related to certain local factors(i.e.,hydrothermal fluids,seawater redox and biological activity).The isochron-derived initial ^(187)Os/^(188)Os ratios of the top Liuchapo Formation(0.902 ± 0.048) and the Doushantuo Formation(0.740 ± 0.042) fall within the range of continental weathering flux(1.54) and oceanic crust(0.126),implying the involvement of marine hydrothermal fluids.Moreover,their difference of initial ^(187)Os/^(188)Os ratios may reflect variations of continental weathering intensity and uplift magnitude.展开更多
Litter is the crucial carrier of soil nutrition transformation.The influence of arbuscular mycorrhizal(AM)fungi on nutrient acquisition in plants has been widely recognized.However,in nutrient-deficient karst habitat,...Litter is the crucial carrier of soil nutrition transformation.The influence of arbuscular mycorrhizal(AM)fungi on nutrient acquisition in plants has been widely recognized.However,in nutrient-deficient karst habitat,how competitive plants utilize nutrients regulated by AM fungi via litter remain largely unknown.The experimental treatments included the inoculation with or without Glomus etunicatum,the litter addition by the mixed leaves of Broussonetia papyrifera and Carpinus pubescens or no addition,and the competition through the intraspecific competition of B.papyrifera and C.pubescens,respectively,and the interspecific competition mixed both plants.AM fungi differently affected plant on nutrient acquisition,increasing nutrients acquisitions of B.papyrifera in intra-and interspecific competitions while decreasing for C.pubescens.Litter presented opposite influences on N acquisitions of both plants in interspecific competition with AM fungi,being positive for C.pubescens and negative for B.papyrifera,respectively.Under the interaction of AM fungi and litter,nitrogen(N),phosphorus(P)and potassium(K)acquisitions by B.papyrifera and N acquisition by C.pubescens in interspecific competition were all greater than intraspecific competition.In the interspecific competition,the competitive ability of plants on nutrient absorption presented significant species difference,which of B.papyrifera on P and K was significantly increased,while was converse for C.pubescens on K.In conclusion,these results suggest that the interspecific competition presents greater nutrient facilitation compared with intraspecific competition through AM fungi interacting with litter for plants in karst soil.展开更多
基金financially supported by the National Natural Science Foundation of China(No.U1812402)the project of the scientific and technological innovation team of sedimentary deposits in Guizhou Province(No.20185613)+1 种基金the project of the graduate scientific research fund of Guizhou Province(No.YJSCXJH[2019]039)the Project of Young Scientific Talent of Guizhou(No.2016117)。
文摘Fossil plants from the carbonaceous shale of upper part of the Lower Carboniferous Jiujialu Formation in Lindai bauxite deposit fill a gap regarding the distribution of Early Carboniferous flora in Central Guizhou Province.Here the Lindai plant assemblage is systematically described,and its composition and geological age are discussed.Research demonstrates that 9 species in 6 genera of the fossil plants are discovered in this study,and they belong to lycopsids,sphenopsids and ferns,respectively.Based on the analysis of the floral composition,the geological age of the Lindai plant assemblage belongs to the Early Carboniferous Viséan.The discovery of Lindai plant assemblage not only provides a new fossil evidence to restrict the age of bauxite deposits in Lower Carboniferous Jiujialu Formation of Central Guizhou Province,but also has great significance to further research the palaeoecological setting and floral evolution during the Early Carboniferous.
基金support from the National Natural Science Foundation of China(Grant.No.42162027)the Science and technology foundation of Guizhou Province(Grant.No.2022-212,2023-006)are greatly appreciated.
文摘Karst sinkholes with natural negative landform provide favorable conditions for the pumped storage reservoir construction for less excavation work.However,the construction of the reservoir would plug the natural karst channels for water and air,which would cause remarkable air pressure in karst channels when the groundwater level fluctuates.A large laboratory simulation test was carried out to study the air pressure variation of a reservoir built on the karst sinkhole.The air pressure in the karst channel and inside the model was monitored during the groundwater rising and falling process.Result showed that the variation of air pressure in the karst channel and the surrounding rock exhibited a high degree of similarity.The air pressure increased rapidly at the initial stage of water level rising,followed by a slight decrease,then the air pressure increased sharply when the water level approached the top of the karst cave.The initial peak of air pressure and the final peak of air pressure were defined,and both air pressure peaks were linearly increasing with the water level rising rate.The negative air pressure was also analyzed during the drainage process,which was linearly correlated with the water level falling rate.The causes of air pressure variation in karst channels of a pumped storage reservoir built on the karst sinkhole were discussed.The initial rapid increase,then slight decrease and final sudden increase of air pressure were controlled by the combined effects of air compression in karst channel and air seepage into the surrounding rock.For the drainage process,the instant negative air pressure and gradual recovering of air pressure were controlled by the combined effects of negative air pressure induced by water level falling and air supply from surrounding rock.This work could provide valuable reference for the reservoir construction in karst area.
基金the National Natural Science Foundation of China(Grant No.41802107)Guizhou Scientific and Technology Fund(Grant No.QKHJC[2019]1315+2 种基金QKHJC[2019]1149H)China Postdoctoral Science Foundation(Grant No.2019M653495)the Talent Introduction Project of Guizhou University(Grant No.201772).
文摘In the northwestern margin of the Youjiang basin(NWYB)in SW China,many Carlin-like gold deposits are highly antimony(Sb)-rich,and many vein-type Sb deposits contain much Au.These deposits have similar ages,host rocks,ore-forming temperatures,ore-related alterations and ore mineral assemblages,but the Au and Sb metallogenic relations and their ore-forming process remain enigmatic.Here we investigate the large Qinglong Sb deposit in the NWYB,which has extensive sub-economic Au mineralization,and present a new metallogenic model based on in-situ trace elements(EPMA and LA-ICP-MS)and sulfur isotopes(NanoSIMS and fs-LA-MC-ICPMS)of the ore sulfides.At Qinglong,economic Sb ores contain coarse-grained stibnite,jasperoid quartz and fluorite,whilst the sub-economic Au–Sb ores comprise dominantly veined quartz,arsenian pyrite and fine-grained stibnite.Three generations of ore-related pyrite(Py1,Py2 and Py3)and two generations of stibnite(Stb1 and Stb2)are identified based on their texture,chemistry,and sulfur isotopes.The pre-ore Py1 is characterized by the lower ore element(Au,As,Sb,Cu and Ag)contents(mostly below the LA-ICP-MS detection limit)and Co/Ni ratios(average 0.31)than the ore-stage pyrites(Py2 and Py3),implying a sedimentary/diagenetic origin.The Py2 and Py3 have elevated ore element abundance(maximum As=6500 ppm,Au=22 ppm,Sb=6300 ppm,Cu=951 ppm,Ag=77 ppm)and Co/Ni ratios(average 1.84),and have positive As vs.Au–Sb–Cu–Ag correlations.Early-ore Stb1 has lower As(0.12–0.30 wt.%)than late-ore Stb2(0.91–1.20 wt.%).These features show that the progressive As enrichment in ore sulfides is accompanied by increasing Au,Sb,Cu and Ag with the hydrothermal evolution,thereby making As a good proxy for Au.As-rich,As-poor and As-free zones are identified via NanoSIMS mapping of the Au-bearing pyrite.The As-rich zones in the Qinglong Au-bearing pyrites(Py2 and Py3)and ore stibnites(Stb1 and Stb2)have narrowδ^(34)SH_(2)S ranges(-8.9‰to +4.1‰,average-3.1‰)and-2.9‰to +6.9‰,average + 1.3‰),respectively,indicating that the Au-rich and Sb-rich fluids may have had the same sulfur source.Published in-situ sulfur isotopic data of pyrite As-rich zones from other Carlin-like Au deposits(Shuiyindong,Taipingdong,Nayang,Getang and Lianhuashan)in the NWYB have similar ore-fluidδSH_(2)S values(-4.5‰to +6.7‰,average-0.6‰)to those of Qinglong.Therefore,we infer that the sulfur of both Au and Sb mineralization was derived from the same magmatic-related source(0±5‰)in the NWYB.Moreover,the core of pyrites(Py1)has variable S isotope fractionation(-18.9‰to +18.1‰,mostly +3‰to +12‰),suggesting that the higher-^(34)S H_(2)S was produced by bacterial sulfate reduction(BSR).The hydrothermal pyrite(Py2 and Py3)δ^(34)S values gradually decrease with increasing As concentrations,and ultimately,within the restricted range(-5‰to +5‰)in As-rich zones.This variation implies that the As-rich pyrite was formed through ongoing interactions of the magmatic-hydrothermal fluid with pre-existing sedimentary pyrites,causing the progressive decreasing δ^(34)S values with As content increase,Hence,the fluid/mineral interaction may have generated the observed variation in δ^(34)S and As contents.Overall,comparing the Au and Sb deposits in the NWYB,we favor a magmatic-related source for the Au–Sb–As-rich fluids,but the Au-and Sb-ore fluids were likely evolved at separate stages in the ore-forming system.
基金supported in part by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA28060201)the National Natural Science Foundation of China(Grant No.42067046)the Science and Technology Planning Project of Guiyang City(Grant No.ZKHT[2023]13-10).
文摘Mining-induced surface deformation disrupts ecological balance and impedes economic progress.This study employs SBAS-InSAR with 107-view of ascending and descending SAR data from Sentinel-1,spanning February 2017 to September 2020,to monitor surface deformation in the Fa’er Coal Mine,Guizhou Province.Analysis on the surface deformation time series reveals the relationship between underground mining and surface shifts.Considering geological conditions,mining activities,duration,and ranges,the study determines surface movement parameters for the coal mine.It asserts that mining depth significantly influences surface movement parameters in mountainous mining areas.Increasing mining depth elevates the strike movement angle on the deeper side of the burial depth by 22.84°,while decreasing by 7.74°on the shallower side.Uphill movement angles decrease by 4.06°,while downhill movement angles increase by 15.71°.This emphasizes the technology's suitability for local mining design,which lays the groundwork for resource development,disaster prevention,and ecological protection in analogous contexts.
基金supported by the National Natural Science Foundation of China(42163003)the Project of Talent Base in Guizhou Province(No.RCJD2018-21).
文摘Carbon dioxide(CO_(2))emissions from aquatic ecosystems are an important component of the karst carbon cycle process and also a key indicator for assessing the effect of karst carbon sinks.This paper reviewed the CO_(2)partial pressure(pCO_(2))and its diffusion flux(FCO_(2))in karst surface aquatic ecosystems,mainly rivers,lakes,and reservoirs,and their influencing factors summarized the methods for monitoring CO_(2)emissions in karst aquatic ecosystems and discussed their adaptation conditions in karst areas.The pCO_(2)and FCO_(2)decreased in the order of rivers>reservoirs>lakes,and the values in karst lakes were eventually significantly lower than those in global lakes.The pCO_(2)and FCO_(2)of karst aquatic ecosystems had patterns of variation with diurnal,seasonal,water depth and hydrological cycles,and spatial and temporal hetero-geneity.The sources of CO_(2)in karst waters are influenced by both internal and external sources,and the key spatial and temporal factors affecting the CO_(2)emissions from karst rivers,lakes,and reservoirs were determined in terms of physicochemical indicators,biological factors,and bio-genic elements;additionally,the process of human activity interference on CO_(2)emissions was discussed.Finally,a conceptual model illustrating the impacts of urban devel-opment,agriculture,mining,and dam construction on the CO_(2)emissions at the karst surface aquatic ecosystem is presented.Meanwhile,based on the disadvantages existing in current research,we proposed several important research fields related to CO_(2)emissions from karst surface aquatic ecosystems.
基金supported by Guizhou Science Cooperation Platform Talents(No.GCC[2023]045)the National Natural Science Foundation of China(Nos.42267030 and 42177237)+2 种基金the Innovation and Entrepreneurship Talents of Guizhou Province(No.GZQ202208091)the Science and Technology Planning Project of Guizhou Province(Qian Ke He Zhi Cheng,2022-217)the Science and Technology Planning Project of Guizhou Province(Qian Ke He Cheng Guo,2023-006).
文摘Humic acid(HA),a principal constituent of natural organic matter(NOM),manifests ubiquitously across diverse ecosystems and can significantly influence the environmental behaviors of Cd(II)in aquatic systems.Previous studies on NOM-Cd(II)interactions have primarily focused on the immobilization of Cd(II)solids,but little is known about the colloidal stability of organically complexed Cd(II)particles in the environment.In this study,we investigated the formation of HA-Cd(II)colloids and quantified their aggregation,stability,and transport behaviors in a saturated porous media representative of typical subsurface conditions.Results from batch experiments indicated that the relative quantity of HA-Cd(II)colloids increased with increasing C/Cd molar ratio and that the carboxyl functional groups of HA dominated the stability of HA-Cd(II)colloids.The results of correlation analysis between particle size,critical aggregation concentration(CCC),and zeta potential indicated that both Derjaguin-Landau-Verwey-Overbeek(DLVO)and non-DLVO interactions contributed to the enhanced colloidal stability of HA-Cd(II)colloids.Column results further confirmed that the stable HA-Cd(II)colloid can transport fast in a saturated media composed of clean sand.Together,this study provides newknowledge of the colloidal behaviors of NOM-Cd(II)nanoparticles,which is important for better understanding the ultimate cycling of Cd(II)in aquatic systems.
基金supported by the National Natural Science Foundation of China (No.42163003)the High-Level Talent Training Program in Guizhou (No.[2016]5664)+1 种基金the Project of Talent Base in Guizhou Province (No.RCJD2018-21)the Talent Introduction Project of Guizhou University (No.[2019]24)。
文摘Dissolved organic matter(DOM)can be removed or transformed by photochemical and biological processes,producing the negative effect of transforming organic carbon into inorganic carbon,which plays a vital role in the karst carbon cycle.However,acid mine drainage(AMD)will affect this process,so the degradation of DOM in karst river water(KRW)needs to be studied in this context.In this study,to reveal the evolution processes of DOM under photochemical and biological conditions in AMD-impacted KRW,AMD and KRW were mixed in different ratios under conditions of visible light irradiation(VL),biodegradation(BD),ultraviolet irradiation(UV)and ultraviolet irradiation+biodegradation(UV+BD).The average DOC concentrations in samples after mixing AMD and KRW in different proportions decreased significantly(by 23%)in UV+BD,which was 1.2–1.4 times higher than under the other conditions and would lead to a significant release of inorganic carbon.Further analysis of the fluorescence parameters via parallel factor analysis(PARAFAC)revealed that the DOM fluorescence components in AMD comprised mainly protein-like substances derived from autochthonous components,while the DOM fluorescence components in KRW were mainly humic-like substances with both autochthonous and allochthonous sources.Therefore,AMD could promote both the photochemical and biological degradation of DOM in karst receiving streams,resulting in the conversion of DOC to inorganic carbon.The results showed that the synergistic effects of UV+BD and AMD accelerated the degradation of DOM and the release of inorganic carbon in KRW,thus affecting the stability of the karst carbon cycle.
基金the financial support by the National Key R&D Program of China(No.2018YFC1504901)Science and technology development project of China Railway 11th Bureau Group Co.,LTD(20210601)+4 种基金Science and technology development project of China Railway Lanzhou Bureau Group Co.,LTD(2021046-2)Science and technology program of Gansu Province(Grant No.21JR7RA739)Science and Technology Development Project of China Railway Research Institute Co.Ltd(2017-KJ008-Z008-XB)Science and technology development project of China Railway Ninth Bureau Group Co.,Ltd(DLF-ML-JSFW-202109)The Science and Technology Foundation of Guizhou Province(NO.ZK[2022]Key018)。
文摘To investigate the stress response characteristics and shear stress transfer mechanism of BFRP(basalt fiber reinforced plastics)anchors under rainfall conditions and to explore the reinforcement effect of BFRP anchors,a comparative indoor physical model test was conducted in this study using loess mudstone slope as a typical case,and multi-attribute response data,such as slope displacement,BFRP anchor strain and axial force,were obtained.Based on the variation law of slope displacement,it can be concluded that the deformation displacement of the slope on the side reinforced by BFRP anchors is smaller than that of slopes reinforced with steel anchors;the bearing capacity of BFRP anchor is given priority in time,and the anchoring effect of BFRP anchor at the top of the slope is given priority,and the axial force value of anchor is characterized by a surface amplification effect in space;the axial force is higher around the anchor head and tends to decay as a negative exponential function as the anchor extends in the direction of the interior of the slope;the shear stress of BFRP anchor and anchorage body are unevenly distributed along the axial direction,with the maximum value occurring in the free section near the slope surface and decreases as the BFRP anchor extends towards the interior of the slope.These results can provide a theoretical basis for the optimal design of BFRP anchors.
基金Support by Sichuan Science and Technology Program(2021YFQ0003,2023YFSY 0026,2023YFH0004).
文摘This study addresses the limitations of Transformer models in image feature extraction,particularly their lack of inductive bias for visual structures.Compared to Convolutional Neural Networks(CNNs),the Transformers are more sensitive to different hyperparameters of optimizers,which leads to a lack of stability and slow convergence.To tackle these challenges,we propose the Convolution-based Efficient Transformer Image Feature Extraction Network(CEFormer)as an enhancement of the Transformer architecture.Our model incorporates E-Attention,depthwise separable convolution,and dilated convolution to introduce crucial inductive biases,such as translation invariance,locality,and scale invariance,into the Transformer framework.Additionally,we implement a lightweight convolution module to process the input images,resulting in faster convergence and improved stability.This results in an efficient convolution combined Transformer image feature extraction network.Experimental results on the ImageNet1k Top-1 dataset demonstrate that the proposed network achieves better accuracy while maintaining high computational speed.It achieves up to 85.0%accuracy across various model sizes on image classification,outperforming various baseline models.When integrated into the Mask Region-ConvolutionalNeuralNetwork(R-CNN)framework as a backbone network,CEFormer outperforms other models and achieves the highest mean Average Precision(mAP)scores.This research presents a significant advancement in Transformer-based image feature extraction,balancing performance and computational efficiency.
基金supported by the Science and Technology Project of Guizhou Province(No.QKHJC[2020]1Y187)the National Natural Science Foundation of China(Nos.41265008,42007305,and 22166009)。
文摘Ultra-low emission(ULE)technology retrofits significantly impact the particulate-bound mercury(Hg)emissions from coal-fired power plants(CFPPs);however,the distribution and bioavailability of Hg in size-fractioned particulate matter(PM)around the ULE-retrofitted CF-PPs are less understood.Here,total Hg and its chemical speciation in TSP(total suspended particles),PM_(10)(aerodynamic particle diameter≤10μm)and PM_(2.5)(aerodynamic particle diameter≤2.5μm)around a ULE-retrofitted CFPP in Guizhou Province were quantified.Atmospheric PM_(2.5)concentration was higher around this ULE-retrofitted CFPP than that in the intra-regional urban cities,and it had higher mass Hg concentration than other sizefractioned PM.Total Hg concentrations in PM had multifarious sources including CFPP,vehicle exhaust and biomass combustion,while they were significantly higher in autumn and winter than those in other seasons(P<0.05).Regardless of particulate size,atmospheric PM-bound Hg had lower residual fractions(<21%)while higher HCl-soluble fractions(>40%).Mass concentrations of exchangeable,HCl-soluble,elemental,and residual Hg in PM_(2.5)were higher than those in other size-fractioned PM,and were markedly elevated in autumn and winter(P<0.05).In PM_(2.5),HCl-soluble Hg presented a significantly positive relationship with elemental Hg(P<0.05),while residual Hg showed the significantly positive relationships with HCl-soluble Hg and elemental Hg(P<0.01).Overall,these results suggested that atmospheric PM-bound Hg around the ULE-retrofitted CFPP tends to accumulate in finer PM,and has higher bioavailable fractions,while has potential transformation between chemical speciation.
基金supported by the National Natural Science Foundation of China(Nos.42007305,22166009,and 42267032)the Science and Technology Project of Guizhou Province(QKHJC[2020]1Y187 and QKHZC[2020]4Y031)the Guizhou Provincial Science and Technology Development Project(QKZYD[2022]4022).
文摘Algal-derived organic matter(AOM)regulates methylmercury(MeHg)fate in aquatic ecosystems,whereas its role in MeHg production and bioaccumulation in Hg-contaminated paddies is unclear.Pot and microcosm experiments were thus performed to understand the response characteristics of MeHg concentrations in soil and rice in different rice-growing periods to algal decomposition.Compared to the control,algal decomposition significantly increased soil water-soluble cysteine concentrations during the rice-tillering and grain-filling periods(P<0.05).It also significantly lowered the molecular weight of soil-dissolved organic matter(SDOM)during the rice-tillering period(P<0.05)and SDOM humification/aromaticity during the grain-filling period.Compared to the control,AOM input increased the abundance of potential Hg and non-Hg methylators in soil.Furthermore,it also greatly increased soil MeHg concentrations by 25.6%-80.2%and 12.6%-66.1%during the rice-tillering and grain-filling periods,with an average of 42.25%and 38.42%,respectively,which were significantly related to the elevated cysteine in soil and the decrease in SDOM molecular weight(P<0.01).In the early stage(within 10 days of microcosm experiments),the MeHg concentrations in decayed algal particles showed a great decrease(P<0.01),suggesting a potential MeHg source in soil.Ultimately,algal decomposition greatly increased the MeHg concentrations and bioaccumulation factors in rice grains,by 72.30%and 16.77%,respectively.Overall,algal decomposition in Hg-contaminated paddies is a non-negligible factor promoting MeHg accumulation in soil-rice systems.
基金financially supported by the project of the graduate scientific research fund of Guizhou Province(No.KYJJ2017009)the National Natural Science Foundation of China(No.U1812402)+1 种基金the project of the scientific and technological innovation team of sedimentary deposits in Guizhou Province(No.20185613)the Project of Talent Base in Guizhou Province(No.RCJD2018-21).
文摘The Zunyi manganese deposits, which formed during the Middle to Late Permian period and are located in northern Guizhou and adjacent areas, are the core area of a series of large-medium scale manganese enrichment minerogenesis in the southern margin and interior of the Yangtze platform, Southern China. This study reports the universal enrichment of rare earth elements(REEs) in Zunyi manganese deposits and examines the enrichment characteristics, metallogenic environment and genesis of REEs. The manganese ore bodies present stratiform or stratoid in shape, hosted in the silicon–mud–limestones of the Late Permian Maokou Formation. The manganese ores generally present lamellar, massive, banded and brecciated structures, and mainly consist of rhodochrosite, ropperite, tetalite, capillitite, as well as contains paragenetic gangue minerals including pyrite, chalcopyrite, rutile, barite, tuffaceous clay rock, etc. The manganese ores have higher ΣREE contents range from 158 to 1138.9 ppm(average 509.54 ppm). In addition, the ΣREE contents of tuffaceous clay rock in ore beds vary from 1032.2 to 1824.5 ppm(average 1396.42 ppm). The REEs from manganese deposits are characterized by La, Ce, Nd and Y enriched, and existing in the form of independent minerals(e.g., monazite and xenotime), indicating Zunyi manganese deposits enriched in light rare earth elements(LREE). The Ceanom ratios(average-0.13) and lithofacies and paleogeography characteristics indicate that Zunyi manganese deposits were formed in a weak oxidation-reduction environment. The(La/Yb)ch, Y/Ho,(La/Nd)N,(Dy/Yb)N, Ce/Ce* and Eu/Eu* values of samples from the Zunyi manganese deposits are 5.53–56.92, 18–39, 1.42–3.15, 0.55–2.20, 0.21–1.76 and 0.48–0.86, respectively, indicating a hydrothermal origin for the manganese mineralization and REEs enrichment. The δ13 CV-PDB(-0.54 to-18.1‰) and δ18 OSMOW(21.6 to 26.0‰) characteristics of manganese ores reveal a mixed source of magmatic and organic matter. Moreover, the manganese ore, tuffaceous clay rock and Emeishan basalt have extremely similar REE fractionation characteristic, suggesting REEs enrichment and manganese mineralization have been mainly origin from hydrothermal fluids.
基金Project of Science and Technology Department of Guizhou Province[ZK(2022)016]Special Fund for Outstanding Youth Talents of Science and Technology of Guizhou Province[YQK[2023]014]+1 种基金Special Research Fund of Natural Science(Special Post)of Guizhou University[(2020)01]Key Cultivation Program of Guizhou University[2019(08)].
文摘The widespread organic pollutants in wastewater are one of the global environmental problems.Advanced oxidation processes(AOPs)are widely used because of their characteristics of high efficiency and strong oxidation.However,AOPs may have some defects,such as incomplete mineralization of organic pollutants and the generation of toxic by-products during the degradation process,thus it is essential to seek efficient and green wastewater treatment technologies.Coupling different AOPs or other processes is beneficial for the mineralization of pollutants and reduces ecological risks to the environment.It is worth noting that carbonaceous materials(CMs)have received widespread attention and application in the degradation of organic pollutants in water by advanced oxidation coupling processes(C-AOPs)due to their excellent physicochemical properties in recent years.However,the behaviors and mechanisms of C-AOPs based on CMs on the degradation of organic pollutants are still unknown.Therefore,it is essential to comprehensively summarize the recent research progress.In this review,the applications of different CMs in C-AOPs were reviewed first.Secondly,the synergistic mechanisms of the C-AOPs based on different CMs were discussed.Then,toxic intermediates were explored and important toxicity assessment methods were proposed.Finally,the application potential of the C-AOPs in the future and the challenges were proposed.This review provides an important reference for the application and optimization of the C-AOPs in organic wastewater treatment in the future.
基金the National Natural Science Foundation of China(41977297)the Special Research Fund of Natural Science(Special Post)of Guizhou University[(2020)01]the Key Cultivation Program of Guizhou University[2019(08)].
文摘The emission of air pollutants from various industries is a major contributor to environmental pollution.The removal of these pollutants before they are discharged into the environment has become an important means of controlling air pollution.Biochar has attracted increasing attention because of its low cost,high porosity,large specific surface area,abundant surface functional groups,and high removal capacity.The physicochemical properties of biochar are greatly affected by feedstock types,preparation,and modification conditions.For this reason,the capacity and propensity of biochar for removing air pollutants are rather variable.To understand the existing research status and grasp the latest research progress,a systematic review on the removal of different air pollutants by biochar is highly needed.Based on the recent research,this paper systematically analyzes and summarizes the preparation and modification methods of biochar commonly used for the removal of six air pollutants(SO_(2),H_(2)S,CO_(2),Hg0,VOCs,and NH_(3)),as well as the removal performance and mechanisms.Then,the potential influencing factors(preparation parameters,physicochemical characteristics of biochar,and removal conditions)are discussed.Finally,the regeneration of biochar,suggestions,and future perspectives are proposed.
基金supported by Science and Technology Project of Guizhou Province (Nos. QKHZC[2020]4Y031QKHJC[2020]1Y187 )+2 种基金the Natural Science Foundation of China (Nos. 4176301742007305 )the Program Foundation of Institute for Scientific Research of Karst Area of NSFC-GZGOV (No. U1612442 )。
文摘Humus is often used as an organic modifier to reduce the bioaccumulation of heavy metals in plants, but the effects of different humus components from different sources on the fate of mercury(Hg) in paddy fields are still unclear. Here, fulvic acid(FA) and humic acid(HA) extracted from composted straw(CS), composted cow dung(CCD), peat soil(PM) and lignite coal(LC) were used to understand their effects on the methylation and bioaccumulation of Hg in paddy soil by pot experiments. Amendments of both FA and HA largely increased the abundance of Hg-methylating microbes and low-molecular-weight organic matters(e.g, cysteine) in paddy soil. They were also found to change the aromaticity, molecular size and Chromophoric DOM concentration of DOM, and resulted in heterogeneous effects on migration and transformation of Hg. All the FA-amended treatments increased the mobility and methylation of Hg in soil and its absorption in roots. Nevertheless, FA from different sources have heterogeneous effects on transport of Hg between rice tissues. FA-CCD and FA-PM promoted the translocation of Me Hg from roots to rice grains by 32.95% and 41.12%, while FA-CS and FA-LC significantly inhibited the translocation of inorganic Hg(IHg) by 52.65% and 66.06% and of Me Hg by 46.65% and 36.23%, respectively. In contrast, all HA-amended treatments reduced the mobility of soil Hg, but promoted Hg methylation in soil. Among which, HA-CCD and HA-PM promoted the translocation of Me Hg in rice tissues by 88.95% and 64.10%, while its accumulation in rice grains by 28.43% and 28.69%, respectively. In general, the application of some FA and HA as organic modifiers to reduce Hg bioaccumulation in rice is not feasible.
基金supported by the National Natural Science Foundation of China(Nos.41963006,42363006)the Geological Research Project of the Bureau of Geology and Mineral Exploration and Development of Guizhou Province(Nos.QDKKH[2020]26,QDKKH[2024]6,QDKKH[2023]1)。
文摘Kimberlite,which is the primary host rock for diamonds,originates from the deepest sources of all the mantle-derived magmas(Giuliani et al.,2023;Foley et al.,2019).This feature provides a vital perspective to explore Earth's internal structure and evolution.The first primary diamond deposit discovered in China was the East No.1 kimberlite pluton(D1)in Maping(26°56′08″N,108°17′07″E),located on the southeastern margin of the Yangtze Craton(Figure 1).
基金supported by the Key-Area Research and Development Program of Guangdong Province(2020B1111380003)Guangdong Provincial Programs for Science and Technology Development(2022A0505030006)+6 种基金National Natural Science Foundation of China(31970110,32370111)GDAS’Special Project of Science and Technology Development(2021GDASYL-20210103022)State Key Laboratory of Applied Microbiology Southern China(Grant SKLAM005-2020)Danish National Research Foundation(DNRF136)Zhenyu Wang(File No.202208080044)is financially supported by the China Scholarship CouncilLeonid Digel was supported by FEMS Research and Training Grant(1725)EMBO Scientific Exchange grant(9720)for a visit to the UFZ in Leipzig,Germany.
文摘At the sediment-water interfaces,filamentous cable bacteria transport electrons from sulfide oxidation along their filaments towards oxygen or nitrate as electron acceptors.These multicellular bacteria belonging to the family Desulfobulbaceae thus form a biogeobattery that mediates redox processes between multiple elements.Cable bacteria were first reported in 2012.In the past years,cable bacteria have been found to be widely distributed across the globe.Their potential in shaping the surface water environments has been extensively studied but is not fully elucidated.In this review,the biogeochemical characteristics,conduction mechanisms,and geographical distribution of cable bacteria,as well as their ecological effects,are systematically reviewed and discussed.Novel insights for understanding and applying the role of cable bacteria in aquatic ecology are summarized.
基金supported by the Key Project of Science and Technology Department of Guizhou Province(No.ZK(2022)016)the Special Research Fund of Natural Science(Special Post)of Guizhou University(No.(2020)01)the Key Cultivation Program of Guizhou University(No.2019(08)).
文摘Antibiotic pollution has become a global eco-environmental issue.To reduce sulfonamide antibiotics in water and improve resource utilization of solid wastes,phosphogypsummodified biochar composite(PMBC)was prepared via facile one-step from distillers grains,wood chips,and phosphogypsum.The physicochemical properties of PMBCwere characterized by scanning electron microscope(SEM),Fourier transform infrared spectroscopy(FTIR),Zeta potential,X-ray diffraction(XRD),etc.The influencing factors,adsorption behaviors,and mechanisms of sulfadiazine(SD)and sulfamethazine(SMT)onto PMBC were studied by batch and fixed bed column adsorption experiments.The results showed that the removal rates of SD and SMT increased with the increase of phosphogypsum proportion,while decreased with the increase of solution pH.The maximum adsorption capacities of modified distillers grain and wood chips biochars for SD were 2.98 and 4.18 mg/g,and for SMT were 4.40 and 8.91mg/g,respectively,which was 9.0–22.3 times that of pristine biochar.Fixed bed column results demonstrated that PMBC had good adsorption capacities for SD and SMT.When the solution flow rate was 2.0 mL/min and the dosage of PMBC was 5.0 g,the removal rates of SD and SMT by modified wood chips biochar were both higher than 50%in 4 hr.The main mechanisms of SD and SMT removal by PMBC are hydrogen bonding,π-πdonor-acceptor,electrostatic interaction,and hydrophobic interaction.This study provides an effective method for the removal of antibiotics in water and the resource utilization of phosphogypsum.
基金jointly supported by the National Natural Science Foundation of China(Nos.41763006,42063009,U1812402)the Talent Base Project of Guizhou Province(No.RCJD2018-21)。
文摘The Ediacaran-Cambrian(E-C) succession in South China records remarkable oceanic,biological and geochemical variations,but it was not well defined geochronologically,which hinders the interpretation of the spatio-temporal seawater chemical architecture during the time E-C interval.This study presents two Re-Os isochron ages of 520.2±6.1 and 561.7±8.5 Ma for the barite-rich black shales from the top Liuchapo and Doushantuo formations respectively in Tianzhu County,Guizhou Province.In combination with existing age data,the two new Re-Os isochron ages suggest that the Liuchapo Formation was deposited between 550 and 520 Ma.Moreover,like the polymetallic Ni-MoPGE layers of shelf margin(or platform) facies and V-rich horizons of transitional(or shelf slope) to deep-water facies,the barite deposits were likely formed due to differential mineralization.The timing offset likely resulted from differential elemental concentration related to certain local factors(i.e.,hydrothermal fluids,seawater redox and biological activity).The isochron-derived initial ^(187)Os/^(188)Os ratios of the top Liuchapo Formation(0.902 ± 0.048) and the Doushantuo Formation(0.740 ± 0.042) fall within the range of continental weathering flux(1.54) and oceanic crust(0.126),implying the involvement of marine hydrothermal fluids.Moreover,their difference of initial ^(187)Os/^(188)Os ratios may reflect variations of continental weathering intensity and uplift magnitude.
基金supported by the National Natural Science Foundation of China(NSFC,31660156,31360106)the First-Class Disciplines Program on Ecology of Guizhou Province(GNYL[2017]007)+2 种基金the Guizhou Hundred-Level Innovative Talents Project(Qian-ke-he platform talents[2020]6004)the Science and Technology Project of Guizhou Province([2021]General-455,[2016]Supporting-2805)the Talent-platform Program of Guizhou Province([2017]5788,[2018]5781).
文摘Litter is the crucial carrier of soil nutrition transformation.The influence of arbuscular mycorrhizal(AM)fungi on nutrient acquisition in plants has been widely recognized.However,in nutrient-deficient karst habitat,how competitive plants utilize nutrients regulated by AM fungi via litter remain largely unknown.The experimental treatments included the inoculation with or without Glomus etunicatum,the litter addition by the mixed leaves of Broussonetia papyrifera and Carpinus pubescens or no addition,and the competition through the intraspecific competition of B.papyrifera and C.pubescens,respectively,and the interspecific competition mixed both plants.AM fungi differently affected plant on nutrient acquisition,increasing nutrients acquisitions of B.papyrifera in intra-and interspecific competitions while decreasing for C.pubescens.Litter presented opposite influences on N acquisitions of both plants in interspecific competition with AM fungi,being positive for C.pubescens and negative for B.papyrifera,respectively.Under the interaction of AM fungi and litter,nitrogen(N),phosphorus(P)and potassium(K)acquisitions by B.papyrifera and N acquisition by C.pubescens in interspecific competition were all greater than intraspecific competition.In the interspecific competition,the competitive ability of plants on nutrient absorption presented significant species difference,which of B.papyrifera on P and K was significantly increased,while was converse for C.pubescens on K.In conclusion,these results suggest that the interspecific competition presents greater nutrient facilitation compared with intraspecific competition through AM fungi interacting with litter for plants in karst soil.
