Carbonaceous debris(CD) is widely disseminated within sandstones in the Shuanglong uranium deposit,southern Ordos Basin,and is the dominant enrichment agent for uranium precipitation.The occurrence and chemical compos...Carbonaceous debris(CD) is widely disseminated within sandstones in the Shuanglong uranium deposit,southern Ordos Basin,and is the dominant enrichment agent for uranium precipitation.The occurrence and chemical composition of uranium minerals within CD were investigated by using scanning electron microscope and electron microprobe analyses.The results show that uranium minerals mostly occur in cell pores in the forms of fructus aurantia and concentric band structure.Pitchblende and coffinite are the main uranium minerals,and the former is dominant.According to the crystal morphology and composition of trace elements of uranium minerals,uranium precipitation on the pores is grouped into two periods,orderly Ⅰ,Ⅱ.Moreover,the Ⅰ period is further divided into two sub-period,orderly Ⅰ_(1),Ⅰ_(2).Moreover,askew sphere uranium minerals could indicate fluid migration.Under certain geological environment condition,uranium is unevenly adsorbed on the surface of the pore by the Van der Waals(i.e.,Ⅰ_(1) period),and then is precipitated towards to the center of the pore until the whole pore is filled up with uranium minerals by complicated process such as microorganism activities(i.e.,Ⅰ_(2),Ⅱ period).It will provide some guidance for studying the metallogenic environment and genesis of sandstone-type uranium deposit.展开更多
The Mianhuakeng uranium deposit,characterized by uranium-rich granite,serves as a key site for research into crustal radioactive heating.Based on 45 rock samples,this study reviews that the host granite in the Mianhua...The Mianhuakeng uranium deposit,characterized by uranium-rich granite,serves as a key site for research into crustal radioactive heating.Based on 45 rock samples,this study reviews that the host granite in the Mianhuakeng uranium deposit has a high radioactive heat production rate(avg.5.50μW/m³)and a low Th/U ratio(avg.2.62).Uranium-rich granite and its alteration zone within the upper crust(0-5 km depth)contribute about 45%of the total radioactive heat production,wich is crucial for controlling geothermal resource distribution.For uranium-thermal at tectonic plate margins,a symbiotic geological model was proposed:Firstly,subduction of the Pacific Plate caused upwelling of the asthenosphere,generating a high heat-flow background.Secondly,heat transfer is enhanced by major faults such as the Youdong and Mianhuakeng faults.Subsequently,uranium was mobilized,transported,and enriched within the granite through deep siliceous hydrothermal activity and associated alteration.Ultimately,the uranium enrichment in granite leads to increased radioactive heat production,resulting in local thermal anomalies.This model provides a theoretical support for exploring and developing uranium-thermal symbiotic resources in South China.展开更多
The lack of macro-continuity and mechanical strength of covalent organic frameworks(COFs)has significantly limited their practical applications.Here,we propose an“alcohol-triggered defect cleavage”strategy to precis...The lack of macro-continuity and mechanical strength of covalent organic frameworks(COFs)has significantly limited their practical applications.Here,we propose an“alcohol-triggered defect cleavage”strategy to precisely regulate the growth and stacking of COF grains through a moderate reversed Schiff base reaction,realizing the direct synthesis of COF nanofibers(CNFs)with high aspect ratio(L/D=103.05)and long length(>20μm).An individual CNF exhibits a biomimetic scale-like architecture,achieving superior flexibility and fatigue resistance under dynamic bending via a multiscale stress dissipation mechanism.Taking advantages of these structural features,we engineer CNF aerogels(CNF-As)with programmable porous structures(e.g.,honeycomb,lamellar,isotropic)via directional ice-template methodology.CNF-As demonstrate 100%COF content,high specific surface area(396.15 m^(2)g^(-1))and superelasticity(~0%elastic deformation after 500 compression cycles at 50%strain),outperforming most COF-based counterparts.Compared with the conventional COF aerogels,the unique structural features of CNF-A enable it to perform outstandingly in uranium extraction,with an 11.72-fold increment in adsorption capacity(920.12 mg g^(-1))and adsorption rate(89.9%),and a 2.48-fold improvement in selectivity(U/V=2.31).This study provides a direct strategy for the development of next-generation COF materials with outstanding functionality and structural robustness.展开更多
Knowing the precise relationship between fuel loading and reactivity is essential for guiding reactor criticality extrapolation and online refueling in molten salt reactors(MSRs).This study aims to explore and explain...Knowing the precise relationship between fuel loading and reactivity is essential for guiding reactor criticality extrapolation and online refueling in molten salt reactors(MSRs).This study aims to explore and explain the linear relationship between reactivity and the reciprocal of uranium concentration in thermal-spectrum MSRs.By applying neutron balance theory,we analyzed the neutron absorption cross sections of various nuclides in single-lattice models with varying fuel concentrations.Our findings reveal a simple linear correlation between reactivity and the reciprocal of uranium concentration,which can be explained from the perspective of nuclear reaction cross sections that adhere to the 1/v law in the thermal neutron spectrum.Furthermore,we identified that the neutron absorption single-group cross sections of structural materials and carrier salts exhibit an approximately linear relationship with the fission single-group cross section of ^(235) U;similarly,the reciprocal of ^(235)U’s fission cross section exhibits an approximately linear relationship with uranium concentration.This linear relationship deviates as the volume fraction of molten salt increases,due to a greater proportion of neutrons being captured in the resonance energy spectrum.However,it remains valid for molten salt volume fractions up to 25%and demonstrates broad applicability in the physical design and operation of thermal molten salt reactors.展开更多
The extraction of uranium from seawater via membrane adsorption is a promising strategy for ensuring a long-term supply of uranium and the sustainability of nuclear energy.However,this approach has been hindered by th...The extraction of uranium from seawater via membrane adsorption is a promising strategy for ensuring a long-term supply of uranium and the sustainability of nuclear energy.However,this approach has been hindered by the longstanding challenge of identifying sustainable membrane materials.In response,we propose a prototypal hybridization strategy to design a novel series of aminated conjugated microporous polymer(CMPN)@collagen fiber membrane(COLM).These sustainable and low-cost membrane materials allow a rapid and high-affinity kinetic to capture 90%of the uranium in just 30 min from 50 ppm with a high selectivity of Kd>105 mL·g^(−1).They also afford a robustly reusable adsorption capacity as high as 345 mg·g^(−1)that could harvest 1.61 mg·g^(−1)of uranium in a short 7-day real marine engineering in Fujian Province,even though suffered from very low uranium concentration of 3.29μg·L^(−1)and tough influence of salts such as 10.77 g·L^(−1)of Na^(+),1.75μg·L^(−1)of VO_(3)^(−)etc.in the rough seas.The structural evidence from both experimental and theoretical studies confirmed the formation of favorable chelating motifs from the amino group on CMPN-COLM,and the intensification by the synergistic effect from the size-sieving action of CMPN and the capillary inflow effect of COLM.展开更多
Many adsorbents have been developed for uranium recovery to ensure global energy and environmental security.However,most reported adsorbents involve complex preparation process and rely heavily on petrochemical feedst...Many adsorbents have been developed for uranium recovery to ensure global energy and environmental security.However,most reported adsorbents involve complex preparation process and rely heavily on petrochemical feedstocks,which undoubtedly increases carbon emissions from production in the nuclear industry.Here,a biomass aerogel(CS-BT)is prepared by the facile cross-linking of chitosan and bayberry tannins with glutaraldehyde.U(Ⅵ)can be adsorbed by hydroxyl groups on CS-BT aerogel via chelation,and the maximum adsorption capacity of the obtained aerogel to U(Ⅵ)is 140 mg·g^(-1)and the removal rate reaches up to 99%(at 298.15 K,pH=5.0).The pseudo-second-order kinetics model and Freundlich model can better match the adsorption process of CS-BT aerogel,implying that its adsorption is a chemical adsorption process dominated by multilayer adsorption.The thermodynamic results show that the adsorption process of U(Ⅵ)by CS-BT aerogel is spontaneous and exothermic.Hence,our biomass aerogel can effectively extract uranium from water,contributing to the sustainable development of the nuclear industry.展开更多
As a key low-carbon energy source,nuclear power plays a vital role in the global transition toward sustainable energy.Photocatalytic uranium extraction from seawater(UES)offers a promising solution to ensure long-term...As a key low-carbon energy source,nuclear power plays a vital role in the global transition toward sustainable energy.Photocatalytic uranium extraction from seawater(UES)offers a promising solution to ensure long-term uranium supply but is challenged by ultra-low uranium concentrations and ion interference.To overcome these issues,we design three diketopyrrolopyrrole-based covalent organic frameworks(COFs)via a synergisticπ-extended lock and carboxyl-functionalized anchor molecular engineering strategy.Among them,TPy-DPP-COF features a covalently lockedπ-conjugated structure that enhances planarity,optimizes energy alignment,and minimizes exciton binding energy,thereby promoting charge transfer and suppressing recombination.Concurrently,carboxyl groups enable uranyl-specific coordination and create local electric fields to facilitate charge separation.These features contribute to the outstanding performance of TPy-DPP-COF,which achieves a high uranium adsorption capacity of 16.33 mg g−1 in natural seawater under irradiation,with only 29.3%capacity loss after 10 cycles,surpassing industrial benchmarks.Density functional theory(DFT)calculations and experimental studies reveal a synergistic photocatalysis-adsorption pathway,with DPP units acting as active sites for uranium reduction.This work highlights a molecular design strategy for developing efficient COF-based photocatalysts for practical marine uranium recovery.展开更多
Simultaneous uranium recovery,organic pollutant degradation,and electricity generation were achieved by employing a self-driven photoelectrochemical(PEC)system equipped with a modified carbon felt(MCF)cathode for the ...Simultaneous uranium recovery,organic pollutant degradation,and electricity generation were achieved by employing a self-driven photoelectrochemical(PEC)system equipped with a modified carbon felt(MCF)cathode for the treatment of complex radioactive wastewater.The MCF cathode was synthesized via a facile hydrothermal method,which modified the surface functional groups on carbon felt(CF)with enhanced active site availability and facilitated interfacial charge transfer,thus improving its UO_(2)^(2+)adsorption and reduction capacities.The self-driven PEC system with the MCF cathode demonstrated remarkable removal efficiencies and rate constants(k)for UO_(2)^(2+)(98.8%and 0.111 min^(−1))and chlortetracycline hydrochloride(CTC)(92.9%and 0.028 min^(−1))within 40 min and 90 min,respectively,coupled with an excellent power output of 1.41 mW/cm^(2).Additionally,the system with the MCF cathode exhibited superior removal performance for UO_(2)^(2+)and CTC in treating model complex wastewater under wide conditions.Even under natural sunlight,the system achieved over 80%removal efficiency for both UO_(2)^(2+)and CTC.Moreover,the uranium immobilized on the MCF cathode was mainly reduced to U(Ⅳ)species(90.51%),and performance remained robust over ten operational cycles.The cathode surface modification strategy and its application in the system provide a cost-effective,multi-functional and high-efficiency approach to controlling nuclides and organic pollutants in complex radioactive wastewater.展开更多
This study proposes a method for^(99)Mo production via electron accelerator irradiation of a natural-uranium-bearing liquid molten salt target,with advantages including low nuclear proliferation risk,online extraction...This study proposes a method for^(99)Mo production via electron accelerator irradiation of a natural-uranium-bearing liquid molten salt target,with advantages including low nuclear proliferation risk,online extraction capability,and low construction costs.The approach primarily produces^(99)Mo through photofission of uranium(~95%),specifically^(238)U(γ,f).Secondary neutrons,originating from photonuclear interactions or fission processes,contribute minimally(~5%)to^(99)Mo production owing to their high energies and low fission cross sections.Key parameter analyses revealed that fluoride salt systems exhibit higher^(99)Mo yield.Their performance stems from high bremsstrahlung energy loss rate and superior photon yield,making them optimal molten salt target materials.To maximize photofission and photoneutron cross sections while minimizing highenergy gamma ray shielding requirements,an electron beam energy range of 40-80 MeV is recommended.To suppress local hot spots and prevent molten salt boiling,flow conditions were introduced to enhance convective heat transfer,effectively reducing the peak temperature.At a flow velocity of 0.5 m/s and under 80 MeV energy conditions,the maximum system temperature is only 808.9 K,which is significantly lower than the boiling point of 1773 K.Under optimized parameters,the maximum annual production capacity of~(99)Mo reaches 4486.49 Ci,sufficient for millions of diagnostic procedures and equivalent to 16.37% of China's projected demand for 2030.This method provides a viable pathway for stable,large-scale^(99)Mo production.展开更多
One of the main issues in designing optimum tapered cascades for uranium enrichment for annual fuel production in a power reactor is whether to employ large(fat)or small(thin)cascades.What will be the permissible and ...One of the main issues in designing optimum tapered cascades for uranium enrichment for annual fuel production in a power reactor is whether to employ large(fat)or small(thin)cascades.What will be the permissible and optimal ranges of the number of machines that can be used in a cascade?For the first time,the permissible and optimal ranges of the number of gas centrifuges that can be utilized in a cascade were investigated using two types of centrifuges,and the performance of small and large tapered cascades was discussed.The particle swarm optimization algorithm(PSO)has been used to optimize tapered cascades.The results show:(1)For the first centrifuge,41 cascades(91≤n≤4897)and for the second centrifuge,49 cascades(18≤n≤3839)with small and large sizes can be used in enrichment facilities,and the best cascade for them has 530(with 23 stages)and 39(with 7 stages)centrifuges,respectively.(2)For both centrifuges,when 600≤n(number of centrifuges=n),the large cascade performance changes are relatively insignificant.(3)For both types of gas centrifuges,the annual los s of separation power in enrichment facilities is approximately 1.25%-4.82%of the total separation work required.展开更多
Uranium,as one of twenty-six kinds of important minerals in China,is strategic resource and energy mineral,which has been thoroughly investigated in the project of National Potential Evaluation of Uranium Resource.Dur...Uranium,as one of twenty-six kinds of important minerals in China,is strategic resource and energy mineral,which has been thoroughly investigated in the project of National Potential Evaluation of Uranium Resource.During the implementation of this project,the authors summarized the metallogenic regularity of uranium resource in China systematically,through the researches of geological characteristics of uranium resource,uranium deposits type（genetic and prediction type）,temporal and spatial distribution,and metallogenic series.Based on the investigation of present situation and progress in uranium exploration,this paper proposes the uranium deposits in China should be divided into 4 classes,9 types,21 subtypes in genetic,and 50 types in prediction;suggests to divide China into 29 uranium metallogenic belts and 20 uranium prospective area,and constructs 20uranium-polymetallic metallogenic series,through summarizing temporal and spatial distribution characteristics and metallogenic regularity of uranium deposits in China.The above research is beneficial to the comprehensive understanding of regional uranium metallogenic regularity,and will direct the uranium exploration in the future.展开更多
The study aims to investigate uranium species in the sediments of the natural-technogenic system within a sludge storage facility in Russia.The relevance of this work is underscored by the need to assess the geochemic...The study aims to investigate uranium species in the sediments of the natural-technogenic system within a sludge storage facility in Russia.The relevance of this work is underscored by the need to assess the geochemical mobility of radionuclides,a critical factor for predicting their migration and environmental impact.The objective of the research was to determine the uranium species in both peat and sedimentary rock samples of the sludge storage facility and the adjacent area.Laboratory analyses included XRD,XRF analysis using synchrotron radiation,and scanning electron microscopy to study the composition and properties of minerals.The uranium species were further identified using a modified Tessier sequential extraction method.The results revealed that uranium predominantly occurs in a stable silicate-bound form(up to 80%)in sedimentary rocks,indicating minimal geochemical mobility.In contrast,in peat deposits,uranium is primarily associated with manganese and iron oxides(30–60%)as well as organic matter(5–40%),with the most mobile forms constituting less than 5%.The decrease in uranium concentration with distance from the facility was attributed to sorption onto organic matter and co-precipitation with mineral compounds,manganese and iron oxides,which serve as effective natural sorbents.The findings highlight the critical role of organic matter and metal oxides in limiting uranium migration,thus identifying them as key components in the formation of natural barriers for radionuclides.These results are crucial for assessing environmental risks associated with radioactive waste management and for developing strategies to minimize the ecological impact of sludge storages.展开更多
Three uranium provinces are recognized in China, the Southeast China uranium province, the Northeast China-Inner Mongolia uranium province and the Northwest China (Xinjiang) uranium province. The latter two promise go...Three uranium provinces are recognized in China, the Southeast China uranium province, the Northeast China-Inner Mongolia uranium province and the Northwest China (Xinjiang) uranium province. The latter two promise good potential for uranium resources and are major exploration target areas in recent years. There are two major types of uranium deposits: the Phanerozoic hydrothermal type (vein type) and the Meso-Cenozoic sandstone type in different proportions in the three uranium provinces. The most important reason or prerequisite for the formation of these uranium provinces is that Precambrian uranium-enriched old basement or its broken parts (median massifs) exists or once existed in these regions, and underwent strong tectonomagmatic activation during Phanerozoic time. Uranium was mobilized from the old basement and migrated upwards to the upper structural level together with the acidic magma originating from anatexis and the primary fluids, which were then mixed with meteoric water and resulted in the formation of Phanerozoic hydrothermal uranium deposits under extensional tectonic environments. Erosion of uraniferous rocks and pre-existing uranium deposits during the Meso-Cenozoic brought about the removal of uranium into young sedimentary basins. When those basins were uplifted and slightly deformed by later tectonic activity, roll-type uranium deposits were formed as a result of redox in permeable sandstone strata.展开更多
The discharge of effluents containing uranium(U)ions into aquatic ecosystems poses significant risks to both human health and marine organisms.This study investigated the biosorption of U(VI)ions from aqueous solution...The discharge of effluents containing uranium(U)ions into aquatic ecosystems poses significant risks to both human health and marine organisms.This study investigated the biosorption of U(VI)ions from aqueous solutions using corncob-sodium alginate(SA)-immobilized Trichoderma aureoviride hyphal pellets.Experimental parameters,including initial solution pH,initial concentration,temperature,and contact time,were systematically examined to understand their influence on the bioadsorption process.Results showed that the corncob-SA-immobilized T.aureoviride hyphal pellets exhibited maximum uranium biosorption capacity at an initial pH of 6.23 and a contact time of 12 h.The equilibrium data aligned with the Langmuir isotherm model,with a maximum biosorption capacity of 105.60 mg/g at 301 K.Moreover,biosorption kinetics followed the pseudo-second-order kinetic model.In terms of thermodynamic parameters,the changes in Gibbs-free energy(△G°)were determined to be-4.29 kJ/mol at 301 K,the changes in enthalpy(△H°)were 46.88 kJ/mol,and the changes in entropy(△S°)was 164.98 J/(mol·K).Notably,the adsorbed U(VI)could be efficiently desorbed using Na_(2)CO_(3),with a maximum readsorption efficiency of 53.6%.Scanning electron microscopic(SEM)analysis revealed U(VI)ion binding onto the hyphal pellet surface.This study underscores the efficacy of corncob-SA-immobilized T.aureoviride hyphal pellets as a cost-effective and environmentally favorable biosorbent material for removing U(VI)from aquatic ecosystems.展开更多
Fast development of nuclear power plants requires sustainable support of uranium for nuclear fuel.Uranium is the most critical radionuclide to prepare nuclear fuel.However,the extraction of low concentration of uraniu...Fast development of nuclear power plants requires sustainable support of uranium for nuclear fuel.Uranium is the most critical radionuclide to prepare nuclear fuel.However,the extraction of low concentration of uranium in uranium ore or complex systems needs highly efficient selective binding of uranium in the presence of other competing metal ions.The excellent oxidative capacity of excited*UO_(2)^(2+)active species makes uranyl-based materials high photocatalytic performance in phototransformation of organic chemicals into high valuable products under visible light irradiation.In this mini review,the selective preconcentration of uranium through photocatalytic and electrocatalytic strategies was mainly described.The application of uranyl-based materials in photocatalytic conversion and degradation of organic pollutants was summarized.This review reports the utilization of uranium from its first step(i.e.,extraction of uranium for nuclear fuel supply)to its last additional application(i.e.,uranyl-based materials as photocatalysts in transformation and conversion of organic pollutants for environmental pollution treatment)from the viewpoint of“turning uranium wastes into treasure,from waste recycling to reutilization.”In the end of this review,the challenges and perspectives of uranium separation and catalytic properties were described.展开更多
It has been shown that the age of minerals in which U±Th are a major(e.g.,uraninite,pitchblende and thorite)or minor(e.g.,monazite,xenotime)component can be calculated from the concentrations of U±Th and Pb ...It has been shown that the age of minerals in which U±Th are a major(e.g.,uraninite,pitchblende and thorite)or minor(e.g.,monazite,xenotime)component can be calculated from the concentrations of U±Th and Pb rather than their isotopes,and such ages are referred to as chemical ages.Although equations for calculating the chemical ages have been well established and various computation programs have been reported,there is a lack of software that can not only calculate the chemical ages of individual analytical points but also provide an evaluation of the errors of individual ages as well as the whole dataset.In this paper,we develop a software for calculating and assessing the chemical ages of uranium minerals(CAUM),an open-source Python-based program with a friendly Graphical User Interface(GUI).Electron probe microanalysis(EPMA)data of uranium minerals are first imported from Excel files and used to calculate the chemical ages and associated errors of individual analytical points.The age data are then visualized to aid evaluating if the dataset comprises one or multiple populations and whether or not there are meaningful correlations between the chemical ages and impurities.Actions can then be taken to evaluate the errors within individual populations and the significance of the correlations.The use of the software is demonstrated with examples from published data.展开更多
Prompt fission neutron uranium logging(PFNUL)is an advanced method for utilizing pulsed neutron bombardment of the ore layer and a fission reaction with uranium(^(235)U)to detect the transient neutrons produced by fis...Prompt fission neutron uranium logging(PFNUL)is an advanced method for utilizing pulsed neutron bombardment of the ore layer and a fission reaction with uranium(^(235)U)to detect the transient neutrons produced by fission and then directly measure and quantify uranium;however,the stability and lifetime performance of pulsed neutron sources are the key constraints to its rapid promotion.To address these problems,this study proposes a PFNUL technique for acquiring the time spectrum of dual-energy neutrons(epithermal and thermal neutrons)from the upper and lower detection structures and establishes a novel uranium quantification algorithm based on the ratio of epithermal and thermal neutron time windows(E/T)via a mathematical-physical modeling derivation.Through simulations on well-logging models with di erent uranium contents,the starting and stopping times of the time window(Δt)for uranium quantification in the dual-energy neutron time spectrum are determined to be 200 and 800μs,respectively.The minimum radius and height of the model wells are 60 and 120 cm,respectively,and the E/T values in the time window show an excellent linear relationship with the uranium content.The scale factor is K_(E/T)=1.92 and R^(2)=0.999,which verifies the validity of the E/T uranium quantification algorithm.In addition,experiments were carried out in the Nu series of uranium standard model wells,and the results showed that under di erent neutron source yields,the E/T-based uranium quantification method reduced the relative standard deviation of the scale factor of the uranium content from 33.41%to 1.09%,compared with a single epithermal neutron quantification method.These results prove that the E/T value uranium quantification method is una ected by the change in the neutron source yield,e ectively improves the accuracy and service life of the logging instrument,and has great scientific and popularization value.展开更多
The Erlian Basin is one of the most important multi-energy basins in China.The Baiyanhua area of the Chuanjing depression in the western Erlian Basin has recently become a favorable area for new progress in sandstone-...The Erlian Basin is one of the most important multi-energy basins in China.The Baiyanhua area of the Chuanjing depression in the western Erlian Basin has recently become a favorable area for new progress in sandstone-type uranium prospecting.However,the Cretaceous source-to-sink evolution of the Chuanjing depression in the Erlian Basin is poorly known.This paper presents the systematic geochemical and zircon U-Pb studies on the Saihantala Formation and Erlian Formation in the Baiyanhua area.The data obtained are functionally important for revealing the provenance and tectonic setting of the source rocks.The results show that the upper part of the Saihantala Formation and the lower part of the Erlian Formation are mainly composed of felsic sedimentary rocks.The source rocks originated from a continental margin arc environment in terms of tectonic setting.The detrital zircons ages have the dominant populations at ca.250-270 Ma,with two subdominant age groups at ca.1400-1800 and 1900-2100 Ma,respectively.Combined with the tectono-sedimentary evolution of the Chuanjing depression,we conclude that:(1)the provenance of the Cretaceous strata was mostly sourced from the Baiyanhua uplift;(2)the water depth became shallow in the Southern Sangendalai sag during the middle period of Saihantala,further preventing the formation of coal beds;(3)the formation of Baiyanhua uplift might provide the beneficial tectonic condition for uranium mineralization in the upper Saihantala Formation in southern Sangendalai sag.This is significant for us to understand the space allocation of coal and uranium in Chuanjing depression and evaluate the uranium metallogenic prospects in southern Sangendalai sag.展开更多
Objective To explore the protective effects and underlying mechanisms of H_(2)S against lipid peroxidation-mediated carbonyl stress in the uranium-treated NRK-52E cells.Methods Cell viability was evaluated using CCK-8...Objective To explore the protective effects and underlying mechanisms of H_(2)S against lipid peroxidation-mediated carbonyl stress in the uranium-treated NRK-52E cells.Methods Cell viability was evaluated using CCK-8 assay. Apoptosis was measured using flow cytometry. Reagent kits were used to detect carbonyl stress markers malondialdehyde, 4-hydroxynonenal, thiobarbituric acid reactive substances, and protein carbonylation. Aldehyde-protein adduct formation and alcohol dehydrogenase, aldehyde dehydrogenase 2, aldo-keto reductase, nuclear factor E2-related factor 2(Nrf2), and cystathionine β-synthase(CBS) expression were determined using western blotting or real-time PCR. Sulforaphane(SFP) was used to activate Nrf2. RNA interference was used to inhibit CBS expression.Results GYY4137(an H_(2)S donor) pretreatment significantly reversed the uranium-induced increase in carbonyl stress markers and aldehyde-protein adducts. GYY4137 effectively restored the uraniumdecreased Nrf2 expression, nuclear translocation, and ratio of nuclear to cytoplasmic Nrf2, accompanied by a reversal of the uranium-decreased expression of CBS and aldehyde-metabolizing enzymes. The application of CBS siRNA efficiently abrogated the SFP-enhanced effects on the expression of CBS, Nrf2 activation, nuclear translocation, and ratio of nuclear to cytoplasmic Nrf2 and concomitantly reversed the SFP-enhanced effects of the uranium-induced mRNA expression of aldehyde-metabolizing enzymes.Simultaneously, CBS siRNA reversed the SFP-mediated alleviation of the uranium-induced increase in reactive aldehyde levels, apoptosis rates, and uranium-induced cell viability.Conclusion H_(2)S induces Nrf2 activation and nuclear translocation, which modulates the expression of aldehyde-metabolizing enzymes and the CBS/H_(2)S axis. Simultaneously, the Nrf2-controlled CBS/H_(2)S axis may at least partially promote Nrf2 activation and nuclear translocation. These events form a cycleregulating mode through which H_(2)S attenuates the carbonyl stress-mediated NRK-52E cytotoxicity triggered by uranium.展开更多
The study of uranium isotopes plays a crucial role in advancing our knowledge of nuclear physics,particularly in the realm of isospin and exotic nuclei.This study focused on the ground-state properties of uranium isot...The study of uranium isotopes plays a crucial role in advancing our knowledge of nuclear physics,particularly in the realm of isospin and exotic nuclei.This study focused on the ground-state properties of uranium isotopes ranging from A=203 to A=305.The key physical quantities examined included binding energy,quadrupole deformation,isotopic displacement,single-particle energy levels,and nucleon density distributions.Recent experimental advancements in uranium isotope studies have emphasized the indispensable role of theoretical models in interpreting experimental data.Moreover,the industrial applications of uranium—especially in nuclear energy production and weapons development—underscore the importance and necessity of accurate theoretical insights.The framework of the finite-range droplet model(FRDM)was utilized for comparative analysis because its predictions closely align with the experimental results.Through an analysis of the single-particle energy levels and continuous-state occupancy,this study identified 207 U as the proton drip line nucleus.This research not only deepens our understanding of uranium isotopes but also provides a solid theoretical foundation to guide future experimental investigations.展开更多
基金supported by the China Postdoctoral Science Foundation (No.2021M703001)Fundamental Research Funds for the Central Universities,China University of Geosciences (Wuhan) (No.G1323521101)+3 种基金open fund of State Key Laboratory of Nuclear Resources and Environment (East China University of Technology) (No.2022NRE02)open fund of Key Laboratory of Tectonics and Petroleum Resources (China University of Geosciences (Wuhan)),Ministry of Education (No.TPR2019-08)Fund of Outstanding Talents in Discipline of China University of Geosciences (Wuhan) (No.102162301192664)support from SINO Shaanxi Industry Group in this study。
文摘Carbonaceous debris(CD) is widely disseminated within sandstones in the Shuanglong uranium deposit,southern Ordos Basin,and is the dominant enrichment agent for uranium precipitation.The occurrence and chemical composition of uranium minerals within CD were investigated by using scanning electron microscope and electron microprobe analyses.The results show that uranium minerals mostly occur in cell pores in the forms of fructus aurantia and concentric band structure.Pitchblende and coffinite are the main uranium minerals,and the former is dominant.According to the crystal morphology and composition of trace elements of uranium minerals,uranium precipitation on the pores is grouped into two periods,orderly Ⅰ,Ⅱ.Moreover,the Ⅰ period is further divided into two sub-period,orderly Ⅰ_(1),Ⅰ_(2).Moreover,askew sphere uranium minerals could indicate fluid migration.Under certain geological environment condition,uranium is unevenly adsorbed on the surface of the pore by the Van der Waals(i.e.,Ⅰ_(1) period),and then is precipitated towards to the center of the pore until the whole pore is filled up with uranium minerals by complicated process such as microorganism activities(i.e.,Ⅰ_(2),Ⅱ period).It will provide some guidance for studying the metallogenic environment and genesis of sandstone-type uranium deposit.
基金supported by the National Natural Science Foundation of China(41902310,42372348,42372286)Deep Earth Probe and Mineral Resources Exploration-National Science and Technology Major Project(2024ZD1003607)+2 种基金China Geological Survey Projects(DD20230700802,DD20221819)the Basic Research Fund of the Chinese Academy of Geological Sciences(JKYQN202306)Key Research and Development Program of Shanxi Province,China(202102090301009).
文摘The Mianhuakeng uranium deposit,characterized by uranium-rich granite,serves as a key site for research into crustal radioactive heating.Based on 45 rock samples,this study reviews that the host granite in the Mianhuakeng uranium deposit has a high radioactive heat production rate(avg.5.50μW/m³)and a low Th/U ratio(avg.2.62).Uranium-rich granite and its alteration zone within the upper crust(0-5 km depth)contribute about 45%of the total radioactive heat production,wich is crucial for controlling geothermal resource distribution.For uranium-thermal at tectonic plate margins,a symbiotic geological model was proposed:Firstly,subduction of the Pacific Plate caused upwelling of the asthenosphere,generating a high heat-flow background.Secondly,heat transfer is enhanced by major faults such as the Youdong and Mianhuakeng faults.Subsequently,uranium was mobilized,transported,and enriched within the granite through deep siliceous hydrothermal activity and associated alteration.Ultimately,the uranium enrichment in granite leads to increased radioactive heat production,resulting in local thermal anomalies.This model provides a theoretical support for exploring and developing uranium-thermal symbiotic resources in South China.
基金supported by the National Natural Science Foundation of China(No.52403035)the Shanghai Sailing Program(23YF1400300)+1 种基金the Fundamental Research Funds for the Central Universities(2232023D-05)the Weiqiao Teaching and Research Innovation Program.
文摘The lack of macro-continuity and mechanical strength of covalent organic frameworks(COFs)has significantly limited their practical applications.Here,we propose an“alcohol-triggered defect cleavage”strategy to precisely regulate the growth and stacking of COF grains through a moderate reversed Schiff base reaction,realizing the direct synthesis of COF nanofibers(CNFs)with high aspect ratio(L/D=103.05)and long length(>20μm).An individual CNF exhibits a biomimetic scale-like architecture,achieving superior flexibility and fatigue resistance under dynamic bending via a multiscale stress dissipation mechanism.Taking advantages of these structural features,we engineer CNF aerogels(CNF-As)with programmable porous structures(e.g.,honeycomb,lamellar,isotropic)via directional ice-template methodology.CNF-As demonstrate 100%COF content,high specific surface area(396.15 m^(2)g^(-1))and superelasticity(~0%elastic deformation after 500 compression cycles at 50%strain),outperforming most COF-based counterparts.Compared with the conventional COF aerogels,the unique structural features of CNF-A enable it to perform outstandingly in uranium extraction,with an 11.72-fold increment in adsorption capacity(920.12 mg g^(-1))and adsorption rate(89.9%),and a 2.48-fold improvement in selectivity(U/V=2.31).This study provides a direct strategy for the development of next-generation COF materials with outstanding functionality and structural robustness.
基金supported by the Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2020261)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA02010000)the Young Potential Program of the Shanghai Institute of Applied Physics,Chinese Academy of Sciences(No.SINAP-YXJH-202412)。
文摘Knowing the precise relationship between fuel loading and reactivity is essential for guiding reactor criticality extrapolation and online refueling in molten salt reactors(MSRs).This study aims to explore and explain the linear relationship between reactivity and the reciprocal of uranium concentration in thermal-spectrum MSRs.By applying neutron balance theory,we analyzed the neutron absorption cross sections of various nuclides in single-lattice models with varying fuel concentrations.Our findings reveal a simple linear correlation between reactivity and the reciprocal of uranium concentration,which can be explained from the perspective of nuclear reaction cross sections that adhere to the 1/v law in the thermal neutron spectrum.Furthermore,we identified that the neutron absorption single-group cross sections of structural materials and carrier salts exhibit an approximately linear relationship with the fission single-group cross section of ^(235) U;similarly,the reciprocal of ^(235)U’s fission cross section exhibits an approximately linear relationship with uranium concentration.This linear relationship deviates as the volume fraction of molten salt increases,due to a greater proportion of neutrons being captured in the resonance energy spectrum.However,it remains valid for molten salt volume fractions up to 25%and demonstrates broad applicability in the physical design and operation of thermal molten salt reactors.
基金supported by National Natural Science Foundation of China(Grant No.22378066,22108040)Collaboration&Innovation Platform Project of National Independent Innovation Demonstration Zone(Fuzhou,Xiamen&Quanzhou)(Project No:3502ZCQXT2023004).
文摘The extraction of uranium from seawater via membrane adsorption is a promising strategy for ensuring a long-term supply of uranium and the sustainability of nuclear energy.However,this approach has been hindered by the longstanding challenge of identifying sustainable membrane materials.In response,we propose a prototypal hybridization strategy to design a novel series of aminated conjugated microporous polymer(CMPN)@collagen fiber membrane(COLM).These sustainable and low-cost membrane materials allow a rapid and high-affinity kinetic to capture 90%of the uranium in just 30 min from 50 ppm with a high selectivity of Kd>105 mL·g^(−1).They also afford a robustly reusable adsorption capacity as high as 345 mg·g^(−1)that could harvest 1.61 mg·g^(−1)of uranium in a short 7-day real marine engineering in Fujian Province,even though suffered from very low uranium concentration of 3.29μg·L^(−1)and tough influence of salts such as 10.77 g·L^(−1)of Na^(+),1.75μg·L^(−1)of VO_(3)^(−)etc.in the rough seas.The structural evidence from both experimental and theoretical studies confirmed the formation of favorable chelating motifs from the amino group on CMPN-COLM,and the intensification by the synergistic effect from the size-sieving action of CMPN and the capillary inflow effect of COLM.
基金supported by Doctoral Scientific Fund Project of Southwest University of Science and Technology(20zx7130)Seawater Uranium Extraction Innovation and Development Fund Project(China National Nuclear Corporation)(CNNCCXLM-202215)。
文摘Many adsorbents have been developed for uranium recovery to ensure global energy and environmental security.However,most reported adsorbents involve complex preparation process and rely heavily on petrochemical feedstocks,which undoubtedly increases carbon emissions from production in the nuclear industry.Here,a biomass aerogel(CS-BT)is prepared by the facile cross-linking of chitosan and bayberry tannins with glutaraldehyde.U(Ⅵ)can be adsorbed by hydroxyl groups on CS-BT aerogel via chelation,and the maximum adsorption capacity of the obtained aerogel to U(Ⅵ)is 140 mg·g^(-1)and the removal rate reaches up to 99%(at 298.15 K,pH=5.0).The pseudo-second-order kinetics model and Freundlich model can better match the adsorption process of CS-BT aerogel,implying that its adsorption is a chemical adsorption process dominated by multilayer adsorption.The thermodynamic results show that the adsorption process of U(Ⅵ)by CS-BT aerogel is spontaneous and exothermic.Hence,our biomass aerogel can effectively extract uranium from water,contributing to the sustainable development of the nuclear industry.
基金the Young Elite Scientists Sponsorship Program by JXAST(2024QT11)the National Natural Science Foundation of China(22465001,22309003)the Jiangxi Provincial Natural Science Foundation(20232BAB203042,20242BAB22002).
文摘As a key low-carbon energy source,nuclear power plays a vital role in the global transition toward sustainable energy.Photocatalytic uranium extraction from seawater(UES)offers a promising solution to ensure long-term uranium supply but is challenged by ultra-low uranium concentrations and ion interference.To overcome these issues,we design three diketopyrrolopyrrole-based covalent organic frameworks(COFs)via a synergisticπ-extended lock and carboxyl-functionalized anchor molecular engineering strategy.Among them,TPy-DPP-COF features a covalently lockedπ-conjugated structure that enhances planarity,optimizes energy alignment,and minimizes exciton binding energy,thereby promoting charge transfer and suppressing recombination.Concurrently,carboxyl groups enable uranyl-specific coordination and create local electric fields to facilitate charge separation.These features contribute to the outstanding performance of TPy-DPP-COF,which achieves a high uranium adsorption capacity of 16.33 mg g−1 in natural seawater under irradiation,with only 29.3%capacity loss after 10 cycles,surpassing industrial benchmarks.Density functional theory(DFT)calculations and experimental studies reveal a synergistic photocatalysis-adsorption pathway,with DPP units acting as active sites for uranium reduction.This work highlights a molecular design strategy for developing efficient COF-based photocatalysts for practical marine uranium recovery.
基金supported by the National Natural Science Foundation of China(Nos.52170083 and 12305352)the Science and Technology Innovation Program of Hunan Province(No.2022RC1125).
文摘Simultaneous uranium recovery,organic pollutant degradation,and electricity generation were achieved by employing a self-driven photoelectrochemical(PEC)system equipped with a modified carbon felt(MCF)cathode for the treatment of complex radioactive wastewater.The MCF cathode was synthesized via a facile hydrothermal method,which modified the surface functional groups on carbon felt(CF)with enhanced active site availability and facilitated interfacial charge transfer,thus improving its UO_(2)^(2+)adsorption and reduction capacities.The self-driven PEC system with the MCF cathode demonstrated remarkable removal efficiencies and rate constants(k)for UO_(2)^(2+)(98.8%and 0.111 min^(−1))and chlortetracycline hydrochloride(CTC)(92.9%and 0.028 min^(−1))within 40 min and 90 min,respectively,coupled with an excellent power output of 1.41 mW/cm^(2).Additionally,the system with the MCF cathode exhibited superior removal performance for UO_(2)^(2+)and CTC in treating model complex wastewater under wide conditions.Even under natural sunlight,the system achieved over 80%removal efficiency for both UO_(2)^(2+)and CTC.Moreover,the uranium immobilized on the MCF cathode was mainly reduced to U(Ⅳ)species(90.51%),and performance remained robust over ten operational cycles.The cathode surface modification strategy and its application in the system provide a cost-effective,multi-functional and high-efficiency approach to controlling nuclides and organic pollutants in complex radioactive wastewater.
基金supported by the National Natural Science Foundation of China(Nos.12435012,12175300,and 12475185)Shanghai Natural Science Foundation(No.24ZR1478500)Nuclear energy development project(HNKF202210(24))。
文摘This study proposes a method for^(99)Mo production via electron accelerator irradiation of a natural-uranium-bearing liquid molten salt target,with advantages including low nuclear proliferation risk,online extraction capability,and low construction costs.The approach primarily produces^(99)Mo through photofission of uranium(~95%),specifically^(238)U(γ,f).Secondary neutrons,originating from photonuclear interactions or fission processes,contribute minimally(~5%)to^(99)Mo production owing to their high energies and low fission cross sections.Key parameter analyses revealed that fluoride salt systems exhibit higher^(99)Mo yield.Their performance stems from high bremsstrahlung energy loss rate and superior photon yield,making them optimal molten salt target materials.To maximize photofission and photoneutron cross sections while minimizing highenergy gamma ray shielding requirements,an electron beam energy range of 40-80 MeV is recommended.To suppress local hot spots and prevent molten salt boiling,flow conditions were introduced to enhance convective heat transfer,effectively reducing the peak temperature.At a flow velocity of 0.5 m/s and under 80 MeV energy conditions,the maximum system temperature is only 808.9 K,which is significantly lower than the boiling point of 1773 K.Under optimized parameters,the maximum annual production capacity of~(99)Mo reaches 4486.49 Ci,sufficient for millions of diagnostic procedures and equivalent to 16.37% of China's projected demand for 2030.This method provides a viable pathway for stable,large-scale^(99)Mo production.
文摘One of the main issues in designing optimum tapered cascades for uranium enrichment for annual fuel production in a power reactor is whether to employ large(fat)or small(thin)cascades.What will be the permissible and optimal ranges of the number of machines that can be used in a cascade?For the first time,the permissible and optimal ranges of the number of gas centrifuges that can be utilized in a cascade were investigated using two types of centrifuges,and the performance of small and large tapered cascades was discussed.The particle swarm optimization algorithm(PSO)has been used to optimize tapered cascades.The results show:(1)For the first centrifuge,41 cascades(91≤n≤4897)and for the second centrifuge,49 cascades(18≤n≤3839)with small and large sizes can be used in enrichment facilities,and the best cascade for them has 530(with 23 stages)and 39(with 7 stages)centrifuges,respectively.(2)For both centrifuges,when 600≤n(number of centrifuges=n),the large cascade performance changes are relatively insignificant.(3)For both types of gas centrifuges,the annual los s of separation power in enrichment facilities is approximately 1.25%-4.82%of the total separation work required.
基金National Mineral Resource Potential Evaluation Project
文摘Uranium,as one of twenty-six kinds of important minerals in China,is strategic resource and energy mineral,which has been thoroughly investigated in the project of National Potential Evaluation of Uranium Resource.During the implementation of this project,the authors summarized the metallogenic regularity of uranium resource in China systematically,through the researches of geological characteristics of uranium resource,uranium deposits type（genetic and prediction type）,temporal and spatial distribution,and metallogenic series.Based on the investigation of present situation and progress in uranium exploration,this paper proposes the uranium deposits in China should be divided into 4 classes,9 types,21 subtypes in genetic,and 50 types in prediction;suggests to divide China into 29 uranium metallogenic belts and 20 uranium prospective area,and constructs 20uranium-polymetallic metallogenic series,through summarizing temporal and spatial distribution characteristics and metallogenic regularity of uranium deposits in China.The above research is beneficial to the comprehensive understanding of regional uranium metallogenic regularity,and will direct the uranium exploration in the future.
基金supported by the Russian Science Foundation grant number 23-27-00362,https://rscf.ru/en/project/23-27-00362/.
文摘The study aims to investigate uranium species in the sediments of the natural-technogenic system within a sludge storage facility in Russia.The relevance of this work is underscored by the need to assess the geochemical mobility of radionuclides,a critical factor for predicting their migration and environmental impact.The objective of the research was to determine the uranium species in both peat and sedimentary rock samples of the sludge storage facility and the adjacent area.Laboratory analyses included XRD,XRF analysis using synchrotron radiation,and scanning electron microscopy to study the composition and properties of minerals.The uranium species were further identified using a modified Tessier sequential extraction method.The results revealed that uranium predominantly occurs in a stable silicate-bound form(up to 80%)in sedimentary rocks,indicating minimal geochemical mobility.In contrast,in peat deposits,uranium is primarily associated with manganese and iron oxides(30–60%)as well as organic matter(5–40%),with the most mobile forms constituting less than 5%.The decrease in uranium concentration with distance from the facility was attributed to sorption onto organic matter and co-precipitation with mineral compounds,manganese and iron oxides,which serve as effective natural sorbents.The findings highlight the critical role of organic matter and metal oxides in limiting uranium migration,thus identifying them as key components in the formation of natural barriers for radionuclides.These results are crucial for assessing environmental risks associated with radioactive waste management and for developing strategies to minimize the ecological impact of sludge storages.
文摘Three uranium provinces are recognized in China, the Southeast China uranium province, the Northeast China-Inner Mongolia uranium province and the Northwest China (Xinjiang) uranium province. The latter two promise good potential for uranium resources and are major exploration target areas in recent years. There are two major types of uranium deposits: the Phanerozoic hydrothermal type (vein type) and the Meso-Cenozoic sandstone type in different proportions in the three uranium provinces. The most important reason or prerequisite for the formation of these uranium provinces is that Precambrian uranium-enriched old basement or its broken parts (median massifs) exists or once existed in these regions, and underwent strong tectonomagmatic activation during Phanerozoic time. Uranium was mobilized from the old basement and migrated upwards to the upper structural level together with the acidic magma originating from anatexis and the primary fluids, which were then mixed with meteoric water and resulted in the formation of Phanerozoic hydrothermal uranium deposits under extensional tectonic environments. Erosion of uraniferous rocks and pre-existing uranium deposits during the Meso-Cenozoic brought about the removal of uranium into young sedimentary basins. When those basins were uplifted and slightly deformed by later tectonic activity, roll-type uranium deposits were formed as a result of redox in permeable sandstone strata.
基金supported by the National Natural Science Foundation of China(Grant No.21968001).
文摘The discharge of effluents containing uranium(U)ions into aquatic ecosystems poses significant risks to both human health and marine organisms.This study investigated the biosorption of U(VI)ions from aqueous solutions using corncob-sodium alginate(SA)-immobilized Trichoderma aureoviride hyphal pellets.Experimental parameters,including initial solution pH,initial concentration,temperature,and contact time,were systematically examined to understand their influence on the bioadsorption process.Results showed that the corncob-SA-immobilized T.aureoviride hyphal pellets exhibited maximum uranium biosorption capacity at an initial pH of 6.23 and a contact time of 12 h.The equilibrium data aligned with the Langmuir isotherm model,with a maximum biosorption capacity of 105.60 mg/g at 301 K.Moreover,biosorption kinetics followed the pseudo-second-order kinetic model.In terms of thermodynamic parameters,the changes in Gibbs-free energy(△G°)were determined to be-4.29 kJ/mol at 301 K,the changes in enthalpy(△H°)were 46.88 kJ/mol,and the changes in entropy(△S°)was 164.98 J/(mol·K).Notably,the adsorbed U(VI)could be efficiently desorbed using Na_(2)CO_(3),with a maximum readsorption efficiency of 53.6%.Scanning electron microscopic(SEM)analysis revealed U(VI)ion binding onto the hyphal pellet surface.This study underscores the efficacy of corncob-SA-immobilized T.aureoviride hyphal pellets as a cost-effective and environmentally favorable biosorbent material for removing U(VI)from aquatic ecosystems.
基金support from the National Natural Science Foundation of China(Nos.U24B20195,U23A20105,U2341289,22341602,22327807)was acknowledged.
文摘Fast development of nuclear power plants requires sustainable support of uranium for nuclear fuel.Uranium is the most critical radionuclide to prepare nuclear fuel.However,the extraction of low concentration of uranium in uranium ore or complex systems needs highly efficient selective binding of uranium in the presence of other competing metal ions.The excellent oxidative capacity of excited*UO_(2)^(2+)active species makes uranyl-based materials high photocatalytic performance in phototransformation of organic chemicals into high valuable products under visible light irradiation.In this mini review,the selective preconcentration of uranium through photocatalytic and electrocatalytic strategies was mainly described.The application of uranyl-based materials in photocatalytic conversion and degradation of organic pollutants was summarized.This review reports the utilization of uranium from its first step(i.e.,extraction of uranium for nuclear fuel supply)to its last additional application(i.e.,uranyl-based materials as photocatalysts in transformation and conversion of organic pollutants for environmental pollution treatment)from the viewpoint of“turning uranium wastes into treasure,from waste recycling to reutilization.”In the end of this review,the challenges and perspectives of uranium separation and catalytic properties were described.
基金supported by the Natural Science Foundation Program of China(42173072,41503037,U1967207)Postgraduate Innovative Cultivation Program(CDUT2023BJCX013)Uranium Resources Exploration and Exploitation Innovation Center&and Everest Scientific Research Program(CDUT).
文摘It has been shown that the age of minerals in which U±Th are a major(e.g.,uraninite,pitchblende and thorite)or minor(e.g.,monazite,xenotime)component can be calculated from the concentrations of U±Th and Pb rather than their isotopes,and such ages are referred to as chemical ages.Although equations for calculating the chemical ages have been well established and various computation programs have been reported,there is a lack of software that can not only calculate the chemical ages of individual analytical points but also provide an evaluation of the errors of individual ages as well as the whole dataset.In this paper,we develop a software for calculating and assessing the chemical ages of uranium minerals(CAUM),an open-source Python-based program with a friendly Graphical User Interface(GUI).Electron probe microanalysis(EPMA)data of uranium minerals are first imported from Excel files and used to calculate the chemical ages and associated errors of individual analytical points.The age data are then visualized to aid evaluating if the dataset comprises one or multiple populations and whether or not there are meaningful correlations between the chemical ages and impurities.Actions can then be taken to evaluate the errors within individual populations and the significance of the correlations.The use of the software is demonstrated with examples from published data.
基金supported by the National Natural Science Foundation of China(No.42374226)Jiangxi Provincial Natural Science Foundation(Nos.20232BAB201043,gpyc20240073,and 20232BCJ23006)+2 种基金Nuclear Energy Development Project(20201192-01)Fundamental Science on Radioactive Geology and Exploration Technology Laboratory(2022RGET20)National Key Laboratory of Uranium Resource Exploration-Mining and Nuclear Remote Sensing(ECUT)(2024QZ-TD-09)。
文摘Prompt fission neutron uranium logging(PFNUL)is an advanced method for utilizing pulsed neutron bombardment of the ore layer and a fission reaction with uranium(^(235)U)to detect the transient neutrons produced by fission and then directly measure and quantify uranium;however,the stability and lifetime performance of pulsed neutron sources are the key constraints to its rapid promotion.To address these problems,this study proposes a PFNUL technique for acquiring the time spectrum of dual-energy neutrons(epithermal and thermal neutrons)from the upper and lower detection structures and establishes a novel uranium quantification algorithm based on the ratio of epithermal and thermal neutron time windows(E/T)via a mathematical-physical modeling derivation.Through simulations on well-logging models with di erent uranium contents,the starting and stopping times of the time window(Δt)for uranium quantification in the dual-energy neutron time spectrum are determined to be 200 and 800μs,respectively.The minimum radius and height of the model wells are 60 and 120 cm,respectively,and the E/T values in the time window show an excellent linear relationship with the uranium content.The scale factor is K_(E/T)=1.92 and R^(2)=0.999,which verifies the validity of the E/T uranium quantification algorithm.In addition,experiments were carried out in the Nu series of uranium standard model wells,and the results showed that under di erent neutron source yields,the E/T-based uranium quantification method reduced the relative standard deviation of the scale factor of the uranium content from 33.41%to 1.09%,compared with a single epithermal neutron quantification method.These results prove that the E/T value uranium quantification method is una ected by the change in the neutron source yield,e ectively improves the accuracy and service life of the logging instrument,and has great scientific and popularization value.
基金funded by the project initiated by the China Geological Survey“Investigation of sandstone-type uranium deposits in the Ordos and Qaidam Basins”(No.DD20190119)the National Key Research and Development Project(No.2018YFC0604200)from the Ministry of Science and Technology of the International Geoscience Programme(No.IGCP675),which is a joint endeavor of UNESCO and IUGS。
文摘The Erlian Basin is one of the most important multi-energy basins in China.The Baiyanhua area of the Chuanjing depression in the western Erlian Basin has recently become a favorable area for new progress in sandstone-type uranium prospecting.However,the Cretaceous source-to-sink evolution of the Chuanjing depression in the Erlian Basin is poorly known.This paper presents the systematic geochemical and zircon U-Pb studies on the Saihantala Formation and Erlian Formation in the Baiyanhua area.The data obtained are functionally important for revealing the provenance and tectonic setting of the source rocks.The results show that the upper part of the Saihantala Formation and the lower part of the Erlian Formation are mainly composed of felsic sedimentary rocks.The source rocks originated from a continental margin arc environment in terms of tectonic setting.The detrital zircons ages have the dominant populations at ca.250-270 Ma,with two subdominant age groups at ca.1400-1800 and 1900-2100 Ma,respectively.Combined with the tectono-sedimentary evolution of the Chuanjing depression,we conclude that:(1)the provenance of the Cretaceous strata was mostly sourced from the Baiyanhua uplift;(2)the water depth became shallow in the Southern Sangendalai sag during the middle period of Saihantala,further preventing the formation of coal beds;(3)the formation of Baiyanhua uplift might provide the beneficial tectonic condition for uranium mineralization in the upper Saihantala Formation in southern Sangendalai sag.This is significant for us to understand the space allocation of coal and uranium in Chuanjing depression and evaluate the uranium metallogenic prospects in southern Sangendalai sag.
基金supported by the National Natural Science Foundation of China(No.82160627)the Natural Science Foundation of the Guangxi Autonomous Region(No.2020GXNFSAA297262)。
文摘Objective To explore the protective effects and underlying mechanisms of H_(2)S against lipid peroxidation-mediated carbonyl stress in the uranium-treated NRK-52E cells.Methods Cell viability was evaluated using CCK-8 assay. Apoptosis was measured using flow cytometry. Reagent kits were used to detect carbonyl stress markers malondialdehyde, 4-hydroxynonenal, thiobarbituric acid reactive substances, and protein carbonylation. Aldehyde-protein adduct formation and alcohol dehydrogenase, aldehyde dehydrogenase 2, aldo-keto reductase, nuclear factor E2-related factor 2(Nrf2), and cystathionine β-synthase(CBS) expression were determined using western blotting or real-time PCR. Sulforaphane(SFP) was used to activate Nrf2. RNA interference was used to inhibit CBS expression.Results GYY4137(an H_(2)S donor) pretreatment significantly reversed the uranium-induced increase in carbonyl stress markers and aldehyde-protein adducts. GYY4137 effectively restored the uraniumdecreased Nrf2 expression, nuclear translocation, and ratio of nuclear to cytoplasmic Nrf2, accompanied by a reversal of the uranium-decreased expression of CBS and aldehyde-metabolizing enzymes. The application of CBS siRNA efficiently abrogated the SFP-enhanced effects on the expression of CBS, Nrf2 activation, nuclear translocation, and ratio of nuclear to cytoplasmic Nrf2 and concomitantly reversed the SFP-enhanced effects of the uranium-induced mRNA expression of aldehyde-metabolizing enzymes.Simultaneously, CBS siRNA reversed the SFP-mediated alleviation of the uranium-induced increase in reactive aldehyde levels, apoptosis rates, and uranium-induced cell viability.Conclusion H_(2)S induces Nrf2 activation and nuclear translocation, which modulates the expression of aldehyde-metabolizing enzymes and the CBS/H_(2)S axis. Simultaneously, the Nrf2-controlled CBS/H_(2)S axis may at least partially promote Nrf2 activation and nuclear translocation. These events form a cycleregulating mode through which H_(2)S attenuates the carbonyl stress-mediated NRK-52E cytotoxicity triggered by uranium.
基金supported by the National Natural Science Foundation of China(Nos.12175170 and 11675066)。
文摘The study of uranium isotopes plays a crucial role in advancing our knowledge of nuclear physics,particularly in the realm of isospin and exotic nuclei.This study focused on the ground-state properties of uranium isotopes ranging from A=203 to A=305.The key physical quantities examined included binding energy,quadrupole deformation,isotopic displacement,single-particle energy levels,and nucleon density distributions.Recent experimental advancements in uranium isotope studies have emphasized the indispensable role of theoretical models in interpreting experimental data.Moreover,the industrial applications of uranium—especially in nuclear energy production and weapons development—underscore the importance and necessity of accurate theoretical insights.The framework of the finite-range droplet model(FRDM)was utilized for comparative analysis because its predictions closely align with the experimental results.Through an analysis of the single-particle energy levels and continuous-state occupancy,this study identified 207 U as the proton drip line nucleus.This research not only deepens our understanding of uranium isotopes but also provides a solid theoretical foundation to guide future experimental investigations.
