Aiming at searching for plant growth promoting rhizobacteria (PGPR), a bacterium strain coded as 7016 was isolated from soybean rhizosphere and was characterized in the present study. It was identiifed as Burkholderia...Aiming at searching for plant growth promoting rhizobacteria (PGPR), a bacterium strain coded as 7016 was isolated from soybean rhizosphere and was characterized in the present study. It was identiifed as Burkholderia sp. based on 16S rDNA sequence analysis, as wel as phenotypic and biochemical characterizations. This bacterium presented nitrogenase activity, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity and phosphate solubilizing ability;inhibited the growth of Sclerotinia sclerotiorum, Gibberel a zeae and Verticil ium dahliae;and produced smal quantities of indole acetic acid (IAA). In green house experiments, signiifcant increases in shoot height and weight, root length and weight, and stem diameter were observed on tomato plants in 30 d after inoculation with strain 7016. Result of 16S rDNA PCR-DGGE showed that 7016 survived in the rhizosphere of tomato seedlings. In the ifeld experiments, Burkholderia sp. 7016 enhanced the tomato yield and signiifcantly promoted activities of soil urease, phosphatase, sucrase, and catalase. Al these results demonstrated Burkholderia sp. 7016 as a valuable PGPR and a candidate of biofertilizer.展开更多
AIM To evaluate the feasibility of reducing the dose of iodinated contrast agent in computed tomography pulmonary angiography(CTPA). METHODS One hundred and twenty-seven patients clinically suspected of having pulmona...AIM To evaluate the feasibility of reducing the dose of iodinated contrast agent in computed tomography pulmonary angiography(CTPA). METHODS One hundred and twenty-seven patients clinically suspected of having pulmonary embolism underwent spiral CTPA, out of whom fifty-seven received 75 mL and the remaining seventy a lower dose of 60 mL of contrast agent. Both doses were administered in a multiphasic injection. A minimum opacification threshold of 250 Hounsfield units(HU) in the main pulmonary artery is used for assessing the technical adequacy of the scans. RESULTS Mean opacification was found to be positively correlated to patient age(Pearson's correlation 0.4255, P < 0.0001) and independent of gender(male:female, 425.6 vs 450.4,P = 0.34). When age is accounted for, the study and control groups did not differ significantly in their mean opacification in the main(436.8 vs 437.9, P = 0.48),left(416.6 vs 419.8, P = 0.45) or the right pulmonary arteries(417.3 vs 423.5, P = 0.40). The number of sub-optimally opacified scans(the mean opacification in the main pulmonary artery < 250 HU) did not differ significantly between the study and control groups(7 vs 10).CONCLUSION A lower dose of iodine contrast at 60 mL can be feasibly used in CTPA without resulting in a higher number of sub-optimally opacified scans.展开更多
Fe-based compounds with good environmental friendliness and high reversible capacity have attracted considerable attention as anode for lithium-ion batteries.But,similar to other transition metal oxides(TMOs),it is al...Fe-based compounds with good environmental friendliness and high reversible capacity have attracted considerable attention as anode for lithium-ion batteries.But,similar to other transition metal oxides(TMOs),it is also affected by large volume changes and inferior kinetics during redox reactions,resulting in the destruction of the crystal structure and poor electrochemical performance.Here,Fe_(3)O_(4)/C nanospheres anchored on the two-dimensional graphene oxide as precursors are phosphated and sintered to build the multiphasic nanocomposite.XRD results confirmed the multiphasic nanocomposite composed of Fe2O3,Fe_(3)O_(4) and Fe_(3)PO_(7),which will facilitate the Li+diffusion.And the carbonaceous matrix will buffer the volume changes and enhance electron conduction.Consequently,the multiphasic Febased anode delivers a large specific capacity of 1086 mAh/g with a high initial Coulombic efficiency of 87%at 0.1 C.It also has excellent cycling stability and rate property,maintaining a capacity retention of~87%after 300 cycles and a high reversible capacity of 632 mAh/g at 10 C.The proposed multiphasic structure offers a new insight into improving the electrochemical properties of TMO-based anodes for advanced alkali-ion batteries.展开更多
Previous studies using magnetic resonance imaging（MRI）and functional MRI to study depression have primarily focused on proton magnetic resonance spectroscopy（1H-MRS）appearance in various areas of the brain and vol...Previous studies using magnetic resonance imaging（MRI）and functional MRI to study depression have primarily focused on proton magnetic resonance spectroscopy（1H-MRS）appearance in various areas of the brain and volume measurements in the limbic system.However,results have not been consistent.To the best of our knowledge,very little is known about the relationship between 1H-MRS appearance and depression inventory.In the present study,the relationship between 1H-MRS appearance in depressive patients and Minnesota Multiphasic Personality Inventory-2 scale was analyzed.MRI and 1H-MRS exhibited widened sulci and cisterns,as well as an absence of abnormal signals in depressive patients.In addition,N-acetyl aspartate/total creatine ratios in bilateral hippocampi and dorsolateral prefrontal cortex were significantly less in depressive patients than in control subjects（P 〈 0.01）.In contrast,choline-containing compounds/total creatine ratios in the dorsolateral prefrontal cortex were significantly greater in depressive patients than in control subjects（P 〈 0.01）.These ratios significantly and positively correlated with patient total depression scores as assessed using the Minnesota Multiphasic Personality Inventory-2 scale（r=0.934 7,0.878 7,P 〈 0.01）.These results suggested that 1H-MRS could be used to reveal a reduced number of neurons in the hippocampus and dorsolateral prefrontal cortex,as well as altered membrane phospholipid metabolism in the dorsolateral prefrontal cortex,in patients with depressive disorder.Abnormal mechanisms partially reflected severity of depressive disorder.展开更多
Multiphasic scaffolds with tailored gradient features hold significant promise for tissue regeneration applications. Herein, this work reports the transformation of two-dimensional (2D) layered fiber mats into three-d...Multiphasic scaffolds with tailored gradient features hold significant promise for tissue regeneration applications. Herein, this work reports the transformation of two-dimensional (2D) layered fiber mats into three-dimensional (3D) multiphasic scaffolds using a ‘solids-of-revolution’ inspired gas-foaming expansion technology. These scaffolds feature precise control over fiber alignment, pore size, and regional structure. Manipulating nanofiber mat layers and Pluronic F127 concentrations allows further customization of pore size and fiber alignment within different scaffold regions. The cellular response to multiphasic scaffolds demonstrates that the number of cells migrated and proliferated onto the scaffolds is mainly dependent on the pore size rather than fiber alignment. In vivo subcutaneous implantation of multiphasic scaffolds to rats reveals substantial cell infiltration, neo tissue formation, collagen deposition, and new vessel formation within scaffolds, greatly surpassing the capabilities of traditional nanofiber mats. Histological examination indicates the importance of optimizing pore size and fiber alignment for the promotion of cell infiltration and tissue regeneration. Overall, these scaffolds have potential applications in tissue modeling, studying tissue-tissue interactions, interface tissue engineering, and highthroughput screening for optimized tissue regeneration.展开更多
Magnesium hydride(MgH_(2))has garnered significant attention as a promising material for high-capacity hydrogen storage.However,its commercial application remains challenging due to the high operating temperature and ...Magnesium hydride(MgH_(2))has garnered significant attention as a promising material for high-capacity hydrogen storage.However,its commercial application remains challenging due to the high operating temperature and slow reaction kinetics.In this study,melt-spun Ti_(45)Cr_(40)Nb_(15)(with a BCC phase)hydride(designated as TiCrNbH_(x-)MS)was synthesized and used to form a nano-multiphase composite to improve the de-/rehydrogenation properties of MgH_(2) through ball milling.The incorporation of TiCrNbH_(x-)MS was shown to significantly enhance the hydrogen de-/rehydrogenation properties of MgH_(2).The MgH_(2)+20 wt%TiCrNbH_(x-)MS composite exhibits an appealing initial dehydrogenation temperature of 163℃ and can absorb hydrogen at room temperature.Notably,it releases 5.8 wt% hydrogen in 700 s at 230℃ and recharges 4.3 wt%hydrogen in just 2 mins at 150℃.Even after 100 cycles,it retains a reversible hydrogen capacity of 4.98 wt%.Kinetic analysis revealed that the dehydrogenation rate follows the Chou surface penetration model.Microstructural analysis showed that the FCC phase of the melt-spun TiCrNbH_(x-)MS hydride reversibly transformed into the BCC phase during the de-/rehydrogenation process in the composite.Numerous phase interfaces were generated and uniformly dispersed on the MgH_(2) surface,providing additional hydrogen diffusion pathways and heterogeneous nucleation sites for Mg/MgH_(2),thereby further improving the hydrogen de-/rehydrogenation kinetics of the system.This study offers valuable insights into the use of multiphase composites to enhance MgH_(2) performance.展开更多
Osteochondral defects are caused by injury to both the articular cartilage and subchondral bone within skeletal joints. They can lead to irreversible joint damage and increase the risk of progression to osteoarthritis...Osteochondral defects are caused by injury to both the articular cartilage and subchondral bone within skeletal joints. They can lead to irreversible joint damage and increase the risk of progression to osteoarthritis. Current treatments for osteochondral injuries are not curative and only target symptoms, highlighting the need for a tissue engineering solution. Scaffold-based approaches can be used to assist osteochondral tissue regeneration, where biomaterials tailored to the properties of cartilage and bone are used to restore the defect and minimise the risk of further joint degeneration. This review captures original research studies published since 2015, on multiphasic scaffolds used to treat osteochondral defects in animal models. These studies used an extensive range of biomaterials for scaffold fabrication, consisting mainly of natural and synthetic polymers. Different methods were used to create multiphasic scaffold designs, including by integrating or fabricating multiple layers, creating gradients, or through the addition of factors such as minerals, growth factors, and cells. The studies used a variety of animals to model osteochondral defects, where rabbits were the most commonly chosen and the vast majority of studies reported small rather than large animal models. The few available clinical studies reporting cell-free scaffolds have shown promising early-stage results in osteochondral repair, but long-term follow-up is necessary to demonstrate consistency in defect restoration. Overall, preclinical studies of multiphasic scaffolds show favourable results in simultaneously regenerating cartilage and bone in animal models of osteochondral defects, suggesting that biomaterials-based tissue engineering strategies may be a promising solution.展开更多
Multiphase flow in porous rock is of great importance in the application of many industrial processes,including reservoir delineation,enhanced oil recovery,and CO_(2) sequestration.However,previous research typically ...Multiphase flow in porous rock is of great importance in the application of many industrial processes,including reservoir delineation,enhanced oil recovery,and CO_(2) sequestration.However,previous research typically investigated the dispersive behaviors when rock saturated with single or two-phase fluids and conducted limited studies on three-phase immiscible fluids.This study investigated the seismic dispersion,attenuation,and reflection features of seismic waves in three-phase immiscible fluidsaturated porous rocks.First,we proposed the calculation formulas of effective fluid modulus and effective fluid viscosity of multiphase immiscible fluids by taking into account the capillary pressure,reservoir wettability,and relative permeability simultaneously.Then,we analysed the frequencydependent behaviors of three-phase immiscible fluid-saturated porous rock under different fluid proportion cases using the Chapman multi-scale model.Next,the seismic responses are analysed using a four-layer model.The results indicate that the relative permeability,capillary pressure parameter,and fluid proportions are all significantly affect dispersion and attenuation.Comparative analyses demonstrate that dispersion and attenuation can be observed within the frequency range of seismic exploration for a lower capillary parameter a3 and higher oil content.Seismic responses reveal that the reflection features,such as travel time,seismic amplitude,and waveform of the bottom reflections of saturated rock and their underlying reflections are significantly dependent on fluid proportions and capillary parameters.For validation,the numerical results are further verified using the log data and real seismic data.This numerical analysis helps to further understand the wave propagation characteristics for a porous rock saturated with multiphase immiscible fluids.展开更多
Based on the energy dissipation caused by consolidation deformation of the porous media under external force and migration of the internal suspended substances,a coupled multiphase-substance flow(CMF)model was establi...Based on the energy dissipation caused by consolidation deformation of the porous media under external force and migration of the internal suspended substances,a coupled multiphase-substance flow(CMF)model was established.This model introduced the new concepts,such as particle temperature and particle entropy,to describe energy dissipation at meso-level.This model used a potential energy density function and migration coefficients to establish the corresponding connection between the dissipative force and dissipative flow.This viewpoint unifies the deformation,seepage,and suspended substance migration of geotechnical materials under the framework of granular thermodynamics.It can reflect the evolution of effective stress in the solid matrix of multi-components in a particle-reorganized state,and considers the temperature driving effect.The proposed CMF model is validated using the experimental results under coupled migration of heavy metal ions(HMs)and suspended particles(SPs).The calculation results demonstrated that the CMF model can describe the flow process under the conditions of arbitrary changes in different suspended substance types,injection concentrations,and injection velocities.展开更多
This review summarizes recent progress in the study of impinging-jet dynamics and atomization,with a focus on liquid sheet formation,instability mechanisms,and the influence of key parameters such as fluid properties,...This review summarizes recent progress in the study of impinging-jet dynamics and atomization,with a focus on liquid sheet formation,instability mechanisms,and the influence of key parameters such as fluid properties,Weber number,and Reynolds number.Special attention is given to atomization behaviors under high pressure and external perturbations.Representative experimental and numerical approaches are introduced,and critical findings under complex conditions are highlighted.In addition,practical applications of impinging-jet technology in aerospace propulsion,biomedical devices,and energy science are discussed.This review aims to serve as a concise reference for researchers interested in multiphase flow dynamics and engineering applications of impinging jets.展开更多
Matter conductivities are crucial physical properties that directly determine the engineering application value of materials.In reality,the majority of materials are multiphase composites.However,there is currently a ...Matter conductivities are crucial physical properties that directly determine the engineering application value of materials.In reality,the majority of materials are multiphase composites.However,there is currently a lack of theoretical models to accurately predict the conductivities of composite materials.In this study,we develop a unified mixed conductivity(UMC)model,achieving unity in three aspects:(1)a unified description and prediction for different conductivities,including elastic modulus,thermal conductivity,electrical conductivity,magnetic permeability,liquid permeability coefficient,and gas diffusion coefficient;(2)a unified-form governing equation for mixed conductivities of various composite structures,conforming to the Riccati equation;(3)a unified-form composite structure,i.e.,a three-dimensional multiphase interpenetrating cuboid structure,encompassing over a dozen of typical composite structures as its specific cases.The UMC model is applicable for predicting the conductivity across six different types of physical fields and over a dozen different composite structures,providing a broad range of applications.Therefore,the current study deepens our understanding of the conduction phenomena and offers a powerful theoretical tool for predicting the conductivities of composite materials and optimizing their structures,which holds significant scientific and engineering implications.展开更多
Icing of water droplets is a ubiquitous phenomenon with significant implications across natural systems and industrial applications.Despite extensive research,the intricate interplay among heat transfer,mass transport...Icing of water droplets is a ubiquitous phenomenon with significant implications across natural systems and industrial applications.Despite extensive research,the intricate interplay among heat transfer,mass transport,and phase change during droplet freezing remains incompletely understood,particularly in the context of multiscale dynamics and environmental dependencies.This review critically examines recent advances in uncovering the fundamental mechanisms of droplet icing through experimental,theoretical,and computational approaches.We begin by revisiting the classical tip singularity problem in the freezing of pure water droplets,analyzing its mathematical formulation and physical significance.Subsequent sections explore how environmental boundary conditions and multicomponent effects influence freezing kinetics,solute redistribution,and ice morphology.Furthermore,we evaluate emerging hybrid numerical frameworks that resolve coupled multiphase physics during solidification processes.Finally,we identify key challenges and open questions that require further investigation in this field.展开更多
Zirconium-based metal-organic cages(Zr-MOCs)typically exhibit high stability,but their structural and application reports are scarce due to stringent crystallization conditions.We have successfully fluorinated the cla...Zirconium-based metal-organic cages(Zr-MOCs)typically exhibit high stability,but their structural and application reports are scarce due to stringent crystallization conditions.We have successfully fluorinated the classical Zr-MOCs(ZrT-3)for the first time,obtaining the fluorinated MOCs(ZrT-3-F).Notably,ZrT-3-F not only inherits the high stability of its parent structure,but also acts as a catalyst for the effective oxidation of benzyl thioether for the first time.The reaction can reach a conversion rate of 99%in 6 h,and the selectivity reaches 95%,which far exceeds the non-fluorinated ZrT-3.This work proves that the specific functionalization of the classical Zr-MOCs can further expand their application potential,such as catalysis.展开更多
Submarine landslides frequently occur on continental margins and slopes,thereby causing serious damage to offshore structures.Therefore,analyzing their motion behavior and predicting their impact forces are crucial.In...Submarine landslides frequently occur on continental margins and slopes,thereby causing serious damage to offshore structures.Therefore,analyzing their motion behavior and predicting their impact forces are crucial.In this work,the smooth particle hydrodynamics(SPH)algorithm is used in the development of a multiphase flow model for submarine landslides.The underwater landslide and the ambient water are simulated using the non-Newtonian and Newtonian fluid models,respectively.An artificial diffusion term of density is incorporated in the governing equation,and the equation of state is modified to improve the stability and accuracy of the SPH model.Three benchmark problems are simulated using the SPH model.The effect of SPH particle size on the simulated results is also explored.The effects of the rheological parameters on the landslide motion behavior are investigated by conducting a sensitivity analysis.Numerical results fit the experimental data well,indicating the good stability of the SPH model and its accuracy in simulating the motion and impact behavior of submarine landslides.展开更多
Powder-Fueled Water Ramjet Engine(PFWRE)is of great attraction for high-speed and long-voyage underwater propulsion,as well as air–water trans-media navigation applications due to its high energy density and thrust a...Powder-Fueled Water Ramjet Engine(PFWRE)is of great attraction for high-speed and long-voyage underwater propulsion,as well as air–water trans-media navigation applications due to its high energy density and thrust adjustability.However,the complex multiphase combustion process in the combustor significantly affects engine performance.In this study,a detailed model for aluminum particle combustion in water vapor is developed and validated via literature data as well as the ground direct-connected test we conducted.Thereafter,the numerical study on the multiphase combustion process inside the aluminum-based PFWRE combustor is carried out within the Euler–Lagrange framework using the developed model.Results show that a reverse rotating vortex pair before the primary water injection causes particles to flow back towards the combustor head and leads to product deposition.Aluminum particles external to the powder jet have shorter preheating time than internal particles and burn out in advance.The analysis of the particle combustion process indicates that the flame structure inside the combustor consists of the particle preheating zone,the surface combustion heat release zone,the gas-phase combustion heat release zone,and the post-flame zone.In the present configuration,as the particle size increases from 10μm to 20μm,the preheating zone length increases from 35 mm to 85 mm.Meanwhile,heat release from gas-phase combustion decreases,and the average temperature of the combustor head first increases and then decreases.This study not only provides insight into the multiphase combustion characteristics of the aluminum-based PFWRE combustor but also offers guidance for the design of the combustion organization schemes and engine structure optimization.展开更多
The rational construction of heterogeneous interfacial engineering presents a critical strategy for advancing efficient electrochemical water-splitting development.Here,a bimetallic sulfide-coupled MoNi alloy heterost...The rational construction of heterogeneous interfacial engineering presents a critical strategy for advancing efficient electrochemical water-splitting development.Here,a bimetallic sulfide-coupled MoNi alloy heterostructure catalyst(VMoS/MoNi)is synthesized via hydrothermal and sulfidation methods for high-performance alkaline water electrolysis.Benefiting from interfacial coupling within the VMoS/MoNi catalyst,the active sites are enriched,and electron transfer is promoted,leading to enhanced synergy and collaboration in electrocatalytic reactions.As a result,at 10 mA·cm^(-2),the VMoS/MoNi catalyst demonstrates excellent HER(26 mV)and OER(223 mV)performance.VMoS/MoNi catalysts used as double electrode in an alkaline electrolytic assembly are noteworthy for achieving a cell voltage of 1.56 V at 10 mA·cm^(-2),a significant improvement above most previously reported bifunctional electrocatalysts.This result provides further momentum for the design of heterostructure electrocatalysts,advancing the study of renewable energy conversion and storage.展开更多
This study calculates the combustion characteristics of various gas-generating and micro gas pyrotechnic charges,including aluminium/potassium perchlorate,boron/potassium nitrate,carbon black/potassium nitrate,and sil...This study calculates the combustion characteristics of various gas-generating and micro gas pyrotechnic charges,including aluminium/potassium perchlorate,boron/potassium nitrate,carbon black/potassium nitrate,and silicon-based delay compositions,using thermodynamic software.A multiphase flowthermal-solid coupling model was established,and the combustion process of the pyrotechnic charges within a closed bomb was simulated.The pyrotechnic shock generated by combustion was predicted.The combustion pressures and pyrotechnic shocks were measured.The simulation results demonstrated good agreement with experimental results.Additionally,the mechanism of shock generation by the combustion of pyrotechnic charges in the closed bomb was analyzed.The effects of the combustion characteristics of the pyrotechnic charges on the resulting pyrotechnic shocks were systematically investigated.Notably,the shock response spectrum of the gas-generating pyrotechnic charges is greater than that of the micro gas compositions at most frequencies,particularly in the mid-field pyrotechnic shocks(3-10 kHz).Furthermore,the pyrotechnic shocks increase approximately linearly with the impulse of the gas-generating pyrotechnic charges.展开更多
The gas kick represents a major risk in deepwater oil and gas exploration.Understanding the dynamics of gas kick evolution and the associated pressure response characteristics is critical for effective well control.In...The gas kick represents a major risk in deepwater oil and gas exploration.Understanding the dynamics of gas kick evolution and the associated pressure response characteristics is critical for effective well control.In this paper,we introduce a transient wellbore multiphase flow model specifically developed to simulate gas kick in deepwater dual-gradient drilling,incorporating a downhole separator.The model accounts for the variable mass flow within the annulus and heat exchange between the annular fluid and the formation.Using this model,we analyzed the multiphase flow and thermodynamic behavior during the gas kick.Simulation results reveal a progressive increase in bottom-hole temperature,underscoring its potential as a key indicator for gas kick early detection.Additionally,variable gradient parameters affect not only the annular equivalent circulating density(ECD)profile but also the evolution of the gas kick.The inclusion of a downhole separator alters the annular ECD profile,creating a“broken line”shape,which enhances adaptability to the multi-pressure systems typically encountered in deepwater forma-tion.By adjusting factors such as hollow sphere concentration,separator position,and separation effi-ciency,the annular ECD profile can be effectively customized.This study provides important theoretical insights and practical applications for utilizing dual-gradient drilling technology to address challenges in deepwater formation drilling.展开更多
In this paper,the liquid–vapor phase separation under viscous shear is investigated by using a pseudopotential central moment lattice Boltzmann method.Physically,the multiphase shear flow is governed by two competing...In this paper,the liquid–vapor phase separation under viscous shear is investigated by using a pseudopotential central moment lattice Boltzmann method.Physically,the multiphase shear flow is governed by two competing mechanisms:surface tension and shear force.It is interesting to find that the liquid tends to form a droplet when the surface tension dominates under conditions of low temperature,shear velocity,and viscosity,and in larger domain size.Otherwise,the liquid tends to form a band if shear force dominates.Moreover,the average density gradient is used as a physical criterion to distinguish the spinodal decomposition and domain growth.Both spatial and temporal changes of density are studied during the phase separation under shear.展开更多
Plasma electrolytic oxidation(PEO)processing of light metals has been established for decades and is in increasing industrial use,even as an alternative surface treatment to produce multifunctional coatings with envir...Plasma electrolytic oxidation(PEO)processing of light metals has been established for decades and is in increasing industrial use,even as an alternative surface treatment to produce multifunctional coatings with environmental-friendly processing concept.One of the benefits of PEO processing claimed already a couple of years ago was the ability to treat dissimilar metal joints,which can obviously improve the surface homogeneity and stability at the interface of the dissimilar components,especially impeding the galvanic corrosion due to the different electrochemical properties of each component.However,the progress and breakthrough develop slowly especially for the macro scales due to the much larger gap between each component.This literature review firstly demonstrates the still low number of studies reporting successful PEO treatment of material combination such as Mg/Al,Mg/Ti,Al/Ti and scarcely light metal combinations with steel.The main issues and challenges to performing PEO processing on the macroscale dissimilar weldments were stated.On the other hand,dissimilar metal joints also widely exist in micrometer scale in alloys and metal matrix composites(MMCs).Moreover,there is a huge knowledge base on PEO treatment of such multiphase substrates.PEO processing of such complicated mixed microstructures is reviewed as well to reveal the basic problems.To some certain degree,these PEO-related studies on alloys and MMCs can be good examples to have an insight into the coating formation mechanism on macro-scaled dissimilar metal joints.Conclusions are drawn from the micro-to macroscale.Finally,critical access to the problems is given and possible solutions and reaming limitations are discussed.展开更多
基金supported by the National Natural Science Foundation of China (31100364)the National Nonprofit Institute Research Grant of Chinese Academy of Agricultural Sciences (CAAS, IARRP-2014-20)
文摘Aiming at searching for plant growth promoting rhizobacteria (PGPR), a bacterium strain coded as 7016 was isolated from soybean rhizosphere and was characterized in the present study. It was identiifed as Burkholderia sp. based on 16S rDNA sequence analysis, as wel as phenotypic and biochemical characterizations. This bacterium presented nitrogenase activity, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity and phosphate solubilizing ability;inhibited the growth of Sclerotinia sclerotiorum, Gibberel a zeae and Verticil ium dahliae;and produced smal quantities of indole acetic acid (IAA). In green house experiments, signiifcant increases in shoot height and weight, root length and weight, and stem diameter were observed on tomato plants in 30 d after inoculation with strain 7016. Result of 16S rDNA PCR-DGGE showed that 7016 survived in the rhizosphere of tomato seedlings. In the ifeld experiments, Burkholderia sp. 7016 enhanced the tomato yield and signiifcantly promoted activities of soil urease, phosphatase, sucrase, and catalase. Al these results demonstrated Burkholderia sp. 7016 as a valuable PGPR and a candidate of biofertilizer.
文摘AIM To evaluate the feasibility of reducing the dose of iodinated contrast agent in computed tomography pulmonary angiography(CTPA). METHODS One hundred and twenty-seven patients clinically suspected of having pulmonary embolism underwent spiral CTPA, out of whom fifty-seven received 75 mL and the remaining seventy a lower dose of 60 mL of contrast agent. Both doses were administered in a multiphasic injection. A minimum opacification threshold of 250 Hounsfield units(HU) in the main pulmonary artery is used for assessing the technical adequacy of the scans. RESULTS Mean opacification was found to be positively correlated to patient age(Pearson's correlation 0.4255, P < 0.0001) and independent of gender(male:female, 425.6 vs 450.4,P = 0.34). When age is accounted for, the study and control groups did not differ significantly in their mean opacification in the main(436.8 vs 437.9, P = 0.48),left(416.6 vs 419.8, P = 0.45) or the right pulmonary arteries(417.3 vs 423.5, P = 0.40). The number of sub-optimally opacified scans(the mean opacification in the main pulmonary artery < 250 HU) did not differ significantly between the study and control groups(7 vs 10).CONCLUSION A lower dose of iodine contrast at 60 mL can be feasibly used in CTPA without resulting in a higher number of sub-optimally opacified scans.
基金supported by the National Natural Science Foundation of China(No.51672109)the Independent Cultivation Program of Innovation Team of Ji’nan City(No.2019GXRC011)Hong Kong Scholars Program(No.XJ2018006)。
文摘Fe-based compounds with good environmental friendliness and high reversible capacity have attracted considerable attention as anode for lithium-ion batteries.But,similar to other transition metal oxides(TMOs),it is also affected by large volume changes and inferior kinetics during redox reactions,resulting in the destruction of the crystal structure and poor electrochemical performance.Here,Fe_(3)O_(4)/C nanospheres anchored on the two-dimensional graphene oxide as precursors are phosphated and sintered to build the multiphasic nanocomposite.XRD results confirmed the multiphasic nanocomposite composed of Fe2O3,Fe_(3)O_(4) and Fe_(3)PO_(7),which will facilitate the Li+diffusion.And the carbonaceous matrix will buffer the volume changes and enhance electron conduction.Consequently,the multiphasic Febased anode delivers a large specific capacity of 1086 mAh/g with a high initial Coulombic efficiency of 87%at 0.1 C.It also has excellent cycling stability and rate property,maintaining a capacity retention of~87%after 300 cycles and a high reversible capacity of 632 mAh/g at 10 C.The proposed multiphasic structure offers a new insight into improving the electrochemical properties of TMO-based anodes for advanced alkali-ion batteries.
文摘Previous studies using magnetic resonance imaging（MRI）and functional MRI to study depression have primarily focused on proton magnetic resonance spectroscopy（1H-MRS）appearance in various areas of the brain and volume measurements in the limbic system.However,results have not been consistent.To the best of our knowledge,very little is known about the relationship between 1H-MRS appearance and depression inventory.In the present study,the relationship between 1H-MRS appearance in depressive patients and Minnesota Multiphasic Personality Inventory-2 scale was analyzed.MRI and 1H-MRS exhibited widened sulci and cisterns,as well as an absence of abnormal signals in depressive patients.In addition,N-acetyl aspartate/total creatine ratios in bilateral hippocampi and dorsolateral prefrontal cortex were significantly less in depressive patients than in control subjects（P 〈 0.01）.In contrast,choline-containing compounds/total creatine ratios in the dorsolateral prefrontal cortex were significantly greater in depressive patients than in control subjects（P 〈 0.01）.These ratios significantly and positively correlated with patient total depression scores as assessed using the Minnesota Multiphasic Personality Inventory-2 scale（r=0.934 7,0.878 7,P 〈 0.01）.These results suggested that 1H-MRS could be used to reveal a reduced number of neurons in the hippocampus and dorsolateral prefrontal cortex,as well as altered membrane phospholipid metabolism in the dorsolateral prefrontal cortex,in patients with depressive disorder.Abnormal mechanisms partially reflected severity of depressive disorder.
基金National Institute of General Medical Sciences,Grant/Award Number:R01GM138552Congressionally Directed Medical Research Program,Grant/Award Number:W81XWH2010207+4 种基金National Heart,Lung,and Blood Institute,Grant/Award Number:R01HL162747University of Nebraska Medical CenterNational Institutes of HealthCongressionally Directed Medical Research ProgramsOffice of Nuclear Energy。
文摘Multiphasic scaffolds with tailored gradient features hold significant promise for tissue regeneration applications. Herein, this work reports the transformation of two-dimensional (2D) layered fiber mats into three-dimensional (3D) multiphasic scaffolds using a ‘solids-of-revolution’ inspired gas-foaming expansion technology. These scaffolds feature precise control over fiber alignment, pore size, and regional structure. Manipulating nanofiber mat layers and Pluronic F127 concentrations allows further customization of pore size and fiber alignment within different scaffold regions. The cellular response to multiphasic scaffolds demonstrates that the number of cells migrated and proliferated onto the scaffolds is mainly dependent on the pore size rather than fiber alignment. In vivo subcutaneous implantation of multiphasic scaffolds to rats reveals substantial cell infiltration, neo tissue formation, collagen deposition, and new vessel formation within scaffolds, greatly surpassing the capabilities of traditional nanofiber mats. Histological examination indicates the importance of optimizing pore size and fiber alignment for the promotion of cell infiltration and tissue regeneration. Overall, these scaffolds have potential applications in tissue modeling, studying tissue-tissue interactions, interface tissue engineering, and highthroughput screening for optimized tissue regeneration.
基金financially supported by the National Key Research and Development program of China(2022YFB3504700)the National Natural Science Foundation of China(U23A20128)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA0400304)the Research Projects of Ganjiang Innovation Academy,Chinese Academy of Sciences(No.E355B0020).
文摘Magnesium hydride(MgH_(2))has garnered significant attention as a promising material for high-capacity hydrogen storage.However,its commercial application remains challenging due to the high operating temperature and slow reaction kinetics.In this study,melt-spun Ti_(45)Cr_(40)Nb_(15)(with a BCC phase)hydride(designated as TiCrNbH_(x-)MS)was synthesized and used to form a nano-multiphase composite to improve the de-/rehydrogenation properties of MgH_(2) through ball milling.The incorporation of TiCrNbH_(x-)MS was shown to significantly enhance the hydrogen de-/rehydrogenation properties of MgH_(2).The MgH_(2)+20 wt%TiCrNbH_(x-)MS composite exhibits an appealing initial dehydrogenation temperature of 163℃ and can absorb hydrogen at room temperature.Notably,it releases 5.8 wt% hydrogen in 700 s at 230℃ and recharges 4.3 wt%hydrogen in just 2 mins at 150℃.Even after 100 cycles,it retains a reversible hydrogen capacity of 4.98 wt%.Kinetic analysis revealed that the dehydrogenation rate follows the Chou surface penetration model.Microstructural analysis showed that the FCC phase of the melt-spun TiCrNbH_(x-)MS hydride reversibly transformed into the BCC phase during the de-/rehydrogenation process in the composite.Numerous phase interfaces were generated and uniformly dispersed on the MgH_(2) surface,providing additional hydrogen diffusion pathways and heterogeneous nucleation sites for Mg/MgH_(2),thereby further improving the hydrogen de-/rehydrogenation kinetics of the system.This study offers valuable insights into the use of multiphase composites to enhance MgH_(2) performance.
基金support from the National Health and Medical Research Council(NHMRC)of Australia(GNT1120249).
文摘Osteochondral defects are caused by injury to both the articular cartilage and subchondral bone within skeletal joints. They can lead to irreversible joint damage and increase the risk of progression to osteoarthritis. Current treatments for osteochondral injuries are not curative and only target symptoms, highlighting the need for a tissue engineering solution. Scaffold-based approaches can be used to assist osteochondral tissue regeneration, where biomaterials tailored to the properties of cartilage and bone are used to restore the defect and minimise the risk of further joint degeneration. This review captures original research studies published since 2015, on multiphasic scaffolds used to treat osteochondral defects in animal models. These studies used an extensive range of biomaterials for scaffold fabrication, consisting mainly of natural and synthetic polymers. Different methods were used to create multiphasic scaffold designs, including by integrating or fabricating multiple layers, creating gradients, or through the addition of factors such as minerals, growth factors, and cells. The studies used a variety of animals to model osteochondral defects, where rabbits were the most commonly chosen and the vast majority of studies reported small rather than large animal models. The few available clinical studies reporting cell-free scaffolds have shown promising early-stage results in osteochondral repair, but long-term follow-up is necessary to demonstrate consistency in defect restoration. Overall, preclinical studies of multiphasic scaffolds show favourable results in simultaneously regenerating cartilage and bone in animal models of osteochondral defects, suggesting that biomaterials-based tissue engineering strategies may be a promising solution.
基金supported in part by the National Natural Science Foundation of China under Grant 41874143 and Grant 42374163in part by the Key Program of Natural Science Foundation of Sichuan Province of China under Grant 2023NSFSC0019in part by the Central Funds Guiding the Local Science and Technology Development under Grant 2024ZYD0124.
文摘Multiphase flow in porous rock is of great importance in the application of many industrial processes,including reservoir delineation,enhanced oil recovery,and CO_(2) sequestration.However,previous research typically investigated the dispersive behaviors when rock saturated with single or two-phase fluids and conducted limited studies on three-phase immiscible fluids.This study investigated the seismic dispersion,attenuation,and reflection features of seismic waves in three-phase immiscible fluidsaturated porous rocks.First,we proposed the calculation formulas of effective fluid modulus and effective fluid viscosity of multiphase immiscible fluids by taking into account the capillary pressure,reservoir wettability,and relative permeability simultaneously.Then,we analysed the frequencydependent behaviors of three-phase immiscible fluid-saturated porous rock under different fluid proportion cases using the Chapman multi-scale model.Next,the seismic responses are analysed using a four-layer model.The results indicate that the relative permeability,capillary pressure parameter,and fluid proportions are all significantly affect dispersion and attenuation.Comparative analyses demonstrate that dispersion and attenuation can be observed within the frequency range of seismic exploration for a lower capillary parameter a3 and higher oil content.Seismic responses reveal that the reflection features,such as travel time,seismic amplitude,and waveform of the bottom reflections of saturated rock and their underlying reflections are significantly dependent on fluid proportions and capillary parameters.For validation,the numerical results are further verified using the log data and real seismic data.This numerical analysis helps to further understand the wave propagation characteristics for a porous rock saturated with multiphase immiscible fluids.
基金supported by the National Natural Science Foundation of China(Grant Nos.52378321 and 52079003).
文摘Based on the energy dissipation caused by consolidation deformation of the porous media under external force and migration of the internal suspended substances,a coupled multiphase-substance flow(CMF)model was established.This model introduced the new concepts,such as particle temperature and particle entropy,to describe energy dissipation at meso-level.This model used a potential energy density function and migration coefficients to establish the corresponding connection between the dissipative force and dissipative flow.This viewpoint unifies the deformation,seepage,and suspended substance migration of geotechnical materials under the framework of granular thermodynamics.It can reflect the evolution of effective stress in the solid matrix of multi-components in a particle-reorganized state,and considers the temperature driving effect.The proposed CMF model is validated using the experimental results under coupled migration of heavy metal ions(HMs)and suspended particles(SPs).The calculation results demonstrated that the CMF model can describe the flow process under the conditions of arbitrary changes in different suspended substance types,injection concentrations,and injection velocities.
基金supported by the National Natural Science Foundation of China(Grant Nos.U23B6009 and 12272050).
文摘This review summarizes recent progress in the study of impinging-jet dynamics and atomization,with a focus on liquid sheet formation,instability mechanisms,and the influence of key parameters such as fluid properties,Weber number,and Reynolds number.Special attention is given to atomization behaviors under high pressure and external perturbations.Representative experimental and numerical approaches are introduced,and critical findings under complex conditions are highlighted.In addition,practical applications of impinging-jet technology in aerospace propulsion,biomedical devices,and energy science are discussed.This review aims to serve as a concise reference for researchers interested in multiphase flow dynamics and engineering applications of impinging jets.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.52322105,52321001,52130002,U22A20114,and 52371084)the Youth Innovation Promotion Association CAS(No.2021192)+1 种基金the IMR Innovation Fund(No.2023-ZD01)the IMR Outstanding Scholar Position(No.E451A804).
文摘Matter conductivities are crucial physical properties that directly determine the engineering application value of materials.In reality,the majority of materials are multiphase composites.However,there is currently a lack of theoretical models to accurately predict the conductivities of composite materials.In this study,we develop a unified mixed conductivity(UMC)model,achieving unity in three aspects:(1)a unified description and prediction for different conductivities,including elastic modulus,thermal conductivity,electrical conductivity,magnetic permeability,liquid permeability coefficient,and gas diffusion coefficient;(2)a unified-form governing equation for mixed conductivities of various composite structures,conforming to the Riccati equation;(3)a unified-form composite structure,i.e.,a three-dimensional multiphase interpenetrating cuboid structure,encompassing over a dozen of typical composite structures as its specific cases.The UMC model is applicable for predicting the conductivity across six different types of physical fields and over a dozen different composite structures,providing a broad range of applications.Therefore,the current study deepens our understanding of the conduction phenomena and offers a powerful theoretical tool for predicting the conductivities of composite materials and optimizing their structures,which holds significant scientific and engineering implications.
基金supported by National Natural Science Foundation of China Excellence Research Group Program for“Multiscale Problems in Nonlinear Mechanics”(Grant No.12588201)the National Natural Science Foundation of China(Grant No.12402321)+3 种基金the National Key R&D Program of China(Grant No.2021YFA0716201)the New Cornerstone Science Foundation through the New Cornerstone Investigator Program and the XPLORER PRIZEthe Postdoctoral Fellowship Program of the China Postdoctoral Science Foundation(Grant Nos.GZB20240366 and 2024M751637)Shuimu Tsinghua Scholar Program(Grant No.2023SM038).
文摘Icing of water droplets is a ubiquitous phenomenon with significant implications across natural systems and industrial applications.Despite extensive research,the intricate interplay among heat transfer,mass transport,and phase change during droplet freezing remains incompletely understood,particularly in the context of multiscale dynamics and environmental dependencies.This review critically examines recent advances in uncovering the fundamental mechanisms of droplet icing through experimental,theoretical,and computational approaches.We begin by revisiting the classical tip singularity problem in the freezing of pure water droplets,analyzing its mathematical formulation and physical significance.Subsequent sections explore how environmental boundary conditions and multicomponent effects influence freezing kinetics,solute redistribution,and ice morphology.Furthermore,we evaluate emerging hybrid numerical frameworks that resolve coupled multiphase physics during solidification processes.Finally,we identify key challenges and open questions that require further investigation in this field.
基金supported by National Natural Science Foundation of China(Nos.22201046,22371054)Local Innovation Research Team Project of Guangdong Pearl River Talent Plan(No.2017BT01Z032)。
文摘Zirconium-based metal-organic cages(Zr-MOCs)typically exhibit high stability,but their structural and application reports are scarce due to stringent crystallization conditions.We have successfully fluorinated the classical Zr-MOCs(ZrT-3)for the first time,obtaining the fluorinated MOCs(ZrT-3-F).Notably,ZrT-3-F not only inherits the high stability of its parent structure,but also acts as a catalyst for the effective oxidation of benzyl thioether for the first time.The reaction can reach a conversion rate of 99%in 6 h,and the selectivity reaches 95%,which far exceeds the non-fluorinated ZrT-3.This work proves that the specific functionalization of the classical Zr-MOCs can further expand their application potential,such as catalysis.
基金supported by the National Natural Science Foundation of China(Nos.42472332,42102318 and 42006143)the Open Research Fund Program of Zhoushan Field Scientific Observation and Research Station for Marine Geo-Hazards,China Geological Survey(No.ZSORS22-07)+1 种基金the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning(No.TP2019037)the Open Research Fund Program of Marine Ecological Restoration and Smart Ocean Engineering Research Center of Hebei Province(No.HB MESO2312)。
文摘Submarine landslides frequently occur on continental margins and slopes,thereby causing serious damage to offshore structures.Therefore,analyzing their motion behavior and predicting their impact forces are crucial.In this work,the smooth particle hydrodynamics(SPH)algorithm is used in the development of a multiphase flow model for submarine landslides.The underwater landslide and the ambient water are simulated using the non-Newtonian and Newtonian fluid models,respectively.An artificial diffusion term of density is incorporated in the governing equation,and the equation of state is modified to improve the stability and accuracy of the SPH model.Three benchmark problems are simulated using the SPH model.The effect of SPH particle size on the simulated results is also explored.The effects of the rheological parameters on the landslide motion behavior are investigated by conducting a sensitivity analysis.Numerical results fit the experimental data well,indicating the good stability of the SPH model and its accuracy in simulating the motion and impact behavior of submarine landslides.
基金supported by the National Natural Science Foundation of China(No.22305053).
文摘Powder-Fueled Water Ramjet Engine(PFWRE)is of great attraction for high-speed and long-voyage underwater propulsion,as well as air–water trans-media navigation applications due to its high energy density and thrust adjustability.However,the complex multiphase combustion process in the combustor significantly affects engine performance.In this study,a detailed model for aluminum particle combustion in water vapor is developed and validated via literature data as well as the ground direct-connected test we conducted.Thereafter,the numerical study on the multiphase combustion process inside the aluminum-based PFWRE combustor is carried out within the Euler–Lagrange framework using the developed model.Results show that a reverse rotating vortex pair before the primary water injection causes particles to flow back towards the combustor head and leads to product deposition.Aluminum particles external to the powder jet have shorter preheating time than internal particles and burn out in advance.The analysis of the particle combustion process indicates that the flame structure inside the combustor consists of the particle preheating zone,the surface combustion heat release zone,the gas-phase combustion heat release zone,and the post-flame zone.In the present configuration,as the particle size increases from 10μm to 20μm,the preheating zone length increases from 35 mm to 85 mm.Meanwhile,heat release from gas-phase combustion decreases,and the average temperature of the combustor head first increases and then decreases.This study not only provides insight into the multiphase combustion characteristics of the aluminum-based PFWRE combustor but also offers guidance for the design of the combustion organization schemes and engine structure optimization.
基金supported by the National Natural Science Foundation of China(No.22369025)Yunnan Applied Basic Research Projects(Nos.202201AT070095,202301AT070098,202301AT070107,202401AT070438,and 202401AT070433)+2 种基金Education Reform Research Project of Yunnan University(No.2021Z06)Yunnan University Graduate Student Practice and Innovation Program(Nos.ZC-23234269,ZC-23235291,KC-23236398,and KC-23234063)Yunnan Revitalization Talent Support Program。
文摘The rational construction of heterogeneous interfacial engineering presents a critical strategy for advancing efficient electrochemical water-splitting development.Here,a bimetallic sulfide-coupled MoNi alloy heterostructure catalyst(VMoS/MoNi)is synthesized via hydrothermal and sulfidation methods for high-performance alkaline water electrolysis.Benefiting from interfacial coupling within the VMoS/MoNi catalyst,the active sites are enriched,and electron transfer is promoted,leading to enhanced synergy and collaboration in electrocatalytic reactions.As a result,at 10 mA·cm^(-2),the VMoS/MoNi catalyst demonstrates excellent HER(26 mV)and OER(223 mV)performance.VMoS/MoNi catalysts used as double electrode in an alkaline electrolytic assembly are noteworthy for achieving a cell voltage of 1.56 V at 10 mA·cm^(-2),a significant improvement above most previously reported bifunctional electrocatalysts.This result provides further momentum for the design of heterostructure electrocatalysts,advancing the study of renewable energy conversion and storage.
文摘This study calculates the combustion characteristics of various gas-generating and micro gas pyrotechnic charges,including aluminium/potassium perchlorate,boron/potassium nitrate,carbon black/potassium nitrate,and silicon-based delay compositions,using thermodynamic software.A multiphase flowthermal-solid coupling model was established,and the combustion process of the pyrotechnic charges within a closed bomb was simulated.The pyrotechnic shock generated by combustion was predicted.The combustion pressures and pyrotechnic shocks were measured.The simulation results demonstrated good agreement with experimental results.Additionally,the mechanism of shock generation by the combustion of pyrotechnic charges in the closed bomb was analyzed.The effects of the combustion characteristics of the pyrotechnic charges on the resulting pyrotechnic shocks were systematically investigated.Notably,the shock response spectrum of the gas-generating pyrotechnic charges is greater than that of the micro gas compositions at most frequencies,particularly in the mid-field pyrotechnic shocks(3-10 kHz).Furthermore,the pyrotechnic shocks increase approximately linearly with the impulse of the gas-generating pyrotechnic charges.
基金supported by the Postdoctoral Fellow-ship Program of CPSF(Grant No.GZC20233105)the Science Foundation of China University of Petroleum,Beijing(Grant No.2462024XKBH006)+2 种基金the China Postdoctoral Science Foundation(Grant No.2024M753615)the Major Scientific Research Instrument Development Program of National Natural Science Foundation of China(Grant No.52227804)the Youth Science Foundation Program of National Natural Science Foundation of China(Grant No.52404012).
文摘The gas kick represents a major risk in deepwater oil and gas exploration.Understanding the dynamics of gas kick evolution and the associated pressure response characteristics is critical for effective well control.In this paper,we introduce a transient wellbore multiphase flow model specifically developed to simulate gas kick in deepwater dual-gradient drilling,incorporating a downhole separator.The model accounts for the variable mass flow within the annulus and heat exchange between the annular fluid and the formation.Using this model,we analyzed the multiphase flow and thermodynamic behavior during the gas kick.Simulation results reveal a progressive increase in bottom-hole temperature,underscoring its potential as a key indicator for gas kick early detection.Additionally,variable gradient parameters affect not only the annular equivalent circulating density(ECD)profile but also the evolution of the gas kick.The inclusion of a downhole separator alters the annular ECD profile,creating a“broken line”shape,which enhances adaptability to the multi-pressure systems typically encountered in deepwater forma-tion.By adjusting factors such as hollow sphere concentration,separator position,and separation effi-ciency,the annular ECD profile can be effectively customized.This study provides important theoretical insights and practical applications for utilizing dual-gradient drilling technology to address challenges in deepwater formation drilling.
基金supported by National Natural Science Foundation of China under Grant No.51806116Guangdong Basic and Applied Basic Research Foundation under Grant No.2024A1515010927+2 种基金China Scholarship Council under Grant No.202306380288Humanities and Social Science Foundation of the Ministry of Education in China under Grant No.24YJCZH163Fundamental Research Funds for the Central Universities,Sun Yat-sen University under Grant No.24qnpy044。
文摘In this paper,the liquid–vapor phase separation under viscous shear is investigated by using a pseudopotential central moment lattice Boltzmann method.Physically,the multiphase shear flow is governed by two competing mechanisms:surface tension and shear force.It is interesting to find that the liquid tends to form a droplet when the surface tension dominates under conditions of low temperature,shear velocity,and viscosity,and in larger domain size.Otherwise,the liquid tends to form a band if shear force dominates.Moreover,the average density gradient is used as a physical criterion to distinguish the spinodal decomposition and domain growth.Both spatial and temporal changes of density are studied during the phase separation under shear.
基金the China Scholarship Council(No.201708510113)for fellowship and funding.
文摘Plasma electrolytic oxidation(PEO)processing of light metals has been established for decades and is in increasing industrial use,even as an alternative surface treatment to produce multifunctional coatings with environmental-friendly processing concept.One of the benefits of PEO processing claimed already a couple of years ago was the ability to treat dissimilar metal joints,which can obviously improve the surface homogeneity and stability at the interface of the dissimilar components,especially impeding the galvanic corrosion due to the different electrochemical properties of each component.However,the progress and breakthrough develop slowly especially for the macro scales due to the much larger gap between each component.This literature review firstly demonstrates the still low number of studies reporting successful PEO treatment of material combination such as Mg/Al,Mg/Ti,Al/Ti and scarcely light metal combinations with steel.The main issues and challenges to performing PEO processing on the macroscale dissimilar weldments were stated.On the other hand,dissimilar metal joints also widely exist in micrometer scale in alloys and metal matrix composites(MMCs).Moreover,there is a huge knowledge base on PEO treatment of such multiphase substrates.PEO processing of such complicated mixed microstructures is reviewed as well to reveal the basic problems.To some certain degree,these PEO-related studies on alloys and MMCs can be good examples to have an insight into the coating formation mechanism on macro-scaled dissimilar metal joints.Conclusions are drawn from the micro-to macroscale.Finally,critical access to the problems is given and possible solutions and reaming limitations are discussed.
