The effect of an adsorbed anionic surfactant sodium dodecyl benzene sulfonate （SDBS） on electron transfer （ET） reaction between ferricyanide aqueous solution and decamethylferrocene （DMFc） located on the adjacen...The effect of an adsorbed anionic surfactant sodium dodecyl benzene sulfonate （SDBS） on electron transfer （ET） reaction between ferricyanide aqueous solution and decamethylferrocene （DMFc） located on the adjacent organic phase was investigated for the first time by thin layer method. The adsorption of SDBS at the interface resulted in a decay in the cathodic plateau current of bimolecular reaction with increasing concentrations of SDBS in aqueous phase. However, the rate constant of electron transfer （ket） increased monotonically as the SDBS concentrations increased from 0 to 200 p, moFL. The experimental results showed that SDBS formed patches on the interface and influenced the structure of electrical double layer. 2009 Xiao Quan Lu. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
Electrochemical transfer behavior of V ⅤW 11 -V Ⅴ 3W 9 heteropoly anions on the water/nitrobenzene interface was investigated by means of cyclic voltammetry. The effect of the solution acidity on the transfe...Electrochemical transfer behavior of V ⅤW 11 -V Ⅴ 3W 9 heteropoly anions on the water/nitrobenzene interface was investigated by means of cyclic voltammetry. The effect of the solution acidity on the transfer behavior and the stable pH range for the heteropoly anions were studied. The stability of mixed tungstovanadate decreases with increasing the number of vanadium atoms. The main transfer species within the potential window have the negative charges of 4 and the transfer process is diffusion controlled. The apparent transfer potential Δ w o Ψ 0 and the free energy Δ G 0 w→o tr for the heteropoly anions can be obtained from the experimental data. For the different anions, the Δ w o Ψ 1/2 pH relationship can be expressed as: Δ w o Ψ 1/2 =constant-53pH.展开更多
The oxidation of hydroquinone(QH_2) was investigated for the first time at liquid/liquid(L/L) interface by scanning electrochemical microscopy(SECM).In this study,electron transfer(ET) from QH_2 in aqueous to ferrocen...The oxidation of hydroquinone(QH_2) was investigated for the first time at liquid/liquid(L/L) interface by scanning electrochemical microscopy(SECM).In this study,electron transfer(ET) from QH_2 in aqueous to ferrocene(Fc) in nitrobenzene (NB) was probed.The apparent heterogeneous rate constants for ET reactions were obtained by fitting the experimental approach curves to the theoretical values.The results showed that the rate constants for oxidation reaction of QH_2 were sensitive to the changes of the dri...展开更多
Comparison in electron transfer(ET) processes from decamethyferrocene(DMFe) in nitrobenzene(NB) to ferric ion in aqueous phase was investigated for the first time by the scanning electrochemical microscopy(SECM).As co...Comparison in electron transfer(ET) processes from decamethyferrocene(DMFe) in nitrobenzene(NB) to ferric ion in aqueous phase was investigated for the first time by the scanning electrochemical microscopy(SECM).As compared with the system of Fe(CN)_6^(3-)-DMFe,the ET rate obtained from Fe^(3+)-DMFe was lower in spite of larger driving force,which may arise from the effect of reorganization energy.Otherwise,the effect of common ion on rate constants was also probed and results suggested additional complexit...展开更多
The ion transfer reaction of 2-benzoylpyridine-thiosemicarbazone (HL), which has antimicrobial and antifungal properties and anticancer activity, has been studied to determine its lipophilicity by cyclic voltammetry a...The ion transfer reaction of 2-benzoylpyridine-thiosemicarbazone (HL), which has antimicrobial and antifungal properties and anticancer activity, has been studied to determine its lipophilicity by cyclic voltammetry at the water/1,2-dichloroethane (1,2-DCE) interface. The physicochemical parameters such as standard partition coefficient (lgPI)andthestandardGibbsenergyoftransfer("G0tr,,wI "o)oftheprotonatedformoftheligandwere measured asa function of pH in aqueous phase. The protonated form of the ligand exhibited reversible or quasi-reversible voltammograms at the1,2-DCEintherangeofpH1-5.Theprotonationconstantsoftheligand,pKa1andpKa2,weredeterminedspectrophotometrically and were found to be 12.14 and 3.24, respectively. The standard Gibbs energy of transfer ("G0tr,,wN" o) and the partition coefficient of neutral species (lgPN) were also determined by the shake-flask method. The standard Gibbs energy of transfer of this compound across the water/1,2-DCE interface was evaluated as the quantitative measure of its lipophilicity. The difference between lgPI and lgPN was related to the degree of charge delocalization and was used to evaluate qualitatively the lipophilicity of the ligand.展开更多
Morphology and growth rate of carbon dioxide hydrate on the interface between liquid carbon dioxide and humic acid solutions were studied in this work.It was found that after the growth of the hydrate film at the inte...Morphology and growth rate of carbon dioxide hydrate on the interface between liquid carbon dioxide and humic acid solutions were studied in this work.It was found that after the growth of the hydrate film at the interface,further growth of hydrate due to the suction of water in the capillary system formed between the wall of the cuvette and the end boundary of the hydrate layer occurs.Most probably,substantial effects on the formation of this capillary system may be caused by variations in reactor wall properties,for example,hydrophobic-hydrophilic balance,roughness,etc.We found,that the rate of CO_(2) hydrate film growth on the surface of the humic acid aqueous solution is 4-fold to lower in comparison with the growth rate on the surface of pure water.We suppose that this is caused by the adsorption of humic acid associates on the surface of hydrate particles and,as a consequence,by the deceleration of the diffusion of dissolved carbon dioxide to the growing hydrate particle.展开更多
We study the effects of gas adsorption on the dynamics and stability of nanobubbles at the solid–liquid interface. The phase diagram and dynamic evolution of surface nanobubbles were analyzed under varying equilibriu...We study the effects of gas adsorption on the dynamics and stability of nanobubbles at the solid–liquid interface. The phase diagram and dynamic evolution of surface nanobubbles were analyzed under varying equilibrium adsorption constant.Four distinct dynamic behaviors appear in the phase diagram: shrinking to dissolution, expanding to bursting, shrinking to stability, and expanding to stability. Special boundary states are identified in phase diagram, where the continuous growth of nanobubbles can take place even under very weak gas–surface interaction or with very small initial bubble size. Surface adsorption plays a critical role in the stability, lifetime, radius, and contact angle of nanobubbles, thereby demonstrating that pinning is not a prerequisite for stabilization. Furthermore, stable equilibrium nanobubbles exhibit a characteristic range of footprint radius, a limited height, and a small contact angle, consistent with experimental observations.展开更多
The oviduct epithelium is the initial maternal contact site for embryos after fertilization,offering the microenviron-ment before implantation.This early gestation period is particularly sensitive to stress,which can ...The oviduct epithelium is the initial maternal contact site for embryos after fertilization,offering the microenviron-ment before implantation.This early gestation period is particularly sensitive to stress,which can cause reduced fertil-ity and reproductive disorders in mammals.Nevertheless,the local impact of elevated stress hormones on the ovi-duct epithelium has received limited attention to date,except for a few reports on polyovulatory species like mice and pigs.In this study,we focused on the effects of chronic maternal stress on cattle,given its association with infertil-ity issues in this monoovulatory species.Bovine oviduct epithelial cells(BOEC)differentiated at the air–liquid interface(ALI)were stimulated with 250 nmol/L cortisol for 1 or 3 weeks.Subsequently,they were assessed for morphology,bioelectrical properties,and gene expression related to oviduct function,glucocorticoid pathway,cortisol metabo-lism,inflammation,and apoptosis.Results revealed adverse effects of cortisol on epithelium structure,featured by deciliation,vacuole formation,and multilayering.Additionally,cortisol exposure led to an increase in transepithelial potential difference,downregulated mRNA expression of the major glucocorticoid receptor(NR3C1),upregulated the expression of cortisol-responsive genes(FKBP5,TSC22D3),and significant downregulation of oviductal glycopro-tein 1(OVGP1)and steroid receptors PGR and ESR1.The systematic comparison to a similar experiment previously performed by us in porcine oviduct epithelial cells,indicated that bovine cultures were more susceptible to elevated cortisol levels than porcine.The distinct responses between both species are likely linked to their divergence in the cortisol-induced expression changes of HSD11B2,an enzyme controlling the cellular capacity to metabolise cortisol.These findings provide insights into the species-specific reactions and reproductive consequences triggered by maternal stress.展开更多
Controllable liquid manipulation is of paramount scientific and technological importance in various fields,such as the chemical industry,biomedicine,and agricultural production.Magnetic actuation,characterized by rapi...Controllable liquid manipulation is of paramount scientific and technological importance in various fields,such as the chemical industry,biomedicine,and agricultural production.Magnetic actuation,characterized by rapid,contactless,and environmentally benign operation,has emerged as a promising approach for precise liquid control.However,conventional magnetic strategies typically govern droplet movement on open surfaces,facing limitations such as restricted liquid volumes,uncertain flow paths,and inevitable evaporation,thereby constraining their broader practical applications.Recently,a variety of magneticdriven strategies have been developed to dynamically regulate liquids within enclosed spaces,especially through physicochemical mechanisms.These approaches provide efficient control over liquid behavior by leveraging magnetically induced chemical changes,structural deformations,and dragging motions,opening new opportunities for flexible and versatile fluid management.This review explores the design and mechanisms of magneto-responsive confined interfaces for the manipulation of nonmagnetic liquids,highlighting key advancements and potential applications including liquid valves,liquid mixing,liquid flow regulation,and liquid pumping.Finally,the existing challenges and future prospects in this field are presented.展开更多
The large-scale commercialization of proton exchange membrane fuel cells(PEMFCs)has been hindered by the high demand of platinum(Pt)in the cathode due to the sluggish kinetics of the oxygen reduction reaction.Reducing...The large-scale commercialization of proton exchange membrane fuel cells(PEMFCs)has been hindered by the high demand of platinum(Pt)in the cathode due to the sluggish kinetics of the oxygen reduction reaction.Reducing the amount of Pt would worsen the problems caused by the adsorption of perfluorinated sulfonic acid(PFSA)ionomers to Pt via the side chains,namely,blocking the active sites of Pt and inducing densely packed layers of fluorocarbon backbones on Pt surface to obstruct local O_(2)transport at the Pt/PFSA interfaces.This work aims at optimizing the Pt/ionomer interface to mitigate the sulfonate adsorption and in the meantime to reduce the local O_(2)transport resistance(R_(local)),by using a porous composite of 1-butyl-3-methylimidazolium hydrogen sulfate ionic liquid(IL)modified MOF-808(BMImHSO_(4)@MOF-808)as additive in cathodic catalyst layer(CCL).Through detailed physical,spectroscopic and electrochemical characterizations,we demonstrate a three-fold optimization mechanism of Pt/ionomer interface structure by BMImHSO_(4)@MOF-808:the unsaturated metal sites in MOF-808 effectively inhibit the sulfonate adsorption on Pt through coordination with the sulfonates of PFSA,thereby improving catalyst utilization;the pores in MOF-808 establish efficient transport channels for gaseous oxygen,significantly reducing R_(local);the IL modification layers facilitate the formation of continuous proton transport networks,increasing proton conductivity.The incorporation of BMImHSO_(4)@MOF-808 in a low-Pt CCL(0.1 mg_(Pt)cm^(-2))yields a peak power density of 1.9 W cm^(-2)for PEMFC under H_(2)-O_(2)condition,and ca.20%increase of power density under H_(2)-air condition as compared with conventional CCL,indicating the prospect of IL-MOF composites as an efficient additive to enhance the performance of PEMFCs.展开更多
The stability of perovskite solar cells(PSCs)is adversely affected by nonradiative recombination resulting from buried interface defects.Herein,we synthesize a polyionic liquid,poly(p-vinylbenzyl trimethylam-monium he...The stability of perovskite solar cells(PSCs)is adversely affected by nonradiative recombination resulting from buried interface defects.Herein,we synthesize a polyionic liquid,poly(p-vinylbenzyl trimethylam-monium hexafluorophosphate)(PTA),and introduce it into the buried interface of PSCs.The quaternary ammonium cation(N(-CH_(3))^(3+))in PTA can fill the vacancies of organic cations within the perovskite structure and reduce shallow energy level defects.Additionally,the hexafluorophosphate(PF6−)in PTA forms a Lewis acid-base interaction with Pb^(2+)in the perovskite layer,effectively passivating deep en-ergy level defects.Furthermore,hydrogen bonding can be established between organic cations and the PF6−anion,preventing the formation of shallow energy level defects.Through this synergistic mecha-nism,the deep and shallow energy level defects are effectively mitigated,resulting in improved device performance.As a result,the resulting treated inverted PSC exhibits an impressive power conversion ef-ficiency(PCE)of 24.72%.Notably,the PTA-treated PSCs exhibit remarkable stability,with 88.5%of the original PCE retained after undergoing heat aging at 85℃ for 1078 h,and 89.1%of the initial PCE main-tained following continuous exposure to light for 1100 h at the maximum power point.Synergistically suppressing multiple defects at the buried interface through the use of polyionic liquids is a promising way to improve the commercial viability of PSCs.展开更多
Pediatric cancers are particularly significant due to their uncommon occurrence in children,driven by a variety of underlying factors.Because of their distinct molecular and genetic makeup,which makes early detection ...Pediatric cancers are particularly significant due to their uncommon occurrence in children,driven by a variety of underlying factors.Because of their distinct molecular and genetic makeup,which makes early detection challenging,they are linked to problems.Diagnostic methods like imaging and tissue biopsy are only effective when the tumor has reached a size that can be identified.The liquid biopsy technique,the least intrusive and most convenient diagnostic method,is the subject of this review.It focuses on the significance of single cell analysis in examining uncommon cancer types.The many biomarkers found in bodily fluids and the cancer types they are linked to in children have been assessed,as has the potential route towards early detection and cancer recurrence forecasting.Combining the single cell liquid biopsy with the newest technologies,such as computational and multi-omics approaches,which have improved the efficiency of processing massive and unique genetic data,appears promising.This article discusses on a number of case reports for uncommon pediatric malignancies,such as Neuroblastoma,Medulloblastoma,Wilms Tumor,Rhabdomyosarcoma,Ewing Sarcoma,and Retinoblastoma,as well as their liquid biopsy profiles.Furthermore,the findings raise ethical questions regarding the therapeutic application of the technology as well as possible difficulties related to clinical translation.The likelihood that this single cell liquid biopsy will be clinically validated and eventually used as a routine diagnostic tool for uncommon pediatric cancers will rise with the realistic approach to sensitivity monitoring,specificity upgrading,and optimization.展开更多
While desalination is a key solution for global freshwater scarcity,its implementation faces environmental challenges due to concentrated brine byproducts mainly disposed of via coastal discharge systems.Solar interfa...While desalination is a key solution for global freshwater scarcity,its implementation faces environmental challenges due to concentrated brine byproducts mainly disposed of via coastal discharge systems.Solar interfacial evaporation offers sustainable management potential,yet inevitable salt nucleation at evaporation interfaces degrades photothermal conversion and operational stability via light scattering and pathway blockage.Inspired by the mangrove leaf,we propose a photothermal 3D polydopamine and polypyrrole polymerized spacer fabric(PPSF)-based upward hanging model evaporation configuration with a reverse water feeding mechanism.This design enables zero-liquiddischarge(ZLD)desalination through phase-separation crystallization.The interconnected porous architecture and the rough surface of the PPSF enable superior water transport,achieving excellent solar-absorbing efficiency of 97.8%.By adjusting the tilt angle(θ),the evaporator separates the evaporation and salt crystallization zones via controlled capillary-driven brine transport,minimizing heat dissipation from brine discharge.At an optimal tilt angle of 52°,the evaporator reaches an evaporation rate of 2.81 kg m^(−2) h^(−1) with minimal heat loss(0.366 W)under 1-sun illumination while treating a 7 wt%waste brine solution.Furthermore,it sustains an evaporation rate of 2.71 kg m^(−2) h^(−1) over 72 h while ensuring efficient salt recovery.These results highlight a scalable,energy-efficient approach for sustainable ZLD desalination.展开更多
The inability to access brain tissue has greatly hindered our ability to study and care for individuals suffering from psychiatric and neurological conditions.Critics have questioned efforts to develop peripheral bloo...The inability to access brain tissue has greatly hindered our ability to study and care for individuals suffering from psychiatric and neurological conditions.Critics have questioned efforts to develop peripheral blood biomarkers in neurological and psychiatric disorders based on the assertion that disease pathology is limited to the brain.The discovery that all tissues,including the brain,release extracellular vesicles(Raposo and Stoorvogel,2013)and cell free DNAs(Chan et al.,2013)into various body fluids has provided a potential way to measure activity from inaccessible tissues like the central nervous system(CNS)and has given rise to the term“liquid biopsy.”The development of liquid biopsies that can diagnose and predict the course of psychiatric and neurological disorders would be transformative.The ability to predict episodic events such as mania,depression,and risk for suicide would be particularly useful for psychiatric care as it would enable the development of interventions that prevent mortality and improve outcomes.Additionally,biomarkers that are informative about drug response and aid in treatment decisions would be a significant advance in psychiatric care as it would prevent patients from having to endure multiple courses of ineffective treatments and side effects.展开更多
Cu/Al clad strips are prepared using solid?liquid cast-rolling bonding(SLCRB)technique with a d160mm×150mm twin-roll experimental caster.The extent of interfacial reactions,composition of the reaction products,an...Cu/Al clad strips are prepared using solid?liquid cast-rolling bonding(SLCRB)technique with a d160mm×150mm twin-roll experimental caster.The extent of interfacial reactions,composition of the reaction products,and their micro-morphology evolution in the SLCRB process are investigated with scanning electron microscope(SEM),energy dispersive spectrometer(EDS),and X-ray diffraction(XRD).In the casting pool,initial aluminized coating is first generated on the copper strip surface,with the diffusion layer mainly consisting ofα(Al)+CuAl2and growing at high temperatures,with the maximum thickness of10μm.After sequent rolling below the kiss point,the diffusion layer is broken by severe elongation,which leads to an additional crack bond process with a fresh interface of virgin base metal.The average thickness is reduced from10to5μm.The reaction products,CuAl2,CuAl,and Cu9Al4,are dispersed along the rolling direction.Peeling and bending test results indicate that the fracture occurs in the aluminum substrate,and the morphology is a dimple pattern.No crack or separation is found at the bonding interface after90°-180°bending.The presented method provides an economical way to fabricate Cu/Al clad strip directly.展开更多
The morphological instability of solid/liquid(S/L)interface during solidification will result in different patterns of microstructure.In this study,two dimension(2 D)and three dimension(3 D)in-situ observation of soli...The morphological instability of solid/liquid(S/L)interface during solidification will result in different patterns of microstructure.In this study,two dimension(2 D)and three dimension(3 D)in-situ observation of solid/liquid interfacial morphology transition in Al-Zn alloy during directional solidification were performed via X-ray imaging.Under a condition of increasing temperature gradient(G),the interface transition from dendritic pattern to cellular pattern,and then to planar growth with perturbation was captured.The effect of solidification parameter(the ratio of temperature gradient and growth velocity(v),G/v)on morphological instabilities was investigated and the experimental results were compared to classical"constitutional supercooling"theory.The results indicate that 2 D and 3 D evolution process of S/L interface morphology under the same thermal condition are different.It seems that the S/L interface in 2 D observation is easier to achieve planar growth than that in 3 D,implying higher S/L interface stability in 2 D thin plate samples.This can be explained as the restricted liquid flow under 2 D solidification which is beneficial to S/L interface stability.The in-situ observation in present study can provide coherent dataset for microstructural formation investigation and related model validation during solidification.展开更多
The study of microscopic structure of a liquid/liquid interface is of fundamental importance due to its close relation to the thermodynamics and kinetics of interfacial charge transfer reactions.In this article,the mi...The study of microscopic structure of a liquid/liquid interface is of fundamental importance due to its close relation to the thermodynamics and kinetics of interfacial charge transfer reactions.In this article,the microscopic structure of a non-polarizable water/nitrobenzene(W/NB)interface was evaluated by scanning ion conductance microscope(SICM).Using SICM with a nanometer-sized quartz pipette filled with an electrolyte solution as the probe,the thickness of this type of W/NB interface could be measured at sub-nanometer scale,based on the continuous change of ionic current from one phase to another one.The effects for thicknesses of the non-polarizable W/NB interfaces with different electrolyte concentrations,the Galvani potentials at the interface and the applied potentials on the probe were measured and systematically analyzed.Both experimental setups,that is an organic phase up and an aqueous down,and a reverse version,were employed to acquire the approach curves.These data were compared with those of an ideal polarizable interface under the similar experimental conditions,and several characteristics of non-polarizable interfaces were found.The thickness of a non-polarizable interface increases with the decrease of electrolyte concentration and the increase of applied potential,which is similar to the situation of a polarizable liquid/liquid interface.We also find that the Galvani potential across a non-polarizable interface can also influence the interfacial thickness,this phenomenon is difficult to observe when using polarizable interface.Most importantly,by the comparison of two kinds of liquid/liquid interfaces,we experimentally proved that much more excess ions are gathered in the space charge layer of non-polarizable interfaces than in that of polarizable interfaces.These results are consistent with the predictions of molecular dynamic simulations and X-ray reflectivity measurements.展开更多
The liquid/solid(L/S)interface of dissimilar metals is critical to the microstructure,mechanical strength,and structural integrity of interconnects in many important applications such as electronics,automotive,aeronau...The liquid/solid(L/S)interface of dissimilar metals is critical to the microstructure,mechanical strength,and structural integrity of interconnects in many important applications such as electronics,automotive,aeronautics,and astronautics,and therefore has drawn increasing research interests.To design preferential microstructure and optimize mechanical properties of the interconnects,it is crucial to understand the formation and growth mechanisms of diversified structures at the L/S interface during interconnecting.In situ synchrotron radiation or tube-generated X-ray radiography and tomography technologies make it possible to observe the evolution of the L/S interface directly and therefore have greatly propelled the research in this field.Here,we review the recent progress in understanding the L/S interface behaviors using advanced in situ X-ray imaging techniques with a particular focus on the following two issues:(1)interface behaviors in the solder joints for microelectronic packaging including the intermetallic compounds(IMCs)during refl ow,Sn dendrites,and IMCs during solidification and refl ow porosities and(2)growth characteristics and morphological transition of IMCs in the interconnect of dissimilar metals at high temperature.Furthermore,the main achievements and future research perspectives in terms of metallurgical bonding mechanisms under complex conditions with improved X-ray sources and detectors are remarked and discussed.展开更多
A modified Bridgman directional solidification technique was used to prepare Fe-Al-Ta eutectic in situ composites at different growth rates ranging from 6 to 80 μm/s. The directionally solidified FeAl-Ta eutectic com...A modified Bridgman directional solidification technique was used to prepare Fe-Al-Ta eutectic in situ composites at different growth rates ranging from 6 to 80 μm/s. The directionally solidified FeAl-Ta eutectic composites are composed of two phases: Fe（Al,Ta） matrix phase, and Fe2 Ta（Al） Laves phase. Solidification microstructure is affected by solidification rate. Microstructure of the Fe-Al-Ta eutectic alloy grown at 6.0 μm/s is broken-lamellar eutectic. Eutectic colonies are formed with the increase of the solidification rate. Microstructures are mainly composed of the lamellar or fibrous eutectic at the center of the colony and coarse lamellar eutectic zone at the boundary. Meanwhile, the inter-lamellar spacing（or the inter-rod spacing） is decreased. The spacing adjustments are also observed in Fe-Al-Ta eutectic alloy. The solid/liquid interface evolves from planar interface to shallow cellular interface, then to deep cellular, and finally to shallow cellular planar with the increase of the solidification rate.展开更多
The effect of the pulsed magnetic field on the grain refinement of superalloy K4169 has been studied in directional solidification.In the presence of the solid-liquid interface condition,the distributions of the elect...The effect of the pulsed magnetic field on the grain refinement of superalloy K4169 has been studied in directional solidification.In the presence of the solid-liquid interface condition,the distributions of the electromagnetic force,flow field,temperature field,and Joule heat in front of the solid-liquid interface in directional solidification with the pulsed magnetic field are simulated.The calculation results show that the largest electromagnetic force in the melt appears near the solid-liquid interface,and the electromagnetic force is distributed in a gradient.There are intensive electromagnetic vibrations in front of the solid-liquid interface.The forced melt convection is mainly concentrated in front of the solid-liquid interface,accompanied by a larger flow velocity.The simulation results indicate that the grain refinement is attributed to that the electromagnetic vibration and forced convection increase the nucleation rate and the probability of dendrite fragments survival,for making dendrite easily fragmented,homogenizing the melt temperature,and increasing the undercooling in front of the solid-liquid interface.展开更多
基金supported by the National Science Foundation of China(No.20775060 and No.20875077)the National Science Foundation of Gansu(No.0701RJZA109 and No.0803RJZA105)and the Key Laboratory of Polymer Materials of Gansu Province
文摘The effect of an adsorbed anionic surfactant sodium dodecyl benzene sulfonate （SDBS） on electron transfer （ET） reaction between ferricyanide aqueous solution and decamethylferrocene （DMFc） located on the adjacent organic phase was investigated for the first time by thin layer method. The adsorption of SDBS at the interface resulted in a decay in the cathodic plateau current of bimolecular reaction with increasing concentrations of SDBS in aqueous phase. However, the rate constant of electron transfer （ket） increased monotonically as the SDBS concentrations increased from 0 to 200 p, moFL. The experimental results showed that SDBS formed patches on the interface and influenced the structure of electrical double layer. 2009 Xiao Quan Lu. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
基金Supported by the NaturalScienceFoundation of China( No.2 0 2 75 0 31) ,the Teaching and Research Award Programfor Outstanding Young Techers in High Education of MOE of China and KJCX- 0 1of Northwest Normal University
文摘Electrochemical transfer behavior of V ⅤW 11 -V Ⅴ 3W 9 heteropoly anions on the water/nitrobenzene interface was investigated by means of cyclic voltammetry. The effect of the solution acidity on the transfer behavior and the stable pH range for the heteropoly anions were studied. The stability of mixed tungstovanadate decreases with increasing the number of vanadium atoms. The main transfer species within the potential window have the negative charges of 4 and the transfer process is diffusion controlled. The apparent transfer potential Δ w o Ψ 0 and the free energy Δ G 0 w→o tr for the heteropoly anions can be obtained from the experimental data. For the different anions, the Δ w o Ψ 1/2 pH relationship can be expressed as: Δ w o Ψ 1/2 =constant-53pH.
基金supported by the Natural Science Foundation of China(No.20775060,No.20875077 and No. 20927004)the Natural Science Foundation of Gansu(No.0701RJZA109 and No.0803RJZA105)Key Projects of Scientific Research Base of Department of Education,Gansu Province(No.08zx-07)
文摘The oxidation of hydroquinone(QH_2) was investigated for the first time at liquid/liquid(L/L) interface by scanning electrochemical microscopy(SECM).In this study,electron transfer(ET) from QH_2 in aqueous to ferrocene(Fc) in nitrobenzene (NB) was probed.The apparent heterogeneous rate constants for ET reactions were obtained by fitting the experimental approach curves to the theoretical values.The results showed that the rate constants for oxidation reaction of QH_2 were sensitive to the changes of the dri...
基金supported by the National Natural Science Foundation of China(No.20875077,No.20775060 and No.20927004)the Natural Science Foundation of Gansu(No.0701RJZA109 and No.0803RJZA105)Key Projects of Scientific Research Base of Department of Education,Gansu Province(No.08zx-07).
文摘Comparison in electron transfer(ET) processes from decamethyferrocene(DMFe) in nitrobenzene(NB) to ferric ion in aqueous phase was investigated for the first time by the scanning electrochemical microscopy(SECM).As compared with the system of Fe(CN)_6^(3-)-DMFe,the ET rate obtained from Fe^(3+)-DMFe was lower in spite of larger driving force,which may arise from the effect of reorganization energy.Otherwise,the effect of common ion on rate constants was also probed and results suggested additional complexit...
基金the Scientific Research Projects (BAP) of Selcuk University, Turkey (2003/151).
文摘The ion transfer reaction of 2-benzoylpyridine-thiosemicarbazone (HL), which has antimicrobial and antifungal properties and anticancer activity, has been studied to determine its lipophilicity by cyclic voltammetry at the water/1,2-dichloroethane (1,2-DCE) interface. The physicochemical parameters such as standard partition coefficient (lgPI)andthestandardGibbsenergyoftransfer("G0tr,,wI "o)oftheprotonatedformoftheligandwere measured asa function of pH in aqueous phase. The protonated form of the ligand exhibited reversible or quasi-reversible voltammograms at the1,2-DCEintherangeofpH1-5.Theprotonationconstantsoftheligand,pKa1andpKa2,weredeterminedspectrophotometrically and were found to be 12.14 and 3.24, respectively. The standard Gibbs energy of transfer ("G0tr,,wN" o) and the partition coefficient of neutral species (lgPN) were also determined by the shake-flask method. The standard Gibbs energy of transfer of this compound across the water/1,2-DCE interface was evaluated as the quantitative measure of its lipophilicity. The difference between lgPI and lgPN was related to the degree of charge delocalization and was used to evaluate qualitatively the lipophilicity of the ligand.
基金supported by the Russian Science Foundation(23-29-00830).
文摘Morphology and growth rate of carbon dioxide hydrate on the interface between liquid carbon dioxide and humic acid solutions were studied in this work.It was found that after the growth of the hydrate film at the interface,further growth of hydrate due to the suction of water in the capillary system formed between the wall of the cuvette and the end boundary of the hydrate layer occurs.Most probably,substantial effects on the formation of this capillary system may be caused by variations in reactor wall properties,for example,hydrophobic-hydrophilic balance,roughness,etc.We found,that the rate of CO_(2) hydrate film growth on the surface of the humic acid aqueous solution is 4-fold to lower in comparison with the growth rate on the surface of pure water.We suppose that this is caused by the adsorption of humic acid associates on the surface of hydrate particles and,as a consequence,by the deceleration of the diffusion of dissolved carbon dioxide to the growing hydrate particle.
基金Project supported by the Natural Science Foundation of Guangxi Zhuang Autonomous Region, China (Grant No. 2022GXNSFAA035487)the National Natural Science Foundation of China (Grant Nos. 12272100, 11474285, and 12074382)+2 种基金the Graduate Education Innovation Project of Guangxi Zhuang Autonomous Region, China (Grant No. XJCY2022012)the Guangxi Normal University Ideological and Political Demonstration Course Construction Project (Grant Nos. 2022kcsz15 and 2023kcsz29)the Innovation Project of Graduate Education of Guangxi Zhuang Autonomous Region, China (Grant No. YCBZ2024087)。
文摘We study the effects of gas adsorption on the dynamics and stability of nanobubbles at the solid–liquid interface. The phase diagram and dynamic evolution of surface nanobubbles were analyzed under varying equilibrium adsorption constant.Four distinct dynamic behaviors appear in the phase diagram: shrinking to dissolution, expanding to bursting, shrinking to stability, and expanding to stability. Special boundary states are identified in phase diagram, where the continuous growth of nanobubbles can take place even under very weak gas–surface interaction or with very small initial bubble size. Surface adsorption plays a critical role in the stability, lifetime, radius, and contact angle of nanobubbles, thereby demonstrating that pinning is not a prerequisite for stabilization. Furthermore, stable equilibrium nanobubbles exhibit a characteristic range of footprint radius, a limited height, and a small contact angle, consistent with experimental observations.
基金German research Foundation(DFG,grant numbers:CH2321/1–1 and SCHO1231/7–1)JH has received a scholarship from the Chinese Scholarship Council(CSC No.:201908350115).
文摘The oviduct epithelium is the initial maternal contact site for embryos after fertilization,offering the microenviron-ment before implantation.This early gestation period is particularly sensitive to stress,which can cause reduced fertil-ity and reproductive disorders in mammals.Nevertheless,the local impact of elevated stress hormones on the ovi-duct epithelium has received limited attention to date,except for a few reports on polyovulatory species like mice and pigs.In this study,we focused on the effects of chronic maternal stress on cattle,given its association with infertil-ity issues in this monoovulatory species.Bovine oviduct epithelial cells(BOEC)differentiated at the air–liquid interface(ALI)were stimulated with 250 nmol/L cortisol for 1 or 3 weeks.Subsequently,they were assessed for morphology,bioelectrical properties,and gene expression related to oviduct function,glucocorticoid pathway,cortisol metabo-lism,inflammation,and apoptosis.Results revealed adverse effects of cortisol on epithelium structure,featured by deciliation,vacuole formation,and multilayering.Additionally,cortisol exposure led to an increase in transepithelial potential difference,downregulated mRNA expression of the major glucocorticoid receptor(NR3C1),upregulated the expression of cortisol-responsive genes(FKBP5,TSC22D3),and significant downregulation of oviductal glycopro-tein 1(OVGP1)and steroid receptors PGR and ESR1.The systematic comparison to a similar experiment previously performed by us in porcine oviduct epithelial cells,indicated that bovine cultures were more susceptible to elevated cortisol levels than porcine.The distinct responses between both species are likely linked to their divergence in the cortisol-induced expression changes of HSD11B2,an enzyme controlling the cellular capacity to metabolise cortisol.These findings provide insights into the species-specific reactions and reproductive consequences triggered by maternal stress.
基金supported by the National Natural Science Foundation of China(Nos.52025132,U24A20205,52303373,21621091,22021001,and 22121001)the China Postdoctoral Science Foundation(No.2024M763174)+2 种基金the 111 Project(Nos.B17027,B16029)the Natural Science Foundation of Fujian Province of China(No.2022J02059)the New Cornerstone Science Foundation through the Xplorer Prize。
文摘Controllable liquid manipulation is of paramount scientific and technological importance in various fields,such as the chemical industry,biomedicine,and agricultural production.Magnetic actuation,characterized by rapid,contactless,and environmentally benign operation,has emerged as a promising approach for precise liquid control.However,conventional magnetic strategies typically govern droplet movement on open surfaces,facing limitations such as restricted liquid volumes,uncertain flow paths,and inevitable evaporation,thereby constraining their broader practical applications.Recently,a variety of magneticdriven strategies have been developed to dynamically regulate liquids within enclosed spaces,especially through physicochemical mechanisms.These approaches provide efficient control over liquid behavior by leveraging magnetically induced chemical changes,structural deformations,and dragging motions,opening new opportunities for flexible and versatile fluid management.This review explores the design and mechanisms of magneto-responsive confined interfaces for the manipulation of nonmagnetic liquids,highlighting key advancements and potential applications including liquid valves,liquid mixing,liquid flow regulation,and liquid pumping.Finally,the existing challenges and future prospects in this field are presented.
文摘The large-scale commercialization of proton exchange membrane fuel cells(PEMFCs)has been hindered by the high demand of platinum(Pt)in the cathode due to the sluggish kinetics of the oxygen reduction reaction.Reducing the amount of Pt would worsen the problems caused by the adsorption of perfluorinated sulfonic acid(PFSA)ionomers to Pt via the side chains,namely,blocking the active sites of Pt and inducing densely packed layers of fluorocarbon backbones on Pt surface to obstruct local O_(2)transport at the Pt/PFSA interfaces.This work aims at optimizing the Pt/ionomer interface to mitigate the sulfonate adsorption and in the meantime to reduce the local O_(2)transport resistance(R_(local)),by using a porous composite of 1-butyl-3-methylimidazolium hydrogen sulfate ionic liquid(IL)modified MOF-808(BMImHSO_(4)@MOF-808)as additive in cathodic catalyst layer(CCL).Through detailed physical,spectroscopic and electrochemical characterizations,we demonstrate a three-fold optimization mechanism of Pt/ionomer interface structure by BMImHSO_(4)@MOF-808:the unsaturated metal sites in MOF-808 effectively inhibit the sulfonate adsorption on Pt through coordination with the sulfonates of PFSA,thereby improving catalyst utilization;the pores in MOF-808 establish efficient transport channels for gaseous oxygen,significantly reducing R_(local);the IL modification layers facilitate the formation of continuous proton transport networks,increasing proton conductivity.The incorporation of BMImHSO_(4)@MOF-808 in a low-Pt CCL(0.1 mg_(Pt)cm^(-2))yields a peak power density of 1.9 W cm^(-2)for PEMFC under H_(2)-O_(2)condition,and ca.20%increase of power density under H_(2)-air condition as compared with conventional CCL,indicating the prospect of IL-MOF composites as an efficient additive to enhance the performance of PEMFCs.
基金supported by the Science,Technology,and Innovation Commission of Shenzhen Municipality(No.GJHZ20220913143204008)the Shccig-Qinling Program(No.SMYJY202300294C)+3 种基金National Natural Science Foundation of China(Nos.22261142666,52372225,52172237,22305191)the Shaanxi Science Fund for Distinguished Young Scholars(No.2022JC-21)the Research Fund of the State Key Laboratory of Solidification Processing(NPU)China(No.2021-QZ-02).
文摘The stability of perovskite solar cells(PSCs)is adversely affected by nonradiative recombination resulting from buried interface defects.Herein,we synthesize a polyionic liquid,poly(p-vinylbenzyl trimethylam-monium hexafluorophosphate)(PTA),and introduce it into the buried interface of PSCs.The quaternary ammonium cation(N(-CH_(3))^(3+))in PTA can fill the vacancies of organic cations within the perovskite structure and reduce shallow energy level defects.Additionally,the hexafluorophosphate(PF6−)in PTA forms a Lewis acid-base interaction with Pb^(2+)in the perovskite layer,effectively passivating deep en-ergy level defects.Furthermore,hydrogen bonding can be established between organic cations and the PF6−anion,preventing the formation of shallow energy level defects.Through this synergistic mecha-nism,the deep and shallow energy level defects are effectively mitigated,resulting in improved device performance.As a result,the resulting treated inverted PSC exhibits an impressive power conversion ef-ficiency(PCE)of 24.72%.Notably,the PTA-treated PSCs exhibit remarkable stability,with 88.5%of the original PCE retained after undergoing heat aging at 85℃ for 1078 h,and 89.1%of the initial PCE main-tained following continuous exposure to light for 1100 h at the maximum power point.Synergistically suppressing multiple defects at the buried interface through the use of polyionic liquids is a promising way to improve the commercial viability of PSCs.
文摘Pediatric cancers are particularly significant due to their uncommon occurrence in children,driven by a variety of underlying factors.Because of their distinct molecular and genetic makeup,which makes early detection challenging,they are linked to problems.Diagnostic methods like imaging and tissue biopsy are only effective when the tumor has reached a size that can be identified.The liquid biopsy technique,the least intrusive and most convenient diagnostic method,is the subject of this review.It focuses on the significance of single cell analysis in examining uncommon cancer types.The many biomarkers found in bodily fluids and the cancer types they are linked to in children have been assessed,as has the potential route towards early detection and cancer recurrence forecasting.Combining the single cell liquid biopsy with the newest technologies,such as computational and multi-omics approaches,which have improved the efficiency of processing massive and unique genetic data,appears promising.This article discusses on a number of case reports for uncommon pediatric malignancies,such as Neuroblastoma,Medulloblastoma,Wilms Tumor,Rhabdomyosarcoma,Ewing Sarcoma,and Retinoblastoma,as well as their liquid biopsy profiles.Furthermore,the findings raise ethical questions regarding the therapeutic application of the technology as well as possible difficulties related to clinical translation.The likelihood that this single cell liquid biopsy will be clinically validated and eventually used as a routine diagnostic tool for uncommon pediatric cancers will rise with the realistic approach to sensitivity monitoring,specificity upgrading,and optimization.
基金supported by National Key Research and Development Program of China(2022YFB3804902,2022YFB3804900)the National Natural Science Foundation of China(52203226,52161145406,42376045)the Fundamental Research Funds for the Central Universities(2232024Y-01,2232025D-02).
文摘While desalination is a key solution for global freshwater scarcity,its implementation faces environmental challenges due to concentrated brine byproducts mainly disposed of via coastal discharge systems.Solar interfacial evaporation offers sustainable management potential,yet inevitable salt nucleation at evaporation interfaces degrades photothermal conversion and operational stability via light scattering and pathway blockage.Inspired by the mangrove leaf,we propose a photothermal 3D polydopamine and polypyrrole polymerized spacer fabric(PPSF)-based upward hanging model evaporation configuration with a reverse water feeding mechanism.This design enables zero-liquiddischarge(ZLD)desalination through phase-separation crystallization.The interconnected porous architecture and the rough surface of the PPSF enable superior water transport,achieving excellent solar-absorbing efficiency of 97.8%.By adjusting the tilt angle(θ),the evaporator separates the evaporation and salt crystallization zones via controlled capillary-driven brine transport,minimizing heat dissipation from brine discharge.At an optimal tilt angle of 52°,the evaporator reaches an evaporation rate of 2.81 kg m^(−2) h^(−1) with minimal heat loss(0.366 W)under 1-sun illumination while treating a 7 wt%waste brine solution.Furthermore,it sustains an evaporation rate of 2.71 kg m^(−2) h^(−1) over 72 h while ensuring efficient salt recovery.These results highlight a scalable,energy-efficient approach for sustainable ZLD desalination.
基金supported by Department of Defense grant HT9425-24-1-0030 a grant from the Stanley Medical Research Institute(to SS).
文摘The inability to access brain tissue has greatly hindered our ability to study and care for individuals suffering from psychiatric and neurological conditions.Critics have questioned efforts to develop peripheral blood biomarkers in neurological and psychiatric disorders based on the assertion that disease pathology is limited to the brain.The discovery that all tissues,including the brain,release extracellular vesicles(Raposo and Stoorvogel,2013)and cell free DNAs(Chan et al.,2013)into various body fluids has provided a potential way to measure activity from inaccessible tissues like the central nervous system(CNS)and has given rise to the term“liquid biopsy.”The development of liquid biopsies that can diagnose and predict the course of psychiatric and neurological disorders would be transformative.The ability to predict episodic events such as mania,depression,and risk for suicide would be particularly useful for psychiatric care as it would enable the development of interventions that prevent mortality and improve outcomes.Additionally,biomarkers that are informative about drug response and aid in treatment decisions would be a significant advance in psychiatric care as it would prevent patients from having to endure multiple courses of ineffective treatments and side effects.
基金Project(51474189)supported by the National Natural Science Foundation of ChinaProject(QN2015214)supported by the Educational Commission of Hebei Province,China
文摘Cu/Al clad strips are prepared using solid?liquid cast-rolling bonding(SLCRB)technique with a d160mm×150mm twin-roll experimental caster.The extent of interfacial reactions,composition of the reaction products,and their micro-morphology evolution in the SLCRB process are investigated with scanning electron microscope(SEM),energy dispersive spectrometer(EDS),and X-ray diffraction(XRD).In the casting pool,initial aluminized coating is first generated on the copper strip surface,with the diffusion layer mainly consisting ofα(Al)+CuAl2and growing at high temperatures,with the maximum thickness of10μm.After sequent rolling below the kiss point,the diffusion layer is broken by severe elongation,which leads to an additional crack bond process with a fresh interface of virgin base metal.The average thickness is reduced from10to5μm.The reaction products,CuAl2,CuAl,and Cu9Al4,are dispersed along the rolling direction.Peeling and bending test results indicate that the fracture occurs in the aluminum substrate,and the morphology is a dimple pattern.No crack or separation is found at the bonding interface after90°-180°bending.The presented method provides an economical way to fabricate Cu/Al clad strip directly.
基金financially supported by National Natural Science Foundation of China(Grants 51690162,51604171 and 51701112)Shanghai Municipal Science and Technology Commission(No.17JC1400602)Shanghai Sailing Program(19YF1415900).
文摘The morphological instability of solid/liquid(S/L)interface during solidification will result in different patterns of microstructure.In this study,two dimension(2 D)and three dimension(3 D)in-situ observation of solid/liquid interfacial morphology transition in Al-Zn alloy during directional solidification were performed via X-ray imaging.Under a condition of increasing temperature gradient(G),the interface transition from dendritic pattern to cellular pattern,and then to planar growth with perturbation was captured.The effect of solidification parameter(the ratio of temperature gradient and growth velocity(v),G/v)on morphological instabilities was investigated and the experimental results were compared to classical"constitutional supercooling"theory.The results indicate that 2 D and 3 D evolution process of S/L interface morphology under the same thermal condition are different.It seems that the S/L interface in 2 D observation is easier to achieve planar growth than that in 3 D,implying higher S/L interface stability in 2 D thin plate samples.This can be explained as the restricted liquid flow under 2 D solidification which is beneficial to S/L interface stability.The in-situ observation in present study can provide coherent dataset for microstructural formation investigation and related model validation during solidification.
基金supported by the National Natural Science Foundation of China(21575006,21335001)the National Key Research and Development Program of China(2016YFA0201300).
文摘The study of microscopic structure of a liquid/liquid interface is of fundamental importance due to its close relation to the thermodynamics and kinetics of interfacial charge transfer reactions.In this article,the microscopic structure of a non-polarizable water/nitrobenzene(W/NB)interface was evaluated by scanning ion conductance microscope(SICM).Using SICM with a nanometer-sized quartz pipette filled with an electrolyte solution as the probe,the thickness of this type of W/NB interface could be measured at sub-nanometer scale,based on the continuous change of ionic current from one phase to another one.The effects for thicknesses of the non-polarizable W/NB interfaces with different electrolyte concentrations,the Galvani potentials at the interface and the applied potentials on the probe were measured and systematically analyzed.Both experimental setups,that is an organic phase up and an aqueous down,and a reverse version,were employed to acquire the approach curves.These data were compared with those of an ideal polarizable interface under the similar experimental conditions,and several characteristics of non-polarizable interfaces were found.The thickness of a non-polarizable interface increases with the decrease of electrolyte concentration and the increase of applied potential,which is similar to the situation of a polarizable liquid/liquid interface.We also find that the Galvani potential across a non-polarizable interface can also influence the interfacial thickness,this phenomenon is difficult to observe when using polarizable interface.Most importantly,by the comparison of two kinds of liquid/liquid interfaces,we experimentally proved that much more excess ions are gathered in the space charge layer of non-polarizable interfaces than in that of polarizable interfaces.These results are consistent with the predictions of molecular dynamic simulations and X-ray reflectivity measurements.
基金supported by the National Key Research and Development Program(Nos.2017YFA0403800 and 2017YFB0305301)the National Natural Science Foundation of ChinaExcellent Young Scholars(No.51922068)+1 种基金the National Natural Science Foundation of China(Nos.51727802,51821001 and 51904187)funded by China Postdoctoral Science Foundation(No.2019M661500)。
文摘The liquid/solid(L/S)interface of dissimilar metals is critical to the microstructure,mechanical strength,and structural integrity of interconnects in many important applications such as electronics,automotive,aeronautics,and astronautics,and therefore has drawn increasing research interests.To design preferential microstructure and optimize mechanical properties of the interconnects,it is crucial to understand the formation and growth mechanisms of diversified structures at the L/S interface during interconnecting.In situ synchrotron radiation or tube-generated X-ray radiography and tomography technologies make it possible to observe the evolution of the L/S interface directly and therefore have greatly propelled the research in this field.Here,we review the recent progress in understanding the L/S interface behaviors using advanced in situ X-ray imaging techniques with a particular focus on the following two issues:(1)interface behaviors in the solder joints for microelectronic packaging including the intermetallic compounds(IMCs)during refl ow,Sn dendrites,and IMCs during solidification and refl ow porosities and(2)growth characteristics and morphological transition of IMCs in the interconnect of dissimilar metals at high temperature.Furthermore,the main achievements and future research perspectives in terms of metallurgical bonding mechanisms under complex conditions with improved X-ray sources and detectors are remarked and discussed.
基金Funded by the National Natural Science Foundation of China(No.51201121)2015 Science and Technology Foundation for Selected Overseas Chinese Scholars of Shaanxi Province,Key Industry Innovation Chain(group)Project of Shaanxi Province(No.2019ZDLGY 04-04)International Science+1 种基金Technology Cooperation and Exchange Program of Shaanxi Province(No.2016KW-055)Research Project of Shaanxi Engineering Technology Research Center for Wear-resisting Materials(No.2016NMZX03)
文摘A modified Bridgman directional solidification technique was used to prepare Fe-Al-Ta eutectic in situ composites at different growth rates ranging from 6 to 80 μm/s. The directionally solidified FeAl-Ta eutectic composites are composed of two phases: Fe（Al,Ta） matrix phase, and Fe2 Ta（Al） Laves phase. Solidification microstructure is affected by solidification rate. Microstructure of the Fe-Al-Ta eutectic alloy grown at 6.0 μm/s is broken-lamellar eutectic. Eutectic colonies are formed with the increase of the solidification rate. Microstructures are mainly composed of the lamellar or fibrous eutectic at the center of the colony and coarse lamellar eutectic zone at the boundary. Meanwhile, the inter-lamellar spacing（or the inter-rod spacing） is decreased. The spacing adjustments are also observed in Fe-Al-Ta eutectic alloy. The solid/liquid interface evolves from planar interface to shallow cellular interface, then to deep cellular, and finally to shallow cellular planar with the increase of the solidification rate.
基金financially supported by the National Natural Science Foundation of China (No. 51674236)the Key Research and Development Program of Liaoning Province (No.2019JH2/10100009)+1 种基金the National Science and Technology Major Project (No.2017-Ⅵ-0003-0073)the National Key Research and Development Program (No.2018Y-FA0702900)。
文摘The effect of the pulsed magnetic field on the grain refinement of superalloy K4169 has been studied in directional solidification.In the presence of the solid-liquid interface condition,the distributions of the electromagnetic force,flow field,temperature field,and Joule heat in front of the solid-liquid interface in directional solidification with the pulsed magnetic field are simulated.The calculation results show that the largest electromagnetic force in the melt appears near the solid-liquid interface,and the electromagnetic force is distributed in a gradient.There are intensive electromagnetic vibrations in front of the solid-liquid interface.The forced melt convection is mainly concentrated in front of the solid-liquid interface,accompanied by a larger flow velocity.The simulation results indicate that the grain refinement is attributed to that the electromagnetic vibration and forced convection increase the nucleation rate and the probability of dendrite fragments survival,for making dendrite easily fragmented,homogenizing the melt temperature,and increasing the undercooling in front of the solid-liquid interface.
