The effects of rare earth Ce on the microstructure and mechanical properties of impure copper containing Pb were investigated using OM,SEM,EPMA,TEM and tensile testing.TEM and EDS analysis reveal that spherical CePb3 ...The effects of rare earth Ce on the microstructure and mechanical properties of impure copper containing Pb were investigated using OM,SEM,EPMA,TEM and tensile testing.TEM and EDS analysis reveal that spherical CePb3 particles form after Ce addition.CePb3 particles,with average size of^3.6μm,homogenously distribute in the Cu matrix.Due to small lattice misfit(~4.62%)with Cu matrix,CePb3 particles can act as effective nucleation sites beneficial to the grain refinement.Pb at grain boundaries seriously deteriorates the mechanical properties of Cu.The tensile strength and the elongation of Cu-0.1 Pb are decreased by 43.1%and 56.7%compared with those of pure copper,respectively.Ce can purify grain boundaries,cause the precipitation of CePb3 particles and refine grain sizes,which contribute to significant improvement of the mechanical properties of Cu.Compared with Cu-0.1Pb,the tensile strength(179 MPa)and the elongation(38.5%)of Cu-0.1Pb-0.3Ce are increased by 117.6%and 151.6%,respectively.展开更多
The effects of rare-earth element Y in refining impure copper were investigated in this paper. The composition, microstructures, and corrosion resistance properties of impure copper before and after refinement with Y ...The effects of rare-earth element Y in refining impure copper were investigated in this paper. The composition, microstructures, and corrosion resistance properties of impure copper before and after refinement with Y were investigated using direct-reading spectrometry, inductively coupled plasma atomic emission spectrometry, optical microscopy, scanning electron microscopy, and potentiodynamic polariza- tion measurements. The results show that the concentrations of impurities S, As, Sb, Bi, A1, Cd, and Se are remarkably decreased. Adding an appropriate amount of Y refines the microstructure and enhances the corrosion resistance properties of impure copper in HC1 solution via a purification effect. The formation enthalpies of compounds formed between Y and various impurity elements were calculated on the basis of Miedema＇s theory. The thermodynamic mechanisms of the refinement of impure copper by Y were also discussed.展开更多
The cleanliness of seed cotton plays a critical role in the pre-treatment of cotton textiles,and the removal of impurity during the harvesting process directly determines the quality and market value of cotton textile...The cleanliness of seed cotton plays a critical role in the pre-treatment of cotton textiles,and the removal of impurity during the harvesting process directly determines the quality and market value of cotton textiles.By fusing band combination optimization with deep learning,this study aims to achieve more efficient and accurate detection of film impurities in seed cotton on the production line.By applying hyperspectral imaging and a one-dimensional deep learning algorithm,we detect and classify impurities in seed cotton after harvest.The main categories detected include pure cotton,conveyor belt,film covering seed cotton,and film adhered to the conveyor belt.The proposed method achieves an impurity detection rate of 99.698%.To further ensure the feasibility and practical application potential of this strategy,we compare our results against existing mainstream methods.In addition,the model shows excellent recognition performance on pseudo-color images of real samples.With a processing time of 11.764μs per pixel from experimental data,it shows a much improved speed requirement while maintaining the accuracy of real production lines.This strategy provides an accurate and efficient method for removing impurities during cotton processing.展开更多
Fuel cell electric vehicles hold great promise for a diverse range of applications in reducing greenhouse gas emissions.In power fuel cell systems,hydrogen fuel serves as an energy vector.To ensure its suitability,it ...Fuel cell electric vehicles hold great promise for a diverse range of applications in reducing greenhouse gas emissions.In power fuel cell systems,hydrogen fuel serves as an energy vector.To ensure its suitability,it is necessary for the quality of hydrogen to adhere to the standards set by ISO 14687:2019,which sets maximum limits for 14 impurities in hydrogen,aiming to prevent any degradation of fuel cell performance.Ammonia(NH_(3))is a prominent pollutant in fuel cells,and accurate measurements of its concentration are crucial for hydrogen fuel cell quantity.In this study,a novel detection platform was developed for determining NH_(3)in real hydrogen samples.The online analysis platform integrates a self-developed online dilution module with a Fourier transform infrared spectrometer(ODM-FTIR).The ODM-FTIR can be operated fully automatically with remote operation.Under the optimum conditions,this method achieved a wide linear range between(50∼1000)nmol/mol.The limit of detection(LOD)was as low as 2 nmol/mol with a relative standard deviation(RSD,n=7)of 3.6%at a content of 50 nmol/mol.To ensure that the quality of the hydrogen products meets the requirement of proton exchange membrane fuel cell vehicles(PEMFCV),the developed ODM-FTIR system was applied to monitor the NH_(3)content in Chengdu Hydrogen Energy Co.,Ltd.for 21 days during Chengdu 2021 FISU World University Games.The proposed method retains several unique advantages,including a low detection limit,excellent repeatability,high accuracy,high speed,good stability,and calibration flexibility.It is an effective analytical method for accurately quantifying NH_(3)in hydrogen,especially suitable for online analysis.It also provides a new idea for the analysis of other impurity components in hydrogen.展开更多
More than 80 years of theories and experiments on water suggested to us, described in our first water-physics report, that pure water＇s ＂abnormally＂ high electrical conductivity is due to transport of positive and ...More than 80 years of theories and experiments on water suggested to us, described in our first water-physics report, that pure water＇s ＂abnormally＂ high electrical conductivity is due to transport of positive and negative quasi-protons, p＋ and p-, between the neutral proton traps V （H20） in the extended water, [（H20）N]＋, converting it respectively to positively and negatively charged proton traps, V＋ = （H30）1＋ and V- = （HO）1-. In this second report, we present the theoretical charge control capacitances of pure and impure water as a function of the DC electric potential applied to water.展开更多
The ＇abnormally＇ high electrical conductivity ofpure water was recently studied by us using our protonic bond, trap and energy band model, with five host particles： the positive and negative protons, and the amphot...The ＇abnormally＇ high electrical conductivity ofpure water was recently studied by us using our protonic bond, trap and energy band model, with five host particles： the positive and negative protons, and the amphoteric protonic trap in three charge states, positive, neutral and negative. Our second report described the electrical charge storage capacitance of pure and impure water. This third report presents the theory of particle density and electrical conductance of pure and impure water, including the impuritons, which consist of an impurity ion bonded to a proton, proton-hole or proton trap and which significantly affect impure waters＇ properties.展开更多
The effects of trace cerium(Ce)addition on the microstructural and textural evolution and the dynamic recrystallization(DRX)of the ultrahigh-purity copper(Cu)containing small amounts of sulfur(S)were investigated usin...The effects of trace cerium(Ce)addition on the microstructural and textural evolution and the dynamic recrystallization(DRX)of the ultrahigh-purity copper(Cu)containing small amounts of sulfur(S)were investigated using a Gleeble-1500 thermal simulation tester at 600℃.The results show that with increasing Ce content,the grain size of the Cu-S(S2)alloy gradually decreases and the grain boundary embrittlement induced by S impurities is considerably inhibited.The addition of Ce promotes the DRX process of the S2 alloy and changes its DRX mechanism from discontinuous to continuous and twinning-induced DRX mechanisms.The texture component and intensity of the S2 alloy vary with the increase of Ce content.The addition of 120×10^(-6) Ce(mass fraction)is favorable for the grain orientation randomization,which is attributed to the promoted DRX.展开更多
Magnesium(Mg),as one of the most abundant elements in earth's crust,is the lightest structural metal with extensive applications across various industries.However,the performance of Mg-based products is highly dep...Magnesium(Mg),as one of the most abundant elements in earth's crust,is the lightest structural metal with extensive applications across various industries.However,the performance of Mg-based products is highly dependent on their impurity levels,and the lack of high-purity Mg,along with efficient purification method,has posed significant challenge to its widespread industrial adoption.This study investigates the impurity behavior in Mg ingots during the vacuum gasification purification process.Through the analysis of binary phase diagrams,iron(Fe)-based foam material was selected for the filtration and purification of Mg vapor in a vacuum tube furnace.A novel approach combining vacuum gasification,vapor purification,and directional condensation is proposed.The effect of filter pore sizes and filtration temperatures on the efficacy of impurity removal was evaluated.Experimental results demonstrate that Fe-based foam with a pore size of 60 ppi,at a filtration temperature of 773 K,effectively removes impurities such as calcium(Ca),potassium(K),sodium(Na),manganese(Mn),silicon(Si),aluminum(Al),and various oxides,sulfides,and chlorides from the vapor phase.Consequently,high-purity Mg with a purity level exceeding 5N3 was obtained in the condensation zone.展开更多
The rapid growth of semiconductor,photovoltaic,and other emerging industries has led to a sharp increase in the demand for high-purity quartz in China,particularly 4N5-grade(99.995%pure SiO_(2)).However,heavy reliance...The rapid growth of semiconductor,photovoltaic,and other emerging industries has led to a sharp increase in the demand for high-purity quartz in China,particularly 4N5-grade(99.995%pure SiO_(2)).However,heavy reliance on imported high-purity quartz poses a significant risk to the security of key national strategic industries.To address this challenge,China is focusing on identifying domestic sources of high-purity quartz and developing efficient evaluation methods.This study investigates the inclusion content in three types of quartz:pegmatite,vein quartz,and white granite.A grading system based on the transmittance of quartz grains was established by analyz-ing the number of inclusions.Five quartz ore samples from different regions were purified,and the resulting concentrates were analyzed using inductively coupled plasma mass spectrometry(ICP-MS).The relationships among the inclusion content of raw quartz,impurity composition of purified quartz,and quality of sintered fused quartz products were examined.The findings demonstrate that quartz with fewer inclusions results in lower impurity levels after purification,higher SiO_(2)purity,and more translucent glass,as confirmed by firing tests.Herein,this study establishes a clear connection between quartz inclusions and the overall quality of high-purity quartz.The pro-posed approach enables the rapid assessment of quartz deposit quality by identifying inclusions,offering a practical and efficient method for locating high-quality quartz resources.展开更多
The purity of electronic-grade chemicals significantly impacts electronic components.Although crystallization has been used to purify cerium ammonium nitrate(CAN),the impurity removal mechanism underlying different cr...The purity of electronic-grade chemicals significantly impacts electronic components.Although crystallization has been used to purify cerium ammonium nitrate(CAN),the impurity removal mechanism underlying different crystallization parameters remains unclear.Traditional analytical methods of inductively coupled plasma mass spectrometry(ICP-MS)have problems in detecting trace Fe accurately,because of the high concentration of Ce and interference of polyatomic ions.Therefore,this study developed a new method integrating the standard addition and internal standard methods and explored the role of the kinetic energy discrimination mode.This new approach effectively overcomes Ce-related matrix interference and fills the gap in ultra-trace impurity detection.Furthermore,the study investigated the effects of cooling rate,seed mass loading and seed size on the removal of Fe impurity.The seed mass loading affects the average crystal size through regulating secondary nucleation and crystal growth.The removal of Fe in CAN is determined by surface adsorption and agglomeration.Under the condition of the cooling rate of 0.2 K·min^(-1),and addition of 0.5%(mass)600-680 μm seeds,the Fe content is the lowest,at only 0.24 mg·L^(-1),and the Fe removal rate reaches 92.28%.展开更多
The effects of the structure and concentration of impurities on the alkylation of naphthalene with 1-octene catalyzed by chloroaluminate ionic liquid(IL)were investigated.The presence of impurities containing oxygen a...The effects of the structure and concentration of impurities on the alkylation of naphthalene with 1-octene catalyzed by chloroaluminate ionic liquid(IL)were investigated.The presence of impurities containing oxygen and nitrogen led to a decrease in the catalytic performance of chloroaluminate IL.As the water concentration increased to 65 mg·g^(-1),the total selectivity of multi-octylnaphthalene gradually decreased to 42.33%,and the average friction coefficient of the multi-octylnaphthalene base oil gradually increased to 0.201.When the concentration of impurities increased to a critical value,the chloroaluminate IL began to deactivate,leading to a decrease in naphthalene conversion.The critical concentrations for ethanolamine,water,methanol,ether,and diisopentyl sulfide were 33 mg·g^(-1),65 mg·g^(-1),67mg·g^(-1),87 mg·g^(-1),and 123 mg·g^(-1),respectively.Impurities with higher basicity resulted in an earlier onset of chloroaluminate IL deactivation.The changes of Lewis and Brønsted acids in chloroaluminate IL under the influence of impurities were investigated using in situ IR and 27Al NMR spectroscopy.2,6-dimethylpyridine as an indicator could detect the changes of Brønsted acid in chloroaluminate IL better,but the changes of Lewis acid were not obvious because of the overlap between the characteristic peaks.2,6-dichloropyridine as an indicator could exclusively detect the changes of Lewis acid in chloroaluminate IL.With the increase inwater concentration,the Lewis acid in chloroaluminate IL was continuously consumed and converted into Brønsted acid,and the Lewis acid gradually decreased,while the Brønsted acid showed a change of increasing first and then decreasing.展开更多
During the EAST radiative divertor experiments,one of the key challenges was how to avoid the occurrence of disruptive events caused by excessive impurity seeding.To estimate the required impurity fraction for diverto...During the EAST radiative divertor experiments,one of the key challenges was how to avoid the occurrence of disruptive events caused by excessive impurity seeding.To estimate the required impurity fraction for divertor detachment,we introduce a reduced edge plasma radiation model.In the model,based on the momentum conservation along the magnetic field line,the upstream pressure is determined by the plasma density and temperature at the divertor target,and then the impurity radiation loss is obtained by the balance of the heat and particle fluxes.It is found that the required impurity fraction shows a non-monotonic variation with divertor electron temperature(T_(d))when 0.1 eV<T_(d)<10 eV.In the range of 0.1 eV<T_(d)<1 e V,the position near the valley of required impurity fraction corresponds to strong plasma recombination.Due to the dependence of the volumetric momentum loss effect on the T_(d)in the range of 1 eV<T_(d)<10 eV,the required impurity fraction peaks and then decreases as T_(d)is increased.Compared to neon,the usage of argon reduces the impurity fraction by about twice.In addition,for the various fitting parameters in the pressure-momentum loss model,it is shown that the tendency of required impurity fraction with T_(d)always increases first and then decreases in the range of 1 eV<T_(d)<10 eV,but the required impurity fraction decreases when the model that characterizes the strong loss in pressure momentum is used.展开更多
Magnesium(Mg)alloys are widely used lightweight structural materials for automobiles and help reduce carbon emissions.However,their use increases the production of Mg alloy scrap,which is recycled at a much lower rate...Magnesium(Mg)alloys are widely used lightweight structural materials for automobiles and help reduce carbon emissions.However,their use increases the production of Mg alloy scrap,which is recycled at a much lower rate than aluminum,and its greater complexity poses challenges to existing recycling processes.Although vacuum distillation can be used to recycle Mg alloy scrap,this requires optimizing and maximizing metal recirculation,but there has been no thermodynamic analysis of this process.In this study,the feasibility and controllability of separating inclusions and 23 metal impurities were evaluated,and their distribution and removal limits were quantified.Thermodynamic analyses and experimental results showed that inclusions and impurity metals of separation coefficient lgβ_(i)≤-5,including Cu,Fe,Co,and Ni below 0.001 ppm,could be removed from the matrix.All Zn entered the recycled Mg,while impurities with-1<lgβ_(i)<-5 such as Li,Ca,and Mn severely affected the purity of the recycled Mg during the later stage of distillation.Therefore,an optimization strategy for vacuum distillation recycling:lower temperatures and higher system pressures for Zn separation in the early stage,and the early termination of the recovery process in the later stage or a continuous supply of raw melt can also prevent contamination during recycling.The alloying elements Al and Zn in Mg alloy scrap can be further recovered and purified by vacuum distillation when economically feasible,to maximize the recycling of metal resources.展开更多
Sulfuric acid slag,a common byproduct with high iron content,poses challenges due to its high levels of harmful impurities and is often discarded as solid waste,leading to significant environmental and water pollution...Sulfuric acid slag,a common byproduct with high iron content,poses challenges due to its high levels of harmful impurities and is often discarded as solid waste,leading to significant environmental and water pollution.To address this issue and improve resource utilization,the preparation process of oxidized pellets from sulfuric acid slag was studied,exploring suitable pelletizing systems and thermal parameters.Additionally,the removal of harmful elements and the consolidation mechanism were established during the oxidation roasting process.The findings revealed that sulfuric acid slag along with specific processing conditions,such as using two high-pressure grinding rolls and adding 1.25 wt.%bentonite,resulted in the production of qualified green pellets with desirable physical properties.Through a thermal treatment process involving preheating and roasting,the desulfurization rate of the pellets reached 95.55%and the removal efficiency of arsenic achieved 27.11%.Hematite recrystallizes,shrinks,and forms a reticulated structure with Fe2O3 recrystallization as the backbone,resulting in higher consolidation strength.展开更多
In past decades,ABX_(3) halide perovskites have attracted great interest in solar cells due to excellent opto-electronic properties,such as high carrier mobility.However,instability and toxicity are obstacles on the c...In past decades,ABX_(3) halide perovskites have attracted great interest in solar cells due to excellent opto-electronic properties,such as high carrier mobility.However,instability and toxicity are obstacles on the commercial route for perovskites.Many studies have turned to exploring A_(2) BX_(6) and A_(3) B_(2) X_(9) for better stability.Unfortunately,the carrier mobilities of these two types are inferior to ABX_(3),lower by an order of magnitude.Furthermore,the mobility of ABX_(3) is distributed over a large range of 1.78-4500 cm^(2) V^(−1) s^(−1) in experiments,which contributes to another diversity of mobilities.In this paper,we aim at reveal-ing the physical origin of the above-mentioned diversities by theoretical studies on CsBX_(3),Cs_(2) BX_(6),and Cs_(3) B_(2) X_(9)(B=Sn,Pb,Sb,Bi,X=Br,Cl).The difference in group velocities is the major reason responsible for the variation in these types.The unique three-dimensional connected conductive network of CsBX_(3) determines its large group velocity.As for carrier scattering,ionized impurity scattering dominates at low carrier and high ionized impurity concentrations.Detailed analysis reveals that band degeneracy is strongly related to the impurity scattering rate,while dielectric constant is almost immune.Our study provides a better understanding of the relationship between electronic structures and mobilities for po-tential applications in photovoltaics.展开更多
Lithium metal batteries have been deemed one of the most promising candidates for new-generation batteries,used in mobile devices,electric vehicles,energy storage,etc.However,due to the volume change of active materia...Lithium metal batteries have been deemed one of the most promising candidates for new-generation batteries,used in mobile devices,electric vehicles,energy storage,etc.However,due to the volume change of active materials and external pressure,the electrode materials and interfaces between battery components have high stresses during the cycling process,resulting in large deformation of the lithium metal anode.Herein,we derive insights into the mechanical behaviors of polycrystalline lithium metal.Specifically,the mechanical properties of lithium metal containing Li_(7-x)La_(3)Zr_(2-x)Ta_(x)O_(12)(x=0.2-0.7)(LLZTO)solid-state electrolyte impurities are experimentally investigated.It is found that its strength is governed by impurity content and impurity particle size.In addition,we explore the Hall-Petch and inverse Hall-Petch effects of nanocrystalline lithium through atomic-scale simulations,revealing the plastic deformation mechanism in polycrystalline lithium metal.This fundamental study sheds light on the impurity-modulated mechanical properties and plastic deformation mechanism of polycrystalline lithium metal.展开更多
The Reference Listed drug(RLD)plays a critical role in the development and research of generic medicinal products,serving as the comparator product used in the marketing authorization application of new generic medici...The Reference Listed drug(RLD)plays a critical role in the development and research of generic medicinal products,serving as the comparator product used in the marketing authorization application of new generic medicinal product and re-evaluation of generic medicinal product.In China,RLDs are sourced from various origins,but their quality and market availability can be constrained by multiple factors,including emergent issues such as nitrosamine impurities.Five classes of medicinal products have been reported to be at risk for containing nitrosamine impurities:sartan-based medicines,metformin-containing products,ranitidine medicines,rifampicin medicines,and Champix.This paper explores the control strategies implemented by drug regulatory agencies in the United States and the European Union to manage nitrosamine impurities and assesses their impact on the market availability and quality of RLDs in China.The aim is to offer valuable insights for generic drug manufacturers and regulatory bodies both domestically and internationally.展开更多
With the rapid development of machine learning,the prediction of the performance of acoustic meta-materials using neural networks is replacing the traditional experiment-based testing methods.In this paper,a Gini impu...With the rapid development of machine learning,the prediction of the performance of acoustic meta-materials using neural networks is replacing the traditional experiment-based testing methods.In this paper,a Gini impurity-based artificial neural network structural optimizer(GIASO)is proposed to optimize the neural network structure,and the effects of five different initialization algorithms on the model performance and struc-ture optimization are investigated.Two physically guided models with additional resonant frequencies and sound transmission loss formula are achieved to further improve the prediction accuracy of the model.The results show that GIASO utilizing the gray wolf optimizer as the initialization method can significantly improve the prediction performance of the model.Simultaneously,the physical guidance model with additional resonant frequencies has the best performance and can better predict the edge data points.Eventually,the effect of each input parameter on the sound transmission loss is explained by combining sensitivity analysis and theoretical formulation.展开更多
Tearing modes may play an important role in the density limit disruption.The Magnetohydrodynamic(MHD)code CLT with impurity modules is used to study the tearing mode excited and driven by impurity radiation.The impuri...Tearing modes may play an important role in the density limit disruption.The Magnetohydrodynamic(MHD)code CLT with impurity modules is used to study the tearing mode excited and driven by impurity radiation.The impurity radiation can lead to plasma contraction and local enhancement of the current density.When the locally enhanced region of the current density approaches to the resonance surface,the tearing mode can be excited,even if the tearing mode is stable in the initial equilibrium.Through a scan of the initial atomic number(Z)and impurity concentrations,it is found that impurities with different Z values exhibit similar behaviors in the radiation-driven tearing mode.The impurity radiation can drive tearing mode growth through temperature cooling near the resonance surface,and there exists a linear relationship between the temperature perturbation caused by impurity radiation and the linear growth rate of the tearing mode.Additionally,the impurity can promote the growth of magnetic islands through the radiation cooling inside the magnetic island,and there exists a correlation between the initial parameters of impurity and the width of the saturated magnetic island.展开更多
High purity magnesium is not only an important basic raw material for semiconductor and electronics industries,but also a promising new generation of electrochemical energy storage materials and biomedical materials.I...High purity magnesium is not only an important basic raw material for semiconductor and electronics industries,but also a promising new generation of electrochemical energy storage materials and biomedical materials.Impurities in high-purity magnesium affect material properties,which has become the most critical factor restricting its application.However,accurate analysis of multiple ultra-trace impurity elements in high-purity magnesium is extremely challenging.In this paper,based on the synergistic effect of N_(2)O/H_(2) reaction gas mixture to eliminate spectral interference of inductively coupled plasma tandem mass spectrometry(ICP-MS/MS),a new strategy for the quantification of 45 ultra-trace impurity elements in high-purity magnesium was proposed.The results indicated that the limits of detection(LOD)were in the range of 0.02–18.5 ng L^(−1);the LODs of the challenging non-metallic elements Si and S were 18.5 and 12.2 ng L^(−1),respectively;and the LODs of all the other analytes were less than 10 ng L^(−1).Even under hot plasma conditions,LODs of alkali metal elements were also less than 5 ng L^(−1).The spike recovery of each analyte was 93.6%–107%,and the relative standard deviation(RSD)was 3.2%–6.9%,respectively.At a 95%level of confidence,no significant differences were found between the results obtained under the optimal conditions for the analyte with the developed method and the measurement results of SF-ICP-MS.The developed method indicated low LOD,high sample throughput,and complete interference elimination,demonstrating a new avenue for the rapid determination of ultra-trace elements in high-purity magnesium.展开更多
基金Projects(ZR2018MEE005,ZR2018MEE016)supported by the Natural Science Foundation of Shandong Province,ChinaProject(J18KA059)supported by the Higher Educational Science and Technology Program of Shandong Province,ChinaProject(HJ16B01)supported by the Doctoral Fund of Yantai University,China。
文摘The effects of rare earth Ce on the microstructure and mechanical properties of impure copper containing Pb were investigated using OM,SEM,EPMA,TEM and tensile testing.TEM and EDS analysis reveal that spherical CePb3 particles form after Ce addition.CePb3 particles,with average size of^3.6μm,homogenously distribute in the Cu matrix.Due to small lattice misfit(~4.62%)with Cu matrix,CePb3 particles can act as effective nucleation sites beneficial to the grain refinement.Pb at grain boundaries seriously deteriorates the mechanical properties of Cu.The tensile strength and the elongation of Cu-0.1 Pb are decreased by 43.1%and 56.7%compared with those of pure copper,respectively.Ce can purify grain boundaries,cause the precipitation of CePb3 particles and refine grain sizes,which contribute to significant improvement of the mechanical properties of Cu.Compared with Cu-0.1Pb,the tensile strength(179 MPa)and the elongation(38.5%)of Cu-0.1Pb-0.3Ce are increased by 117.6%and 151.6%,respectively.
基金financially supported by the Natural Science Foundation of Shandong Province, China (Grant No. ZR2014JL031)by the Undergraduate Scientific and Technological Innovation Project of the School of Environment and Materials Engineering, Yantai University
文摘The effects of rare-earth element Y in refining impure copper were investigated in this paper. The composition, microstructures, and corrosion resistance properties of impure copper before and after refinement with Y were investigated using direct-reading spectrometry, inductively coupled plasma atomic emission spectrometry, optical microscopy, scanning electron microscopy, and potentiodynamic polariza- tion measurements. The results show that the concentrations of impurities S, As, Sb, Bi, A1, Cd, and Se are remarkably decreased. Adding an appropriate amount of Y refines the microstructure and enhances the corrosion resistance properties of impure copper in HC1 solution via a purification effect. The formation enthalpies of compounds formed between Y and various impurity elements were calculated on the basis of Miedema＇s theory. The thermodynamic mechanisms of the refinement of impure copper by Y were also discussed.
基金supported in part by the Six Talent Peaks Project in Jiangsu Province under Grant 013040315in part by the China Textile Industry Federation Science and Technology Guidance Project under Grant 2017107+1 种基金in part by the National Natural Science Foundation of China under Grant 31570714in part by the China Scholarship Council under Grant 202108320290。
文摘The cleanliness of seed cotton plays a critical role in the pre-treatment of cotton textiles,and the removal of impurity during the harvesting process directly determines the quality and market value of cotton textiles.By fusing band combination optimization with deep learning,this study aims to achieve more efficient and accurate detection of film impurities in seed cotton on the production line.By applying hyperspectral imaging and a one-dimensional deep learning algorithm,we detect and classify impurities in seed cotton after harvest.The main categories detected include pure cotton,conveyor belt,film covering seed cotton,and film adhered to the conveyor belt.The proposed method achieves an impurity detection rate of 99.698%.To further ensure the feasibility and practical application potential of this strategy,we compare our results against existing mainstream methods.In addition,the model shows excellent recognition performance on pseudo-color images of real samples.With a processing time of 11.764μs per pixel from experimental data,it shows a much improved speed requirement while maintaining the accuracy of real production lines.This strategy provides an accurate and efficient method for removing impurities during cotton processing.
基金financial support by Sichuan Science and Technology,China(No.2023YFG0070).
文摘Fuel cell electric vehicles hold great promise for a diverse range of applications in reducing greenhouse gas emissions.In power fuel cell systems,hydrogen fuel serves as an energy vector.To ensure its suitability,it is necessary for the quality of hydrogen to adhere to the standards set by ISO 14687:2019,which sets maximum limits for 14 impurities in hydrogen,aiming to prevent any degradation of fuel cell performance.Ammonia(NH_(3))is a prominent pollutant in fuel cells,and accurate measurements of its concentration are crucial for hydrogen fuel cell quantity.In this study,a novel detection platform was developed for determining NH_(3)in real hydrogen samples.The online analysis platform integrates a self-developed online dilution module with a Fourier transform infrared spectrometer(ODM-FTIR).The ODM-FTIR can be operated fully automatically with remote operation.Under the optimum conditions,this method achieved a wide linear range between(50∼1000)nmol/mol.The limit of detection(LOD)was as low as 2 nmol/mol with a relative standard deviation(RSD,n=7)of 3.6%at a content of 50 nmol/mol.To ensure that the quality of the hydrogen products meets the requirement of proton exchange membrane fuel cell vehicles(PEMFCV),the developed ODM-FTIR system was applied to monitor the NH_(3)content in Chengdu Hydrogen Energy Co.,Ltd.for 21 days during Chengdu 2021 FISU World University Games.The proposed method retains several unique advantages,including a low detection limit,excellent repeatability,high accuracy,high speed,good stability,and calibration flexibility.It is an effective analytical method for accurately quantifying NH_(3)in hydrogen,especially suitable for online analysis.It also provides a new idea for the analysis of other impurity components in hydrogen.
基金supported by the Xiamen Universitysupported by the CTSAH Associates which was founded by the late Linda Su-nan Chang Sa
文摘More than 80 years of theories and experiments on water suggested to us, described in our first water-physics report, that pure water＇s ＂abnormally＂ high electrical conductivity is due to transport of positive and negative quasi-protons, p＋ and p-, between the neutral proton traps V （H20） in the extended water, [（H20）N]＋, converting it respectively to positively and negatively charged proton traps, V＋ = （H30）1＋ and V- = （HO）1-. In this second report, we present the theoretical charge control capacitances of pure and impure water as a function of the DC electric potential applied to water.
文摘The ＇abnormally＇ high electrical conductivity ofpure water was recently studied by us using our protonic bond, trap and energy band model, with five host particles： the positive and negative protons, and the amphoteric protonic trap in three charge states, positive, neutral and negative. Our second report described the electrical charge storage capacitance of pure and impure water. This third report presents the theory of particle density and electrical conductance of pure and impure water, including the impuritons, which consist of an impurity ion bonded to a proton, proton-hole or proton trap and which significantly affect impure waters＇ properties.
基金financially supported by the National Natural Science Foundation of China(Nos.52071133,U21A2051)the Henan Province Science and Technology Tackling Key Problems Project,China(No.222102230001)+2 种基金the Zhongyuan Scholar Workstation Funded Project,China(No.224400510025)the Henan Key Research and Development Project,China(No.221111230600)Luoyang Major Science and Technology Innovation Special Project,China(No.2201017A)。
文摘The effects of trace cerium(Ce)addition on the microstructural and textural evolution and the dynamic recrystallization(DRX)of the ultrahigh-purity copper(Cu)containing small amounts of sulfur(S)were investigated using a Gleeble-1500 thermal simulation tester at 600℃.The results show that with increasing Ce content,the grain size of the Cu-S(S2)alloy gradually decreases and the grain boundary embrittlement induced by S impurities is considerably inhibited.The addition of Ce promotes the DRX process of the S2 alloy and changes its DRX mechanism from discontinuous to continuous and twinning-induced DRX mechanisms.The texture component and intensity of the S2 alloy vary with the increase of Ce content.The addition of 120×10^(-6) Ce(mass fraction)is favorable for the grain orientation randomization,which is attributed to the promoted DRX.
基金supported by the Yunnan Province Nonferrous Metal Vacuum Metallurgy Top Team[No.202305AS350012]。
文摘Magnesium(Mg),as one of the most abundant elements in earth's crust,is the lightest structural metal with extensive applications across various industries.However,the performance of Mg-based products is highly dependent on their impurity levels,and the lack of high-purity Mg,along with efficient purification method,has posed significant challenge to its widespread industrial adoption.This study investigates the impurity behavior in Mg ingots during the vacuum gasification purification process.Through the analysis of binary phase diagrams,iron(Fe)-based foam material was selected for the filtration and purification of Mg vapor in a vacuum tube furnace.A novel approach combining vacuum gasification,vapor purification,and directional condensation is proposed.The effect of filter pore sizes and filtration temperatures on the efficacy of impurity removal was evaluated.Experimental results demonstrate that Fe-based foam with a pore size of 60 ppi,at a filtration temperature of 773 K,effectively removes impurities such as calcium(Ca),potassium(K),sodium(Na),manganese(Mn),silicon(Si),aluminum(Al),and various oxides,sulfides,and chlorides from the vapor phase.Consequently,high-purity Mg with a purity level exceeding 5N3 was obtained in the condensation zone.
基金financially supported by the Consulting Research Project of the Chinese Academy of Engineering,China(Nos.2024-XBZD-10 and 2024-XZ-20).
文摘The rapid growth of semiconductor,photovoltaic,and other emerging industries has led to a sharp increase in the demand for high-purity quartz in China,particularly 4N5-grade(99.995%pure SiO_(2)).However,heavy reliance on imported high-purity quartz poses a significant risk to the security of key national strategic industries.To address this challenge,China is focusing on identifying domestic sources of high-purity quartz and developing efficient evaluation methods.This study investigates the inclusion content in three types of quartz:pegmatite,vein quartz,and white granite.A grading system based on the transmittance of quartz grains was established by analyz-ing the number of inclusions.Five quartz ore samples from different regions were purified,and the resulting concentrates were analyzed using inductively coupled plasma mass spectrometry(ICP-MS).The relationships among the inclusion content of raw quartz,impurity composition of purified quartz,and quality of sintered fused quartz products were examined.The findings demonstrate that quartz with fewer inclusions results in lower impurity levels after purification,higher SiO_(2)purity,and more translucent glass,as confirmed by firing tests.Herein,this study establishes a clear connection between quartz inclusions and the overall quality of high-purity quartz.The pro-posed approach enables the rapid assessment of quartz deposit quality by identifying inclusions,offering a practical and efficient method for locating high-quality quartz resources.
基金the National Natural Science Foundation of China(22308358,22208346,22421003)IPE Project for Frontier Basic Research(QYJC-2023-05)+1 种基金National Key Research and Development Program(2022YFC3902701)CAS Project for Young Scientists in Basic Research(YSBR-038).
文摘The purity of electronic-grade chemicals significantly impacts electronic components.Although crystallization has been used to purify cerium ammonium nitrate(CAN),the impurity removal mechanism underlying different crystallization parameters remains unclear.Traditional analytical methods of inductively coupled plasma mass spectrometry(ICP-MS)have problems in detecting trace Fe accurately,because of the high concentration of Ce and interference of polyatomic ions.Therefore,this study developed a new method integrating the standard addition and internal standard methods and explored the role of the kinetic energy discrimination mode.This new approach effectively overcomes Ce-related matrix interference and fills the gap in ultra-trace impurity detection.Furthermore,the study investigated the effects of cooling rate,seed mass loading and seed size on the removal of Fe impurity.The seed mass loading affects the average crystal size through regulating secondary nucleation and crystal growth.The removal of Fe in CAN is determined by surface adsorption and agglomeration.Under the condition of the cooling rate of 0.2 K·min^(-1),and addition of 0.5%(mass)600-680 μm seeds,the Fe content is the lowest,at only 0.24 mg·L^(-1),and the Fe removal rate reaches 92.28%.
基金financial support of the Scientific Research Funds of Huaqiao University (605-50Y17073)
文摘The effects of the structure and concentration of impurities on the alkylation of naphthalene with 1-octene catalyzed by chloroaluminate ionic liquid(IL)were investigated.The presence of impurities containing oxygen and nitrogen led to a decrease in the catalytic performance of chloroaluminate IL.As the water concentration increased to 65 mg·g^(-1),the total selectivity of multi-octylnaphthalene gradually decreased to 42.33%,and the average friction coefficient of the multi-octylnaphthalene base oil gradually increased to 0.201.When the concentration of impurities increased to a critical value,the chloroaluminate IL began to deactivate,leading to a decrease in naphthalene conversion.The critical concentrations for ethanolamine,water,methanol,ether,and diisopentyl sulfide were 33 mg·g^(-1),65 mg·g^(-1),67mg·g^(-1),87 mg·g^(-1),and 123 mg·g^(-1),respectively.Impurities with higher basicity resulted in an earlier onset of chloroaluminate IL deactivation.The changes of Lewis and Brønsted acids in chloroaluminate IL under the influence of impurities were investigated using in situ IR and 27Al NMR spectroscopy.2,6-dimethylpyridine as an indicator could detect the changes of Brønsted acid in chloroaluminate IL better,but the changes of Lewis acid were not obvious because of the overlap between the characteristic peaks.2,6-dichloropyridine as an indicator could exclusively detect the changes of Lewis acid in chloroaluminate IL.With the increase inwater concentration,the Lewis acid in chloroaluminate IL was continuously consumed and converted into Brønsted acid,and the Lewis acid gradually decreased,while the Brønsted acid showed a change of increasing first and then decreasing.
基金supported by National Natural Science Foundation of China(No.12375227)Innovation in Fusion Engineering Technology of Institute(No.E35QT1080C)。
文摘During the EAST radiative divertor experiments,one of the key challenges was how to avoid the occurrence of disruptive events caused by excessive impurity seeding.To estimate the required impurity fraction for divertor detachment,we introduce a reduced edge plasma radiation model.In the model,based on the momentum conservation along the magnetic field line,the upstream pressure is determined by the plasma density and temperature at the divertor target,and then the impurity radiation loss is obtained by the balance of the heat and particle fluxes.It is found that the required impurity fraction shows a non-monotonic variation with divertor electron temperature(T_(d))when 0.1 eV<T_(d)<10 eV.In the range of 0.1 eV<T_(d)<1 e V,the position near the valley of required impurity fraction corresponds to strong plasma recombination.Due to the dependence of the volumetric momentum loss effect on the T_(d)in the range of 1 eV<T_(d)<10 eV,the required impurity fraction peaks and then decreases as T_(d)is increased.Compared to neon,the usage of argon reduces the impurity fraction by about twice.In addition,for the various fitting parameters in the pressure-momentum loss model,it is shown that the tendency of required impurity fraction with T_(d)always increases first and then decreases in the range of 1 eV<T_(d)<10 eV,but the required impurity fraction decreases when the model that characterizes the strong loss in pressure momentum is used.
文摘Magnesium(Mg)alloys are widely used lightweight structural materials for automobiles and help reduce carbon emissions.However,their use increases the production of Mg alloy scrap,which is recycled at a much lower rate than aluminum,and its greater complexity poses challenges to existing recycling processes.Although vacuum distillation can be used to recycle Mg alloy scrap,this requires optimizing and maximizing metal recirculation,but there has been no thermodynamic analysis of this process.In this study,the feasibility and controllability of separating inclusions and 23 metal impurities were evaluated,and their distribution and removal limits were quantified.Thermodynamic analyses and experimental results showed that inclusions and impurity metals of separation coefficient lgβ_(i)≤-5,including Cu,Fe,Co,and Ni below 0.001 ppm,could be removed from the matrix.All Zn entered the recycled Mg,while impurities with-1<lgβ_(i)<-5 such as Li,Ca,and Mn severely affected the purity of the recycled Mg during the later stage of distillation.Therefore,an optimization strategy for vacuum distillation recycling:lower temperatures and higher system pressures for Zn separation in the early stage,and the early termination of the recovery process in the later stage or a continuous supply of raw melt can also prevent contamination during recycling.The alloying elements Al and Zn in Mg alloy scrap can be further recovered and purified by vacuum distillation when economically feasible,to maximize the recycling of metal resources.
基金financially supported by the Fundamental Research Funds for the Central Universities of Central South University(2023ZZTS0506).
文摘Sulfuric acid slag,a common byproduct with high iron content,poses challenges due to its high levels of harmful impurities and is often discarded as solid waste,leading to significant environmental and water pollution.To address this issue and improve resource utilization,the preparation process of oxidized pellets from sulfuric acid slag was studied,exploring suitable pelletizing systems and thermal parameters.Additionally,the removal of harmful elements and the consolidation mechanism were established during the oxidation roasting process.The findings revealed that sulfuric acid slag along with specific processing conditions,such as using two high-pressure grinding rolls and adding 1.25 wt.%bentonite,resulted in the production of qualified green pellets with desirable physical properties.Through a thermal treatment process involving preheating and roasting,the desulfurization rate of the pellets reached 95.55%and the removal efficiency of arsenic achieved 27.11%.Hematite recrystallizes,shrinks,and forms a reticulated structure with Fe2O3 recrystallization as the backbone,resulting in higher consolidation strength.
基金supported by the National Key Research and Development Program of China(No.2021YFB3502200)the National Natural Science Foundation of China(Nos.52172216 and 92163212)+1 种基金support from the Shanghai Engi-neering Research Center for Integrated Circuits and Advanced Dis-play Materialssupported by Shanghai Techni-cal Service Center of Science and Engineering Computing,Shanghai University and Hefei Advanced Computing Center.
文摘In past decades,ABX_(3) halide perovskites have attracted great interest in solar cells due to excellent opto-electronic properties,such as high carrier mobility.However,instability and toxicity are obstacles on the commercial route for perovskites.Many studies have turned to exploring A_(2) BX_(6) and A_(3) B_(2) X_(9) for better stability.Unfortunately,the carrier mobilities of these two types are inferior to ABX_(3),lower by an order of magnitude.Furthermore,the mobility of ABX_(3) is distributed over a large range of 1.78-4500 cm^(2) V^(−1) s^(−1) in experiments,which contributes to another diversity of mobilities.In this paper,we aim at reveal-ing the physical origin of the above-mentioned diversities by theoretical studies on CsBX_(3),Cs_(2) BX_(6),and Cs_(3) B_(2) X_(9)(B=Sn,Pb,Sb,Bi,X=Br,Cl).The difference in group velocities is the major reason responsible for the variation in these types.The unique three-dimensional connected conductive network of CsBX_(3) determines its large group velocity.As for carrier scattering,ionized impurity scattering dominates at low carrier and high ionized impurity concentrations.Detailed analysis reveals that band degeneracy is strongly related to the impurity scattering rate,while dielectric constant is almost immune.Our study provides a better understanding of the relationship between electronic structures and mobilities for po-tential applications in photovoltaics.
基金supported by the National Key R&D Program of China(Grant No.2023YFB2408000)Guangdong Basic and Applied Basic Research Foundation(Grant No.2022A1515010950)the National Natural Science Foundation of China(Grant No.12002192).
文摘Lithium metal batteries have been deemed one of the most promising candidates for new-generation batteries,used in mobile devices,electric vehicles,energy storage,etc.However,due to the volume change of active materials and external pressure,the electrode materials and interfaces between battery components have high stresses during the cycling process,resulting in large deformation of the lithium metal anode.Herein,we derive insights into the mechanical behaviors of polycrystalline lithium metal.Specifically,the mechanical properties of lithium metal containing Li_(7-x)La_(3)Zr_(2-x)Ta_(x)O_(12)(x=0.2-0.7)(LLZTO)solid-state electrolyte impurities are experimentally investigated.It is found that its strength is governed by impurity content and impurity particle size.In addition,we explore the Hall-Petch and inverse Hall-Petch effects of nanocrystalline lithium through atomic-scale simulations,revealing the plastic deformation mechanism in polycrystalline lithium metal.This fundamental study sheds light on the impurity-modulated mechanical properties and plastic deformation mechanism of polycrystalline lithium metal.
基金Subject construction funding project of Institute for Chemical Drug Control(Grant No.2024HYZX42)in National Institutes for Food and Drug Control,Beijing,China。
文摘The Reference Listed drug(RLD)plays a critical role in the development and research of generic medicinal products,serving as the comparator product used in the marketing authorization application of new generic medicinal product and re-evaluation of generic medicinal product.In China,RLDs are sourced from various origins,but their quality and market availability can be constrained by multiple factors,including emergent issues such as nitrosamine impurities.Five classes of medicinal products have been reported to be at risk for containing nitrosamine impurities:sartan-based medicines,metformin-containing products,ranitidine medicines,rifampicin medicines,and Champix.This paper explores the control strategies implemented by drug regulatory agencies in the United States and the European Union to manage nitrosamine impurities and assesses their impact on the market availability and quality of RLDs in China.The aim is to offer valuable insights for generic drug manufacturers and regulatory bodies both domestically and internationally.
基金the Science and Technology Commission of Shanghai Municipality(No.19030501100)the Technical Service Platform for Vibration and Noise Testing and Control of New Energy Vehicles(No.18DZ2295900)。
文摘With the rapid development of machine learning,the prediction of the performance of acoustic meta-materials using neural networks is replacing the traditional experiment-based testing methods.In this paper,a Gini impurity-based artificial neural network structural optimizer(GIASO)is proposed to optimize the neural network structure,and the effects of five different initialization algorithms on the model performance and struc-ture optimization are investigated.Two physically guided models with additional resonant frequencies and sound transmission loss formula are achieved to further improve the prediction accuracy of the model.The results show that GIASO utilizing the gray wolf optimizer as the initialization method can significantly improve the prediction performance of the model.Simultaneously,the physical guidance model with additional resonant frequencies has the best performance and can better predict the edge data points.Eventually,the effect of each input parameter on the sound transmission loss is explained by combining sensitivity analysis and theoretical formulation.
基金supported by the National Magnetic Confinement Fusion Energy R&D Program of China (Nos.2019YFE03030004 and 2022YFE03100001)。
文摘Tearing modes may play an important role in the density limit disruption.The Magnetohydrodynamic(MHD)code CLT with impurity modules is used to study the tearing mode excited and driven by impurity radiation.The impurity radiation can lead to plasma contraction and local enhancement of the current density.When the locally enhanced region of the current density approaches to the resonance surface,the tearing mode can be excited,even if the tearing mode is stable in the initial equilibrium.Through a scan of the initial atomic number(Z)and impurity concentrations,it is found that impurities with different Z values exhibit similar behaviors in the radiation-driven tearing mode.The impurity radiation can drive tearing mode growth through temperature cooling near the resonance surface,and there exists a linear relationship between the temperature perturbation caused by impurity radiation and the linear growth rate of the tearing mode.Additionally,the impurity can promote the growth of magnetic islands through the radiation cooling inside the magnetic island,and there exists a correlation between the initial parameters of impurity and the width of the saturated magnetic island.
基金supported by the Natural Science Foundation of China(52171103 and 21975289).
文摘High purity magnesium is not only an important basic raw material for semiconductor and electronics industries,but also a promising new generation of electrochemical energy storage materials and biomedical materials.Impurities in high-purity magnesium affect material properties,which has become the most critical factor restricting its application.However,accurate analysis of multiple ultra-trace impurity elements in high-purity magnesium is extremely challenging.In this paper,based on the synergistic effect of N_(2)O/H_(2) reaction gas mixture to eliminate spectral interference of inductively coupled plasma tandem mass spectrometry(ICP-MS/MS),a new strategy for the quantification of 45 ultra-trace impurity elements in high-purity magnesium was proposed.The results indicated that the limits of detection(LOD)were in the range of 0.02–18.5 ng L^(−1);the LODs of the challenging non-metallic elements Si and S were 18.5 and 12.2 ng L^(−1),respectively;and the LODs of all the other analytes were less than 10 ng L^(−1).Even under hot plasma conditions,LODs of alkali metal elements were also less than 5 ng L^(−1).The spike recovery of each analyte was 93.6%–107%,and the relative standard deviation(RSD)was 3.2%–6.9%,respectively.At a 95%level of confidence,no significant differences were found between the results obtained under the optimal conditions for the analyte with the developed method and the measurement results of SF-ICP-MS.The developed method indicated low LOD,high sample throughput,and complete interference elimination,demonstrating a new avenue for the rapid determination of ultra-trace elements in high-purity magnesium.
