13 results about "Isotopic composition" patented technology

The invention discloses a rare metal mineralization potential comprehensive evaluation method based on rock geochemistry, and aims to solve the problems of single evaluation index and disjunction between field observation and indoor analysis in the prior art. The method comprises the following steps: obtaining geological data of an analysis area, and screening a target area based on a favorable structure background and an exposed feature criterion; identifying mineralogical and lithofacies markers and collecting sampling data; the method comprises the following steps: acquiring rock geochemical data of a sample sampled by a previous person, including multi-dimensional data including major elements, trace elements, isotope composition and the like, and calculating a quantitative evaluation index according to the data; and finally, establishing a comprehensive evaluation model by adopting a weighted scoring method to realize mineralization potential grade division and target region accurate delineation in a three-dimensional space. According to the method, organic combination of macroscopic geologic features and microcosmic geochemical data is realized, and a complete technical system from field observation to indoor analysis to engineering decision is formed.

The present application belongs to the technical field of geochemistry, and particularly relates to the estimation of the carbon flux of the earth system, and especially relates to a method and system for estimating the carbon flux of the deep-time earth system. The method for estimating the carbon flux of the deep-time earth system provided by the present application solves the four defects in the traditional technology caused by the fixed carbon pool assumption, the neglect of the atmospheric / biosphere carbon content, the isotopic error, and the failure to consider the fractionation effect through dynamic carbon pool segmentation, the inclusion of multi-sphere isotopic composition, and the correction of fractionation effect. The high-precision and verifiable model framework not only improves the scientificity of the deep-time carbon cycle research, but also provides a key tool for analyzing the climate evolution mechanism in the geological history period and predicting the future climate change trend, and has important theoretical innovation and practical application value.

This invention relates to a method for determining the assumed uranium-plutonium isotope composition of a reprocessing plant solution system. Based on the reprocessing target, the method determines the component parameters and irradiation history parameters of the target, and then determines a conservative combination of nuclide composition calculation parameters for criticality safety analysis. Nuclide composition calculations are performed for different control rod insertion states, and a nuclide composition database is established. Combining the control rod insertion range in the irradiation history of different reactor types' spent fuel assemblies and the conservative axial burnout distribution of the target components, the method determines the average burnout limit for spent fuel assemblies with different initial enrichment levels that satisfies the uranium-plutonium isotope composition assumption. After comparing and adjusting the iterative analysis with the range and distribution of average burnout of spent fuel assemblies with different initial enrichment levels, the method ensures that, under the determined uranium-plutonium isotope composition assumption and its corresponding average burnout limit for spent fuel assemblies, the reprocessing plant can handle the vast majority of spent fuel assemblies, thereby maximizing the economic efficiency of criticality safety design.

A device has a substrate comprising first, second and third layers of a crystalline material such as silicon. The second layer is between the first and third layers. A radiation damage centre (RDC) is located in the second layer. In some embodiments the RDC is optically coupled to an optical resonator The second layer has an isotopic composition that is different from that of the first and third layers. The RDC may be formed by ion implantation. The RDC may be addressable independently of any RDCs located outside of the second layer as a result of characteristics of the RDC that vary depending on the isotopic composition of the environment of the RDC. Methods for making and testing devices are also described.

The application discloses a kind of based on organic matter interference evaluation cadmium isotope standard substance stability verification method, belongs to environmental monitoring and geology reference material analysis technical field, the method first from the mixed to be evaluated Cd standard reference material large sample Randomly equal amount takes two samples;Two samples are respectively subjected to acid digestion and Cd separation and purification, then MC-ICP-MS measurement is carried out, obtains the δ 114 / 110 Cd value of each sample;Finally, the difference of the δ 114 / 110 Cd value of two samples is calculated and compared with threshold value to judge the homogeneity and stability of the Cd isotope composition of the standard substance, and the effectiveness of the method is verified by the fact that the measurement results of the control sample are within the known demonstration interval. The verification method directly separates the sample when taking the solid powder sample, classifies and evaluates it based on its inherent physical and chemical properties, and provides a reliable reference standard substance screening method for Cd isotope research of environmental samples.

The invention discloses a method for measuring an element distribution coefficient and an isotope fractionation value between a fluid and a melt, and belongs to the field of stable isotope geochemistry, and the method comprises the following steps: preparing an initial fluid and an initial solid phase; performing isotope exchange reaction by using the initial fluid and the initial solid phase; an experimental fluid phase and an experimental melt phase in a reaction product are separated through freezing and deionized water cleaning; and determining the metal element content and stable isotope composition of the experimental fluid phase and the experimental melt phase, and calculating the metal element distribution coefficient and isotope fractionation value between the experimental fluid phase and the experimental melt phase. According to the method, after isotope exchange equilibrium of the rapid quenching cold-sealed autoclave, the fluid phase and the silicate rock phase are frozen and then separated, the fluid phase and the silicate rock phase are precisely separated and recovered through multi-step deionized water cleaning, precise analysis of the metal element content and the isotope composition of the two phases is achieved, and the analysis precision of the metal element content and the isotope composition of the two phases is improved. And the method has positive significance on isotope geochemistry development.

The disclosure provides a method for determining the evolution process of carbon dioxide injection into sandstone post-diagenetic fluid, comprising: obtaining the microscopic characteristics of davyne sandstone, determining the diagenetic paragenetic sequence of CO2 injection into davyne sandstone according to the microscopic characteristics; determining the fluid inclusion characteristics of davyne sandstone, determining the filling time and filling period of the fluid according to the fluid inclusion characteristics; according to the diagenetic paragenetic sequence and the filling time and filling period of the fluid, analyzing the diagenetic fluid properties corresponding to the injection of CO2 and oil and gas into davyne sandstone before and after; obtaining the characteristics of present formation water, determining the present fluid characteristics of davyne sandstone according to the characteristics of present formation water; determining the paleofluid characteristics of davyne sandstone according to the carbon and oxygen isotopic composition of davyne sandstone; determining the evolution process of diagenetic fluid after CO2 injection into davyne sandstone according to the present fluid characteristics, diagenetic fluid properties and paleofluid characteristics. The method can comprehensively analyze the evolution process of diagenetic fluid after CO2 injection into sandstone.

The application discloses high-purity silver nitrate for determining isotopic composition in natural water bodies and a method and application thereof, and belongs to the technical field of oxygen and nitrogen isotope determination. The method comprises the following steps: pretreating Ag2O powder, Cl type anion resin and H type cation resin respectively to obtain pretreated Ag2O powder, Cl type anion resin and H type cation resin; enriching a natural water sample containing interfering ions by using the pretreated Cl type anion resin, then eluting the sample by using a BaCl2 solution to obtain an eluent A; ensuring complete exchange of the eluent by using the pretreated H type cation resin, and then collecting the obtained eluent B again; and putting the pretreated Ag2O powder into the obtained eluent B for neutralization treatment, and then performing centrifugation and freeze-drying to obtain high-purity silver nitrate. The technical problems that the existing method is difficult to reduce cost and causes isotopic exchange caused by an acidic eluent are solved.

A thermal simulation experiment method for hydrocarbon-water-rock interactions based on isotope tracing is disclosed. N-eicosane, water and feldspar grains are first heated and reacted in a high temperature high pressure (HTHP) reactor. The reactor is quenched in water to room temperature and samples from the reaction are tested to obtain the composition and content of gas products, the isotopic compositions of gas products, the water solutions and authigenic clays, the nuclear magnetic resonance (NMR) spectra of the liquid hydrocarbons and water solutions, and textures and compositions of minerals. The genetic mechanisms of mass exchange and occurrence of hydrocarbon-water-rock interactions are analyzed. A thermal simulation experiment method using multiple isotope tracing, calibrates the exchange processes and paths for H and O between the hydrocarbons, water and minerals to provide evidence for deciphering the mechanism of the organic-inorganic interactions is disclosed.

This invention relates to the field of plant water source ratio calculation technology, and discloses a normalized method for calculating the plant water source ratio, comprising the following steps: S1, data acquisition, determining the isotopic composition of xylem water and soil water in each layer through stable water isotope analysis; S2, contribution ratio calculation, calculating the contribution ratio of each soil layer to plant water; S3, water source score calculation, calculating the water source score WSS according to the formula; S4, evaluation and application, constructing the relationship with ecosystem variables through the WSS score. By normalizing the water source score WSS value from 0 to 1, and eliminating absolute depth differences through mathematical standardization, the research results of different regions or different soil stratification schemes are directly comparable, thereby solving the defect of traditional methods that cannot be compared horizontally due to the subjectivity of depth boundaries, and realizing an objective comparison of the degree of plant deep water dependence across regions.

This invention belongs to the field of isotope geochronology, specifically relating to a laser ablation fractionation method and system for analyzing the U-Pb age, trace elements, and Hf isotopes of zircon. This invention employs wet plasma technology to improve the uranium detection sensitivity of Q-ICP-MS and ensure the consistency of thorium / uranium fractionation behavior, reducing the difficulty of Q-ICP-MS setup. A gas path connection design with different inner diameters replaces the micro diaphragm pump, achieving stable transmission of unequal amounts of aerosol to two mass spectrometers, reducing experimental costs and improving instrument setup efficiency. The acquired data is converted into a time series, and a multi-external standard correction scheme is used to achieve automated and accurate LASS analysis. This invention utilizes LASS technology to conveniently and accurately determine the U-Pb geochronology, trace element, and Hf isotopic composition of zircon simultaneously, which is beneficial for expanding the application of zircon in geological research.

The invention discloses a cadmium isotope standard substance stability verification method based on organic matter interference assessment, and belongs to the technical field of environmental monitoring and geological reference material analysis, and the method comprises the following steps: firstly, randomly taking two samples in equal amount from a uniformly mixed Cd standard reference substance bulk sample to be assessed; respectively carrying out acid digestion and Cd separation and purification on the two samples, and then carrying out MC-ICP-MS measurement to obtain the delta 114 / 110 Cd value of each sample; finally, the difference value of the delta 114 / 110 Cd values of the two samples is calculated and compared with a threshold value, the uniformity and stability of the Cd isotope composition of the standard substance are judged, and the effectiveness of the method is verified according to the fact that the measurement result of the contrast sample is located in the known demonstration interval. According to the verification method disclosed by the invention, the solid powder sample is directly and separately sampled when being taken, and the standard substance is classified and evaluated according to the inherent physical and chemical properties of the standard substance, so that a reliable reference standard substance screening means is provided for the research on the Cd isotope of the environmental sample.

This invention discloses a method for analyzing heavy metal pollution sources in groundwater based on characteristic ion screening. This method utilizes multi-media collaborative sampling to determine the concentration of heavy metals in groundwater, the content of BCR speciation in sediments, and the isotopic ratios of lead, zinc, and copper. Characteristic ion combinations are extracted through a three-level screening process using enrichment factors, ion ratio variation coefficients, and Pearson correlation. Three types of fingerprint vectors—water chemistry, solid phase speciation, and isotopic composition—are normalized and fused, and candidate pollution sources are matched using cosine similarity. With mass conservation as the primary likelihood and BCR speciation and isotopic mass balance as additional constraints, the spatial distribution field and high-risk areas are obtained through Kriging interpolation using the posterior mean of the MCMC output contribution rate and a 95% confidence interval. This invention can identify four types of pollution sources, reducing reconstruction error by 73% compared to the PMF method, compressing the confidence interval width by 65%–73%, and achieving a field compliance rate of 92%, providing quantitative evidence for pollution prevention and control and accountability.