In the past decade or so,AI(artificial intelligence)technology has been growing with such a mesmerizing speed that today its presence in almost any industry that deals with any huge sheer volume of data is taking adva...In the past decade or so,AI(artificial intelligence)technology has been growing with such a mesmerizing speed that today its presence in almost any industry that deals with any huge sheer volume of data is taking advantage of AI by integrating it into their day-to-day operation.Meanwhile,seven billion people worldwide shape the world’s energy system and directly impact the fundamental drivers of energy,both renewable and non-renewable sources,to meet the demand for electricity from them.These energy sources can be reached from nature such as solar,wind,etc.,and human-made such as NPPs(nuclear power plants)in the form of either fission as an old technology since the Manhattan project and in the near future as fusion in the form of magnetic or inertial confinements.Meanwhile,AI controlling nuclear reactors are about to happen.The basic idea is to apply AI with its two subset components as ML(machine learning),and DL(deep learning)techniques to go through the mountains of data that come from a reactor,spot patterns in it,and calling them to the unit’s human attention operators is not invadable either.Designers of such nuclear reactors will combine simulation and real-world data,comparing scenarios from each to develop“confidence[in]what they can predict and what is the range of uncertainty of their prediction”.Adding that,in the end,the operator will make the final decisions in order to keep these power plants safe while they are in operation and how to secure them against cyber-attack natural or human-made disasters.In this short communication article,we would like to see how we can prove some of these concepts;then a NPP manufacturer can pick it up and use it in their designs of a new generation of these reactors.展开更多
This article is focused on technical and economic evaluation of more than 6-years experiences of operating the Waste Heat Recovery technology—the manner and system of flue gas processing generated in the combustion p...This article is focused on technical and economic evaluation of more than 6-years experiences of operating the Waste Heat Recovery technology—the manner and system of flue gas processing generated in the combustion process in heat & power plants, cogeneration units, etc., which burn the gaseous fuel, primarily natural gas, or methane, biogas, geothermal gas, or other gaseous mixtures containing hydrogen. The solution proposes a more effective and non-traditional use of gaseous fuel for heating, the flue gases of which are processed in order to extract additional utilisable heat, with potential elimination of CO2 from them. Deploying of the heating plant in an island regime (OFF-GRID) enables definition of the benefits brought by the 3 years of operational experience and presents visions for the future offering the possibility to utilise the support energy services at the municipal as well as regional level.展开更多
Ultrafast electron sources, which enable high spatiotemporal resolution in time-resolved electron microscopy and scanning probe microscopy, are receiving increased attention. The most widely used method for achieving ...Ultrafast electron sources, which enable high spatiotemporal resolution in time-resolved electron microscopy and scanning probe microscopy, are receiving increased attention. The most widely used method for achieving ultrafast electron sources involves irradiating metal tips by ultrashort laser pulses, causing electron beam emission via the photoelectric effect [including photon-driven(quantum) or field-driven(classical) emission]. However, the thermionic electrons emission process due to the heating effect of ultrashort lasers, particularly its dynamic aspects, has rarely been addressed in previous studies. In this paper, we improved the signal-to-noise ratio of a two-pulse correlation measurement on the tip electron emission by nearly two orders of magnitude using a delay time modulation method. This allowed us to obtain information on the temperature evolution of hot electrons and phonons in a non-equilibrium state, and to extract characteristic time scales for electron-phonon and phonon-phonon scattering. Our findings indicate that the thermionic electrons emission, unlike the instantaneous photoelectric effect, causes electron emission to lag behind the laser pulse by tens of picoseconds, thus significantly affecting the detection of ultrafast dynamics of samples. Furthermore, such a lagging effect was found to be sensitive to the local structure of the metal tip, offering new insights into the improved design of ultrafast electron sources.展开更多
Precipitation isotopes(δ^(18)O and δ^(2)H)are closely related to meteorological conditions for precipitation generation and the initial state of water vapor source areas,and are essential to the study of the regiona...Precipitation isotopes(δ^(18)O and δ^(2)H)are closely related to meteorological conditions for precipitation generation and the initial state of water vapor source areas,and are essential to the study of the regional hydrological cycle.The deuterium excess(d-excess)indicates deviation in isotope fractionation during evaporation and can trace water vapor sources.This study analyzed 443 precipitation samples collected from the Gannan Plateau,China in 2022 to assess precipitation isotope variations and their driving factors.Water vapor sources were evaluated using the Hybrid Single-Particle Lagrangian Integrated Trajectory(HYSPLIT),Concentration Weighted Trajectory(CWT),and Potential Source Contribution Factor(PSCF)models.Results showed that precipitation isotope values showed significant spatial and temporal variations on the Gannan Plateau.Temporally,precipitation isotope values peaked in June(when evaporation dominated)and minimized in March(depletion effect of air masses in the westerly wind belt).Spatially,the isotope values showed a distribution pattern of"high in the east and low in the west",which was mainly regulated by the differences in altitude and local meteorological conditions.Compared with the global meteoric water line(GMWL)with equation of δ^(2)H=8.00δ^(18)O+10.00,the slope and intercept of local meteoric water line(LMWL)for precipitation on the Gannan Plateau were smaller(7.49 and 7.63,respectively),reflecting the existence of a stronger secondary evaporation effect under the clouds in the region.The sources of water vapor on the Gannan Plateau showed significant seasonality and spatial heterogeneity.Specifically,the westerly belt and monsoon were the main water vapor transport paths at each sampling point,with Central Asian continental water vapor dominating in spring(53.49%),Indian Ocean water vapor dominating in summer(52.53%),Atlantic Ocean water vapor dominating in autumn(46.74%),and Atlantic Ocean and Mediterranean Sea water vapor dominating in winter(42.30%and 33.68%,respectively).Changes in the intensity of convective activity and Outgoing Longwave Radiation(OLR)affected the enrichment of isotopic values,which exhibited the same change trends as δ^(18)O.During the precipitation process,the δ^(18)O value first decreased and then increased.During the initial and final stages of precipitation process,precipitation was mainly influenced by continental air masses,while during the middle stage,it was controlled by marine air masses.The systematic research on precipitation isotopes and water vapor sources is important for climate change research and extreme precipitation prediction on the Gannan Plateau and other similar areas.展开更多
Pharmaceuticals and personal care products(PPCPs)are receiving attention as emerging pollutants due to their extensive applications and persistent emissions.The Qiantang River Basin,a representative region in eastern ...Pharmaceuticals and personal care products(PPCPs)are receiving attention as emerging pollutants due to their extensive applications and persistent emissions.The Qiantang River Basin,a representative region in eastern China that relies on surface water for drinking purposes,experiences the movement and accumulation of PPCPs in its water and sediment,which can directly affect the safety of drinking water in the basin.This study focuses on the Qiantang River Basin’s surface water,sediment,and drinking water to determine the occurrence and potential risks of 31 PPCPs.It aims to address whether PPCPs in the environment could migrate and accumulate,thereby affecting human health.The findings indicated that PPCPs are ubiquitous in various environmental media,with surface and pore water showing distinct spatial distribution characteristics,specifically,concentrations escalated with urban scale expansion,indicating that domestic sewage discharge is the primary source of PPCP input.Bisphenol A(BPA),ketoprofen(KTP),and diethyltoluamide(DEET)were the primary contaminants.The movement of PPCPs within the surface water-sediment-pore water system was affected by various circumstances.Substances like Sulfamethoxazole(SMX)(RQ>103)and KTP(RQ=22.3)present in surface water and sediment pose significant ecological concerns,and KTP and atrazine(ATZ)(0.6<RQ<2.1)also pose a high risk in drinking water.This study performed an extensive analysis of the distribution and risks associated with typical PPCPs in the Qiantang River Basin,offering a scientific foundation and theoretical support for research on the environmental behavior of PPCPs in this area and the development of targeted pollution control strategies.展开更多
This paper presents a case study for a complex contaminated groundwater site impacted by a historical release of chlorinated solvents in Silicon Valley, California. The original conceptual site model (CSM) inferred a ...This paper presents a case study for a complex contaminated groundwater site impacted by a historical release of chlorinated solvents in Silicon Valley, California. The original conceptual site model (CSM) inferred a contaminant migration pathway based on the groundwater gradient interpreted from groundwater elevation data, which is based on the underlying assumption that the subsurface conditions are homogeneous. However, the buried channel deposits render the underlying geology highly heterogeneous, and this heterogeneity plays a significant role in the subsurface migration of contaminants. Chemical fingerprinting evidence suggested that contamination at the downgradient property boundary was related to an off-site contaminant source. But, this alone was not a compelling argument. However, Environmental Sequence Stratigraphy (ESS), a geology-based environmental forensic technique, was applied to define the permeability architecture or the “plumbing” that controls subsurface fluid flow and contaminant migration. First, the geologic and depositional setting was synthesized based on regional geologic data, and representative facies models were identified for the site. Second, the existing CSM and site lithology data were reviewed and existing lithology data were graphically presented to display vertical grain-size patterns. This analysis focused on the nexus between the depositional environment and the site-specific subsurface data resulting in correlations/interpretations between and beyond data points that are based on established stratigraphic principles. The depositional environment results in buried river channels as the primary control on subsurface fluid flow, which defines hydrostratigraphic units (or HSUs). Finally, a hydrostratigraphic CSM that includes maps and cross sections was constructed to depict the HSUs present as a framework to integrate hydro-geology and chemistry data. This study demonstrates that: 1) Highly per-meable buried river channel deposits control subsurface fluid flow and contaminant transport, and have distinct chemical constituents and concentrations (i.e., they represent distinct HSUs), 2) Mapping of such HSUs is feasible with existing boring log data, 3) In settings such as the Santa Clara Valley where groundwater flow is governed by subsurface channel deposits, a hydrostratigraphic mapping approach is superior to a depth-based aquifer zonation approach, and 4) For heterogeneous subsurface, a detailed geology-based definition of the subsurface is an integral component of an environmental forensic analyses to determine contaminant source(s) and pathways.展开更多
Rice is very sensitive to low zinc(Zn) supply in submerged paddy soils and Zn deficiency is one of the major limiting factors in determining rice production in India. A field experiment was conducted during the summer...Rice is very sensitive to low zinc(Zn) supply in submerged paddy soils and Zn deficiency is one of the major limiting factors in determining rice production in India. A field experiment was conducted during the summer-rainy seasons of 2009 and 2010 at the research farm of the Indian Agricultural Research Institute, New Delhi, to determine the effects of summer green manure crops and Zn fertilizers on diethylenetriaminepentaacetic acid(DTPA)-extractable(available) Zn concentration in soil and total Zn content in Basmati rice cultivar Pusa Basmati 1 at periodic intervals. Summer green manure crops included Sesbania aculeata(Dhaincha),Crotalaria juncea(Sunhemp), and Vigna unguiculata(Cowpea) and the Zn fertilizers used were ethylenediaminetetraacetic acid(EDTA)-chelated Zn, ZnSO4·7H2O, ZnSO4·H2O, ZnO, and ZnSO4·7H2O + ZnO. Beneficial effects of summer green manure crops and Zn fertilizers on DTPA-extractable Zn concentration in soil and total Zn content in dry matter of Basmati rice at periodic intervals were observed, with significant increases in all the determined parameters, in comparison with those in the control(no Zn application or summer fallow). The rate of increase varied among summer green manure crops and Zn fertilizers during both years. Among the summer green manures, incorporation of S. aculeata led to a significant increase in mean Zn content in Basmati rice grain and straw when compared with C. juncea, V. unguiculata, and summer fallow treatments. Among the Zn fertilizers, significant increases in Zn content in Basmati rice dry matter and DTPA-extractable Zn concentration in soil during various growth stages of the plant were recorded with EDTA-chelated Zn application, followed by the application of ZnSO4·7H2O, ZnSO4·H2O, ZnSO4·7H2O + ZnO, ZnO,and no Zn. The highest mean Zn content in Basmati rice grain and straw was recorded with EDTA-chelated Zn application in 2009 and 2010, respectively. The application of ZnSO4·7H2O was the second best treatment after EDTA-chelated Zn;however, it was statistically inferior to EDTA-chelated Zn. The lowest values were recorded with the control(no Zn application) during both years of study. The amount of Zn concentration in soil was found to be significantly positively correlated with the Zn content in Basmati rice dry matter during both years. Significantly higher levels of residual fertility in soil after the harvest of Basmati rice were observed with application of EDTA-chelated Zn and incorporation of S. aculeata when compared with those of other Zn sources and summer green manures.展开更多
Forest resources play a vital role in supporting the livelihoods of rural communities residing in forest-rich areas.In India,a forest-rich country,a significant proportion of non-timber forest products(NTFPs)is consum...Forest resources play a vital role in supporting the livelihoods of rural communities residing in forest-rich areas.In India,a forest-rich country,a significant proportion of non-timber forest products(NTFPs)is consumed locally,supporting numerous rural communities relying on forests for essential resources,such as firewood,timber,and NTFPs.This study focuses on two forest-dominant districts in West Bengal of India,namely,Jhargram District and Paschim Medinipur District.Furthermore,this study aims to enhance the understanding of forest-dependent communities by comparing the standard of living among different village classes.Thus,we categorized villages into three classes based on the distance from home to forests,including inner villages,fringe villages,and outer villages.Through focus group discussions and household surveys,we explored the sources of local economy,income sources of household,and reasons for economic diversification in different village classes.The study findings confirm that substantial variations existed in the income sources and the standard of living in these villages.Forest income varied dramatically among the three village classes,with inner villages having greater forest income than fringe villages and outer villages.Meanwhile,households in outer villages depended on forests and engaged in diverse economic activities for their livelihoods.Compared with inner and fringe villages,households in outer villages derived a significant portion of their income from livestock.This discrepancy can be attributed to challenges,such as inadequate transportation,communication,and underdeveloped market chains in inner villages.Moreover,these findings emphasize the need to develop sustainable forest management practices,create alternative income-generation opportunities,and improve infrastructure and market access in inner villages,as well as promote economic diversification in outer villages.Through targeted policy measures,these forest-rich regions can achieve improved livelihoods,enhanced standard of living,and increased resilience for their communities.展开更多
Excessive concentrations of toxic metals are a global threat to aquatic systems.Taking a typical tributary(Zijiang River,ZR)of the midstream of the Yangtze River as the research area,the concentration distribution and...Excessive concentrations of toxic metals are a global threat to aquatic systems.Taking a typical tributary(Zijiang River,ZR)of the midstream of the Yangtze River as the research area,the concentration distribution and chemical fractions occurrence characteristics of five toxic metals(Cd,Cr,Cu,Pb,and Zn)were analyzed,their potential sources were explored,and their contamination and ecological risk was assessed.In the surface waters and sediments,there were high concentrations of Zn,a low concentration of Cd,and small spatial differences in concentration among the upstream,midstream,and downstream.In terms of speciation,Cd mainly existed in the acid-soluble fraction,Pb mainly existed in the reducible fraction,and Cr,Cu,and Zn mainly existed in the residue fraction.The potential sources in surface waters and sediments were determined to be industrial emissions and agricultural non-point sources through the absolute principal component scores–multiple linear regression model(APCS–MLR).Based on the assessment results of total concentration and speciation,Cd was the typical contamination element in ZR sediments.In addition,the secondary phase enrichment factor(SPEF)based on speciation underestimates the degree of Pb contamination,and the ecological risk of Zn assessed by the ratio of secondary phase and primary phase(RSP)and the risk assessment code(RAC)was higher than that of Cr,which was inconsistent with the results based on total concentrations.SOM and Al/Fe/Mn cycles in sediments influenced the geochemical behavior of toxic metals.展开更多
In this study,different types of small molecular carbon sources such as melamine,dicyandiamine,pyrocatechol,and o-phenylenediamine were used to regulate the surface structures of iron/nitrogen/carbonbased composites(F...In this study,different types of small molecular carbon sources such as melamine,dicyandiamine,pyrocatechol,and o-phenylenediamine were used to regulate the surface structures of iron/nitrogen/carbonbased composites(Fe-N/C),which were used to activate peroxymonosulfate(PMS).The relationship between different small molecular carbon sources and the electronic structure was investigated.The characteristics of metal-carrier interaction in the Fe-N/C were clarified.As a result,there were significant differences in the degradation efficiency of catalysts prepared with different small molecular carbon sources,which was related to the types of active sites.Density functional theory(DFT)and experiments results showed that the catalyst rich in C-O-C and FeN_(x)exhibited better catalytic activity,which may be attributed to the higher adsorption energy for PMS.The main active species for catalytic degradation of ofloxacin were identified as sulfate radical(SO_(4)^(·-))and hydroxyl radical(^(·)OH)by electron paramagnetic resonance(EPR)spectra.The introduction of different small molecular carbon sources can significantly affect the distribution and electronic structure of active sites on the catalyst surface,thereby regulating the generation and migration of radicals.展开更多
Heavy metal(loid)(HM)pollution in agricultural soils has become an environmental concern in antimony(Sb)mining areas.However,priority pollution sources identification and deep understanding of environmental risks of H...Heavy metal(loid)(HM)pollution in agricultural soils has become an environmental concern in antimony(Sb)mining areas.However,priority pollution sources identification and deep understanding of environmental risks of HMs face great challenges due to multiple and complex pollution sources coexist.Herein,an integrated approach was conducted to distinguish pollution sources and assess human health risk(HHR)and ecological risk(ER)in a typical Sb mining watershed in Southern China.This approach combines absolute principal component score-multiple linear regression(APCS-MLR)and positivematrix factorization(PMF)models with ER and HHR assessments.Four pollution sources were distinguished for both models,and APCS-MLR model was more accurate and plausible.Predominant HM concentration source was natural source(39.1%),followed by industrial and agricultural activities(23.0%),unknown sources(21.5%)and Sb mining and smelting activities(16.4%).Although natural source contributed the most to HM concentrations,it did not pose a significant ER.Industrial and agricultural activities predominantly contributed to ER,and attention should be paid to Cd and Sb.Sb mining and smelting activities were primary anthropogenic sources of HHR,particularly Sb and As contaminations.Considering ER and HHR assessments,Sb mining and smelting,and industrial and agricultural activities are critical sources,causing serious ecological and health threats.This study showed the advantages of multiple receptor model application in obtaining reliable source identification and providing better source-oriented risk assessments.HM pollution management,such as regulating mining and smelting and implementing soil remediation in polluted agricultural soils,is strongly recommended for protecting ecosystems and humans.展开更多
With the development of integrated power and gas distribution systems(IPGS)incorporating renewable energy sources(RESs),coordinating the restoration processes of the power distribution system(PS)and the gas distributi...With the development of integrated power and gas distribution systems(IPGS)incorporating renewable energy sources(RESs),coordinating the restoration processes of the power distribution system(PS)and the gas distribution system(GS)by utilizing the benefits of RESs enhances service restoration.In this context,this paper proposes a coordinated service restoration framework that considers the uncertainty in RESs and the bi-directional restoration interactions between the PS and GS.Additionally,a coordinated service restoration model is developed considering the two systems’interdependency and the GS’s dynamic characteristics.The objective is to maximize the system resilience index while adhering to operational,dynamic,restoration logic,and interdependency constraints.A method for managing uncertainties in RES output is employed,and convexification techniques are applied to address the nonlinear constraints arising from the physical laws of the IPGS,thereby reducing solution complexity.As a result,the service restoration optimization problem of the IPGS can be formulated as a computationally tractable mixed-integer second-order cone programming problem.The effectiveness and superiority of the proposed framework are demonstrated through numerical simulations conducted on the interdependent IEEE 13-bus PS and 9-node GS.The comparative results show that the proposed framework improves the system resilience index by at least 65.07%compared to traditional methods.展开更多
Traditional beamforming techniques may not accurately locate sources in scenarios with both stationary and rotating sound sources.The existence of rotating sound sources can cause blurring in the stationary beamformin...Traditional beamforming techniques may not accurately locate sources in scenarios with both stationary and rotating sound sources.The existence of rotating sound sources can cause blurring in the stationary beamforming map.Current algorithms for separating different moving sound sources have limited effectiveness,leading to significant residual noise,especially when the rotating source is strong enough to mask stationary sources completely.To overcome these challenges,a novel solution utilizing a virtual rotating array in the modal domain combined with robust principal component analysis is proposed to separate sound sources with different rotational speeds.This approach,named Robust Principal Component Analysis in the Modal domain(RPCA-M),investigates the performance of convex nuclear norm and non-convex Schatten-p norm to distinguish stationary and rotating sources.By comparing the errors in Cross-Spectral Matrix(CSM)recovery and acoustic imaging across different algorithms,the effectiveness of RPCA-M in separating stationary and moving sound sources is demonstrated.Importantly,this method effectively separates sound sources,even when there are significant variations in their amplitudes at different rotation speeds.展开更多
Inhalation of atmospheric PM_(2.5)can induce the generation of excessive reactive oxygen species(ROS)in human alveoli,triggering local and systemic inflammation,which can directly or indirectly result in respiratory a...Inhalation of atmospheric PM_(2.5)can induce the generation of excessive reactive oxygen species(ROS)in human alveoli,triggering local and systemic inflammation,which can directly or indirectly result in respiratory and cardiovascular diseases.In this study,we assessed the oxidative potential(OP)of fresh and O_(3)-aged PM_(2.5)particles from various urban and rural emission sources using the dithiothreitol(DTT)method.Our results revealed variations in the OP of fresh PM_(2.5)among different emission sources,with biomass burning sources exhibiting the highest OP,followed by industrial areas,vehicular emissions,cooking emissions,and suburban areas,respectively.Water-soluble organics and transition metals might potentially exert significant influence on particle OP.O_(3)aging notably decreased the OP of PM_(2.5)particles,possibly due to the oxidation of highly DTT-active components into low redox-active small molecules.Moreover,the evolution of OP in different PM_(2.5)components,including methanol-soluble and insoluble fractions,exhibited distinct responses to O_(3)aging for source-oriented PM_(2.5).Additionally,differences in chemical composition between fresh and aged PM_(2.5)were further elucidated through measurements of component-dependent hygroscopic behaviors and phase transitions.This study systematically delineates variances in the toxic potential of fresh and O_(3)-aged PM_(2.5)from various anthropogenic sources.The findings highlight the intrinsic compositional dependence of particle OP and provide essential insights for assessing the health effects of source-oriented PM_(2.5),as well as for formulating human health protection policies.展开更多
Lead(Pb)plays a significant role in the nuclear industry and is extensively used in radiation shielding,radiation protection,neutron moderation,radiation measurements,and various other critical functions.Consequently,...Lead(Pb)plays a significant role in the nuclear industry and is extensively used in radiation shielding,radiation protection,neutron moderation,radiation measurements,and various other critical functions.Consequently,the measurement and evaluation of Pb nuclear data are highly regarded in nuclear scientific research,emphasizing its crucial role in the field.Using the time-of-flight(ToF)method,the neutron leakage spectra from three^(nat)Pb samples were measured at 60°and 120°based on the neutronics integral experimental facility at the China Institute of Atomic Energy(CIAE).The^(nat)Pb sample sizes were30 cm×30 cm×5 cm,30 cm×30 cm×10 cm,and 30 cm×30 cm×15 cm.Neutron sources were generated by the Cockcroft-Walton accelerator,producing approximately 14.5 MeV and 3.5 MeV neutrons through the T(d,n)^(4)He and D(d,n)^(3)He reactions,respectively.Leakage neutron spectra were also calculated by employing the Monte Carlo code of MCNP-4C,and the nuclear data of Pb isotopes from four libraries:CENDL-3.2,JEFF-3.3,JENDL-5,and ENDF/B-Ⅷ.0 were used individually.By comparing the simulation and experimental results,improvements and deficiencies in the evaluated nuclear data of the Pb isotopes were analyzed.Most of the calculated results were consistent with the experimental results;however,a few areas did not fit well.In the(n,el)energy range,the simulated results from CENDL-3.2 were significantly overestimated;in the(n,inl)D and the(n,inl)C energy regions,the results from CENDL-3.2 and ENDF/B-Ⅷ.0 were significantly overestimated at 120°,and the results from JENDL-5 and JEFF-3.3 are underestimated at 60°in the(n,inl)D energy region.The calculated spectra were analyzed by comparing them with the experimental spectra in terms of the neutron spectrum shape and C/E values.The results indicate that the theoretical simulations,using different data libraries,overestimated or underestimated the measured values in certain energy ranges.Secondary neutron energies and angular distributions in the data files have been presented to explain these discrepancies.展开更多
Polycyclic Aromatic Hydrocarbons(PAHs),along with their derivatives nitro-PAHs and oxy-PAHs,are globally recognized toxic pollutants.This research conducted daily PM_(2.5)sampling in winter 2021 at three urban(YNCE,SW...Polycyclic Aromatic Hydrocarbons(PAHs),along with their derivatives nitro-PAHs and oxy-PAHs,are globally recognized toxic pollutants.This research conducted daily PM_(2.5)sampling in winter 2021 at three urban(YNCE,SWP,and NG)and three suburban sites(HC,CTV,and YNE)in the Ili River Valley(IRV).For the first time in the IRV,a comprehensive study on 39 PAHs and derivatives was carried out.The results showed that the average∑_(16)PAHs concentration was 130.21±98.94 ng/m^(3),with 16PAHs constituting the dominant fraction(112.51±86.48 ng/m^(3)).The mean BaP and the total BaP equivalent quotient(TEQ)concentrations were 10.28±8.85 ng/m^(3)and 19.74±16.70 ng/m^(3),respectively.Approximately 88%of the daily BaP averages and 98%of the daily TEQ averages exceeded the national daily average standard of BaP(2.5 ng/m^(3)),indicating severe local BaP pollution.Urban sites had notably higher∑PAHs and TEQ concentrations than suburban sites,attributed to increased vehicular traffic and coal combustion in urban areas.PMF results showed that traffic emissions(32.7%-60.5%),coal combustion(13.9%-24.3%)and secondary formation(14.7%-22.7%)were the primary contributors to∑PAHs.Urban sites experienced a greater influence from traffic,while suburban sites were more impacted by coal and biomass burning.On polluted days,traffic sources’contributions increased significantly at HC,YNE,NG and YNCE sites,and secondary formation sources’contributions grew at CTV and YNCE sites.The sourcedependent BaPeq results underscored the role of secondary-formed PAH derivatives in TEQ.展开更多
For an improved understanding of gas enrichment mechanism in the eastern Sichuan Basin,South China,twelve natural gas samples were obtained from carbonate reservoirs of the Upper Permian strata to analyze the hydrocar...For an improved understanding of gas enrichment mechanism in the eastern Sichuan Basin,South China,twelve natural gas samples were obtained from carbonate reservoirs of the Upper Permian strata to analyze the hydrocarbon and non-hydrocarbon gas compositions,stable carbon and hydrogen isotopes ratios of hydrocarbons,and noble gas isotope ratios.The gas samples in the Upper Permian reservoirs principally consist of alkane gas with a dryness ratio ranging from 127.9 to 1564.4.The carbon isotope ratio of methane(δ^(13)C_(1))was almost constant at-34.1 to-31.3‰,but the carbon isotope ratio of ethane(δ^(13)C2)varied from-36.6‰to-25.8‰.The hydrogen isotope ratio of methane(δ^2HC_(1))also displayed a wide range from-137‰to-127‰.The large variations in the dryness ratio,δ^(13)C_(2),andδ^2HC_(1)with almost constantδ^(13)C_(1)suggest the mixing of sapropelic and humic origins for hydrocarbon gases in these reservoirs.A high concentration of hydrogen sulfide(H_(2)S)originated from the thermochemical sulfate reduction(TSR),which was positively correlated withδ^(13)C_(1)(orδ^(13)C_(2))in individual gas fields.TSR alteredδ^(13)C_(1)(orδ^(13)C_(2))and resulted in the abnormal character of isotopic reversal in the individual samples.Theδ^(13)C_(1)(orδ^(13)C_(2))in most gas samples,independent of H_(2)S concentration,further displayed reversed carbon isotopes because of the mixture of thermogenic gases with various thermal maturity levels.The measured argon isotope ratio(^(40)Ar/^(36)Ar)varied from 310 to 1225,which suggests that the oldest 320 Ma source rock age corresponds to Permian shales.The analysis of the gas origin and the identification of primary source rock have made a significant contribution to further understanding the resource potential and distribution of natural gas in the Upper Permian,and have great implications for gas exploration in the eastern Sichuan Basin.展开更多
Black carbon (BC) aerosols are considered key factors that contribute to rapid climate warming and ice melt in the Arctic region.However,compared with long-term observations from land-based stations,observational data...Black carbon (BC) aerosols are considered key factors that contribute to rapid climate warming and ice melt in the Arctic region.However,compared with long-term observations from land-based stations,observational data over the Arctic Ocean remain relatively scarce.Four Arctic scientific expeditions were conducted in the summer and early autumn of 2010,2012,2016,and 2018 via the Chinese research vessel Xue Long,during which the BC concentrations along the routes were measured via light absorption methods.In this work,the spatiotemporal distribution characteristics of BC over the Arctic Ocean were examined on the basis of these observations.The potential sources of BC along the various routes were analyzed via the weighted potential source contribution function and weighted concentrationweighted trajectory methods of the hybrid single-particle Lagrangian integrated trajectory model in conjunction with Arctic transport potential climate model simulations.The analysis results indicated that wildfires in the western Aleutian Islands,Siberia,and Far East regions were the primary contributors to the BC aerosol concentration observed along the Arctic expedition routes in summer,identifying these regions as major potential source areas.展开更多
Historical mining activities often lead to continuing wide spread contaminants in both groundwater and surface water in previously operational mine site areas. The contamination may continue for many years after closi...Historical mining activities often lead to continuing wide spread contaminants in both groundwater and surface water in previously operational mine site areas. The contamination may continue for many years after closing down the mining activities. The essential first step for sustainable management of groundwater and development of remediation strategies is the unknown contaminant source characterization. In a mining site, there are multiple species of contaminants involving complex geochemical processes. It is difficult to identify the potential sources and pathways incorporating the chemically reactive multiple species of contaminants making the source characterization process more challenging. To address this issue, a reactive transport simulation model PHT3D is linked to a Simulated Annealing based the optimum decision model. The numerical simulation model PHT3D is utilized for numerically simulating the reactive transport process involving multiple species in the former mine site area. The simulation results from the calibrated PHT3D model are illustrated, with and without incorporating the chemical reactions. These comparisons show the utility of using a reactive, geochemical transport process’ simulation model. Performance evaluation of the linked simulation optimization methodology is evaluated for a contamination scenario in a former mine site in Queensland, Australia. These performance evaluation results illustrate the applicability of linked simulation optimization model to identify the source characteristics while using PHT3D as a numerical reactive chemical species’ transport simulation model for the hydro-geochemically complex aquifer study area.展开更多
A major challenge of any optimization problem is to find the global optimum solution. In a multi-dimensional solution space which is highly non-linear, often the optimization algorithm gets trapped around some local o...A major challenge of any optimization problem is to find the global optimum solution. In a multi-dimensional solution space which is highly non-linear, often the optimization algorithm gets trapped around some local optima. Optimal Identification of unknown groundwater pollution sources poses similar challenges. Optimization based methodology is often applied to identify the unknown source characteristics such as location and flux release history over time, in a polluted aquifer. Optimization based models for identification of these characteristics of unknown ground-water pollution sources rely on comparing the simulated effects of candidate solutions to the observed effects in terms of pollutant concentration at specified sparse spatiotemporal locations. The optimization model minimizes the difference between the observed pollutant concentration measurements and simulated pollutant concentration measurements. This essentially constitutes the objective function of the optimization model. However, the mathematical formulation of the objective function can significantly affect the accuracy of the results by altering the response contour of the solution space. In this study, two separate mathematical formulations of the objective function are compared for accuracy, by incorporating different scenarios of unknown groundwater pollution source identification problem. Simulated Annealing (SA) is used as the solution algorithm for the optimization model. Different mathematical formulations of the objective function for minimizing the difference between the observed and simulated pollutant concentration measurements show different levels of accuracy in source identification results. These evaluation results demonstrate the impact of objective function formulation on the optimal identification, and provide a basis for choosing an appropriate mathematical formulation for unknown pollution source identification in contaminated aquifers.展开更多
文摘In the past decade or so,AI(artificial intelligence)technology has been growing with such a mesmerizing speed that today its presence in almost any industry that deals with any huge sheer volume of data is taking advantage of AI by integrating it into their day-to-day operation.Meanwhile,seven billion people worldwide shape the world’s energy system and directly impact the fundamental drivers of energy,both renewable and non-renewable sources,to meet the demand for electricity from them.These energy sources can be reached from nature such as solar,wind,etc.,and human-made such as NPPs(nuclear power plants)in the form of either fission as an old technology since the Manhattan project and in the near future as fusion in the form of magnetic or inertial confinements.Meanwhile,AI controlling nuclear reactors are about to happen.The basic idea is to apply AI with its two subset components as ML(machine learning),and DL(deep learning)techniques to go through the mountains of data that come from a reactor,spot patterns in it,and calling them to the unit’s human attention operators is not invadable either.Designers of such nuclear reactors will combine simulation and real-world data,comparing scenarios from each to develop“confidence[in]what they can predict and what is the range of uncertainty of their prediction”.Adding that,in the end,the operator will make the final decisions in order to keep these power plants safe while they are in operation and how to secure them against cyber-attack natural or human-made disasters.In this short communication article,we would like to see how we can prove some of these concepts;then a NPP manufacturer can pick it up and use it in their designs of a new generation of these reactors.
文摘This article is focused on technical and economic evaluation of more than 6-years experiences of operating the Waste Heat Recovery technology—the manner and system of flue gas processing generated in the combustion process in heat & power plants, cogeneration units, etc., which burn the gaseous fuel, primarily natural gas, or methane, biogas, geothermal gas, or other gaseous mixtures containing hydrogen. The solution proposes a more effective and non-traditional use of gaseous fuel for heating, the flue gases of which are processed in order to extract additional utilisable heat, with potential elimination of CO2 from them. Deploying of the heating plant in an island regime (OFF-GRID) enables definition of the benefits brought by the 3 years of operational experience and presents visions for the future offering the possibility to utilise the support energy services at the municipal as well as regional level.
基金supported by the National Key R&D Program under Grant No.2021YFA1400500the National Natural Science Foundation of China under Grant No.22273029+1 种基金the New Cornerstone Science Foundation through the New Cornerstone Investigator Program under Grant No.NCI202303 and the XPLORER PRIZEthe Beijing Outstanding Young Scientist Program under Grant No.JWZQ20240101002。
文摘Ultrafast electron sources, which enable high spatiotemporal resolution in time-resolved electron microscopy and scanning probe microscopy, are receiving increased attention. The most widely used method for achieving ultrafast electron sources involves irradiating metal tips by ultrashort laser pulses, causing electron beam emission via the photoelectric effect [including photon-driven(quantum) or field-driven(classical) emission]. However, the thermionic electrons emission process due to the heating effect of ultrashort lasers, particularly its dynamic aspects, has rarely been addressed in previous studies. In this paper, we improved the signal-to-noise ratio of a two-pulse correlation measurement on the tip electron emission by nearly two orders of magnitude using a delay time modulation method. This allowed us to obtain information on the temperature evolution of hot electrons and phonons in a non-equilibrium state, and to extract characteristic time scales for electron-phonon and phonon-phonon scattering. Our findings indicate that the thermionic electrons emission, unlike the instantaneous photoelectric effect, causes electron emission to lag behind the laser pulse by tens of picoseconds, thus significantly affecting the detection of ultrafast dynamics of samples. Furthermore, such a lagging effect was found to be sensitive to the local structure of the metal tip, offering new insights into the improved design of ultrafast electron sources.
基金supported by the National Natural Science Foundation of China(42161007)the Innovation Foundation of Higher Education Institutions of Gansu Province(2021B-081)the Foundation for Distinguished Young Scholars of Gansu Province(20JR10RA112).
文摘Precipitation isotopes(δ^(18)O and δ^(2)H)are closely related to meteorological conditions for precipitation generation and the initial state of water vapor source areas,and are essential to the study of the regional hydrological cycle.The deuterium excess(d-excess)indicates deviation in isotope fractionation during evaporation and can trace water vapor sources.This study analyzed 443 precipitation samples collected from the Gannan Plateau,China in 2022 to assess precipitation isotope variations and their driving factors.Water vapor sources were evaluated using the Hybrid Single-Particle Lagrangian Integrated Trajectory(HYSPLIT),Concentration Weighted Trajectory(CWT),and Potential Source Contribution Factor(PSCF)models.Results showed that precipitation isotope values showed significant spatial and temporal variations on the Gannan Plateau.Temporally,precipitation isotope values peaked in June(when evaporation dominated)and minimized in March(depletion effect of air masses in the westerly wind belt).Spatially,the isotope values showed a distribution pattern of"high in the east and low in the west",which was mainly regulated by the differences in altitude and local meteorological conditions.Compared with the global meteoric water line(GMWL)with equation of δ^(2)H=8.00δ^(18)O+10.00,the slope and intercept of local meteoric water line(LMWL)for precipitation on the Gannan Plateau were smaller(7.49 and 7.63,respectively),reflecting the existence of a stronger secondary evaporation effect under the clouds in the region.The sources of water vapor on the Gannan Plateau showed significant seasonality and spatial heterogeneity.Specifically,the westerly belt and monsoon were the main water vapor transport paths at each sampling point,with Central Asian continental water vapor dominating in spring(53.49%),Indian Ocean water vapor dominating in summer(52.53%),Atlantic Ocean water vapor dominating in autumn(46.74%),and Atlantic Ocean and Mediterranean Sea water vapor dominating in winter(42.30%and 33.68%,respectively).Changes in the intensity of convective activity and Outgoing Longwave Radiation(OLR)affected the enrichment of isotopic values,which exhibited the same change trends as δ^(18)O.During the precipitation process,the δ^(18)O value first decreased and then increased.During the initial and final stages of precipitation process,precipitation was mainly influenced by continental air masses,while during the middle stage,it was controlled by marine air masses.The systematic research on precipitation isotopes and water vapor sources is important for climate change research and extreme precipitation prediction on the Gannan Plateau and other similar areas.
基金jointly supported by the Open Research Fund of State Environmental Protection Key Laboratory of Drinking Water Source Protection,Chinese Research Academy of Environmental Sciences(2022YYSYKFYB07)the Fundamental Research Funds for the Central Publicinterest Scientific Institution(2022YSKY-07)the China Geological Survey Project(DD20211414).
文摘Pharmaceuticals and personal care products(PPCPs)are receiving attention as emerging pollutants due to their extensive applications and persistent emissions.The Qiantang River Basin,a representative region in eastern China that relies on surface water for drinking purposes,experiences the movement and accumulation of PPCPs in its water and sediment,which can directly affect the safety of drinking water in the basin.This study focuses on the Qiantang River Basin’s surface water,sediment,and drinking water to determine the occurrence and potential risks of 31 PPCPs.It aims to address whether PPCPs in the environment could migrate and accumulate,thereby affecting human health.The findings indicated that PPCPs are ubiquitous in various environmental media,with surface and pore water showing distinct spatial distribution characteristics,specifically,concentrations escalated with urban scale expansion,indicating that domestic sewage discharge is the primary source of PPCP input.Bisphenol A(BPA),ketoprofen(KTP),and diethyltoluamide(DEET)were the primary contaminants.The movement of PPCPs within the surface water-sediment-pore water system was affected by various circumstances.Substances like Sulfamethoxazole(SMX)(RQ>103)and KTP(RQ=22.3)present in surface water and sediment pose significant ecological concerns,and KTP and atrazine(ATZ)(0.6<RQ<2.1)also pose a high risk in drinking water.This study performed an extensive analysis of the distribution and risks associated with typical PPCPs in the Qiantang River Basin,offering a scientific foundation and theoretical support for research on the environmental behavior of PPCPs in this area and the development of targeted pollution control strategies.
文摘This paper presents a case study for a complex contaminated groundwater site impacted by a historical release of chlorinated solvents in Silicon Valley, California. The original conceptual site model (CSM) inferred a contaminant migration pathway based on the groundwater gradient interpreted from groundwater elevation data, which is based on the underlying assumption that the subsurface conditions are homogeneous. However, the buried channel deposits render the underlying geology highly heterogeneous, and this heterogeneity plays a significant role in the subsurface migration of contaminants. Chemical fingerprinting evidence suggested that contamination at the downgradient property boundary was related to an off-site contaminant source. But, this alone was not a compelling argument. However, Environmental Sequence Stratigraphy (ESS), a geology-based environmental forensic technique, was applied to define the permeability architecture or the “plumbing” that controls subsurface fluid flow and contaminant migration. First, the geologic and depositional setting was synthesized based on regional geologic data, and representative facies models were identified for the site. Second, the existing CSM and site lithology data were reviewed and existing lithology data were graphically presented to display vertical grain-size patterns. This analysis focused on the nexus between the depositional environment and the site-specific subsurface data resulting in correlations/interpretations between and beyond data points that are based on established stratigraphic principles. The depositional environment results in buried river channels as the primary control on subsurface fluid flow, which defines hydrostratigraphic units (or HSUs). Finally, a hydrostratigraphic CSM that includes maps and cross sections was constructed to depict the HSUs present as a framework to integrate hydro-geology and chemistry data. This study demonstrates that: 1) Highly per-meable buried river channel deposits control subsurface fluid flow and contaminant transport, and have distinct chemical constituents and concentrations (i.e., they represent distinct HSUs), 2) Mapping of such HSUs is feasible with existing boring log data, 3) In settings such as the Santa Clara Valley where groundwater flow is governed by subsurface channel deposits, a hydrostratigraphic mapping approach is superior to a depth-based aquifer zonation approach, and 4) For heterogeneous subsurface, a detailed geology-based definition of the subsurface is an integral component of an environmental forensic analyses to determine contaminant source(s) and pathways.
文摘Rice is very sensitive to low zinc(Zn) supply in submerged paddy soils and Zn deficiency is one of the major limiting factors in determining rice production in India. A field experiment was conducted during the summer-rainy seasons of 2009 and 2010 at the research farm of the Indian Agricultural Research Institute, New Delhi, to determine the effects of summer green manure crops and Zn fertilizers on diethylenetriaminepentaacetic acid(DTPA)-extractable(available) Zn concentration in soil and total Zn content in Basmati rice cultivar Pusa Basmati 1 at periodic intervals. Summer green manure crops included Sesbania aculeata(Dhaincha),Crotalaria juncea(Sunhemp), and Vigna unguiculata(Cowpea) and the Zn fertilizers used were ethylenediaminetetraacetic acid(EDTA)-chelated Zn, ZnSO4·7H2O, ZnSO4·H2O, ZnO, and ZnSO4·7H2O + ZnO. Beneficial effects of summer green manure crops and Zn fertilizers on DTPA-extractable Zn concentration in soil and total Zn content in dry matter of Basmati rice at periodic intervals were observed, with significant increases in all the determined parameters, in comparison with those in the control(no Zn application or summer fallow). The rate of increase varied among summer green manure crops and Zn fertilizers during both years. Among the summer green manures, incorporation of S. aculeata led to a significant increase in mean Zn content in Basmati rice grain and straw when compared with C. juncea, V. unguiculata, and summer fallow treatments. Among the Zn fertilizers, significant increases in Zn content in Basmati rice dry matter and DTPA-extractable Zn concentration in soil during various growth stages of the plant were recorded with EDTA-chelated Zn application, followed by the application of ZnSO4·7H2O, ZnSO4·H2O, ZnSO4·7H2O + ZnO, ZnO,and no Zn. The highest mean Zn content in Basmati rice grain and straw was recorded with EDTA-chelated Zn application in 2009 and 2010, respectively. The application of ZnSO4·7H2O was the second best treatment after EDTA-chelated Zn;however, it was statistically inferior to EDTA-chelated Zn. The lowest values were recorded with the control(no Zn application) during both years of study. The amount of Zn concentration in soil was found to be significantly positively correlated with the Zn content in Basmati rice dry matter during both years. Significantly higher levels of residual fertility in soil after the harvest of Basmati rice were observed with application of EDTA-chelated Zn and incorporation of S. aculeata when compared with those of other Zn sources and summer green manures.
基金the Department of Science and Technology and Biotechnology,West Bengal,India(1433(Sanc.)/STBT-11012(20)/8/2021-ST SEC).
文摘Forest resources play a vital role in supporting the livelihoods of rural communities residing in forest-rich areas.In India,a forest-rich country,a significant proportion of non-timber forest products(NTFPs)is consumed locally,supporting numerous rural communities relying on forests for essential resources,such as firewood,timber,and NTFPs.This study focuses on two forest-dominant districts in West Bengal of India,namely,Jhargram District and Paschim Medinipur District.Furthermore,this study aims to enhance the understanding of forest-dependent communities by comparing the standard of living among different village classes.Thus,we categorized villages into three classes based on the distance from home to forests,including inner villages,fringe villages,and outer villages.Through focus group discussions and household surveys,we explored the sources of local economy,income sources of household,and reasons for economic diversification in different village classes.The study findings confirm that substantial variations existed in the income sources and the standard of living in these villages.Forest income varied dramatically among the three village classes,with inner villages having greater forest income than fringe villages and outer villages.Meanwhile,households in outer villages depended on forests and engaged in diverse economic activities for their livelihoods.Compared with inner and fringe villages,households in outer villages derived a significant portion of their income from livestock.This discrepancy can be attributed to challenges,such as inadequate transportation,communication,and underdeveloped market chains in inner villages.Moreover,these findings emphasize the need to develop sustainable forest management practices,create alternative income-generation opportunities,and improve infrastructure and market access in inner villages,as well as promote economic diversification in outer villages.Through targeted policy measures,these forest-rich regions can achieve improved livelihoods,enhanced standard of living,and increased resilience for their communities.
基金supported by the National Natural Science Foundation of China(No.42030706).
文摘Excessive concentrations of toxic metals are a global threat to aquatic systems.Taking a typical tributary(Zijiang River,ZR)of the midstream of the Yangtze River as the research area,the concentration distribution and chemical fractions occurrence characteristics of five toxic metals(Cd,Cr,Cu,Pb,and Zn)were analyzed,their potential sources were explored,and their contamination and ecological risk was assessed.In the surface waters and sediments,there were high concentrations of Zn,a low concentration of Cd,and small spatial differences in concentration among the upstream,midstream,and downstream.In terms of speciation,Cd mainly existed in the acid-soluble fraction,Pb mainly existed in the reducible fraction,and Cr,Cu,and Zn mainly existed in the residue fraction.The potential sources in surface waters and sediments were determined to be industrial emissions and agricultural non-point sources through the absolute principal component scores–multiple linear regression model(APCS–MLR).Based on the assessment results of total concentration and speciation,Cd was the typical contamination element in ZR sediments.In addition,the secondary phase enrichment factor(SPEF)based on speciation underestimates the degree of Pb contamination,and the ecological risk of Zn assessed by the ratio of secondary phase and primary phase(RSP)and the risk assessment code(RAC)was higher than that of Cr,which was inconsistent with the results based on total concentrations.SOM and Al/Fe/Mn cycles in sediments influenced the geochemical behavior of toxic metals.
基金supported by National Natural Science Foundation of China(Nos.52170086,52300056)Natural Science Foundation of Shandong Province(Nos.ZR2021ME013,ZR202211280298)。
文摘In this study,different types of small molecular carbon sources such as melamine,dicyandiamine,pyrocatechol,and o-phenylenediamine were used to regulate the surface structures of iron/nitrogen/carbonbased composites(Fe-N/C),which were used to activate peroxymonosulfate(PMS).The relationship between different small molecular carbon sources and the electronic structure was investigated.The characteristics of metal-carrier interaction in the Fe-N/C were clarified.As a result,there were significant differences in the degradation efficiency of catalysts prepared with different small molecular carbon sources,which was related to the types of active sites.Density functional theory(DFT)and experiments results showed that the catalyst rich in C-O-C and FeN_(x)exhibited better catalytic activity,which may be attributed to the higher adsorption energy for PMS.The main active species for catalytic degradation of ofloxacin were identified as sulfate radical(SO_(4)^(·-))and hydroxyl radical(^(·)OH)by electron paramagnetic resonance(EPR)spectra.The introduction of different small molecular carbon sources can significantly affect the distribution and electronic structure of active sites on the catalyst surface,thereby regulating the generation and migration of radicals.
基金supported by the National Natural Science Foundation of China(No.42107394)the Major Project of the National Natural Science Foundation of China(No.71991483)the Central Public-interest Scientific Institution Basal Research Fund(No.BSRF202309).
文摘Heavy metal(loid)(HM)pollution in agricultural soils has become an environmental concern in antimony(Sb)mining areas.However,priority pollution sources identification and deep understanding of environmental risks of HMs face great challenges due to multiple and complex pollution sources coexist.Herein,an integrated approach was conducted to distinguish pollution sources and assess human health risk(HHR)and ecological risk(ER)in a typical Sb mining watershed in Southern China.This approach combines absolute principal component score-multiple linear regression(APCS-MLR)and positivematrix factorization(PMF)models with ER and HHR assessments.Four pollution sources were distinguished for both models,and APCS-MLR model was more accurate and plausible.Predominant HM concentration source was natural source(39.1%),followed by industrial and agricultural activities(23.0%),unknown sources(21.5%)and Sb mining and smelting activities(16.4%).Although natural source contributed the most to HM concentrations,it did not pose a significant ER.Industrial and agricultural activities predominantly contributed to ER,and attention should be paid to Cd and Sb.Sb mining and smelting activities were primary anthropogenic sources of HHR,particularly Sb and As contaminations.Considering ER and HHR assessments,Sb mining and smelting,and industrial and agricultural activities are critical sources,causing serious ecological and health threats.This study showed the advantages of multiple receptor model application in obtaining reliable source identification and providing better source-oriented risk assessments.HM pollution management,such as regulating mining and smelting and implementing soil remediation in polluted agricultural soils,is strongly recommended for protecting ecosystems and humans.
基金funded by the Science and Technology Project of State Grid Shanxi Electric Power Company(5205E0230001).
文摘With the development of integrated power and gas distribution systems(IPGS)incorporating renewable energy sources(RESs),coordinating the restoration processes of the power distribution system(PS)and the gas distribution system(GS)by utilizing the benefits of RESs enhances service restoration.In this context,this paper proposes a coordinated service restoration framework that considers the uncertainty in RESs and the bi-directional restoration interactions between the PS and GS.Additionally,a coordinated service restoration model is developed considering the two systems’interdependency and the GS’s dynamic characteristics.The objective is to maximize the system resilience index while adhering to operational,dynamic,restoration logic,and interdependency constraints.A method for managing uncertainties in RES output is employed,and convexification techniques are applied to address the nonlinear constraints arising from the physical laws of the IPGS,thereby reducing solution complexity.As a result,the service restoration optimization problem of the IPGS can be formulated as a computationally tractable mixed-integer second-order cone programming problem.The effectiveness and superiority of the proposed framework are demonstrated through numerical simulations conducted on the interdependent IEEE 13-bus PS and 9-node GS.The comparative results show that the proposed framework improves the system resilience index by at least 65.07%compared to traditional methods.
基金supported by the National Key Research and Development Plan of China(No.2023YFB3406500)the National Natural Science Foundation of China(No.52475132)+2 种基金the Aeronautical Science Foundation of China(No.20200015053001)the Shaanxi Key Research Program Project,China(No.2024GX-ZDCYL-01–16)the Xi’an Key Industrial Chain Technology Research Project,China(No.2023JH-RGZNGG-0033)。
文摘Traditional beamforming techniques may not accurately locate sources in scenarios with both stationary and rotating sound sources.The existence of rotating sound sources can cause blurring in the stationary beamforming map.Current algorithms for separating different moving sound sources have limited effectiveness,leading to significant residual noise,especially when the rotating source is strong enough to mask stationary sources completely.To overcome these challenges,a novel solution utilizing a virtual rotating array in the modal domain combined with robust principal component analysis is proposed to separate sound sources with different rotational speeds.This approach,named Robust Principal Component Analysis in the Modal domain(RPCA-M),investigates the performance of convex nuclear norm and non-convex Schatten-p norm to distinguish stationary and rotating sources.By comparing the errors in Cross-Spectral Matrix(CSM)recovery and acoustic imaging across different algorithms,the effectiveness of RPCA-M in separating stationary and moving sound sources is demonstrated.Importantly,this method effectively separates sound sources,even when there are significant variations in their amplitudes at different rotation speeds.
基金supported by the National Natural Science Foundation of China(No.42305109)Quzhou Municipal Science and Technology Bureau(No.2023K222).
文摘Inhalation of atmospheric PM_(2.5)can induce the generation of excessive reactive oxygen species(ROS)in human alveoli,triggering local and systemic inflammation,which can directly or indirectly result in respiratory and cardiovascular diseases.In this study,we assessed the oxidative potential(OP)of fresh and O_(3)-aged PM_(2.5)particles from various urban and rural emission sources using the dithiothreitol(DTT)method.Our results revealed variations in the OP of fresh PM_(2.5)among different emission sources,with biomass burning sources exhibiting the highest OP,followed by industrial areas,vehicular emissions,cooking emissions,and suburban areas,respectively.Water-soluble organics and transition metals might potentially exert significant influence on particle OP.O_(3)aging notably decreased the OP of PM_(2.5)particles,possibly due to the oxidation of highly DTT-active components into low redox-active small molecules.Moreover,the evolution of OP in different PM_(2.5)components,including methanol-soluble and insoluble fractions,exhibited distinct responses to O_(3)aging for source-oriented PM_(2.5).Additionally,differences in chemical composition between fresh and aged PM_(2.5)were further elucidated through measurements of component-dependent hygroscopic behaviors and phase transitions.This study systematically delineates variances in the toxic potential of fresh and O_(3)-aged PM_(2.5)from various anthropogenic sources.The findings highlight the intrinsic compositional dependence of particle OP and provide essential insights for assessing the health effects of source-oriented PM_(2.5),as well as for formulating human health protection policies.
基金supported by the National Natural Science Foundation of China(Nos.11775311 and U2067205)the Stable Support Basic Research Program Grant(BJ010261223282)the Research and Development Project of China National Nuclear Corporation。
文摘Lead(Pb)plays a significant role in the nuclear industry and is extensively used in radiation shielding,radiation protection,neutron moderation,radiation measurements,and various other critical functions.Consequently,the measurement and evaluation of Pb nuclear data are highly regarded in nuclear scientific research,emphasizing its crucial role in the field.Using the time-of-flight(ToF)method,the neutron leakage spectra from three^(nat)Pb samples were measured at 60°and 120°based on the neutronics integral experimental facility at the China Institute of Atomic Energy(CIAE).The^(nat)Pb sample sizes were30 cm×30 cm×5 cm,30 cm×30 cm×10 cm,and 30 cm×30 cm×15 cm.Neutron sources were generated by the Cockcroft-Walton accelerator,producing approximately 14.5 MeV and 3.5 MeV neutrons through the T(d,n)^(4)He and D(d,n)^(3)He reactions,respectively.Leakage neutron spectra were also calculated by employing the Monte Carlo code of MCNP-4C,and the nuclear data of Pb isotopes from four libraries:CENDL-3.2,JEFF-3.3,JENDL-5,and ENDF/B-Ⅷ.0 were used individually.By comparing the simulation and experimental results,improvements and deficiencies in the evaluated nuclear data of the Pb isotopes were analyzed.Most of the calculated results were consistent with the experimental results;however,a few areas did not fit well.In the(n,el)energy range,the simulated results from CENDL-3.2 were significantly overestimated;in the(n,inl)D and the(n,inl)C energy regions,the results from CENDL-3.2 and ENDF/B-Ⅷ.0 were significantly overestimated at 120°,and the results from JENDL-5 and JEFF-3.3 are underestimated at 60°in the(n,inl)D energy region.The calculated spectra were analyzed by comparing them with the experimental spectra in terms of the neutron spectrum shape and C/E values.The results indicate that the theoretical simulations,using different data libraries,overestimated or underestimated the measured values in certain energy ranges.Secondary neutron energies and angular distributions in the data files have been presented to explain these discrepancies.
基金supported by the National Key R&D Program of China(No.2017YFC0212501)the Fundamental Research Funds for the Central Universities(No.2021YJSMT09)the research project on deep source apportionment of urban air pollution and pollution control strategies in the core area of the Ili River Valley。
文摘Polycyclic Aromatic Hydrocarbons(PAHs),along with their derivatives nitro-PAHs and oxy-PAHs,are globally recognized toxic pollutants.This research conducted daily PM_(2.5)sampling in winter 2021 at three urban(YNCE,SWP,and NG)and three suburban sites(HC,CTV,and YNE)in the Ili River Valley(IRV).For the first time in the IRV,a comprehensive study on 39 PAHs and derivatives was carried out.The results showed that the average∑_(16)PAHs concentration was 130.21±98.94 ng/m^(3),with 16PAHs constituting the dominant fraction(112.51±86.48 ng/m^(3)).The mean BaP and the total BaP equivalent quotient(TEQ)concentrations were 10.28±8.85 ng/m^(3)and 19.74±16.70 ng/m^(3),respectively.Approximately 88%of the daily BaP averages and 98%of the daily TEQ averages exceeded the national daily average standard of BaP(2.5 ng/m^(3)),indicating severe local BaP pollution.Urban sites had notably higher∑PAHs and TEQ concentrations than suburban sites,attributed to increased vehicular traffic and coal combustion in urban areas.PMF results showed that traffic emissions(32.7%-60.5%),coal combustion(13.9%-24.3%)and secondary formation(14.7%-22.7%)were the primary contributors to∑PAHs.Urban sites experienced a greater influence from traffic,while suburban sites were more impacted by coal and biomass burning.On polluted days,traffic sources’contributions increased significantly at HC,YNE,NG and YNCE sites,and secondary formation sources’contributions grew at CTV and YNCE sites.The sourcedependent BaPeq results underscored the role of secondary-formed PAH derivatives in TEQ.
基金supported by the National Natural Science Foundation of China(Nos.42072184 and 41702157)the Science and Technology Cooperation Project of the CNPC-SWPU Innovation Alliance。
文摘For an improved understanding of gas enrichment mechanism in the eastern Sichuan Basin,South China,twelve natural gas samples were obtained from carbonate reservoirs of the Upper Permian strata to analyze the hydrocarbon and non-hydrocarbon gas compositions,stable carbon and hydrogen isotopes ratios of hydrocarbons,and noble gas isotope ratios.The gas samples in the Upper Permian reservoirs principally consist of alkane gas with a dryness ratio ranging from 127.9 to 1564.4.The carbon isotope ratio of methane(δ^(13)C_(1))was almost constant at-34.1 to-31.3‰,but the carbon isotope ratio of ethane(δ^(13)C2)varied from-36.6‰to-25.8‰.The hydrogen isotope ratio of methane(δ^2HC_(1))also displayed a wide range from-137‰to-127‰.The large variations in the dryness ratio,δ^(13)C_(2),andδ^2HC_(1)with almost constantδ^(13)C_(1)suggest the mixing of sapropelic and humic origins for hydrocarbon gases in these reservoirs.A high concentration of hydrogen sulfide(H_(2)S)originated from the thermochemical sulfate reduction(TSR),which was positively correlated withδ^(13)C_(1)(orδ^(13)C_(2))in individual gas fields.TSR alteredδ^(13)C_(1)(orδ^(13)C_(2))and resulted in the abnormal character of isotopic reversal in the individual samples.Theδ^(13)C_(1)(orδ^(13)C_(2))in most gas samples,independent of H_(2)S concentration,further displayed reversed carbon isotopes because of the mixture of thermogenic gases with various thermal maturity levels.The measured argon isotope ratio(^(40)Ar/^(36)Ar)varied from 310 to 1225,which suggests that the oldest 320 Ma source rock age corresponds to Permian shales.The analysis of the gas origin and the identification of primary source rock have made a significant contribution to further understanding the resource potential and distribution of natural gas in the Upper Permian,and have great implications for gas exploration in the eastern Sichuan Basin.
基金supported by the National Natural Science Foundation of China (No.42201151)the Basic Research Fund of the Chinese Academy of Meteorological Sciences (Nos.2023Z004 and 2024Z007)。
文摘Black carbon (BC) aerosols are considered key factors that contribute to rapid climate warming and ice melt in the Arctic region.However,compared with long-term observations from land-based stations,observational data over the Arctic Ocean remain relatively scarce.Four Arctic scientific expeditions were conducted in the summer and early autumn of 2010,2012,2016,and 2018 via the Chinese research vessel Xue Long,during which the BC concentrations along the routes were measured via light absorption methods.In this work,the spatiotemporal distribution characteristics of BC over the Arctic Ocean were examined on the basis of these observations.The potential sources of BC along the various routes were analyzed via the weighted potential source contribution function and weighted concentrationweighted trajectory methods of the hybrid single-particle Lagrangian integrated trajectory model in conjunction with Arctic transport potential climate model simulations.The analysis results indicated that wildfires in the western Aleutian Islands,Siberia,and Far East regions were the primary contributors to the BC aerosol concentration observed along the Arctic expedition routes in summer,identifying these regions as major potential source areas.
文摘Historical mining activities often lead to continuing wide spread contaminants in both groundwater and surface water in previously operational mine site areas. The contamination may continue for many years after closing down the mining activities. The essential first step for sustainable management of groundwater and development of remediation strategies is the unknown contaminant source characterization. In a mining site, there are multiple species of contaminants involving complex geochemical processes. It is difficult to identify the potential sources and pathways incorporating the chemically reactive multiple species of contaminants making the source characterization process more challenging. To address this issue, a reactive transport simulation model PHT3D is linked to a Simulated Annealing based the optimum decision model. The numerical simulation model PHT3D is utilized for numerically simulating the reactive transport process involving multiple species in the former mine site area. The simulation results from the calibrated PHT3D model are illustrated, with and without incorporating the chemical reactions. These comparisons show the utility of using a reactive, geochemical transport process’ simulation model. Performance evaluation of the linked simulation optimization methodology is evaluated for a contamination scenario in a former mine site in Queensland, Australia. These performance evaluation results illustrate the applicability of linked simulation optimization model to identify the source characteristics while using PHT3D as a numerical reactive chemical species’ transport simulation model for the hydro-geochemically complex aquifer study area.
文摘A major challenge of any optimization problem is to find the global optimum solution. In a multi-dimensional solution space which is highly non-linear, often the optimization algorithm gets trapped around some local optima. Optimal Identification of unknown groundwater pollution sources poses similar challenges. Optimization based methodology is often applied to identify the unknown source characteristics such as location and flux release history over time, in a polluted aquifer. Optimization based models for identification of these characteristics of unknown ground-water pollution sources rely on comparing the simulated effects of candidate solutions to the observed effects in terms of pollutant concentration at specified sparse spatiotemporal locations. The optimization model minimizes the difference between the observed pollutant concentration measurements and simulated pollutant concentration measurements. This essentially constitutes the objective function of the optimization model. However, the mathematical formulation of the objective function can significantly affect the accuracy of the results by altering the response contour of the solution space. In this study, two separate mathematical formulations of the objective function are compared for accuracy, by incorporating different scenarios of unknown groundwater pollution source identification problem. Simulated Annealing (SA) is used as the solution algorithm for the optimization model. Different mathematical formulations of the objective function for minimizing the difference between the observed and simulated pollutant concentration measurements show different levels of accuracy in source identification results. These evaluation results demonstrate the impact of objective function formulation on the optimal identification, and provide a basis for choosing an appropriate mathematical formulation for unknown pollution source identification in contaminated aquifers.
