Available molybdenum(Mo) in soil is an important indicator for evaluating the fertility of soil.However,its content in soil is relatively low.The accurate and rapid determination of available molybdenum in soil is of great significance for guiding the agricultural production.In this study,three kinds of extractants were used to extract available molybdenum from soil samples.Then its content was determined by inductively coupled plasma mass spectrometry(ICP-MS) using ⁹⁵Mo as the determination isotope.It was found that the matrix effect could be effectively eliminated using ¹⁰³Rh as internal standard when the available molybdenum was determined in helium(He) collision mode.The determination results of 3 extractants were compared and analyzed.It indicated that ammonium oxalate solution had certain advantage in extracting available molybdenum from soil and could better reflect the actual supply status of available molybdenum in agricultural soil.The limit of detection of this method was 0.002 mg/kg.The precision test and trueness test of soil samples were conducted.The relative standard deviation(RSD,n=6) of determination results of available molybdenum was between 1.2% and 5.4%.Two certified reference materials for analysis of soil available nutrients were determined,and the results of available molybdenum were within the reference range of certified values with relative error of 0-4.7%.Different types of soil samples were determined using two determination methods,and t-test was used for comparison and validation.It was found that there was no significant difference in measured results.The proposed method could provide reliable technical support for the determination of available molybdenum in different types of soil.

The morphology and size of sulfide inclusions in free-cutting steel have a significant impact on the cutting performance of the steel.Currently,there is a lack of effective methods for the evaluation of sulfide inclusions in free-cutting steel in China,which affects the determination of cutting performance and quality of free-cutting steel.In this study,based on the evaluation standards,including the national standard GB/T 10561-2023,the German standard SEP 1572-2019,the French standard NF A04-108-1986,and the newly formulated industry standard in China YB/T 6458-2026,for sulfides in free-cutting steel at home and abroad,4 methods for evaluating sulfides in free-cutting steel were introduced.The evaluation process,content,and results of each method were introduced.The methods adopted in these 4 standards were different.In national standard GB/T 10561-2003,the grade of various types of inclusions is evaluated based on their length and width,and the inclusions include sulfides,aluminum oxide,silicates and oxides.This method is not applicable for the evaluation of sulfide inclusions in free-cutting steel.German standard SEP 1572-2019 is a set of 26 spectra arranged in rows and columns based on the length,width,and area of sulfides.Comparison and image analysis methods are used for evaluation,and the results are represented by K.Z indicating the rows and columns.In French standard NF A04-108-1986,the sulfides are divided into two morphologies,i.e.,spindle-shaped and stringer-shaped.The sulfide inclusions are classified into 9 levels from A to I for comparative evaluation based on the ratio of spindle-shaped to stringer-shaped inclusions.The newly formulated sulfide industry standard in China YB/T 6458-2026 includes the grade assessment of vertical sulfide inclusions and the distribution uniformity assessment of horizontal sulfide inclusions.Wherein the grade assessment of vertical sulfide inclusions is developed based on the adoption of German standard SEP 1572-2019,while the distribution uniformity assessment of horizontal sulfides adopts Delaunay triangulation method.In this paper,some examples were provided to illustrate the image analysis method in German standard and the evaluation method for the transverse distribution uniformity of sulfides in the domestic industrial standard which were relatively difficult to understand,so as to facilitate their better application.Through the description and introduction of various methods,it is hoped that appropriate sulfide evaluation methods can be adopted in practice.This article provided useful reference and support for the research and development of free-cutting steel products.

Accurate determination of available molybdenum in soil is crucial for the scientific fertilization and sustainable agricultural development.The existing standard method(NY/T 1121.9-2023),i.e.,oxalic acid-ammonium oxalate solution extraction(oscillation),suffers from time-consuming sample pretreatment(standing for 10 h) and low batch analysis efficiency.In this study,a method for the determination of available molybdenum in soil by inductively coupled plasma optical emission spectrometry(ICP-OES) after oxalic acid-ammonium oxalate solution extraction(constant-temperature vortex) was established.The single-factor and orthogonal experiments indicated that the efficient extraction could be achieved with 10 min under the optimal conditions as follows:the sample particle size was 60-100 mesh(0.250-0.149 mm),the extraction temperature was (25±3) ℃,the solid-to-liquid ratio(main controlling factor) was 1∶10,the extraction time was 10 min,and the vortex speed was 1 200 r/min.The limit of detection of this method was 0.009 mg/kg,and the limit of quantification was 0.036 mg/kg.The content of available molybdenum in certified reference material for analysis of soil available nutrients(GBW07412b,GBW07413b,GBW07414b) were determined according to the experimental method.The standard deviation(n=8) of determination results was not more than 0.017 mg/kg.The relative standard deviation(RSD, n=8) was not more than 8.4%,and the absolute value of relative error(RE) was not more than 10%.The proposed method was applied for the determination of available molybdenum in soil samples from Jiangsu Xuzhou,Hubei Jingmen and Zhejiang Jiaxing,and the RSD(n=8) of determination results was between 3.7% and 5.5%.The oscillation method in NY/T 1121.9-2023 and constant-temperature vortex method in this method were employed to treat certified reference material for analysis of soil available nutrients(GBW07412b,GBW07413b,GBW07414b,GBW07416b,GBW07458a,GBW07460a) and soil samples.Then the content of available molybdenum was determined by ICP-OES.The results indicated that the difference of average determination value between two methods was not more than 0.05 mg/kg.There was no significant difference in RSD(n=8).The measured results were all within the tolerance range.The proposed method could meet the quality control requirements of batch analysis for available molybdenum in soil.

The rare earth elements in weathering steel exhibit a strong tendency to combine with non-metallic elements such as oxygen(O) and sulfur(S),leading to the complex and diverse morphologies of rare earth inclusions in the steel,which brings severe challenges to the statistical distribution characterization of rare earth inclusions in steel.In this study,a method for the in-situ statistical distribution characterization of cerium(Ce)-containing inclusions within a large size range was established by combining the multi-field continuous observation technology of scanning electron microscope(SEM),the rapid localization and recognition algorithm for characteristic particle images,and the automated energy dispersive spectrometry(EDS) analysis.The in-situ statistical distribution characterization of rare earth inclusions in weathering steel plates with 3 different Ce contents along the rolling direction was realized.The statistical characterization area was up to 200 mm².The information regarding Ce-containing inclusions in 3 types of rare earth weathering steel was obtained,including the position,chemical composition,morphological characteristic,size range and quantity distribution.Additionally,the influence law of Ce addition amount and gaseous element content on the formation of rare earth inclusions in steel was investigated.It was found that the content of S and O in steel and their ratio had a significant impact on the type and quantity distribution of rare earth inclusions.Specifically,the particle size of Ce-O-S type inclusions was generally larger than that of Ce-O and Ce-S type inclusions,and the combination of multiple elements promoted the growth of rare earth inclusions toward larger particle size.The P-containing rare earth inclusions were affected by oxygen content,and the main distribution range of the equivalent circle diameter(ECD) shifts from (2,3] μm to (5,7] μm.

The size and number of inclusions have a direct influence on the performance and service life of bearing steel.Therefore,the requirements for inclusions in bearing steel are extremely strict.Due to the characteristics of inclusions including small size,complex types,and concealed nature,a single testing method cannot fully characterize their properties.In this study,based on an extreme value statistical model and multi-scale characterization technology,combined with a field emission scanning electron microscope(FESEM) and Aztec inclusion analysis software,three-dimensional quantitative analysis of the composition,morphology,and size of inclusions in bearing steel was realized.Using the extreme value statistical model,the limitation of the visual field in traditional microscopic detection was overcome,and the maximum size inclusions was successfully predicted and verified experimentally.The results showed that the Aztec inclusion analysis software could detect all inclusions on the inspection surface,including nitrides,oxysulfides(complex),sulfides, and oxides. Among them,the oxysulfides(complex) accounted for approximately 60%,and the nitrides accounted for about 30%.By detecting the maximum size inclusions on 24 inspection surfaces of inclusion specimens,the extreme value statistical model predicted that the maximum length of aluminum oxides inclusions at a reversal period of T=1 000 was approximately 226 μm,and the maximum diameter of point inclusions was approximately 40 μm.After actual sampling and verification,the maximum length of aluminum oxides inclusions detected at T=50 was approximately 188 μm,and the maximum diameter of point inclusions was approximately 28.2 μm,which was close to the predicted values of 151.07 μm and 28.77 μm.

At present,the hydrochloric acid-calcium acetate centrifugal exchange method is the mainstream method for the determination of cation exchange capacity in calcareous soils.However,the operation of each link in this determination method is complex,and it requires a high level of skill from the operator.It is difficult to precisely control the actual operation,and the precision of the experimental results can hardly meet the quality requirements of relevant specifications.Based on the industrial standard NY/T 1121.5-2006 Soil testing-Part 5: Determination of cation exchange capacity in calcareous soils,the experimental conditions were optimized through experiments in this paper,which specifically included the following items:the appropriate concentration of hydrochloric acid was selected to effectively destroy and decompose the carbonates and gypsum in the soil,so that the soil solution reached a hydrogen-saturated state;during the process of using 40% ethanol (volume fraction) to remove the excess hydrochloric acid,a high-speed centrifuge was selected and the number of washing was determined,which significantly reduced the risk of soil colloid loss and destruction.The potentiometric titration method was used for the determination to ensure the stability and accuracy of the data.The cation exchange capacity(CEC) in 5 reference material for available nutrients of soil was determined according to the experimental method.The relative standard deviation(RSD,n=5) of determination results was between 1.4% and 3.7%,and the absolute value of relative error(RE) was between 0.5% and 2.4%.The determination results were compared with those obtained by traditional titration method,and the results of two methods were consistent with each other,and both could meet the quality control requirements of the technical specifications for the third national soil survey.The proposed method was applied for the determination of CEC in actual calcareous soil samples,and the RSD(n=12) of measured results ranged from 3.8% to 9.3%,which could meet the quality control requirements of the technical specifications for the third national soil survey.

Since the advent of focused ion beam(FIB) technology,it has developed from a micro/nanofabrication tool in the semiconductor industry into an indispensable platform for multimodal characterization in materials science.This paper systematically summarizes the fundamental principles and equipment configuration FIB technology as well as the key applications in micro/nanofabrication.The combination characterization strategies of FIB with scanning electron microscope(SEM),energy-dispersive X-ray spectroscopy(EDS),electron backscatter diffraction(EBSD),transmission electron microscope(TEM),and atom probe tomography(APT) are emphasized.The correlative characterization is classified into two categories,i.e.,in situ integration and offline correlative analysis.The advantages of two categories in dynamic process observation and cross-scale information association are discussed,respectively.In addition,the possible irradiation damage mechanisms in FIB fabrication and the mitigation strategy are analyzed in depth.The latest developments in FIB-related standardization efforts at home and abroad are introduced.Finally,the development trend of FIB technology toward higher performance,intelligent operation and deeper integration are prospected.The key roles of FIB technology in constructing material genome map and promoting materials design and property optimization are highlighted.

Focused ion beam-scanning electron microscope(FIB-SEM) has become a crucial tool in shale oil and gas research due to its ability in nanoscale precision in micro-nano fabrication,high-resolution imaging capability,and extensive range of accessory functions.Particularly,it demonstrates unique advantages in characterizations of shale reservoirs microstructure,pore characteristics,and organic matter distribution.The technical advancements and comprehensive applications of FIB-SEM in shale oil and gas research in recent years were systematically reviewed in this article,which covered multiple aspects such as the three-dimensional quantitative characterization of nanopore systems,microscopic distribution analysis of organic and inorganic matters,analysis of residual oil distribution,mineral identification and analysis,and the construction of digital rock core models based on serial sectioning-imaging.Furthermore,as a vital component in shale characterization,FIB-SEM could be integrated with other advanced techniques,which enabled the comprehensive characterizations that spanned from the nanoscale to the macroscale,encompassed multiple dimensions from chemical composition to physical structure,and covered multiple temporal domains from static imaging to dynamic evolution.The evolutionary behavior of shale under subsurface conditions or extreme environments could be revealed.The multi-scale and multi-dimensional comprehensive analysis platform built based FIB-SEM as the core,combined with the automation of equipment and the application of artificial intelligence(AI) technology,could provide unprecedented integrated research solutions for addressing complex systemic challenges in shale oil and gas,which willprovide critical technical support for research on microscopic mechanisms and the construction of macro-scale cognition in the field of petroleum geology.

This paper systematically investigated the differences among the standard curve method,the certified reference material(CRM) curve method,and the standard addition method in inductively coupled plasma atomic emission spectrometry(ICP-AES) analysis,as well as their requirements for blank solutions.By deconstructing the spectral intensity composition of the calibration,sample,and blank solutions,the following conclusions were drawn:1)For the calibration curve based on the concentration of the added standard solution versus the spectral intensity,its intercept comprised the blank value,the content of matrix elements,and the fitting error.The measurement results required compensation for the over-deducted analyte content in the matrix metal.For the calibration curve based on the sum of the standard solution concentration and the matrix element content versus the spectral intensity,its intercept reflected only the blank value and fitting error,and the measurement results were final.No dedicated blank solution preparation was necessary in both cases.2)In the CRM curve method,the intercept encompassed the blank,CRM uncertainty,and fitting error.The test results were final,blank solution preparation was unnecessary,and abnormalities could not be judged solely by the blank value.3)The standard addition method required a blank solution and had the limitation of being unable to eliminate spectral interference from coexisting elements completely.4)When the calibration and sample solutions were prepared in separate batches,deducting their respective reagent blanks before calibration effectively eliminated blank variations caused by reagent batch differences.This approach solved the problem of reusing calibration solutions and yielded accurate test results.The study also showed that a full-process blank should be used when the matrix effect is minor,whereas a matrix metal blank solution should be employed when the matrix effect is strong (with results compensation).Moreover,the content of the analyte in the blank solution must be strictly controlled below half of the quantification limit to ensure accurate determination of elements at that level.

Focused ion beam(FIB) technology demonstrates significant value in semiconductor device research due to its high-precision micro/nano fabrication and in-situ analysis capabilities.This paper aimed to provide an in-depth exploration in typical applications of FIB in semiconductor device processing and elemental analysis.The FIB system was employed to realize the microelectrode fabrication for two-dimensional materials and one-dimensional nanowires,as well as to precisely process optical microstructures such as solid immersion lens(SIL) and two-dimensional photonic crystals.Furthermore,by combining FIB with time-of-flight secondary ion mass spectrometry(ToF-SIMS),a high-resolution analysis of elemental depth distribution in semiconductor multilayer film structures was achieved.The experimental results indicated that FIB enabled precise control of fabrication scales down to the 10-nanometer level,which significantly enhanced the device integration and performance.The combined FIB-ToF-SIMS technique effectively revealed the doping element and interface diffusion behavior.The study demonstrated that FIB was not only an efficient micro/nano fabrication tool,but also could synergize with characterization techniques such as ToF-SIMS to highlight its critical role as an advanced tool in the semiconductor field.It could provide essential technical support for the design,processing,and failure analysis of advanced semiconductor devices.

Inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) has great advantages in the analysis of trace and ultra-trace impurity elements in high-purity refractory metals. In this study, the high matrix introduction (HMI) ICP-MS/MS method was employed to analyze specific interfering elements in high-purity refractory metals, such as trace silver (Ag) in high-purity niobium (Nb), trace platinum (Pt) in high-purity hafnium (Hf), and trace gold (Au) in high-purity tantalum (Ta). The HMI parameters were optimized: the carrier gas flow was 0.45 L/min, and the dilution gas flow was 0.65 L/min,enabling direct quantification using calibration curves without matrix matching.The reaction mode and action mechanism of O₂/NH₃ in tandem quadrupole mass spectrometer (MS/MS) mode was investigated to eliminate the mass spectral interference of matrix on tested elements. Ag was analyzed in the O₂ on-mass mode (primary mass filter Q1=107, secondary mass filter Q2=107) with the flow rate of 0.50 mL/min. Pt and Au were analyzed in the NH₃ mass shift mode (Pt: Q1=194, Q2=228; Q1=195, Q2=229. Au: Q1=197, Q2=231) with the flow rate of 0.75 mL/min and 0.50 mL/min, respectively. The linear ranges of Ag, Pt, and Au were 0.10-50.0 ng/mL,with correlation coefficients (r) all greater than 0.999.The limits of detection were in range of 0.001-0.035 μg/g. The standard solution of Ag, Pt, and Au with known concentration was added into high-purity Nb, Hf and Ta matrixes for the standard addition recovery tests. Moreover, the precision investigations of measurement results were also conducted. The experimental results showed that the spiked recoveries of Ag, Pt, and Au were between 83.0% and 113.0%. The relative standard deviations (RSD, n=6) of determination results were between 3.0% and 7.9%. The proposed method was applied for the analysis of three high-purity refractory metals, and the results were compared with those obtained by glow discharge mass spectrometry (GDMS). It was found that the determination results of two analysis methods were basically consistent.

The unique advantage of the focused ion beam-dual beam scanning electron microscope(FIB-SEM dual-beam system) lies in its simultaneous capability for high-resolution imaging and nanoscale micro-area processing precision.In this paper,the fundamental functions of FIB-SEM dual-beam system and the conventional procedures of chip failure analysis are first briefly introduced.Then the application cases of FIB-SEM dual-beam system in defect and failure analysis of different types of chips are discussed,including three-dimensional failure analysis of silicon-based integrated circuits and hot spot cross-sectional analysis of power devices.In the case of three-dimensional failure analysis of silicon-based integrated circuits,a novel three-dimensional failure analysis method is introduced,which is more time-efficient and high-effective compared with the traditional FIB-SEM three-dimensional reconstruction method.In this method a planar transmission electron microscope(TEM) sample which covers the hot spot area is prepared in the X-Y direction,i.e.,the direction parallel to the chip surface.Subsequently,the planar-to-cross-sectional sample preparation method is adopted to convert the planar sample into a cross-sectional sample perpendicular to the chip surface.This three-dimensional analysis confirms that the abnormal point is indeed an abnormal overlap of tungsten(W).In another case of hot spot cross-sectional analysis of power devices,the silicon-based insulated gate bipolar transistors(Si-IGBT) is used as an example.The key steps and parameter selections for failure analysis of power devices using FIB-SEM are introduced in detail,including the selection of currents for ion beam cutting and protective layer deposition.Finally,the development prospect of FIB-SEM technology in this area is summarized.

As the chip structures continue to scale down,the surface defects generated during focused ion beam(FIB) sample preparation significantly affect the subsequent cross-section exposure and failure analysis results.However,the traditional manual evaluation of scanning electron microscope(SEM) images is increasingly unable to meet the efficiency and stability required by current sample preparation workflows.To address this issue,this study constructed an SEM image dataset covering 15 typical FIB-related defects and proposed a lightweight YOLOv5s-based deep learning detection method,which enabled the high-precision identification of defects under weak contrast,small target size,and complex texture backgrounds.Combined with batch detection and comma-separated value(CSV) based structured output modules,the system could automatically generate the defect categories and statistical summaries,which provided data-driven support for quality assessment and process monitoring.The experimental results demonstrated that the proposed method achieved good detection performance,robustness,and engineering applicability,which could effectively improve the automation and standardization of FIB sample quality inspection,thus offering a feasible approach for the intelligentization of microscopy analysis workflows.

The gold ore is one of the scarce strategic ores in China.The sample processing and preparation process and the representativeness of samples are the main factors affecting the gold measurement results.In this paper,the research reports on domestic gold ore sample preparation since 2000 were retrieved and summarized.The paper publication overview,the source of gold samples,the occurrence state and particle size of gold in ore samples,the number of gold ore samples and gold grade characteristics,the coarse,middle and fine crushing of ore samples,the sample reduction and the processing research on difficult-to-break samples such as coarse gold were systematically sorted in order to provide support and reference for the processing,preparation,application and in-depth research of gold ore samples.

Microbeam X-ray fluorescence spectrometry(μ-XRF) is a non-destructive technique for composition distribution characterization,and it can obtain the quantitative parameters of composition distribution at the original position of sample.Due to the high spatial resolution of μ-XRF and large size of test sample,the amount of raw data generated in test increases greatly.It is difficult for the traditional manual method to handle the processing of large conventional data and the calculation of parameters for precision testing in standard method.In this study,a DouBao artificial intelligence(AI)-assisted scheme for data automation processing and precision calculation was proposed.μ-XRF was employed for the original position quantitative statistical distribution analysis of superalloy.The quantitative statistics and precision calculation process of chromium(Cr) in superalloy were selected as an example to introduce the application of AI in raw data processing,consistency and outlier of test results,calculation of total mean and variance,establishment of precision value and average level relationship,and visual output,etc. Python codes were automatically generated using the DouBao AI tool,realizing the high-throughput processing of original position quantitative statistic results and rapid handling of precision testing data.The function relationships between repeatability limits,quasi-reproducibility limits and content were obtained.The time for raw data processing and precision calculation by μ-XRF was shortened.This study provided an innovative solution for high-throughput data processing in the field of material analysis, and it had broad application prospects.

Angola possesses favorable geological conditions with high-purity quartz deposits.However,there is no report on the analysis method for impurity elements and silicon dioxide purity in Angolan quartz ore to date.In this study,1 g of sample was calcined at 960 ℃ for 1 h,and the loss on ignition(LOI) was calculated by measuring the mass difference before and after calcination.Then 0.25 g of sample was completely digested with 5 mL of HF,0.5 mL of HNO₃,and 0.1 mL of HClO₄.After evaporation,the residue was redissolved with 5 mL of aqua regia.The contents of 16 impurity elements(potassium,calcium,sodium,magnesium,aluminum,iron,titanium,manganese,barium,zinc,nickel,copper,cobalt,chromium,lithium,and vanadium) were determined by inductively coupled plasma atomic emission spectrometry(ICP-AES).The linear correlation coefficients of calibration curves for all elements were not less than 0.999 8.The limit of detection for each element ranged from 0.02 to 2.78 μg/g.The content of impurity elements in Angolan quartz ore samples was determined according to the experimental method,and the relative standard deviations(RSD,n=6)was all less than 11%.The proposed method was applied for the determination of impurity elements in certified reference material quartz rock GBW07837,and the absolute value of relative errors(RE) of results was all below 5.8%.The LOI and impurity elements of 10 Angolan quartz ore samples were analyzed according to the experimental method.By converting the impurity contents into oxides and summing them with the LOI,the silicon dioxide purity(in mass fraction) was calculated through subtraction method.The results indicated that the silicon dioxide purity in samples all exceeded 99%.

In the field of superalloy research and development, the accurate characterization of the global composition distribution of materials is of vital importance for optimizing preparation processes, improving service performance, and realizing material quality monitoring and evaluation. In this paper, the spark mapping analysis for large sample was adopted to systematically investigate the evolution law of composition segregation for eight key elements, namely C, Si, Mn, Cr, Fe, Mo, Nb and Al, during the entire manufacturing process of GH4169 superalloy from ingot casting and bar preparation to turbine disk forging. By obtaining the two-dimensional composition distribution maps and original position statistical analysis data of the samples (including the average content, the content limits at 95% confidence level, the positive and negative segregation degrees, etc.), the changes in the uniformity of elemental distribution at each process stage were quantitatively revealed. The results showed that obvious elemental segregation existed in GH4169 ingots. The content limits of Fe at a 97.5 percentile and Nb at the 2.5 percentile exceeded the specification ranges of the alloy grade, and the segregation degrees of C, Si, Mn and Al were relatively high (approximately ±10%). After the treatment of homogenization treatment and hot rolling, the distribution of most elements on the cross-section of the bar tended to be uniform, and the elemental segregation degrees were significantly reduced (the segregation degrees of most elements decreased by more than 50%), with only Si showing central enrichment. The overall distribution of all elements in the turbine disk forging was uniform and could meet the standard requirements, but slight regional content differences were observed for Mn, Al in the rim area and Mo, Nb in the hub area due to differences in temperature and deformation. A comprehensive comparison indicated that homogenization and subsequent heat treatment significantly improved the elemental segregation, whereas the die forging process of the turbine disk forging had a relatively limited overall impact on the segregation. This study provided systematic data support for the composition control and process optimization of GH4169 superalloy.

The accurately determination of impurity elements content in high-purity cesium is crucial for guiding the production impurity removal,improving the material performance,and ensuring the stable operation of national defense,military industry,satellite navigation and other fields.Due to the high chemical reactivity of cesium(it can be rapidly oxidized upon contact with air and it is explosive when exposed to liquid solvents),its sampling and decomposition pose severe challenges.In this study,the sampling was conducted in an argon atmosphere within an oxygen-isolated glove box.Based on the characteristic of cesium that its melting point (28.5 ℃) is slightly higher than room temperature but lower than hand temperature,the solid samples were melted into liquid using hand warmth as a heat source.A pipette was used for quantitative liquid transfer,overcoming the difficulty of sampling high-viscosity solids.The wall-hung samples were placed in open air for over 10 h.Utilizing the properties of easy oxidation for cesium,susceptibility to hydration for cesium oxides and deliquescence for cesium hydroxides,a three-stage gas-solid reaction chain of "oxidation→hydration→deliquescence" was constructed with oxygen and water vapor as reactants to achieve gradual passivation and mild decomposition.Based on this,a method for determination of 9 impurity elements in high-purity cesium,including lithium,sodium,potassium,calcium,magnesium,iron,aluminum,lead and rubidium,by inductively coupled plasma atomic emission spectrometry(ICP-AES) was established.To address the coupled ionization and physical interference effects caused by cesium matrix,a strategy was adopted that primarily used the matrix matching method(for correcting lithium,sodium,potassium,calcium,magnesium,iron,aluminum,lead) and supplemented by the standard addition method(for correcting rubidium).The calibration curves had good linear relationships,and the correlation coefficients (r) were all not less than 0.999 6.The limit of detection ranged from 0.000 001% to 0.000 042%,and the limit of quantification ranged from 0.000 01% to 0.000 42%.The content of 9 impurity elements in actual and synthetic high-purity cesium samples were determined according to the experimental method.The relative standard deviations(RSD,n=5) of the determination results were between 0.86% and 9.5%,and the recoveries ranged from 94.9% to 103% (except rubidium).The content of rubidium in sample was determined by inductively coupled plasma mass spectrometry(ICP-MS) and compared with the experimental method.It was found that the measurement results of two methods were basically consistent.

The literature data in the field of inductively coupled plasma mass spectrometry (ICP-MS) was systemically collected and its technological development sequence was analyzed by visualization technology based on bibliometric method. The results indicated that the technological development of ICP-MS presented three different stages, there is a differentiation phenomenon in current industrialization stage, i.e., a decrease in the number of papers and an increase in patents. The research hotspot analysis showed that although the detection objectives have extended to the fields of food and biomedicine, the environmental heavy metal detection and geological dating still dominate. The technological development has a dual path of deepening methods and expanding applications. The highly cited papers and journals jointly confirm its core support role in geochronology, petrogenesis and deposit research. The study showed that the interdisciplinary collaboration is a key driving force for the sustainable technology innovation, and the technology fusion and application boundary expansion are required in the future to jointly drive the innovation. This study can provide reference for the technical layout and interdisciplinary intersection in the field of analytical chemistry.

To address the corrosion issue of platinum-gold crucible during the fusion sample preparation of ferroniobium, the effects of sample particle size, oxidant composition and dosage, and a stepwise pre-oxidation procedure were investigated. The results indicated that when the sample particle size was controlled at 0.074 mm, the fusion time could be reduced by 10 min compared to the sample particle size of 0.096 mm. A novel composite oxidant system of Li₂CO₃-LiOH-KNO₃ (mass ratio of 12∶20∶5) was employed. This system leveraged the alkaline fusion by LiOH and the assisted fusion from CO₂ release during Li₂CO₃ decomposition, while utilizing the mild oxidation characteristics of KNO₃ to replace the traditional Na₂O₂/BaO₂, significantly enhancing the reaction controllability. The interference from Br with the determination of 0.20% Al could be completely eliminated under the following experimental conditions: the fusion temperature of 1 100 ℃, 1.0 mL of LiBr solution, and a fusion time of 20 min. Based on these findings, a three-stage pre-oxidation method suitable for programmable fully automatic electric fusion furnaces was developed. In this method, the commercially available Li₂B₄O₇ crucible was used. The mass ratio of sample (0.25 g) to Li₂B₄O₇ and composite oxidant was controlled. After gradient pre-oxidation at 500-750 ℃, the sample was fused at 1 100 ℃. This approach not only completely avoided the corrosion risk of platinum-gold crucible, but also ensured the homogeneous formation of glass fusion beads. The calibration curves were established using standard reference materials, primary standard substances, and standard solutions of ferroniobium. The analysis method for simultaneous determination of eleven major and minor components (including Nb, Ta, Si, Al, P, Mn, Co, Cr, Ti, Fe and Sn) in ferroniobium by X-ray fluorescence spectrometry (XRF) was established. The linear correlation coefficients of calibration curves in this method were all not less than 0.999 5. One synthetic ferroniobium sample was determined according to the experimental method. The relative standard deviations (RSD, n=8) of determination results for Nb, Ta, Si, Al, P, Mn, Co, Cr, Ti, Fe and Sn were between 0.14% and 2.9%. One actual production sample of ferroniobium was selected for the comparison of this method and other methods as well as standard addition recovery tests. The results indicated that the determination values of Nb, Ta, Si, Al, P, Mn, Ti and Sn were consistent in two methods. The spiked recoveries of Fe, Cr and Co were between 101% and 110%.

During the analysis of associated elements in coal and gangue samples by conventional methods, the ashing treatment is required. However, the operation of this process is complicated, and some elements are easily volatilized and lost. The traditional acid dissolution method cannot effectively remove organic matter, which will lead to lower determination results. In addition, there is no standard method for the determination of Li. In this study, referring to the idea of acid used for decomposing samples in GB/T 16659-2024 and DZ/T 0279.3-2016, the strong oxidizability of HNO₃, H₂SO₄ and H₂O₂ was employed to oxidize the organic matter in samples into carbon dioxide for removal. The adsorption and wrapping of carbon-containing substances on the samples were eliminated and the process of decarbonization by high-temperature burning was avoided. The addition of HF significantly enhanced the decomposition effect of silicon-containing minerals. The method for determination of Li, Be, V, Co, Ni, Cu, Ga, Pb, Mo, Sb, Th and U contents in coal and gangue by inductively coupled plasma mass spectrometry (ICP-MS) was established. The linear correlation coefficients (r) of calibration curves were between 0.999 1 and 1.000. The limits of detection in this method were 0.012-0.58 μg/g, and the limits of quantification were 0.08-2.32 μg/g. Three certified reference materials for composition analysis of trace harmful elements in coal were determined according to the experimental method. The relative standard deviations (RSD,n=7) of the measurement results for Be, Co, Ni, Cu, Pb, Mo, Sb, Th and U were between 1.9% and 8.7%, and the absolute values of relative error (RE, n=7) were between 0.28% and 7.31%. For the elements of Li,V,Ga, which have no certified values, the relative standard deviations (RSD,n=7) of the measured results were between 1.8% and 4.5%, and recovery rates were between 98% and 103%. Additionally, the results were compared with those obtained by sealed-vessel digestion-ICP-MS and they were found to be in good agreement. A statistical comparison using a t-test indicated no significant difference between the results derived from the two sample preparation methods.

The high mineralization degree and complex matrix components of brine result in severe matrix interference in the quantitative analysis of multiple elements. In this study, a method of standard addition correction-inductively coupled plasma emission spectrometry (ICP-AES) was developed. The gradient addition of standard solution into sample solution was used to eliminate the matrix effect. Under the recommended working parameters of the instrument, K 769.897 nm, Mg 279.078 nm, B 249.678 nm, Li 670.790 nm, Rb 780.027 nm and Cs 894.347 nm were selected as the analytical lines for potassium, magnesium, boron, lithium, rubidium and cesium, respectively. The simultaneous determination of potassium, magnesium, boron, lithium, rubidium and cesium in brine with the same matrix was achieved. The linear correlation coefficients of calibration curves for tested elements were all greater than 0.999 5. The limits of quantification in this method were between 0.036 mg/L and 1.20 mg/L. The contents of potassium, magnesium, boron, lithium, rubidium and cesium in brine samples from different regions were determined according to the experimental method. The relative standard deviations (RSD, n=11) of determination results were not more than 2.0%, and the recoveries were between 97.4% and 104.5%.

To meet the higher requirements for material purity and impurity control driven by the rapid development of the rare earth market, a method for the determination of trace calcium in high-purity rare earth oxides was established using triple quadrupole inductively coupled plasma mass spectrometry (ICP-MS/MS). To address the isobaric interference encountered in the determination of calcium by ICP-MS, CH₄ was introduced as a reaction gas in MS/MS mode. This approach utilizes the charge exchange and chain reactions between CH₄ and ⁴⁰Ar⁺ to effectively suppress argon-based polyatomic ion interferences. By optimizing key parameters such as reaction gas flow rate and hexapole bias voltage, the background equivalent concentration (BEC) for ⁴⁰Ca was reduced to 3.77 μg/L under the conditions of a CH₄ flow rate of 3.0 mL/min and a hexapole bias voltage of -2 V. The method was applied to four high-purity rare earth oxide samples (purity not less than 99.99%). The relative standard deviation (RSD, n=6) ranged from 1.3% to 3.2%, and the spike recovery rates were between 94.6% and 105.8%. The results were in good agreement with those obtained from other laboratories, indicating that the proposed method is accurate, reliable, and suitable for the determination of trace calcium in high-purity rare earth oxides.

This article systematically reviews the research progress and application status of machine learning in the field of metallographic analysis.It emphatically analyzes the technological breakthroughs of machine learning in key links,including grain size rating,microstructure identification,non-metallic inclusion analysis,case depth detection and intergranular corrosion assessment.Meanwhile,the existing issues are pointed out,such as uneven data quality,insufficient algorithm applicability and poor model interpretability.Combined with the development of artificial intelligence(AI) technology,future development directions are prospected,including the construction of standardized databases,the development of multimodal learning frameworks and the improvement of model interpretability.This study aims to promote the evolution of metallographic analysis towards intelligence and standardization,and provide stronger technical support for material research and quality control.

Due to the high-resolution imaging ability and site-specific nanoscale processing capacity,the focused ion beam dual-beam scanning electron microscope(FIB-SEM dual-beam system) has become an important approach for material information analysis such as microscopic morphology and structure of fracture crack as well as the internal cracks and porosity distribution.The micron-to-nanometer scale site-specific processing at targeted regions such as crack tips by FIB-SEM dual-beam system was systematically introduced in this paper.The in-situ analysis technique was employed to expose and observe the crack propagation paths and tip microstructure.In addition,the three-dimensional morphological reconstruction inside the material was realized by combining with serial sectioning.The distribution of internal cracks and pores were deeply analyzed.On this basis,a comprehensive and standardized FIB-based specimen preparation method for site-specific analysis was established.This method delineated the operation specifications and parameter instructions of key steps such as protective layer deposition,coarse milling,fine polishing,specimen lift-out and transfer.The proposed method effectively solved the longstanding limitations of conventional techniques in fractography,namely imprecise localization,introduction of mechanical damage,and limited structural information,thereby providing method reference and technical support for crack analysis and lift-out from fracture.

Too high content of calcium in rare earth concentrate will affect the mass transfer efficiency in subsequent extraction,thus influencing the yield of rare earths.Therefore,the accurate determination of calcium in rare earth concentrate is of great significance.At present,the determination of calcium content in rare earth concentrate mainly adopts flame atomic absorption spectrometry(FAAS) or EDTA titration in national standard GB/T 18114.3-2010 Chemical analysis methods of rare earth concentrates-Part 3:Determination of calcium oxide content.But the operation requirements are strict in EDTA titration and the endpoint of titration is hardly controlled,and the determination range of calcium content(the determination range of calcium oxide was 0.50%-3.00%) is limited in FAAS method.In experiments,the sample was melted at high temperature with the mixed flux of anhydrous sodium carbonate and boric acid followed by dissolution with hydrochloric acid.The calibration curve was plotted by matrix matching method.Ca 393.366 nm was selected as the analytical line of calcium.The content of calcium in rare earth concentrate was determined by inductively coupled plasma atomic emission spectrometry(ICP-AES).The experiments showed that the mass concentration of calcium in range of 1.0-10.0 μg/mL had a good linear relationship with the emission spectral intensity,and the linear correlation coefficient(r) was 0.999 94.The limit of detection was 0.008 7%.It was found that the coexisting elements almost had no influence on the determination results.The content of calcium in 3 rare earth concentrate samples was determined according to the experimental method,and the relative standard deviation(RSD,n=7) was between 0.25% and 0.53%.The content of calcium in certified reference materials of Bayan Obo rare earth concentrate(GSB04-3309-2016,GSB04-3310-2016 and GSB04-3311-2016) were determined by the proposed method and EDTA titration in GB/T 18114.3-2010,respectively.The determination results of two methods were consistent and in good agreement with the standard values.

In the analysis of geochemical samples, traditional methods for determining silver (Ag), tin (Sn), and tungsten (W) often face challenges such as time-consuming sample treatment, complex operational procedures, and high requirements for operators’ technical proficiency and specialized knowledge. In this study, samples were digested using a high-pressure closed system with a hydrofluoric acid-nitric acid mixture, followed by the simultaneous determination of Ag, Sn, and W contents using inductively coupled plasma mass spectrometry (ICP-MS). Various digestion systems were investigated. Spectral and non-spectral interferences with the analytical isotopes of the target elements were systematically evaluated. The dilution technique and internal standard method were employed to effectively mitigate non-spectral interferences. Meanwhile, spectral interferences were successfully eliminated using the kinetic energy discrimination (KED) mode and online interference correction equations. The performance of the method was evaluated using certified reference materials (CRMs) of soil, stream sediment, and rock. The results demonstrated that the limits of detection for Ag, Sn, and W ranged from 0.016 to 0.24 μg/g. The relative errors (RE) between the measured and certified values were 0.43% to 8.33%, the logarithmic deviations (Δlg) were 0.003 to 0.035, and the relative standard deviations (RSD,n=6) were 2.0% to 7.6%. The method meets the determination requirements of the multi-objective regional geochemical survey specification (1∶250 000). It achieves simultaneous determination of multiple elements from a single digestion, significantly improving the work efficiency.

The composition design of certified reference material of cerium oxide is required for practical application based on cerium oxide product standard.In this study,the high-purity cerium oxide was used as the main matrix,then total components including 15 rare earth impurities and 23 non-rare earth impurities were added according to the properties of impurities.The methods of physical mixing,low-temperature drying and high-temperature burning were adopted.The dry-basis,pale yellow and powdery certified reference material candidates of cerium oxide for chemical composition analysis were prepared through grinding,sieving and mechanical mixing.The homogeneity and stability test results indicated the prepared certified reference material could meet the requirements.The content of 38 chemical components in certified reference material of cerium oxide for chemical composition analysis were characterized by various method with different principles in at least 9 laboratories with a high level of testing capability.The measured values were accurate and reliable,and the uncertainty evaluation was reasonable.The developed certified reference material could meet the traceability needs in actual production and scientific research.It gradually filled the gap of reference materials in the field of rare earths,and also provided a reference for the development of other types of reference materials.

Sulfur in tungsten tailings will cause environmental pollution and affect the product performance.Therefore,the accurate determination of sulfur content in tungsten tailings is essential to monitoring the environmental impact and support the development and utilization of tungsten tailings.In experiments,300 mg of copper sheet was used as flux agent to cover 150 mg of sample. The air was selected as the carrier gas.The sample was heated and burned at 1 250 ℃ for 4 min to convert the sulfur into sulfur dioxide.The potassium iodate standard solution was used to titrate the generated sulfurous acid with starch-potassium iodide as indicator.A method for the determination of sulfur in tungsten tailings by combustion-iodometry was established.The determination range of sulfur was 0.032%-26.58%.The content of sulfur in tungsten tailings sample was determined according to the experimental method.The relative standard deviations(RSD,n=11) of the results were between 0.13% and 2.2%,and the recoveries were between 93.4% and 101.4%.

Focused ion beam(FIB) technology,with its micron/nanoscale precision machining and targeted positioning capabilities,has become one of the core technologies for semiconductor packaged chip characterization and failure analysis.In this paper,the core principles of FIB technology(including the ion source generation,ion-material interactions and so on) were systematically elaborated,which focused on the application processes,key parameter control and technical advantages in packaged chip cross-sectional analysis(such as defect detection of key structures including solder balls,through-silicon via(TSV),and redistribution layer(RDL)) and transmission electron microscope(TEM) sample preparation.Through specific application scenarios,the irreplaceability of FIB technology in revealing the internal microstructures of packaged chips,verifying process quality,and locating root causes of failures were demonstrated, thereby providing technical references for process optimization and reliability improvement in the field of semiconductor packaging.The procedures for TEM conventional cross-section sample preparation,inverted cross-section sample preparation,and plan-view sample preparation were introduced in detail.Due to the ability to provide atomic-scale resolution in chip packaging analysis,TEM technology is the ultimate tool for observing microstructures,interfacial reactions,and crystal defects.However,to obtain the qualified TEM samples(typically requiring a thickness less than 100 nm) remains the primary challenge.FIB technology demonstrates its irreplaceable core value in such critical step.With its unparalleled site-specific and area-specific machining capabilities,FIB technology enables high-resolution TEM analysis of specific microstructures inside packaged chips.It serves not only as a bridge connecting macroscale failures with microscale mechanisms,but also as an indispensable core analytical tool to drive the development of advanced packaging technologies toward higher density and higher reliability.

Silver(Ag),as an important indicator in geochemical analysis,is of great significance for understanding the laws of element enrichment and changes,exploring the genesis of mineral deposits,and predicting mineral resources.During the determination of Ag in geological sample by inductively coupled plasma mass spectrometry(ICP-MS),the mass spectral interference of niobium(Nb) and zirconium(Zr) is encountered.On the basis of previous studies,the interference elimination mechanism and effect of the oxides and hydroxides of Nb,Zr with kinetic energy discrimination(KED) mode were further explored,and the determination method of Ag in geological samples by aqua regia digestion-KED-ICP-MS was established.The results showed that the polyatomic ion interference of Nb and Zr could be basically eliminated when the flow rate of collision gas(He) increased to 5.0 mL/min.Rh was selected as the internal standard,and its quantitative addition in sample digestion could effectively reduce the errors from operations including constant volume,thus ensuring the analysis quality and improving the analysis efficiency.After verification with national first-class certified reference materials,it was found that the analysis results of ¹⁰⁷Ag were better than those of ¹⁰⁹Ag.The limit of detection of ¹⁰⁷Ag and ¹⁰⁹Ag was 0.006 μg/g and 0.007 μg/g,respectively.The relative standard deviation(RSD,n=12) was 0.75%-6.98% and 0.82%-8.33%,respectively.These results could all meet the requirements of DZ/T 0130.5-2006.The method comparison results for samples exhibited good consistency.

Accurate determination of rare earth elements (REEs) in vanadium-titanium magnetite is essential for evaluating the resource potential of REEs in such ores. Samples were digested using an open-vessel digestion method with an HNO₃-HF-H₂SO₄ acid system. Instrumental conditions were optimized as follows: sampling depth of 3 mm, radio-frequency power of 1 350 W, and nebulizer gas flow rate of 1.05 L/min. The isotopes ⁸⁹Y, ¹³⁹La, ¹⁴⁰Ce, ¹⁴¹Pr, ¹⁴⁶Nd, ¹⁴⁷Sm, ¹⁵¹Eu, ¹⁵⁷Gd, ¹⁵⁹Tb, ¹⁶³Dy, ¹⁶⁵Ho, ¹⁶⁶Er, ¹⁶⁹Tm, ¹⁷²Yb, and ¹⁷⁵Lu were selected for determination. Interference equations were applied to correct for polyatomic ion interference on ¹⁵⁷Gd, ¹⁵⁹Tb, ¹⁶⁵Ho, ¹⁶⁶Er, and ¹⁶⁹Tm. The interference from high concentrations of Ti and Fe in the solution was also evaluated and compensated. A method for the determination of REEs in vanadium-titanium magnetite by open-vessel acid digestion-ICP-MS was established. Under the optimized conditions, the correlation coefficients of the calibration curves for all REEs were not less than 0.999 3. The limits of detection (LOD) ranged from 0.007 to 0.25 μg/g, and the limits of quantification (LOQ) were between 0.028 and 1.00 μg/g. The proposed method was applied to the determination of REEs in actual samples, yielding relative standard deviations (RSDs, n=6) of 0.85% to 3.6% for all elements. The similar REE distribution patterns observed for three vanadium-titanium magnetite samples from different mining areas in Chengde, Hebei Province, indicate they share a similar material source.

The morphology and distribution of free-cutting phases in free-cutting steel are important factors influencing their cutting properties. In order to develop new austenitic free-cutting stainless steels, the free-cutting phases in chalcogenide (303F, 303Cu, 304F), lead-based (303Pb), and selenium-based (304Se) austenitic free-cutting stainless steels were observed and analyzed by metallographic microscopy, scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), electron probe microanalyzer (EPMA), microhardness tester and inclusion three-dimensional corrosion etching technology. The existence forms of each free-cutting element in steel were investigated, and the differences of free-cutting phases and microhardness in each austenitic free-cutting stainless steel were compared. The results showed that among all kinds of austenitic free-cutting stainless steels, the 304 (Se addition) steel exhibited the largest average equivalent diameter and average area. Specifically, the average equivalent diameter was 3.66 μm, and the average area was 15.10 μm². The average aspect ratio of inclusions in 304 (Se addition) steel was 2.54, and most of the inclusions were ellipsoidal-shaped. The inclusions with aspect ratio of 1-3 accounted for 73%, which was significantly higher than that of 58% in 303Cu steel and 55% in 303Pb steel. The existence forms of free-cutting elements in the steel were different: S in the steel formed free-cutting phase MnS; Cu existed in solid solution in the steel matrix; Pb existed in steel in the form of agglomerate or it was distributed in two ends of MnS; Se formed Mn (Se,S) composite inclusions in the steel which could resist rolling deformation so that the morphology tended to be fusiform; some Mn (Se,S) composite inclusions wrapped the hard Al₂O₃ core to improve the cutting performance of steel. Among various types of austenitic free-cutting stainless steel, 304F steel had the highest average micro-hardness value, which was 309 HV_0.1. The average micro-hardness value of 304 (Se addition) steel was 229HV_0.1. Due to the effect of Cu to reduce the strain hardening, the average micro-hardness value of 303Cu steel was the lowest, i.e., 156HV_0.1.

In order to ensure the stability of results of nanoscale length measurement obtained with scanning electron microscope(SEM) and transmission electron microscope(TEM) in scientific research laboratories,a universal quality control sample for two types of electron microscopes was developed.The sample is not only suitable for the high magnification length calibration of SEM,but also suitable for the medium magnification length calibration of TEM.In this paper,the development process of quality control sample was introduced in detail,including the substrate selection and periodic structure fabrication.Wherein the structure fabrication was achieved with focused ion beam(FIB) instrument,which could fabricate the target sample with positive or negative structures in nanoscale.Subsequently,the target sample was loaded into SEM and TEM for imaging tests.To address the issue of insufficient contrast in TEM imaging,the structural parameters were continuously optimized.Finally,the uniformity and stability tests of the developed sample were conducted,and the results indicated that the quality control sample could meet the requirements of flexible usage in scientific research laboratories.

Vanadium-aluminum alloy is an important additive for the smelting of high-performance titanium alloys. The accurate determination of elemental contents is of great importance for the smelting process of titanium alloys. In this study, a method for the simultaneous determination of the contents of seven elements (including aluminum, silicon, iron, chromium, molybdenum, yttrium, and phosphorus) in vanadium-aluminum alloys by aqua regia digestion-inductively coupled plasma atomic emission spectrometry (ICP-AES) was established. Al 396.15 nm, Si 251.61 nm, Fe 259.94 nm, Cr 205.55 nm, Mo 202.03 nm, Y 371.03 nm and P 213.62 nm were selected as the spectral lines for aluminum, silicon, iron, chromium, molybdenum, yttrium, and phosphorus, respectively. The linearity of calibration curves of testing elements was good with correlation coefficients (r) all higher than 0.999. The limits of detection in this method were 0.000 3%-0.002 1% (mass fraction, the same below), and the limits of quantification were 0.001%-0.007%. The proposed method was applied for the determination of aluminum, silicon, iron, chromium, molybdenum, yttrium, and phosphorus in actual AlV55 vanadium-aluminum alloy sample. The relative standard deviation (RSD, n=7) of determination results were between 0.50% and 7.8%, and the spiked recoveries were between 96% and 105%.

With the miniaturization and high density of chip packaging,as well as the continuous emergence of various new packaging technologies,the detection requirements for chip packaging process are becoming increasingly higher.This paper mainly expounds the detection methods for chip packaging processes,including non-destructive analysis methods and destructive analysis methods.Among them,the focused ion beam(FIB) analysis method is introduced in detail,including its principle and related applications.In addition,the typical applications,advantages and disadvantages of several detection methods for chip packaging processes are compared.These methods are of great significance for the quality evaluation and defect detection of chip packaging processes.

A significant systematic bias exists between the aluminum chloride gravimetry and X-ray fluorescence spectrometry(XRF) in the determination of Al₂O₃ content in silicon-containing complex aluminum electrolyte.This study revealed the interference mechanism that impurity phases such as SiO₂,Fe₂O₃,and TiO₂ were hardly dissolved in AlCl₃ solution and underwent heterogeneous coprecipitation with Al₂O₃.The experimental results showed that the total mass fraction of impurity phases reached 31.14%,leading to systematically higher results by the gravimetry compared with XRF.Based on this interference mechanism,a combined XRF-gravimetry correction model was proposed.The aluminum content in the precipitate obtained after Al₂O₃ dissolution was accurately determined by XRF.After conversion according to the stoichiometric relation(the conversion factor between Al and Al₂O₃ was 1.889 5),the true Al₂O₃ content in sample could be obtained.Then the proposed method was validated by the analysis of silicon-containing complex aluminum electrolyte.This model effectively eliminated the systematic error caused by co-precipitation,and controlled the detection error of Al₂O₃ content within 0.1%.It overcame the interference from variable chemical forms of impurity phases,and significantly improved the accuracy and applicability of traditional gravimetry for Al₂O₃ analysis in high-silicon complex aluminum electrolyte system.

This paper proposed a geometric prior enhanced edge detection algorithm for the focused ion beam-scanning electron microscope(FIB-SEM) nanostructure measurement,aiming to address the insufficient detection accuracy of traditional edge detection methods for regular nanopatterns in scanning electron microscope images.The core innovation lied in the geometric prior enhanced pixel difference convolution network(PiDiNet-GP),which explicitly constructed the specialized convolution kernels that preferentially respond to specific geometric structures through direction-enhanced pixel difference convolution(PDC) and curvature-aware PDC.The direction-enhanced PDC module specifically targeted the structures with obvious directionality such as rectangles,constructing differential kernels in multiple fundamental directions to significantly improve the detection accuracy of straight edges.The curvature-aware PDC module mainly targeted the curved structures such as circles,constructing radial differential kernels at multiple radius scales to enhance the detection capability of circular contours,thus enabling the network to possess geometric structure perception capability from shallow layers.The algorithm adopted a two-stage pipeline architecture:the first stage used the PiDiNet-GP model for high-quality edge detection,while the second stage performed contour classification and parameter fitting based on traditional image processing and machine learning methods.The experimental results demonstrated that the proposed method achieved higher precision and robustness in detecting circular and rectangular nanostructures in FIB-SEM images,showing significant advantages particularly in the detection of regular geometric patterns.The accurate detection of regular patterns was crucial for defect detection and quality control in nanomanufacturing.It could effectively identify the shape anomalies,dimensional deviations,and geometric deformations in nanostructures,which provided key evidence for the early detection of process defects.The quantification of dimensional consistency,positional precision,and shape integrity of nanostructures through high-precision geometric parameter measurement provided reliable data support for objective evaluation of product quality,and offered powerful technical support for the quality control and process optimization in nanomanufacturing processes.

The addition of zinc into steel can enhance strength and corrosion resistance. However, excessive zinc addition will compromise material properties. Therefore, accurate determination of zinc content is crucial for producing high-quality steel alloys. In this study, a method for the determination of zinc in steel by inductively coupled plasma atomic emission spectrometry (ICP-AES) was established. Elements causing significant spectral interference with zinc were identified, and their influences were analyzed under varying matrix compositions and sample masses. A mathematical correction model was developed for interference correction of the target spectral lines. The method was validated using various certified reference materials (CRMs) and samples. The results demonstrated that copper caused significant interference with Zn 202.548 nm, while nickel interfered significantly with Zn 213.856 nm. The interference effects of copper and nickel on zinc were stable across different matrices. The interference contribution varied significantly with sample mass, and the determination error correlated with it. After correction, the determination accuracy for six samples was significantly improved using Zn 202.548 nm and Zn 213.856 nm as analytical lines. The Zn 206.200 nm line experienced the minimum interference from coexisting elements and could be selected as the optimal analytical line. The determination range of this method was 0.001 0%-0.10% (mass fraction, the same below), with a linear correlation coefficient of the calibration curve not less than 0.999 8. The limit of detection was 0.000 14%, and the limit of quantification was 0.000 48%. Zinc contents in CRMs/samples were determined using the experimental method, yielding relative standard deviations (RSD, n=11) between 2.2% and 5.7%. The measured results agreed with certified/reference values. Comparison tests showed good agreement between the results of this method and those obtained by inductively coupled plasma mass spectrometry (ICP-MS).

Asbestos,as a filler and associated mineral, is widely present in various fields such as building materials, rubber, pharmaceuticals,and cosmetics. In view of the long-term shortage of domestic certified reference material(CRM) of asbestos, a set of qualitative CRMs of asbestos(GSB 08-4340-2025) was developed in this study. The set included chrysotile,tremolite asbestos, actinolite asbestos,crocidolite,and anthophyllite asbestos.The tests verified that the homogeneity and stability of these asbestos CRMs could meet the requirements for CRMs.The property values and corresponding uncertainties were assigned through collaborative characterization by 8 qualified laboratories.This set of developed CRM can be applied to operator proficiency testing,validation of analytical methods,instrument calibration,and quality supervision,filling the domestic gap in CRMs asbestos.