In order to mitigate the harm of alumina,calcium aluminate,and magnesium aluminum spinel inclusions on the fatigue performance of bearing steel,the effect of Ce-Mg composite treatment on the cleanliness of silicon-kil...In order to mitigate the harm of alumina,calcium aluminate,and magnesium aluminum spinel inclusions on the fatigue performance of bearing steel,the effect of Ce-Mg composite treatment on the cleanliness of silicon-killed GCr15 bearing steel and the evolution of Ce-Mg-Mn-O-S composite inclusions during heat treatment of the steels at 1523 K were investigated in this present work.The results indicate that the cleanliness of S2 with 0.0045 wt%Ce and 0.0016 wt%Mg is better than that in S1 with0.0020 wt%Ce and 0.0011 wt%Mg,which is attributed to the more effective removal of Ce-Mg-Mn-O-S composite inclusions,with help of good aggregation capacity of Ce-containing inclusions and small volume density of Mg-containing inclusions,due to the increase of rare earth and magnesium content.The aspect ratio and area fraction of the Ce-Mg-Mn-O-S composite inclusions in as-cast steel decrease significantly with isothermal treatment at 1523 K for 150 min,due to the effect of(ⅰ)Ostwald aging mechanism of inclusions and(ⅱ)sulfide solid solution during isothermal treatment.With the increase of isothermal treatment time from 150 to 550 min,the aspect ratio and area fraction of the inclusions in SO(untreated steel)and S1 decrease slightly,because spheroidization and solid solution of inclusions reach their basic equilibrium at 1523 K.However,the aspect ratio and area fraction of the Ce-Mg-Mn-O-S composite inclusions in S2 actually increase,and the inclusions evolve into three-phase(two-phase)inclusions,which is attributed to(ⅲ)transformation of phase compositions in inclusions and interfacial reaction between inclusions and steel matrix during isothermal heating.Therefore,the control of inclusions in silicon-killed bearing steel with Ce and Mg composite treatment should be combined with specific heat treatment processes and appropriate rare earth and magnesium contents,to minimize the damage of inclusions on the fatigue performance of bearing steel products.展开更多
The characteristics of nonmetallic inclusions formed during steel production have a significant influence on steel performance.In this paper,studies on inclusions using confocal scanning laser microscopy(CSLM)are revi...The characteristics of nonmetallic inclusions formed during steel production have a significant influence on steel performance.In this paper,studies on inclusions using confocal scanning laser microscopy(CSLM)are reviewed and summarized,particularly the col-lision of various inclusions,dissolution of inclusions in liquid slag,and reactions between inclusions and steel.Solid inclusions exhibited a high collision tendency,whereas pure liquid inclusions exhibited minimal collisions because of the small attraction force induced by their<90°contact angle with molten steel.The collision of complex inclusions in molten steel was not included in the scope of this study and should be evaluated in future studies.Higher CaO/Al_(2)O_(3)and CaO/SiO_(2)ratios in liquid slag promoted the dissolution of Al_(2)O_(3)-based in-clusions.The formation of solid phases in the slag should be prevented to improve dissolution of inclusions.To accurately simulate the dissolution of inclusions in liquid slag,in-situ observation of the dissolution of inclusions at the steel-slag interface is necessary.Using a combination of CSLM and scanning electron microscopy-energy dispersive spectroscopy,the composition and morphological evolution of the inclusions during their modification by the dissolved elements in steel were observed and analyzed.Although the in-situ observa-tion of MnS and TiN precipitations has been widely studied,the in-situ observation of the evolution of oxide inclusions in steel during so-lidification and heating processes has rarely been reported.The effects of temperature,heating and cooling rates,and inclusion character-istics on the formation of acicular ferrites(AFs)have been widely studied.At a cooling rate of 3-5 K/s,the order of AF growth rate in-duced by different inclusions,as reported in literature,is Ti-O<Ti-Ca-Zr-Al-O<Mg-O<Ti-Zr-Al-O<Mn-Ti-Al-O<Ti-Al-O<Zr-Ti-Al-O.Further comprehensive experiments are required to investigate the quantitative relationship between the formation of AFs and inclusions.展开更多
Rare earth La was introduced into 40Cr steel in industrial experiments to achieve the purpose of modifying inclusions.The impact of La on the inclusion modification was studied,and its influence on the solidification ...Rare earth La was introduced into 40Cr steel in industrial experiments to achieve the purpose of modifying inclusions.The impact of La on the inclusion modification was studied,and its influence on the solidification structure was further investigated.With adding 0.0023%La,the Al_(2)O_(3)·CaO·CaS inclusions were modified to the LaAlO_(3)·CaO·CaS inclusions.Additionally,the morphology tended to be more spherical,and the proportion of small-sized inclusions increased significantly from 77.8%to 93.5%.The large-sized inclusions were almost completely eliminated.Based on experimental results,a dynamical model elucidating the process of inclusion modification by La was developed.Furthermore,the ratio of equiaxed zone of the solidification structure increased from 22.9%to 31.0%,and the average primary dendrite arm spacing decreased significantly from 288.4 to 226.2μm.Two-dimensional lattice mismatch analysis results determined that LaAlO_(3)can serve as an effective heterogeneous nucleation core,leading to solidification structure refinement.The beneficial transformation of inclusions and refinement of solidification structure are conducive to the cold heading process of 40Cr steel.展开更多
With the increasing demand for high-performance metallic materials,the improvement of fatigue strength(FS)has become a crucial issue.This study focuses on the AISI 52100 steel,a material with leading fatigue performan...With the increasing demand for high-performance metallic materials,the improvement of fatigue strength(FS)has become a crucial issue.This study focuses on the AISI 52100 steel,a material with leading fatigue performance and low-cost raw material,aiming to further improve its FS.It is found that the fatigue damage mechanism of 52100 steels with different tensile strengths has undergone significant changes,and the inclusions,mainly nitride and oxide,are key factors limiting the further improvement of FS.Therefore,the size reduction and modification of inclusions were attempted through the rare earth addition and strict control of harmful elements.Combining targeted microstructure adjustment,the FS of the 52100 steel has been further enhanced to~1.6 GPa,exceeding that of other metallic materials(performed in uniaxial tension with a stress ratio of R=0.1),and thus establishing it as a standout for its exceptional performance-to-cost ratio.By clarifying the influences of different types of inclusions on fatigue performance and establishing the correlation between micro-hardness(or strength)and FS,an optimization strategy for FS improvement of the 52100 steel was proposed.The FS has been improved by approximately 187 MPa at most by implementing this strategy.These achievements provide feasible technical approaches and theoretical foundations for the anti-fatigue design of metallic materials.展开更多
Non-metallic inclusions in steel are a significant challenge,affecting material properties and leading to issues such as stress concentration,cracking,and accelerated corrosion.Current methods for removing inclusions,...Non-metallic inclusions in steel are a significant challenge,affecting material properties and leading to issues such as stress concentration,cracking,and accelerated corrosion.Current methods for removing inclusions,including bubble,electromagnetic stirring,filtration separation,fluid flow,and sedimentation,often struggle with the removal of fine inclusions.Apart from these known methods,pulsed electric current(PEC),as an emerging technology,has demonstrated immense potential and environmental advantages.PEC offers adjustable current parameters and simple equipment,making it an attractive alternative to traditional methods.Its green energy-saving features and excellent results in regulating inclusion morphology and migration,as well as inhibiting submerged entry nozzle(SEN)clogging,make it a promising technology.In comparison to continuous current technology,PEC has shown significant advantages in regulating inclusions,not only improving purification efficiency but also demonstrating outstanding performance in flow stability and energy consumption.The ability of PEC to efficiently reduce inclusion numbers enhances the purity and quality of molten steel,improving its mechanical properties.Currently,the theoretical basis for controlling the movement of inclusions by current is mainly composed of three major theories:the double electric layer theory,electromagnetic force reverse separation theory,and electric free energy drive theory.These theories together form an important framework for researchers to understand and optimize the behavior of impurity movement controlled by electric current.Looking ahead,PEC is expected to pave the way for new solutions in directional regulation of inclusion migration,efficient inclusion removal,SEN clogging prevention,and the purification of molten steel.展开更多
The dissolution behavior of complex inclusions in refining slag was studied using confocal laser scanning microscope.Based on the dissolution curve of complex inclusions,the main rate-limiting link of CaO-SiO_(2)-Al_(...The dissolution behavior of complex inclusions in refining slag was studied using confocal laser scanning microscope.Based on the dissolution curve of complex inclusions,the main rate-limiting link of CaO-SiO_(2)-Al_(2)O_(3)complex inclusions was the diffusion in the molten slag.The dissolution rate of CaO-SiO_(2)-Al_(2)O_(3)complex inclusions was affected by the composition and size of inclusion.The functional relationship between the dimensionless inclusion capacity(Zh)and the dimensionless dissolution rate(Ry)of CaO-SiO_(2)-Al_(2)O_(3)complex inclusions was calculated as Ry=2.10×10^(-6)Zh^(0.160),while it was Ry=2.10×10^(-6)Zh^(0.0087)for Al_(2)O_(3)-CaO complex inclusions.On this basis,the complete dissolution time and rate of the complex inclusions were calculated by using the function relation between the Zh and Ry numbers.展开更多
The transformation mechanism of the inclusions and microstructure in 316L stainless steel after post-isothermal heat treatment(IHT)was revealed,along with the pitting behavior of the inclusions in a chloride environme...The transformation mechanism of the inclusions and microstructure in 316L stainless steel after post-isothermal heat treatment(IHT)was revealed,along with the pitting behavior of the inclusions in a chloride environment before and after the transformation.The effect of the inclusion transformation on the pitting corrosion behavior of 316L stainless steel and its intrinsic mechanism was also revealed.Results revealed a gradual transformation of MnO-SiO_(2)inclusions into MnO-Cr_(2)O_(3) within the temperature range of 1373 to 1573 K.MnO-Cr_(2)O_(3)inclusions exhibited minimal dissolution in chloride ion corrosion environments,while MnO-SiO_(2)oxides demonstrated higher electrochemical activity and were more prone to dissolve and form pits.Meanwhile,IHT significantly reduced the dislocation density of stainless steel,rendering it more stable in corrosive environments.X-ray photoelectron spectroscopy peak distributions of the passive films demonstrated that IHT increased the proportion of Cr and Fe oxides and hydroxides in the passive film which improved the stability and corrosion resistance of the steel.展开更多
The purpose of this article is to introduce a new method with a self-adaptive stepsize for approximating a common solution of monotone inclusion problems and variational inequality problems in reflexive Banach spaces....The purpose of this article is to introduce a new method with a self-adaptive stepsize for approximating a common solution of monotone inclusion problems and variational inequality problems in reflexive Banach spaces.The strong convergence result for our method is established under some standard assumptions without any requirement of the knowledge of the Lipschitz constant of the mapping.Several numerical experiments are provided to verify the advantages and efficiency of proposed algorithms.展开更多
Aim To prepare and characterize the QURC-HP-β-CD inclusion complexes and investigate the thermodynamic parameters of the process. Methods QURC-HP-β-CD inclusion complexes were prepared by the grinding method. The eq...Aim To prepare and characterize the QURC-HP-β-CD inclusion complexes and investigate the thermodynamic parameters of the process. Methods QURC-HP-β-CD inclusion complexes were prepared by the grinding method. The equilibrium inclusion constants and thermodynamic parameters were determinated by phase solubility analysis. Dissolution tests were performed to study the dissolution rate of inclusion complexes. The formation of inclusion complexes was confirmed by differential scanning calorimetry （ DSC）, infrared spectroscopy （IR） , powder X-ray diffractometry （PXRD） and scanning electron microscopy （SEM）. Results The aqueous solubility of quercetin was greatly increased （ about 37 folds） by inclusion technique, and the initial dissolution rate was markedly improved （10 folds） in the first 5 min. The results of DSC and SEM photographs showed that quercetin crystal disappeared in inclusion complexes, which indicated the formation of new phase. FT-IR spectra showed that the carbonyl quercetin crystal grinding method. absorption band of quercetin was shifted. PXRD showed that the diffraction peak of disappeared. Conclusion QURC-HP-β-CD inclusion complexes are produced by the The solubility of quercetin is improved by the inclusion technique.展开更多
This study employs bibliometric and visualisation techniques to analyse global trends in financial inclusion and the innovative tools that promote it.By examining a multidatabase compilation of 4202 documents sourced ...This study employs bibliometric and visualisation techniques to analyse global trends in financial inclusion and the innovative tools that promote it.By examining a multidatabase compilation of 4202 documents sourced from Scopus and Web of Science,the significant role of book chapters in disseminating research in this field is highlighted.Our analysis reveals rapid growth in publications,particularly from China and India,and identifies key influential works and authors.Additionally,it is observed that financial inclusion is approached from a multidisciplinary perspective.The findings of this study also indicate a shift in research focus from traditional concepts such as“housing”and“banking”to“digitalisation”and“sustainability.”Key research trends in financial innovative tools include regulatory frameworks,mobile money,and financial education.The issues discussed in this article seek to contribute to the ongoing dialogue on developing intellectual frameworks withing the financial inclusion literature.They offer valuable insights for policymakers,industry practitioners,and researchers in the fields of financial innovation and inclusion.展开更多
To mitigate the harmful effects of Al_(2)O_(3) inclusions in steel,it is necessary to conduct comprehensive research on the mechanisms and kinetic laws of Al_(2)O_(3) inclusion modification by Ce.Combined with laborat...To mitigate the harmful effects of Al_(2)O_(3) inclusions in steel,it is necessary to conduct comprehensive research on the mechanisms and kinetic laws of Al_(2)O_(3) inclusion modification by Ce.Combined with laboratory experiments,first-principles calculations,and molecular dynamics simulations,the kinetic model of Ce modification for Al_(2)O_(3) inclusions was established.Based on first-principles calculations,differential charge analysis,density of states analysis,and adsorption energy analysis were performed on the transformation process from Al_(2)O_(3) to CeAlO_(3) at the atomic scale,and the microscopic transformation mechanism of inclusions at the atomic scale was obtained.Molecular dynamics simulations and the solution of mean square displacement function show that the diffusion coefficient for Ce atoms was 2.169×10^(−4) cm^(2)/s,which agreed well with experimental results.In this model,the rate-determining step is the diffusion of Ce atoms across Ce–Al–O inclusions.The relationship between the conversion rate,refining time,and initial radius was discussed.A refining time of 60 s can completely transform Al_(2)O_(3) inclusions less than 2.56μm into CeAlO_(3) inclusions,while refining time of 1200 s is sufficient to modify inclusions size below 11.47μm.展开更多
Trimethoprim(TMP),as a broad-spectrum bacteriostatic antibiotic,is widely used in clinical anti-infection therapy and livestock breeding.However,its low water solubility leads to insufficient bioavailability,which has...Trimethoprim(TMP),as a broad-spectrum bacteriostatic antibiotic,is widely used in clinical anti-infection therapy and livestock breeding.However,its low water solubility leads to insufficient bioavailability,which has become a key problem restricting its development.Cyclodextrins and their derivatives,with their unique cyclic structures,can form inclusion complexes with TMP to improve its properties.This article reviews the pharmacological characteristics of TMP,the types and properties of common cyclodextrins,focusing on introducing various preparation methods of trimethoprim cyclodextrin inclusion complexes and multiple characterization methods for identifying the inclusion complexes,aiming to provide a reference for further research and development of trimethoprim cyclodextrin inclusion complexes.展开更多
Model calculations and laboratory experiments were conducted to investigate the influence of surface tension of the molten steel on the agglomeration trend of Al_(2)O_(3) inclusions.The agglomeration trends of inclusi...Model calculations and laboratory experiments were conducted to investigate the influence of surface tension of the molten steel on the agglomeration trend of Al_(2)O_(3) inclusions.The agglomeration trends of inclusions were compared using the calculated attractiveness.When the S content in the steel increased from 2.7×10^(-6) to 789×10^(-6),the surface tension of the molten steel decreased from 1.91 to 1.39 N/m,while the attractive force between inclusions increased from 5×10^(-18) to 5×10^(-16) N,and the critical collision distance of Al_(2)O_(3) inclusions gradually increased from 30 to 70μm.A model of the relationship between the capillary force of inclusions and S content in steel was established.It was found that the capillary force calculated by the model showed the same trend as the attractive force obtained from experiments,and an increase in the S content promoted the attraction between inclusions.展开更多
The addition of Ce significantly enhances cleanliness of steel and modifies precipitation phases.However,there are differences in the effects of different alloy systems,especially its role in M54 steel is insufficient...The addition of Ce significantly enhances cleanliness of steel and modifies precipitation phases.However,there are differences in the effects of different alloy systems,especially its role in M54 steel is insufficiently understood.This study investigates the evolution of inclusions and precipitation phases in M54 steel ingots with varying Ce additions.Results indicate that the addition of Ce reduces the content of impurity elements(O and S)and transforms Mg and Al inclusions into Ce inclusions,which is due to the stronger affinity between Ce and impurity elements such as O and S.Ce inclusions serve as nucleation sites for dendrites,reducing secondary dendrite arm spacing.In addition,these inclusions and Cecontaining precipitated phase also act as nucleation sites for carbide precipitates,effectively refining their distribution by reducing growth spaces and increasing nucleation density.Notably,as Ce content increases from 0 to 0.01 wt%,the precipitation phase content decreases significantly but rises slightly with further increases in Ce content due to the formation of additional Ce-containing precipitates.By quantitatively comparing the dendrite arm spacing,cleanliness,content and size of precipitated phase,it is determined that the optimum addition amount of Ce for M54 steel is about 0.01 wt%.展开更多
Formation and evolution of inclusions in low-aluminum Ti-containing 51CrV4 spring steel under BOF(basic oxygen furnace)–LF(ladle furnace)–CC(continuous casting)process were investigated by industrial trials and ther...Formation and evolution of inclusions in low-aluminum Ti-containing 51CrV4 spring steel under BOF(basic oxygen furnace)–LF(ladle furnace)–CC(continuous casting)process were investigated by industrial trials and thermodynamic calculations.During LF refining,deoxidation products including Al_(2)O_(3),Al_(2)O_(3)–Ti_(3)O_(5)–SiO_(2)–MnO and Al_(2)O_(3)–SiO_(2)–MnO are modified as MgO–Al_(2)O_(3),CaO–Al_(2)O_(3)–SiO_(2),CaO–Al_(2)O_(3)–MgO and CaO–Al_(2)O_(3)–SiO_(2)–MgO.When reoxidation during ladle casting is quite serious,inclusions such as Al_(2)O_(3),Al_(2)O_(3)–Ti_(3)O_(5)–SiO_(2)–MnO,and Al_(2)O_(3)–SiO_(2)–MnO may regenerate.A handful of Ti carried by alloy into liquid steel has less influence on inclusions during LF refining;Ti-containing inclusions mainly transiently exist as an intermediate product of deoxidation process and then are gradually modified by[Al],[Ca]or[Mg].Thermodynamic calculation and experimental results reveal that tundish flux is the main source of reoxidation in ladle casting process.Further calculations taking into account of the influence of inclusions before casting indicate that reoxidation within a certain of degree leads to the generation of a large amount of high melting point inclusions including CaO·2MgO·8Al_(2)O_(3),CaO·MgO·7Al_(2)O_(3),MgO·Al_(2)O_(3),CaO·6Al_(2)O_(3)and Al_(2)O_(3)in molten steel,which is basically consistent with experimental results,and more high melting point inclusions will generate as reoxidation becomes severer.On this basis,severer reoxidation will deplete[Si],[Mn],and[Ti]in steel melt,resulting in the formation of liquid inclusions composed of Al_(2)O_(3)–Ti_(3)O_(5)–SiO_(2)–MnO(–CaO).These results are of guiding significance for controlling inclusions in Al-killed Ti-containing spring steel.展开更多
The micro-area characterization experiments like scanning Kelvin probe force microscope(SKPFM)and Kernel average misorientation have the defects of complex sample preparation and occasional errors in test results,whic...The micro-area characterization experiments like scanning Kelvin probe force microscope(SKPFM)and Kernel average misorientation have the defects of complex sample preparation and occasional errors in test results,which makes it impossible to accurately and quickly analyze the pitting behavior induced by inclusions in some cases,prompting attempts to turn to simulation calculation research.The method of calculating band structure and work function can be used to replace current-sensing atomic force microscopy and SKPFM to detect the potential and conductivity of the sample.The band structure results show that Al_(2)O_(3) inclusion is an insulator and non-conductive,and it will not form galvanic corrosion with the matrix.Al_(2)O_(3) inclusion does not dissolve because its work function is higher than that of the matrix.Moreover,the stress concentration of the matrix around the inclusion can be characterized by first-principles calculation coupled with finite element simulation.The results show that the stress concentration degree of the matrix around Al_(2)O_(3) inclusion is serious,and the galvanic corrosion is formed between the high and the low stress concentration areas,which can be used to explain the reason of the pitting induced by Al_(2)O_(3) inclusions.展开更多
This study presents an all-inclusive analysis of the literature on the augmentation of financial inclusion through fintech.Ninety-six papers were selected from the 2951 articles in the Web of Science,Scopus,and EBSCO ...This study presents an all-inclusive analysis of the literature on the augmentation of financial inclusion through fintech.Ninety-six papers were selected from the 2951 articles in the Web of Science,Scopus,and EBSCO databases.This study uses bibliometric and content analysis techniques to illuminate the underexplored aspects of fintech’s impact on financial inclusion.Unlike previous studies,this study consolidates a significant amount of the literature on financial inclusion by systematically contextualizing theories and viewpoints from the fintech sector.The key findings include the identification of three main research clusters:(1)the advent of novel services,(2)the transformation of the market landscape,and(3)the roles of stakeholders in the fintech ecosystem.The analysis reveals gaps in the existing research,such as the need for more studies on the tangible impact of fintech on financial inclusion and regulation.This study concludes by highlighting potential directions for future research and emphasizing the importance of policymakers paying greater attention to fintech’s implications for financial inclusion.展开更多
Understanding the motion behaviors of non-metallic inclusions in the liquid metal is important for clean steel production.High-temperature confocal laser scanning microscopy is applied to investigate the effect of dif...Understanding the motion behaviors of non-metallic inclusions in the liquid metal is important for clean steel production.High-temperature confocal laser scanning microscopy is applied to investigate the effect of different Ti and Al contents on the agglomeration behavior of non-metallic inclusions in low carbon steels.Furthermore,the agglomeration mechanism of inclusions was investigated through quantitative analysis of in-situ observation experiments and a modified Kralchevsky-Paunov model.The obtained results indicate that Al_(2)O_(3)is the main type inclusion in the low-alloys steels with both Al and Ti addition.This type of inclusion is more likely to absorb surrounding small-size inclusion particles,leading to a further growth for the cluster formation and contributing to a serious engineering problem,nozzle clogging.Besides,TiO_(x)is the main type inclusion in the molten steel with only Ti addition,and this type of inclusion is less likely to agglomerate and the individual inclusion particles show a‘free’motion with the fluid of molten steel.The difference between these two types of inclusions is due to the difference in attractive force and action distance at the meniscus created by the inclusion/steel/Ar multiple interfaces and influenced by the physical parameters,e.g.,contact angle and interface energy between inclusion and steel,and surface tension of the melt.展开更多
The formation of large-sized inclusions cluster severely impacts the continuous casting process and product quality of titanium-containing steel.Thermodynamic calculations were initially conducted to predict the forma...The formation of large-sized inclusions cluster severely impacts the continuous casting process and product quality of titanium-containing steel.Thermodynamic calculations were initially conducted to predict the formation of various complex oxide inclusions,namely Al_(2)O_(3),TiO_(x)and Al-Ti-O.Based on that,laboratory-scale experiments were designed to prepare samples with a single type of inclusions.Then,the scanning electron microscope-energy dispersive spectrometer was used for quantitative characterization.Subsequently,the agglomeration behavior of inclusions in Fe-Al-Ti-O melt was observed in situ by high-temperature confocal laser scanning microscopy.Furthermore,a quantitative analysis of the agglomeration characteristics of the various inclusions was conducted based on the attractive forces in accordance with Newton's second law and the capillary forces as described by the Kralchevsky-Paunov model.The results indicate that the size of Al_(2)O_(3)inclusions is larger than that of TiO_(x)and Al-Ti-O,but the number density of TiO_(x)is the highest.Based on the in situ observation and the theoretical calculation,Al_(2)O_(3),TiO_(x)and Al-Ti-O inclusions can all agglomerate into large-sized clusters without segregation,but the agglomeration tendency of Al_(2)O_(3)and TiO_(x)is stronger than that of Al-Ti-O.The attractive force between Al_(2)O_(3)inclusions’pair is the largest,ranging from 2.26×10^(-15)to 6.12×10^(-14)N,followed by TiO_(x)(7.13×10^(-16)to 3.56×10^(-14)N)and Al-Ti-O(1.16×10^(-17)to 3.77×10^(-16)N).展开更多
The development of cost-effective and high-efficiency catalysts for sustainable hydrogen production through electrocatalytic hydrogen evolution reaction(HER) is crucial yet remains challenging. In this work, we synthe...The development of cost-effective and high-efficiency catalysts for sustainable hydrogen production through electrocatalytic hydrogen evolution reaction(HER) is crucial yet remains challenging. In this work, we synthesized two types of bimetallic Pt Ni nanoparticles embedded in N-doped porous carbons derived from Ni-ABDC(5-aminoisophthalate) using both in-situ and ex-situ Pt inclusion methods. The in-situ Pt doping notably disrupted the effective growth of Ni-ABDC nanostrips owing to strong interactions between Pt and ABDC, resulting in an amorphous nanostructure. The optimized PtinNi-NC exhibited remarkable HER performance with a low overpotential of 29 mV at 10 mA/cm^(2), a Tafel slope of 47.4 mV/dec, and a current retention of 91.2% after 200 h in 1.0 mol/L KOH solution, surpassing the performance of Ni-NC, PtexNi-NC, and Pt/C. This research demonstrates the rational design and preparation of transition metal-based coordination polymer-derived metal-carbon nanomaterials with low Pt loading,emphasizing their considerable potential in energy conversion and storage technologies.展开更多
基金Project supported by the National Natural Science Foundation of China(52174323,52231003)。
文摘In order to mitigate the harm of alumina,calcium aluminate,and magnesium aluminum spinel inclusions on the fatigue performance of bearing steel,the effect of Ce-Mg composite treatment on the cleanliness of silicon-killed GCr15 bearing steel and the evolution of Ce-Mg-Mn-O-S composite inclusions during heat treatment of the steels at 1523 K were investigated in this present work.The results indicate that the cleanliness of S2 with 0.0045 wt%Ce and 0.0016 wt%Mg is better than that in S1 with0.0020 wt%Ce and 0.0011 wt%Mg,which is attributed to the more effective removal of Ce-Mg-Mn-O-S composite inclusions,with help of good aggregation capacity of Ce-containing inclusions and small volume density of Mg-containing inclusions,due to the increase of rare earth and magnesium content.The aspect ratio and area fraction of the Ce-Mg-Mn-O-S composite inclusions in as-cast steel decrease significantly with isothermal treatment at 1523 K for 150 min,due to the effect of(ⅰ)Ostwald aging mechanism of inclusions and(ⅱ)sulfide solid solution during isothermal treatment.With the increase of isothermal treatment time from 150 to 550 min,the aspect ratio and area fraction of the inclusions in SO(untreated steel)and S1 decrease slightly,because spheroidization and solid solution of inclusions reach their basic equilibrium at 1523 K.However,the aspect ratio and area fraction of the Ce-Mg-Mn-O-S composite inclusions in S2 actually increase,and the inclusions evolve into three-phase(two-phase)inclusions,which is attributed to(ⅲ)transformation of phase compositions in inclusions and interfacial reaction between inclusions and steel matrix during isothermal heating.Therefore,the control of inclusions in silicon-killed bearing steel with Ce and Mg composite treatment should be combined with specific heat treatment processes and appropriate rare earth and magnesium contents,to minimize the damage of inclusions on the fatigue performance of bearing steel products.
基金supported by the National Key R&D Program(No.2023YFB3709900)the National Nature Science Foundation of China(No.U22A20171)+2 种基金China Baowu Low Carbon Metallurgy Innovation Foundation(No.BWLCF202315)the High Steel Center(HSC)at North China University of TechnologyUniversity of Science and Technology Beijing,China.
文摘The characteristics of nonmetallic inclusions formed during steel production have a significant influence on steel performance.In this paper,studies on inclusions using confocal scanning laser microscopy(CSLM)are reviewed and summarized,particularly the col-lision of various inclusions,dissolution of inclusions in liquid slag,and reactions between inclusions and steel.Solid inclusions exhibited a high collision tendency,whereas pure liquid inclusions exhibited minimal collisions because of the small attraction force induced by their<90°contact angle with molten steel.The collision of complex inclusions in molten steel was not included in the scope of this study and should be evaluated in future studies.Higher CaO/Al_(2)O_(3)and CaO/SiO_(2)ratios in liquid slag promoted the dissolution of Al_(2)O_(3)-based in-clusions.The formation of solid phases in the slag should be prevented to improve dissolution of inclusions.To accurately simulate the dissolution of inclusions in liquid slag,in-situ observation of the dissolution of inclusions at the steel-slag interface is necessary.Using a combination of CSLM and scanning electron microscopy-energy dispersive spectroscopy,the composition and morphological evolution of the inclusions during their modification by the dissolved elements in steel were observed and analyzed.Although the in-situ observa-tion of MnS and TiN precipitations has been widely studied,the in-situ observation of the evolution of oxide inclusions in steel during so-lidification and heating processes has rarely been reported.The effects of temperature,heating and cooling rates,and inclusion character-istics on the formation of acicular ferrites(AFs)have been widely studied.At a cooling rate of 3-5 K/s,the order of AF growth rate in-duced by different inclusions,as reported in literature,is Ti-O<Ti-Ca-Zr-Al-O<Mg-O<Ti-Zr-Al-O<Mn-Ti-Al-O<Ti-Al-O<Zr-Ti-Al-O.Further comprehensive experiments are required to investigate the quantitative relationship between the formation of AFs and inclusions.
基金the National Natural Science Foundation of China(52004180,52204350)the China Postdoctoral Science Foundation(2020M683706XB)the Research Project Supported by Shanxi Scholarship Council of China(2023-080).
文摘Rare earth La was introduced into 40Cr steel in industrial experiments to achieve the purpose of modifying inclusions.The impact of La on the inclusion modification was studied,and its influence on the solidification structure was further investigated.With adding 0.0023%La,the Al_(2)O_(3)·CaO·CaS inclusions were modified to the LaAlO_(3)·CaO·CaS inclusions.Additionally,the morphology tended to be more spherical,and the proportion of small-sized inclusions increased significantly from 77.8%to 93.5%.The large-sized inclusions were almost completely eliminated.Based on experimental results,a dynamical model elucidating the process of inclusion modification by La was developed.Furthermore,the ratio of equiaxed zone of the solidification structure increased from 22.9%to 31.0%,and the average primary dendrite arm spacing decreased significantly from 288.4 to 226.2μm.Two-dimensional lattice mismatch analysis results determined that LaAlO_(3)can serve as an effective heterogeneous nucleation core,leading to solidification structure refinement.The beneficial transformation of inclusions and refinement of solidification structure are conducive to the cold heading process of 40Cr steel.
基金financially supported by the National Key Research and Development Program of China(No.2022YFB3705200)the National Natural Science Foundation of China(NSFC)(Nos.52321001,52130002 and 52371123)the IMR Innovation Fund(No.2024-PY07).
文摘With the increasing demand for high-performance metallic materials,the improvement of fatigue strength(FS)has become a crucial issue.This study focuses on the AISI 52100 steel,a material with leading fatigue performance and low-cost raw material,aiming to further improve its FS.It is found that the fatigue damage mechanism of 52100 steels with different tensile strengths has undergone significant changes,and the inclusions,mainly nitride and oxide,are key factors limiting the further improvement of FS.Therefore,the size reduction and modification of inclusions were attempted through the rare earth addition and strict control of harmful elements.Combining targeted microstructure adjustment,the FS of the 52100 steel has been further enhanced to~1.6 GPa,exceeding that of other metallic materials(performed in uniaxial tension with a stress ratio of R=0.1),and thus establishing it as a standout for its exceptional performance-to-cost ratio.By clarifying the influences of different types of inclusions on fatigue performance and establishing the correlation between micro-hardness(or strength)and FS,an optimization strategy for FS improvement of the 52100 steel was proposed.The FS has been improved by approximately 187 MPa at most by implementing this strategy.These achievements provide feasible technical approaches and theoretical foundations for the anti-fatigue design of metallic materials.
基金supported by the Fundamental Research Funds for the Central Universities(No.FRF-BD-23-01).
文摘Non-metallic inclusions in steel are a significant challenge,affecting material properties and leading to issues such as stress concentration,cracking,and accelerated corrosion.Current methods for removing inclusions,including bubble,electromagnetic stirring,filtration separation,fluid flow,and sedimentation,often struggle with the removal of fine inclusions.Apart from these known methods,pulsed electric current(PEC),as an emerging technology,has demonstrated immense potential and environmental advantages.PEC offers adjustable current parameters and simple equipment,making it an attractive alternative to traditional methods.Its green energy-saving features and excellent results in regulating inclusion morphology and migration,as well as inhibiting submerged entry nozzle(SEN)clogging,make it a promising technology.In comparison to continuous current technology,PEC has shown significant advantages in regulating inclusions,not only improving purification efficiency but also demonstrating outstanding performance in flow stability and energy consumption.The ability of PEC to efficiently reduce inclusion numbers enhances the purity and quality of molten steel,improving its mechanical properties.Currently,the theoretical basis for controlling the movement of inclusions by current is mainly composed of three major theories:the double electric layer theory,electromagnetic force reverse separation theory,and electric free energy drive theory.These theories together form an important framework for researchers to understand and optimize the behavior of impurity movement controlled by electric current.Looking ahead,PEC is expected to pave the way for new solutions in directional regulation of inclusion migration,efficient inclusion removal,SEN clogging prevention,and the purification of molten steel.
基金support from the National Key R&D Program(No.2023YFB3709900)the National Natural Science Foundation of China(Grant No.U22A20171)+1 种基金the High Steel Center at the North China University of Technologythe University of Science and Technology Beijing,China.
文摘The dissolution behavior of complex inclusions in refining slag was studied using confocal laser scanning microscope.Based on the dissolution curve of complex inclusions,the main rate-limiting link of CaO-SiO_(2)-Al_(2)O_(3)complex inclusions was the diffusion in the molten slag.The dissolution rate of CaO-SiO_(2)-Al_(2)O_(3)complex inclusions was affected by the composition and size of inclusion.The functional relationship between the dimensionless inclusion capacity(Zh)and the dimensionless dissolution rate(Ry)of CaO-SiO_(2)-Al_(2)O_(3)complex inclusions was calculated as Ry=2.10×10^(-6)Zh^(0.160),while it was Ry=2.10×10^(-6)Zh^(0.0087)for Al_(2)O_(3)-CaO complex inclusions.On this basis,the complete dissolution time and rate of the complex inclusions were calculated by using the function relation between the Zh and Ry numbers.
基金the support from the National Natural Science Foundation of China(Grant Nos.52074198,52374342,and U21A20113)the Department of Science and Technology of Hubei Province(Grant Nos.2023AFB603 and 2023DJC140).
文摘The transformation mechanism of the inclusions and microstructure in 316L stainless steel after post-isothermal heat treatment(IHT)was revealed,along with the pitting behavior of the inclusions in a chloride environment before and after the transformation.The effect of the inclusion transformation on the pitting corrosion behavior of 316L stainless steel and its intrinsic mechanism was also revealed.Results revealed a gradual transformation of MnO-SiO_(2)inclusions into MnO-Cr_(2)O_(3) within the temperature range of 1373 to 1573 K.MnO-Cr_(2)O_(3)inclusions exhibited minimal dissolution in chloride ion corrosion environments,while MnO-SiO_(2)oxides demonstrated higher electrochemical activity and were more prone to dissolve and form pits.Meanwhile,IHT significantly reduced the dislocation density of stainless steel,rendering it more stable in corrosive environments.X-ray photoelectron spectroscopy peak distributions of the passive films demonstrated that IHT increased the proportion of Cr and Fe oxides and hydroxides in the passive film which improved the stability and corrosion resistance of the steel.
基金Supported by NSFC(No.12171062)the Natural Science Foundation of Chongqing(No.CSTB2022NSCQ-JQX0004)+1 种基金the Chongqing Talent Support Program(No.cstc2024ycjh-bgzxm0121)Science and Technology Project of Chongqing Education Committee(No.KJZD-M202300503)。
文摘The purpose of this article is to introduce a new method with a self-adaptive stepsize for approximating a common solution of monotone inclusion problems and variational inequality problems in reflexive Banach spaces.The strong convergence result for our method is established under some standard assumptions without any requirement of the knowledge of the Lipschitz constant of the mapping.Several numerical experiments are provided to verify the advantages and efficiency of proposed algorithms.
文摘Aim To prepare and characterize the QURC-HP-β-CD inclusion complexes and investigate the thermodynamic parameters of the process. Methods QURC-HP-β-CD inclusion complexes were prepared by the grinding method. The equilibrium inclusion constants and thermodynamic parameters were determinated by phase solubility analysis. Dissolution tests were performed to study the dissolution rate of inclusion complexes. The formation of inclusion complexes was confirmed by differential scanning calorimetry （ DSC）, infrared spectroscopy （IR） , powder X-ray diffractometry （PXRD） and scanning electron microscopy （SEM）. Results The aqueous solubility of quercetin was greatly increased （ about 37 folds） by inclusion technique, and the initial dissolution rate was markedly improved （10 folds） in the first 5 min. The results of DSC and SEM photographs showed that quercetin crystal disappeared in inclusion complexes, which indicated the formation of new phase. FT-IR spectra showed that the carbonyl quercetin crystal grinding method. absorption band of quercetin was shifted. PXRD showed that the diffraction peak of disappeared. Conclusion QURC-HP-β-CD inclusion complexes are produced by the The solubility of quercetin is improved by the inclusion technique.
文摘This study employs bibliometric and visualisation techniques to analyse global trends in financial inclusion and the innovative tools that promote it.By examining a multidatabase compilation of 4202 documents sourced from Scopus and Web of Science,the significant role of book chapters in disseminating research in this field is highlighted.Our analysis reveals rapid growth in publications,particularly from China and India,and identifies key influential works and authors.Additionally,it is observed that financial inclusion is approached from a multidisciplinary perspective.The findings of this study also indicate a shift in research focus from traditional concepts such as“housing”and“banking”to“digitalisation”and“sustainability.”Key research trends in financial innovative tools include regulatory frameworks,mobile money,and financial education.The issues discussed in this article seek to contribute to the ongoing dialogue on developing intellectual frameworks withing the financial inclusion literature.They offer valuable insights for policymakers,industry practitioners,and researchers in the fields of financial innovation and inclusion.
基金supported by the National Natural Science Foundation of China(Nos.52064011,52274331 and 52264041)Guizhou Provincial Basic Research Program(Natural Science)(Nos.ZK[2021]258 and ZK[2023]Zhongdian 020)+6 种基金Guizhou Provincial Key Technology R&D Program(No.[2021]342)Guizhou Provincial Program on Commercialization of Scientific and Technological Achievements(No.[2022]089)supported by Open Project of State Key Laboratory of Advanced Special Steel,Shanghai Key Laboratory of Advanced Ferrometallurgy,Shanghai University(No.SKLASS 2023-08)the Science and Technology Commission of Shanghai Municipality(No.19DZ2270200)supported by State Key Laboratory of Advanced Metallurgy(No.K23-04)China Postdoctoral Science Foundation(No.2023MD744232)Key Research Projects in Higher Education Institutions of Henan Province(No.24B450003).
文摘To mitigate the harmful effects of Al_(2)O_(3) inclusions in steel,it is necessary to conduct comprehensive research on the mechanisms and kinetic laws of Al_(2)O_(3) inclusion modification by Ce.Combined with laboratory experiments,first-principles calculations,and molecular dynamics simulations,the kinetic model of Ce modification for Al_(2)O_(3) inclusions was established.Based on first-principles calculations,differential charge analysis,density of states analysis,and adsorption energy analysis were performed on the transformation process from Al_(2)O_(3) to CeAlO_(3) at the atomic scale,and the microscopic transformation mechanism of inclusions at the atomic scale was obtained.Molecular dynamics simulations and the solution of mean square displacement function show that the diffusion coefficient for Ce atoms was 2.169×10^(−4) cm^(2)/s,which agreed well with experimental results.In this model,the rate-determining step is the diffusion of Ce atoms across Ce–Al–O inclusions.The relationship between the conversion rate,refining time,and initial radius was discussed.A refining time of 60 s can completely transform Al_(2)O_(3) inclusions less than 2.56μm into CeAlO_(3) inclusions,while refining time of 1200 s is sufficient to modify inclusions size below 11.47μm.
基金Academic Fund for Students of Foshan University in 2024(Project No.:xsjj202409zrb11)。
文摘Trimethoprim(TMP),as a broad-spectrum bacteriostatic antibiotic,is widely used in clinical anti-infection therapy and livestock breeding.However,its low water solubility leads to insufficient bioavailability,which has become a key problem restricting its development.Cyclodextrins and their derivatives,with their unique cyclic structures,can form inclusion complexes with TMP to improve its properties.This article reviews the pharmacological characteristics of TMP,the types and properties of common cyclodextrins,focusing on introducing various preparation methods of trimethoprim cyclodextrin inclusion complexes and multiple characterization methods for identifying the inclusion complexes,aiming to provide a reference for further research and development of trimethoprim cyclodextrin inclusion complexes.
基金the National Natural Science Foundation of China(Grant No.U22A20171)the National Key Research and Development Program Project of China(2023YFB3709900)+1 种基金the China Baowu Low Carbon Metallurgical Innovation Fund(BWLCF202315)the Pangang-USTB Vanadium and Titanium Research Institute Research Project,the High Steel Center(HSC)at North China University of Technology,Yanshan University and University of Science and Technology Beijing,China.
文摘Model calculations and laboratory experiments were conducted to investigate the influence of surface tension of the molten steel on the agglomeration trend of Al_(2)O_(3) inclusions.The agglomeration trends of inclusions were compared using the calculated attractiveness.When the S content in the steel increased from 2.7×10^(-6) to 789×10^(-6),the surface tension of the molten steel decreased from 1.91 to 1.39 N/m,while the attractive force between inclusions increased from 5×10^(-18) to 5×10^(-16) N,and the critical collision distance of Al_(2)O_(3) inclusions gradually increased from 30 to 70μm.A model of the relationship between the capillary force of inclusions and S content in steel was established.It was found that the capillary force calculated by the model showed the same trend as the attractive force obtained from experiments,and an increase in the S content promoted the attraction between inclusions.
基金Project supported by the National Natural Science Foundation of China(52374330,52325406)。
文摘The addition of Ce significantly enhances cleanliness of steel and modifies precipitation phases.However,there are differences in the effects of different alloy systems,especially its role in M54 steel is insufficiently understood.This study investigates the evolution of inclusions and precipitation phases in M54 steel ingots with varying Ce additions.Results indicate that the addition of Ce reduces the content of impurity elements(O and S)and transforms Mg and Al inclusions into Ce inclusions,which is due to the stronger affinity between Ce and impurity elements such as O and S.Ce inclusions serve as nucleation sites for dendrites,reducing secondary dendrite arm spacing.In addition,these inclusions and Cecontaining precipitated phase also act as nucleation sites for carbide precipitates,effectively refining their distribution by reducing growth spaces and increasing nucleation density.Notably,as Ce content increases from 0 to 0.01 wt%,the precipitation phase content decreases significantly but rises slightly with further increases in Ce content due to the formation of additional Ce-containing precipitates.By quantitatively comparing the dendrite arm spacing,cleanliness,content and size of precipitated phase,it is determined that the optimum addition amount of Ce for M54 steel is about 0.01 wt%.
基金support from the project of Xinjiang Bayi Iron and Steel Co.,Ltd.(No.2022-0460).
文摘Formation and evolution of inclusions in low-aluminum Ti-containing 51CrV4 spring steel under BOF(basic oxygen furnace)–LF(ladle furnace)–CC(continuous casting)process were investigated by industrial trials and thermodynamic calculations.During LF refining,deoxidation products including Al_(2)O_(3),Al_(2)O_(3)–Ti_(3)O_(5)–SiO_(2)–MnO and Al_(2)O_(3)–SiO_(2)–MnO are modified as MgO–Al_(2)O_(3),CaO–Al_(2)O_(3)–SiO_(2),CaO–Al_(2)O_(3)–MgO and CaO–Al_(2)O_(3)–SiO_(2)–MgO.When reoxidation during ladle casting is quite serious,inclusions such as Al_(2)O_(3),Al_(2)O_(3)–Ti_(3)O_(5)–SiO_(2)–MnO,and Al_(2)O_(3)–SiO_(2)–MnO may regenerate.A handful of Ti carried by alloy into liquid steel has less influence on inclusions during LF refining;Ti-containing inclusions mainly transiently exist as an intermediate product of deoxidation process and then are gradually modified by[Al],[Ca]or[Mg].Thermodynamic calculation and experimental results reveal that tundish flux is the main source of reoxidation in ladle casting process.Further calculations taking into account of the influence of inclusions before casting indicate that reoxidation within a certain of degree leads to the generation of a large amount of high melting point inclusions including CaO·2MgO·8Al_(2)O_(3),CaO·MgO·7Al_(2)O_(3),MgO·Al_(2)O_(3),CaO·6Al_(2)O_(3)and Al_(2)O_(3)in molten steel,which is basically consistent with experimental results,and more high melting point inclusions will generate as reoxidation becomes severer.On this basis,severer reoxidation will deplete[Si],[Mn],and[Ti]in steel melt,resulting in the formation of liquid inclusions composed of Al_(2)O_(3)–Ti_(3)O_(5)–SiO_(2)–MnO(–CaO).These results are of guiding significance for controlling inclusions in Al-killed Ti-containing spring steel.
基金supported by the National Natural Science Foundation of China(Nos.52364044 and 52204364)Central Guidance on Local Science and Technology Development Fund Projects of Inner Mongolia Autonomous Region(No.2022ZY0090)Basic Scientific Research Business Expenses of Colleges and Universities in Inner Mongolia Autonomous Region(Nos.2023QNJS011 and 0406082226).
文摘The micro-area characterization experiments like scanning Kelvin probe force microscope(SKPFM)and Kernel average misorientation have the defects of complex sample preparation and occasional errors in test results,which makes it impossible to accurately and quickly analyze the pitting behavior induced by inclusions in some cases,prompting attempts to turn to simulation calculation research.The method of calculating band structure and work function can be used to replace current-sensing atomic force microscopy and SKPFM to detect the potential and conductivity of the sample.The band structure results show that Al_(2)O_(3) inclusion is an insulator and non-conductive,and it will not form galvanic corrosion with the matrix.Al_(2)O_(3) inclusion does not dissolve because its work function is higher than that of the matrix.Moreover,the stress concentration of the matrix around the inclusion can be characterized by first-principles calculation coupled with finite element simulation.The results show that the stress concentration degree of the matrix around Al_(2)O_(3) inclusion is serious,and the galvanic corrosion is formed between the high and the low stress concentration areas,which can be used to explain the reason of the pitting induced by Al_(2)O_(3) inclusions.
文摘This study presents an all-inclusive analysis of the literature on the augmentation of financial inclusion through fintech.Ninety-six papers were selected from the 2951 articles in the Web of Science,Scopus,and EBSCO databases.This study uses bibliometric and content analysis techniques to illuminate the underexplored aspects of fintech’s impact on financial inclusion.Unlike previous studies,this study consolidates a significant amount of the literature on financial inclusion by systematically contextualizing theories and viewpoints from the fintech sector.The key findings include the identification of three main research clusters:(1)the advent of novel services,(2)the transformation of the market landscape,and(3)the roles of stakeholders in the fintech ecosystem.The analysis reveals gaps in the existing research,such as the need for more studies on the tangible impact of fintech on financial inclusion and regulation.This study concludes by highlighting potential directions for future research and emphasizing the importance of policymakers paying greater attention to fintech’s implications for financial inclusion.
基金National Natural Science Foundation of China(Nos.U21A20116,U21A20117 and 52304347)National Natural Science Foundation of Liaoning(Nos.2023-MSBA-135 and 2023-BSBA-107)+1 种基金the Fundamental Research Funds for the Central Universities(Nos.N2409006 and N2409008)are acknowledged to support this workSwedish Foundation for International Cooperation in Research and Higher Education(STINT,Project No.IB2022-9228)is acknowledged by W.Mu to support his visit between KTH(Sweden)and NEU(China).
文摘Understanding the motion behaviors of non-metallic inclusions in the liquid metal is important for clean steel production.High-temperature confocal laser scanning microscopy is applied to investigate the effect of different Ti and Al contents on the agglomeration behavior of non-metallic inclusions in low carbon steels.Furthermore,the agglomeration mechanism of inclusions was investigated through quantitative analysis of in-situ observation experiments and a modified Kralchevsky-Paunov model.The obtained results indicate that Al_(2)O_(3)is the main type inclusion in the low-alloys steels with both Al and Ti addition.This type of inclusion is more likely to absorb surrounding small-size inclusion particles,leading to a further growth for the cluster formation and contributing to a serious engineering problem,nozzle clogging.Besides,TiO_(x)is the main type inclusion in the molten steel with only Ti addition,and this type of inclusion is less likely to agglomerate and the individual inclusion particles show a‘free’motion with the fluid of molten steel.The difference between these two types of inclusions is due to the difference in attractive force and action distance at the meniscus created by the inclusion/steel/Ar multiple interfaces and influenced by the physical parameters,e.g.,contact angle and interface energy between inclusion and steel,and surface tension of the melt.
基金support of Postdoctoral Fellowship Program of CPSF(GZC20230393)Natural Science Foundation of Liaoning Province in China(2023-BSBA-112)Fundamental Research Funds for the Central Universities(N2425032).
文摘The formation of large-sized inclusions cluster severely impacts the continuous casting process and product quality of titanium-containing steel.Thermodynamic calculations were initially conducted to predict the formation of various complex oxide inclusions,namely Al_(2)O_(3),TiO_(x)and Al-Ti-O.Based on that,laboratory-scale experiments were designed to prepare samples with a single type of inclusions.Then,the scanning electron microscope-energy dispersive spectrometer was used for quantitative characterization.Subsequently,the agglomeration behavior of inclusions in Fe-Al-Ti-O melt was observed in situ by high-temperature confocal laser scanning microscopy.Furthermore,a quantitative analysis of the agglomeration characteristics of the various inclusions was conducted based on the attractive forces in accordance with Newton's second law and the capillary forces as described by the Kralchevsky-Paunov model.The results indicate that the size of Al_(2)O_(3)inclusions is larger than that of TiO_(x)and Al-Ti-O,but the number density of TiO_(x)is the highest.Based on the in situ observation and the theoretical calculation,Al_(2)O_(3),TiO_(x)and Al-Ti-O inclusions can all agglomerate into large-sized clusters without segregation,but the agglomeration tendency of Al_(2)O_(3)and TiO_(x)is stronger than that of Al-Ti-O.The attractive force between Al_(2)O_(3)inclusions’pair is the largest,ranging from 2.26×10^(-15)to 6.12×10^(-14)N,followed by TiO_(x)(7.13×10^(-16)to 3.56×10^(-14)N)and Al-Ti-O(1.16×10^(-17)to 3.77×10^(-16)N).
基金financially supported by National Natural Science Foundation of China (No. 21601137)Basic Science and Technology Research Project of Wenzhou, Zhejiang Province (No. G20240038)+2 种基金the Special Basic Cooperative Research Programs of Yunnan Provincial Undergraduate Universities Association (Nos. 202101BA070001-031, 202101BA070001-042 and 202301BA070001-093)Yunnan Province Young and Middle-aged Academic and Technical Leaders Reserve Talent Project (No. 202105AC160060)Yunnan Province High-level Talent Training Support Program “Youth Top Talent” Project (2020)。
文摘The development of cost-effective and high-efficiency catalysts for sustainable hydrogen production through electrocatalytic hydrogen evolution reaction(HER) is crucial yet remains challenging. In this work, we synthesized two types of bimetallic Pt Ni nanoparticles embedded in N-doped porous carbons derived from Ni-ABDC(5-aminoisophthalate) using both in-situ and ex-situ Pt inclusion methods. The in-situ Pt doping notably disrupted the effective growth of Ni-ABDC nanostrips owing to strong interactions between Pt and ABDC, resulting in an amorphous nanostructure. The optimized PtinNi-NC exhibited remarkable HER performance with a low overpotential of 29 mV at 10 mA/cm^(2), a Tafel slope of 47.4 mV/dec, and a current retention of 91.2% after 200 h in 1.0 mol/L KOH solution, surpassing the performance of Ni-NC, PtexNi-NC, and Pt/C. This research demonstrates the rational design and preparation of transition metal-based coordination polymer-derived metal-carbon nanomaterials with low Pt loading,emphasizing their considerable potential in energy conversion and storage technologies.
