In recent years,oil spills caused by human activities have occurred frequently,and the resultant oil pollution has received extensive attention worldwide.In this paper,a total of 50 water samples were collected from t...In recent years,oil spills caused by human activities have occurred frequently,and the resultant oil pollution has received extensive attention worldwide.In this paper,a total of 50 water samples were collected from the northeastern part of the South China Sea,and total petroleum hydrocarbons(TPHs)and n-alkane content in the samples were analyzed by gas chromatography-flame ionization detector(GC-FID)technology.The petroleum hydrocarbon characteristic indices,such as carbon predominance index(CPI)and terrigenous/aquatic ratio(TAR),were calculated to trace the source of petroleum hydrocarbons.The measured value of TPHs ranged from 121.31-603.02μg/L.For surface waters,the TPHs in the no rthern coastal waters and the central waters were higher than that in the far shore.For ve rtical waters,the TPHs sharply decreased at first,and then increased slowly and finally reached a steady state.The n-alkanes in the water samples were concentrated in C10-C38,and they were mainly from terrestrial higher plant.The waters in the near shore,mid-layer and deep sea showed a strong reducing terrestrial characteristic,while the surface waters in the open sea showed an obvious oxidizing endogenous characteristic.展开更多
The distribution patterns of rare earth elements(REEs)in fine-grained materials in various depositions were often found to be similar to those of the aeolian sediments deposited in the Loess Plateau in North China and...The distribution patterns of rare earth elements(REEs)in fine-grained materials in various depositions were often found to be similar to those of the aeolian sediments deposited in the Loess Plateau in North China and the fine-grained materials were suggested to be derived from wind-blown dust.However,increasing evidence indicated that the REEs in the water-soluble portion of atmospheric depositions also displayed similar patterns to those of aeolian sediments.In this study,water-soluble REEs in three atmospheric depositions collected from different climatic zones in China were adsorbed with two adsorbents with distinct adsorption capacity,glass powder,and co-precipitated iron hydroxide.The results showed that the REEs adsorbed by the two adsorbents displayed patterns similar to those of the original atmospheric depositions.The typical characteristics of the REE patterns of atmospheric deposition can be well reproduced in the adsorbed REEs.The higher the REE concentrations in the atmospheric depositions,or the higher adsorption efficiency of the adsorbents,the better reproducibility of the REEs patterns.The results suggest that the REEs of the fine-grained materials in various sediments,which have a high adsorption capacity,especially those deposited in South China,may come from the water-soluble REEs in atmospheric deposition,and may not be appropriate tracers of wind-blown dust from North China.展开更多
Abstract This paper deals with characteristics of silicon isotope compositions and siliceous cathodoluminescence of host rocks, ores and hydrothermal silicified quartz of the Carlin-type ore deposits in the Yunnan-Gui...Abstract This paper deals with characteristics of silicon isotope compositions and siliceous cathodoluminescence of host rocks, ores and hydrothermal silicified quartz of the Carlin-type ore deposits in the Yunnan-Guizhou-Guangxi triangle area. The study shows that primary silicified quartz is nonluminescent but quartz in host rocks and secondary silicified quartz are luminescent by the action of cathode rays. Correspondingly, silicon isotope compositions of host rocks, ores and hydro6thermal quartz veins are clearly distinguished. In strata from the Middle Triassic to the “Dachang” host bed, δ30Si of the host rocks ranges from 0.0% ?0.3%, while that of primary ore-forming silicified fluids from ?0.1% to ?0.4%; in the Upper Permian and Lower Carboniferous strata and Indosinian diabase host beds, δ30Si of the host rocks is from ?0.1% to ?0.2% and that of the primary silicified quartz veins from 0.3 % ?0.5 %. This pattern demonstrates the following geochemical mineralization process, primary ore-forming siliceous fluids migrated upwards quickly along the main passages of deep-seated faults from mantle to crust and entered secondary faults where gold deposits were eventually formed as a result of permeation and replacement of the siliceous ore-forming fluids into different ore-bearing strata. This gives important evidence for the fact that ore-forming fluids of this type of gold deposits were mainly derived from upper mantle differentiation and shows good prospects for deep gold deposits and geochemical background for large and superlarge gold deposits.展开更多
The core sampling experiments were conducted after hydraulic fracturing in the three-dimensional development zone of Fuling shale gas.Six coring wells of different well types were systematically designed.Based on the ...The core sampling experiments were conducted after hydraulic fracturing in the three-dimensional development zone of Fuling shale gas.Six coring wells of different well types were systematically designed.Based on the integrated engineering technology of post-fracturing drilling,coring and monitoring of shale and the analysis of fracture source tracing,the evaluation of the fracture network after fracturing in the three-dimensional development of shale gas was conducted.The data of core fractures after fracturing indicate that three major types of fractures are formed after fracturing:natural fractures,hydraulic fractures,and fractures induced by external mechanical force,which are further classified into six subcategories:natural structural fractures,natural bedding fractures,hydraulic fractures,hydraulically activated fractures,drilling induced fractures,and fractures induced by core transportation.The forms of the artificial fracture network after fracturing are complex.Hydraulic fractures and hydraulically activated fractures interweave with each other,presenting eight forms of artificial fracture networks,among which the“一”-shaped fracture is the most common,accounting for approximately 70%of the total fractures.When the distance to the fractured wellbore is less than 35 m,the density of the artificial fracture network is relatively high;when it is 35–100 m,the density is lower;and when it is beyond 100 m,the density gradually increases.The results of the fracture tracing in the core sampling area confirm that the current fracturing technology can essentially achieve the differential transformation of the reservoir in the main area of Jiaoshiba block in Fuling.The three-layer three-dimensional development model can efficiently utilize shale gas reserves,although there is still room for improvement in the complexity and propagation uniformity of fractures.It is necessary to further optimize technologies such as close-cutting combined with temporary blocking and deflection within fractures or at fracture mouths,as well as limited flow perforation techniques,to promote the balanced initiation and extension of fractures.展开更多
Coal power plants annually generate quantities of byproducts that release environmentally hazardous heavy metals like Cd and Pb.Understanding the behavior and spatiotemporal impacts on soils of these releases is cruci...Coal power plants annually generate quantities of byproducts that release environmentally hazardous heavy metals like Cd and Pb.Understanding the behavior and spatiotemporal impacts on soils of these releases is crucial for pollution control.This study investigated the concentrations and isotope ratios of Cd/Pb in combustion byproducts,depositions and soils collected froma coal-fired power plant or its surrounding area.The pulverized fuel ash(PFA)and desulfurized gypsum(DG)exhibited heavier Cd isotopes withΔ^(114)Cd values of 0.304‰and 0.269‰,respectively,while bottom ash(BA)showed lighter Cd isotopes(Δ^(114)CdBA-coal=–0.078‰),compared to feed coal.We proposed a two-stage condensation process that governs the distribution of Cd/Pb,including accumulation on PFA and DG within electrostatic precipitators and desulfurization unit,as well as condensation onto fine particles upon release from the stack.Emissions from combustion and large-scale transport make a significant contribution to deposition,while the dispersion of Cd/Pb in deposition is primarily influenced by the prevailing wind patterns.However,the distribution of Cd/Pb in soils not only exhibit predominant wind control but is also potentially influenced by the resuspension of long-term storage byproducts.The power plant significantly contributes to soil in the NW–N–NE directions,even at a considerable distance(66%–79%),demonstrating its pervasive impact on remote regions along these orientations.Additionally,based on the vertical behavior in the profile,we have identified that Cd tends to migrate downward through leaching,while variations in Pb respond to the historical progression of dust removal.展开更多
The growth of tidal flats off Zhejiang coasts in southwestern China has provided substantial areas for local agriculture and construction activities.To evaluate modern and future development of tidal flats in the regi...The growth of tidal flats off Zhejiang coasts in southwestern China has provided substantial areas for local agriculture and construction activities.To evaluate modern and future development of tidal flats in the region,a good understanding of sediment sources is necessary.Previous research has concluded that the Changjiang(Yangtze)River is the dominant supplier of sediments to this part of the southeast Chinese coast,despite the fact that sediment delivery from this source has been decreased markedly in the past two decades.In this study,we investigated the sources of tidal flat sediments,and the magnetic and geochemical properties of recent tidal flat sediments along the Zhejiang coast were compared with those discharged from rivers.Magnetic and geochemical properties of the tidal flat samples reveal statistically distinct sediment provenance groups.The magnetic and geochemical scatter plots show that the suspended sediment samples are naturally divided into two different groups,one including the Changjiang River and Qiantang River material,and the other including the Jiaojiang,Oujiang,and Feiyun Rivers that located in the central and southern parts of the study areas.At last,a binary source of tidal flat sediments along the Zhejiang coast was determined,with the substantial majority originating from local rivers,while a much smaller proportion emanates from the Changjiang River to the north.We conclude that the sediment contribution of the Changjiang River to tidal flat development in the region has been markedly overestimated,with important implications for management.展开更多
Deepfake poses significant threats to various fields,including politics,journalism,and entertainment.Although many defense methods against deepfake have been proposed based on either passive detection or proactive def...Deepfake poses significant threats to various fields,including politics,journalism,and entertainment.Although many defense methods against deepfake have been proposed based on either passive detection or proactive defense,few have achieved both passive detection and proactive defense.To address this issue,we propose a full-defense framework(FDF)based on cross-domain feature fusion and separable watermarks(SepMark)to achieve copyright protection and deepfake detection,combining the ideas of passive detection and proactive defense.The proactive defense module consists of one encoder and two separable decoders,where the encoder embeds one watermark into the protected face,and two decoders separately extract two watermarks with different robustness.The robust watermark can reliably trace the trusted marked face while the semi-robust watermark is sensitive to malicious distortions that make the watermark disappear after deepfake or watermark removal attack.The passive detection module fuses spatial-and frequency-domain features to further differentiate between deepfake content and watermark removal attacks in the absence of watermarks.The proposed cross-domain feature fusion involves substituting the "secondary" channels of spatial-domain features with the "primary" channels of frequency-domain features.Subsequently,the "primary"channels of spatial-domain features are used to replace the "secondary"channels of frequency-domain features.Extensive experiments demonstrate that our approach not only offers proactive defense mechanisms by using extracted watermarks,i.e.,source tracing and copyright protection,but also achieves passive detection when there are no watermarks,to further differentiate between deepfake content and watermark removal attacks,thereby offering a full-defense approach.展开更多
Understanding the redistribution of soil organic carbon(OC)driven by erosion contributes to the global carbon budget and watershed management.Quantifying the sources of eroded OC in sediments provides new insights to ...Understanding the redistribution of soil organic carbon(OC)driven by erosion contributes to the global carbon budget and watershed management.Quantifying the sources of eroded OC in sediments provides new insights to addressing this issue.However,limited quantitative information on the factors influencing OC sources has constrained the behavior of regulating the OC exported from the watershed.Here,we explored the sources of OC in lake sediments over the last 100 years and quantified the effects of climate change and human activities on OC sources.Results from the stable isotope fingerprinting and MixSIAR model indicated that phragmites(30.34%)and croplands(21.48%)were consistently the main OC sources.Therefore,efforts should be concentrated on controlling soil erosion from cropland and managing the endogenous environment.In addition,the partial least squares pathways(PLS-PM)and random forests revealed that human activities(Path coefficients(r∂):0.45 to 0.61)have controlled the OC sources over the last hundred years.Agricultural activities,urbanization,and land use change altered the quality of OC sources by affecting the vegetation productivity in source areas.The quantity of OC sources was also influenced by underlying surface and surface connectivity changes.The effects of climate change(temperature(r∂):-0.41 to 0.1;precipitation(r∂):0.1 to 0.29)on OC sources have not been significant,but their long-term effects cannot be ignored.These findings provide a better insight into the origin and behavior of OC in lake sediments under global change,which is crucial for basin management and lake governance.展开更多
The epidemiological characteristics of emerging infectious disease outbreaks in recent years have underscored the critical importance of controlling imported infectious diseases.In this study,we implemented dynamic tr...The epidemiological characteristics of emerging infectious disease outbreaks in recent years have underscored the critical importance of controlling imported infectious diseases.In this study,we implemented dynamic tracking of microbial invasions by monitoring environmental microbes at the customs and ports.From July to September 2024,a total of 126 environmental samples were collected from three ports of entry in Shenzhen,China.Metagenomic analysis detected 55 non-viral microbial communities and 12 viral taxa.Among these,26.8%of the bacteria,100%of the fungi,71.4%of the protists,and none of the archaea exhibited potential pathogenic properties.Viruses were the most prevalent,including bacteriophages(100%),unclassified viruses(96.8%),giant viruses(27.8%),fungal viruses(4.8%),and vertebrate viruses(1.6%).No statistical differences were observed in viral distribution across areas(χ^(2)=18.70,P=0.541),sites(χ^(2)=14.02,P=0.597),or ports of entry(χ^(2)=10.27,P=0.247).However,viral distribution varied significantly across three sampling months(χ^(2)=21.06,P=0.002),with a higher proportion of giant viruses detected in July.Thirty-nine and forty microorganisms were identified across the six areas and five sites,respectively,with relatively few area/site-specific microorganisms.Four distinct disinfection level zones were categorized:relatively safe zone,less safe zone,general disinfection zone and key disinfection zone.Two strains of viruses with potential pathogenicity were identified:pigeon circovirus and Influenza A virus(H4N2).This study established a metagenomics-based surveillance framework for microbial risk assessment in high-risk port environments and proposed a four-tier disinfection strategy to prioritize high-contact zones.Our findings highlighted environmental metagenomics as a critical complement to traveler screening and provided early warning signals for the prevention and control of imported infectious diseases.展开更多
Trace metals associated with PM10 aerosols and their variation during day and nighttime as well as during different seasons have been studied for the year 2012. PCA analysis suggested5 PCs,which accounted for 86.8% cu...Trace metals associated with PM10 aerosols and their variation during day and nighttime as well as during different seasons have been studied for the year 2012. PCA analysis suggested5 PCs,which accounted for 86.8% cumulative variance. PC1 accounted for 30% with a significant loading of metals of anthropogenic origin,while PC2 showed 28% variance with the loading of metals of crustal origin. These trace metals showed seasonal distinct day and night time characteristics. The concentrations of Cu,Pb,and Cd were found to be higher during nighttime in all the seasons. Only Fe was observed with significantly higher mean concentrations during daytime of all seasons except monsoon. The highest mean values of Cu,Cd,Zn,and Pb during post-monsoon might be attributed to winds advection over the regions of waste/biomass burning and industrial activities in Punjab and Haryana regions.Furthermore,concentration weighted trajectory analysis suggested that metals of crustal origin were contributed by long-range transport while metals of anthropogenic and industrial activities were contributed by regional/local source regions.展开更多
Particulate matter （PM） emissions from steelworks cause public concern. Although end-of-pipe and pro- cess integrated measures have led to a significant drop in emissions of large particles from stacks, fine aerosol...Particulate matter （PM） emissions from steelworks cause public concern. Although end-of-pipe and pro- cess integrated measures have led to a significant drop in emissions of large particles from stacks, fine aerosols were not specifically considered, nor were emissions from fugitive and open sources. In this study, we deployed aerosol samplers together with a scanning ultra-violet （UV） lidar to characterize total suspended particles （TSP）, PM10, and PM2.5, in emissions from a large integrated steelworks in Spain over a 16-day period. We determined the content of carbonaceous, soluble inorganic, mineral dust, and metal species. A positive matrix factorization was carried out on our dataset. Despite mineral dust being predominant in all size fractions, the steelworks was clearly a source of carbonaceous species, resulting in production of secondary inorganic aerosols. In particular, stack emissions were a major contributor of fine particles, while open sources dominated the emissions of TSP, yielding up to 80% of particles larger than PM10. UV lidar provided 2D maps of aerosols in real time, with an ability to detect PM emissions and to visualize complex plumes. We suggest that air quality management of steelworks needs to focus on controlling large and coarse oarticle emissions, esoeciallv those from onen sources.展开更多
基金the National Natural Science Foundation of China(Nos.91851110,41701541)。
文摘In recent years,oil spills caused by human activities have occurred frequently,and the resultant oil pollution has received extensive attention worldwide.In this paper,a total of 50 water samples were collected from the northeastern part of the South China Sea,and total petroleum hydrocarbons(TPHs)and n-alkane content in the samples were analyzed by gas chromatography-flame ionization detector(GC-FID)technology.The petroleum hydrocarbon characteristic indices,such as carbon predominance index(CPI)and terrigenous/aquatic ratio(TAR),were calculated to trace the source of petroleum hydrocarbons.The measured value of TPHs ranged from 121.31-603.02μg/L.For surface waters,the TPHs in the no rthern coastal waters and the central waters were higher than that in the far shore.For ve rtical waters,the TPHs sharply decreased at first,and then increased slowly and finally reached a steady state.The n-alkanes in the water samples were concentrated in C10-C38,and they were mainly from terrestrial higher plant.The waters in the near shore,mid-layer and deep sea showed a strong reducing terrestrial characteristic,while the surface waters in the open sea showed an obvious oxidizing endogenous characteristic.
基金financially supported by the National Natural Science Foundation of China (Grant Nos. 41473093 and 41271212)。
文摘The distribution patterns of rare earth elements(REEs)in fine-grained materials in various depositions were often found to be similar to those of the aeolian sediments deposited in the Loess Plateau in North China and the fine-grained materials were suggested to be derived from wind-blown dust.However,increasing evidence indicated that the REEs in the water-soluble portion of atmospheric depositions also displayed similar patterns to those of aeolian sediments.In this study,water-soluble REEs in three atmospheric depositions collected from different climatic zones in China were adsorbed with two adsorbents with distinct adsorption capacity,glass powder,and co-precipitated iron hydroxide.The results showed that the REEs adsorbed by the two adsorbents displayed patterns similar to those of the original atmospheric depositions.The typical characteristics of the REE patterns of atmospheric deposition can be well reproduced in the adsorbed REEs.The higher the REE concentrations in the atmospheric depositions,or the higher adsorption efficiency of the adsorbents,the better reproducibility of the REEs patterns.The results suggest that the REEs of the fine-grained materials in various sediments,which have a high adsorption capacity,especially those deposited in South China,may come from the water-soluble REEs in atmospheric deposition,and may not be appropriate tracers of wind-blown dust from North China.
文摘Abstract This paper deals with characteristics of silicon isotope compositions and siliceous cathodoluminescence of host rocks, ores and hydrothermal silicified quartz of the Carlin-type ore deposits in the Yunnan-Guizhou-Guangxi triangle area. The study shows that primary silicified quartz is nonluminescent but quartz in host rocks and secondary silicified quartz are luminescent by the action of cathode rays. Correspondingly, silicon isotope compositions of host rocks, ores and hydro6thermal quartz veins are clearly distinguished. In strata from the Middle Triassic to the “Dachang” host bed, δ30Si of the host rocks ranges from 0.0% ?0.3%, while that of primary ore-forming silicified fluids from ?0.1% to ?0.4%; in the Upper Permian and Lower Carboniferous strata and Indosinian diabase host beds, δ30Si of the host rocks is from ?0.1% to ?0.2% and that of the primary silicified quartz veins from 0.3 % ?0.5 %. This pattern demonstrates the following geochemical mineralization process, primary ore-forming siliceous fluids migrated upwards quickly along the main passages of deep-seated faults from mantle to crust and entered secondary faults where gold deposits were eventually formed as a result of permeation and replacement of the siliceous ore-forming fluids into different ore-bearing strata. This gives important evidence for the fact that ore-forming fluids of this type of gold deposits were mainly derived from upper mantle differentiation and shows good prospects for deep gold deposits and geochemical background for large and superlarge gold deposits.
文摘The core sampling experiments were conducted after hydraulic fracturing in the three-dimensional development zone of Fuling shale gas.Six coring wells of different well types were systematically designed.Based on the integrated engineering technology of post-fracturing drilling,coring and monitoring of shale and the analysis of fracture source tracing,the evaluation of the fracture network after fracturing in the three-dimensional development of shale gas was conducted.The data of core fractures after fracturing indicate that three major types of fractures are formed after fracturing:natural fractures,hydraulic fractures,and fractures induced by external mechanical force,which are further classified into six subcategories:natural structural fractures,natural bedding fractures,hydraulic fractures,hydraulically activated fractures,drilling induced fractures,and fractures induced by core transportation.The forms of the artificial fracture network after fracturing are complex.Hydraulic fractures and hydraulically activated fractures interweave with each other,presenting eight forms of artificial fracture networks,among which the“一”-shaped fracture is the most common,accounting for approximately 70%of the total fractures.When the distance to the fractured wellbore is less than 35 m,the density of the artificial fracture network is relatively high;when it is 35–100 m,the density is lower;and when it is beyond 100 m,the density gradually increases.The results of the fracture tracing in the core sampling area confirm that the current fracturing technology can essentially achieve the differential transformation of the reservoir in the main area of Jiaoshiba block in Fuling.The three-layer three-dimensional development model can efficiently utilize shale gas reserves,although there is still room for improvement in the complexity and propagation uniformity of fractures.It is necessary to further optimize technologies such as close-cutting combined with temporary blocking and deflection within fractures or at fracture mouths,as well as limited flow perforation techniques,to promote the balanced initiation and extension of fractures.
基金supported by the National Natural Science Foundation of China(No.42025705)the Construction Project of Modern Agricultural Science and Technology Innovation Alliance of Guangdong Province,China(No.2023KJ112)+1 种基金the National Natural Science Foundation of China(Nos.41977291 and 42177242)the GDAS’Project of Science and Technology Development,China(No.2019GDASYL-0103048).
文摘Coal power plants annually generate quantities of byproducts that release environmentally hazardous heavy metals like Cd and Pb.Understanding the behavior and spatiotemporal impacts on soils of these releases is crucial for pollution control.This study investigated the concentrations and isotope ratios of Cd/Pb in combustion byproducts,depositions and soils collected froma coal-fired power plant or its surrounding area.The pulverized fuel ash(PFA)and desulfurized gypsum(DG)exhibited heavier Cd isotopes withΔ^(114)Cd values of 0.304‰and 0.269‰,respectively,while bottom ash(BA)showed lighter Cd isotopes(Δ^(114)CdBA-coal=–0.078‰),compared to feed coal.We proposed a two-stage condensation process that governs the distribution of Cd/Pb,including accumulation on PFA and DG within electrostatic precipitators and desulfurization unit,as well as condensation onto fine particles upon release from the stack.Emissions from combustion and large-scale transport make a significant contribution to deposition,while the dispersion of Cd/Pb in deposition is primarily influenced by the prevailing wind patterns.However,the distribution of Cd/Pb in soils not only exhibit predominant wind control but is also potentially influenced by the resuspension of long-term storage byproducts.The power plant significantly contributes to soil in the NW–N–NE directions,even at a considerable distance(66%–79%),demonstrating its pervasive impact on remote regions along these orientations.Additionally,based on the vertical behavior in the profile,we have identified that Cd tends to migrate downward through leaching,while variations in Pb respond to the historical progression of dust removal.
基金Supported by the Natural Science Foundation of Zhejiang Province,China(No.LY20D040001)the National Undergraduate Innovation and Entrepreneurship Training Program of China。
文摘The growth of tidal flats off Zhejiang coasts in southwestern China has provided substantial areas for local agriculture and construction activities.To evaluate modern and future development of tidal flats in the region,a good understanding of sediment sources is necessary.Previous research has concluded that the Changjiang(Yangtze)River is the dominant supplier of sediments to this part of the southeast Chinese coast,despite the fact that sediment delivery from this source has been decreased markedly in the past two decades.In this study,we investigated the sources of tidal flat sediments,and the magnetic and geochemical properties of recent tidal flat sediments along the Zhejiang coast were compared with those discharged from rivers.Magnetic and geochemical properties of the tidal flat samples reveal statistically distinct sediment provenance groups.The magnetic and geochemical scatter plots show that the suspended sediment samples are naturally divided into two different groups,one including the Changjiang River and Qiantang River material,and the other including the Jiaojiang,Oujiang,and Feiyun Rivers that located in the central and southern parts of the study areas.At last,a binary source of tidal flat sediments along the Zhejiang coast was determined,with the substantial majority originating from local rivers,while a much smaller proportion emanates from the Changjiang River to the north.We conclude that the sediment contribution of the Changjiang River to tidal flat development in the region has been markedly overestimated,with important implications for management.
基金Project supported by the Liaoning Provincial Education Department Science Project(No.JYTMS20231039)the Liaoning Provincial Education Science Planning Project(No.JG22CB252)the National Natural Science Foundation of China(Nos.61976109 and 61601214)。
文摘Deepfake poses significant threats to various fields,including politics,journalism,and entertainment.Although many defense methods against deepfake have been proposed based on either passive detection or proactive defense,few have achieved both passive detection and proactive defense.To address this issue,we propose a full-defense framework(FDF)based on cross-domain feature fusion and separable watermarks(SepMark)to achieve copyright protection and deepfake detection,combining the ideas of passive detection and proactive defense.The proactive defense module consists of one encoder and two separable decoders,where the encoder embeds one watermark into the protected face,and two decoders separately extract two watermarks with different robustness.The robust watermark can reliably trace the trusted marked face while the semi-robust watermark is sensitive to malicious distortions that make the watermark disappear after deepfake or watermark removal attack.The passive detection module fuses spatial-and frequency-domain features to further differentiate between deepfake content and watermark removal attacks in the absence of watermarks.The proposed cross-domain feature fusion involves substituting the "secondary" channels of spatial-domain features with the "primary" channels of frequency-domain features.Subsequently,the "primary"channels of spatial-domain features are used to replace the "secondary"channels of frequency-domain features.Extensive experiments demonstrate that our approach not only offers proactive defense mechanisms by using extracted watermarks,i.e.,source tracing and copyright protection,but also achieves passive detection when there are no watermarks,to further differentiate between deepfake content and watermark removal attacks,thereby offering a full-defense approach.
基金supported by the National Natural Science Foundation of China(U19A2047,42277335)athe Natural Science Foundation of Hunan Province(2022JJ30390).
文摘Understanding the redistribution of soil organic carbon(OC)driven by erosion contributes to the global carbon budget and watershed management.Quantifying the sources of eroded OC in sediments provides new insights to addressing this issue.However,limited quantitative information on the factors influencing OC sources has constrained the behavior of regulating the OC exported from the watershed.Here,we explored the sources of OC in lake sediments over the last 100 years and quantified the effects of climate change and human activities on OC sources.Results from the stable isotope fingerprinting and MixSIAR model indicated that phragmites(30.34%)and croplands(21.48%)were consistently the main OC sources.Therefore,efforts should be concentrated on controlling soil erosion from cropland and managing the endogenous environment.In addition,the partial least squares pathways(PLS-PM)and random forests revealed that human activities(Path coefficients(r∂):0.45 to 0.61)have controlled the OC sources over the last hundred years.Agricultural activities,urbanization,and land use change altered the quality of OC sources by affecting the vegetation productivity in source areas.The quantity of OC sources was also influenced by underlying surface and surface connectivity changes.The effects of climate change(temperature(r∂):-0.41 to 0.1;precipitation(r∂):0.1 to 0.29)on OC sources have not been significant,but their long-term effects cannot be ignored.These findings provide a better insight into the origin and behavior of OC in lake sediments under global change,which is crucial for basin management and lake governance.
基金supported by the National Key R&D Program of China(2023YFC2605300&2024YFC2311500).
文摘The epidemiological characteristics of emerging infectious disease outbreaks in recent years have underscored the critical importance of controlling imported infectious diseases.In this study,we implemented dynamic tracking of microbial invasions by monitoring environmental microbes at the customs and ports.From July to September 2024,a total of 126 environmental samples were collected from three ports of entry in Shenzhen,China.Metagenomic analysis detected 55 non-viral microbial communities and 12 viral taxa.Among these,26.8%of the bacteria,100%of the fungi,71.4%of the protists,and none of the archaea exhibited potential pathogenic properties.Viruses were the most prevalent,including bacteriophages(100%),unclassified viruses(96.8%),giant viruses(27.8%),fungal viruses(4.8%),and vertebrate viruses(1.6%).No statistical differences were observed in viral distribution across areas(χ^(2)=18.70,P=0.541),sites(χ^(2)=14.02,P=0.597),or ports of entry(χ^(2)=10.27,P=0.247).However,viral distribution varied significantly across three sampling months(χ^(2)=21.06,P=0.002),with a higher proportion of giant viruses detected in July.Thirty-nine and forty microorganisms were identified across the six areas and five sites,respectively,with relatively few area/site-specific microorganisms.Four distinct disinfection level zones were categorized:relatively safe zone,less safe zone,general disinfection zone and key disinfection zone.Two strains of viruses with potential pathogenicity were identified:pigeon circovirus and Influenza A virus(H4N2).This study established a metagenomics-based surveillance framework for microbial risk assessment in high-risk port environments and proposed a four-tier disinfection strategy to prioritize high-contact zones.Our findings highlighted environmental metagenomics as a critical complement to traveler screening and provided early warning signals for the prevention and control of imported infectious diseases.
基金Partial financial support from the CSIR network project(PSC 0112)CSIR fellowship to Subhash Chandra,SRF
文摘Trace metals associated with PM10 aerosols and their variation during day and nighttime as well as during different seasons have been studied for the year 2012. PCA analysis suggested5 PCs,which accounted for 86.8% cumulative variance. PC1 accounted for 30% with a significant loading of metals of anthropogenic origin,while PC2 showed 28% variance with the loading of metals of crustal origin. These trace metals showed seasonal distinct day and night time characteristics. The concentrations of Cu,Pb,and Cd were found to be higher during nighttime in all the seasons. Only Fe was observed with significantly higher mean concentrations during daytime of all seasons except monsoon. The highest mean values of Cu,Cd,Zn,and Pb during post-monsoon might be attributed to winds advection over the regions of waste/biomass burning and industrial activities in Punjab and Haryana regions.Furthermore,concentration weighted trajectory analysis suggested that metals of crustal origin were contributed by long-range transport while metals of anthropogenic and industrial activities were contributed by regional/local source regions.
文摘Particulate matter （PM） emissions from steelworks cause public concern. Although end-of-pipe and pro- cess integrated measures have led to a significant drop in emissions of large particles from stacks, fine aerosols were not specifically considered, nor were emissions from fugitive and open sources. In this study, we deployed aerosol samplers together with a scanning ultra-violet （UV） lidar to characterize total suspended particles （TSP）, PM10, and PM2.5, in emissions from a large integrated steelworks in Spain over a 16-day period. We determined the content of carbonaceous, soluble inorganic, mineral dust, and metal species. A positive matrix factorization was carried out on our dataset. Despite mineral dust being predominant in all size fractions, the steelworks was clearly a source of carbonaceous species, resulting in production of secondary inorganic aerosols. In particular, stack emissions were a major contributor of fine particles, while open sources dominated the emissions of TSP, yielding up to 80% of particles larger than PM10. UV lidar provided 2D maps of aerosols in real time, with an ability to detect PM emissions and to visualize complex plumes. We suggest that air quality management of steelworks needs to focus on controlling large and coarse oarticle emissions, esoeciallv those from onen sources.
