The study investigated the oxidation behavior of T91 steel modified with Al(T91-Al)and Si(T91-Si)in lead-bismuth eutectic(LBE)at 450℃under oxygen-saturated conditions(10^(−7)-10^(−8)wt.%)and oxygen-controlled conditi...The study investigated the oxidation behavior of T91 steel modified with Al(T91-Al)and Si(T91-Si)in lead-bismuth eutectic(LBE)at 450℃under oxygen-saturated conditions(10^(−7)-10^(−8)wt.%)and oxygen-controlled conditions(3.2×10^(−4)wt.%).Advanced characterization techniques were employed to under-stand the thermodynamic and kinetic mechanisms of enhanced oxidation properties of the modified T91 steel.The results indicate that the oxidation resistance of the materials follows this order:T91<T91-Al<T91-Si.Noteworthy,the oxidation resistance of T91-Si material exhibited minimal correlation with dissolved oxygen.Under oxygen-controlled conditions,the oxide film of T91 and T91-Al was attacked and broken by LBE,with the former eventually peeling off.In contrast,both materials showed significant ox-ide film thickening,except T91-Si under oxygen-saturated conditions.The addition of Al improved the quality of the inner oxide film on T91-Al by generating Al_(2)O_(3),thereby slowing down the diffusion of Fe from the matrix and enhancing oxidation resistance.Conversely,Si actively participated in the oxidation process of T91-Si,slowing down the diffusion of Fe,and facilitating the diffusion of Cr,thereby strength-ening the oxide film protection.Consequently,the oxide thickness of T91-Si material was only 24%of T91 and 35%of T91-Al under saturated oxygen conditions.展开更多
Deep eutectic solvents(DESs)are a kind of potential lixiviant for selective metal processing due to their versatile complexation properties.In this study,we investigated the recovery of zinc from zinc oxide dust using...Deep eutectic solvents(DESs)are a kind of potential lixiviant for selective metal processing due to their versatile complexation properties.In this study,we investigated the recovery of zinc from zinc oxide dust using choline chloride-ureaethylene glycol(ChCl-urea-EG)DESs.The zinc extraction efficiency can be up to 85.2%when the slurry concentration is 50 g/L,leaching temperature is 80°C and stirring speed is 600 r/min.The leaching process is controlled by the diffusion and the corresponding activation energy is 32.1 k J/mol.The resultant solution was directly used for the electrodeposition of zinc.The pure zinc deposit is obtained with a current efficiency of 82.6%.Furthermore,the ChCl-urea-EG DESs can be recycled.This approach is shown to be promising for the recycling of zinc from the zinc-containing dust.展开更多
Developing a new type of deep eutectic solvents(DESs)is indispensable for expanding their application in various fields.Here,we report a series of new highly basic DESs.FT-IR,quantitative 1 H NMR,MD simulation and phy...Developing a new type of deep eutectic solvents(DESs)is indispensable for expanding their application in various fields.Here,we report a series of new highly basic DESs.FT-IR,quantitative 1 H NMR,MD simulation and physical properties show that these basic liquids are made up of hydroxide acceptor of alkali metal hydroxides in which the hydrogen bonding interactions coordinate the donor.These DESs can be played three roles as new solvents,template and reactant for facile and ultra-fast preparation of transition metal oxide nanomaterials such as NiCo2 O4,MnCo2 O4,NiMn2 O4,CoCu2 O4 and Co3 O4 under mild condition.This work shows one of the low energy-intensive methods for nanomaterial preparation.These initial findings of basic deep eutectic solvents provide a potential applicability around the systematic development of transition metal oxide nanosheets.展开更多
Indole-3-carbinol(I3C),an important anticancer compound found in broccoli,has attracted considerable attention.The rapid extraction and accurate analysis of I3C in the pharmaceutical industry in broccoli is challengin...Indole-3-carbinol(I3C),an important anticancer compound found in broccoli,has attracted considerable attention.The rapid extraction and accurate analysis of I3C in the pharmaceutical industry in broccoli is challenging as I3C is unstable at low pH and high temperature.In this study,a rapid,accurate,and lowcost ultrasound-assisted dispersive-filter extraction(UADFE)technique based on poly(deep eutectic solvent)-graphene oxide(PDES-GO)adsorbent was developed for the isolation and analysis of I3C in broccoli for the first time.PDES-GO with multiple adsorption interactions and a fast mass transfer rate was synthesized to accelerate adsorption and desorption.UADFE was developed by combining dispersive solid-phase extraction(DSPE)and filter solid-phase extraction(FSPE)to realize rapid extraction and separation.Based on the above two strategies,the proposed PDES-GO-UADFE method coupled with high-performance liquid chromatography(HPLC)allowed the rapid(15-16 min),accurate(84.3%-96.4%),and low-cost(adsorbent:3.00 mg)analysis of I3C in broccoli and was superior to solid-phase extraction,DSPE,and FSPE methods.The proposed method showed remarkable linearity(r=0.9998;range:0.0840-48.0 mg/g),low limit of quantification(0.0840 mg/g),and high precision(relative standard deviation<5.6%).Therefore,the PDES-GO-UADFE-HPLC method shows significant potential in the field of pharmaceutical analysis for the separation and analysis of anti-cancer compounds in complex plant samples.展开更多
Al-Cu-Y alloys were prepared by molten salt electrolysis in fluoride-oxide system composed of electrolyte（Na3 AlF6-AlF3-LiF-MgF2） and oxide（Al2 O3-CuO-Y2 O3）. Cathodic reduction process of Al2 O3,CuO and Y2 O3 wer...Al-Cu-Y alloys were prepared by molten salt electrolysis in fluoride-oxide system composed of electrolyte（Na3 AlF6-AlF3-LiF-MgF2） and oxide（Al2 O3-CuO-Y2 O3）. Cathodic reduction process of Al2 O3,CuO and Y2 O3 were analyzed by cyclic voltammetry and chronoamperometry. Components and phase composition of alloy samples prepared by potentiostatic electrolysis were characterized by scanning electron microscopy and energy dispersive spectroscopy. The results show that the Al-Cu-Y alloy can be prepared in the AIF3-NaF-5 wt%LiF-5 wt%MgF2（NaF/AlF3 = 2.2, molecular ratio） eutectic system with mixed oxide（Al2 O3-CuO-Y2 O3） through 2 h at the conditions of a temperature of 1208 K, cell voltage3.0 V, cathode current density 0.7 A/cm^2. Al（Ⅲ） and Cu（Ⅱ） ions can be reduced to zero valence Al（0） and Cu（0） directly on carbonaceous electrode surface by instantaneous nucleation, respectively, the reduction process is controlled by diffusion. The reduction potential of Y（Ⅲ） ions is close to the active ions of fluoride melts, but strengthened phase AI3 Y can be formed through electrochemical reduction and alloyed process with active Al（Ⅲ） and Cu（Ⅱ） ions, meanwhile, the Al2 Cu and Al3 Y phases are distributed at the grain boundary of Al matrix.展开更多
The isothermal oxidation behavior of NiAl-31Cr-2.9Mo-0.1Hf-0.05Ho directional eutectic alloy was investigated with the help of scanning electron microscopy and X-ray diffraction.The results revealed that a continuous ...The isothermal oxidation behavior of NiAl-31Cr-2.9Mo-0.1Hf-0.05Ho directional eutectic alloy was investigated with the help of scanning electron microscopy and X-ray diffraction.The results revealed that a continuous Al2O3 scale was formed and owned excellent oxidation resistance in the temperature range of 900-1100°C.When the temperature was up to 1150°C,the continuous Al2O3 oxide film ruptured.Trace rare earth element Ho distributed uniformly in the alloy and relatively high level of Al in Cr（Mo）phase are beneficial to the formation of continuous and compact Al2O3 scale.During the oxidation,a phase transformation fromθ-Al2O3 toα-Al2O3 existed on the surface of oxidation film.It resulted in the abnormal oxidation mass gain happening when the alloy was oxidized at 1000°C or 1050°C.展开更多
Deep eutectic solvents(DESs) are a new class of green solvents analogous to ionic liquids due to their biodegradable capacity and low cost. However, the direct extractive desulfurization of diesel oil by DESs cannot m...Deep eutectic solvents(DESs) are a new class of green solvents analogous to ionic liquids due to their biodegradable capacity and low cost. However, the direct extractive desulfurization of diesel oil by DESs cannot meet the government’s standard. In this work, amphiphilic polyoxometalates were synthesized and characterized by FT-IR and mass spectrometry.The oxidative desulfurization results showed that benzothiophene(BT) could be completely removed by employing a [(CH)P(CH)]PMoO, DES(ChCl/2 Ac) and HOsystem. It was also found that the organic cation of catalysts played a positive role in oxidative desulfurization. The reaction conditions, such as reaction temperature and time, the amount of catalyst and DES and HO/S(O/S) molar ratio, were optimized. Different sulfides were tested to determine the desulfurization selectivity of the optimal reaction system, and it was found that 97.2% of dibenzothiophene(DBT) could be removed followed by 80.7% of 4-MDBT and 76.0% of 4,6-DMDBT. After reaction, the IR spectra showed that the catalyst [(CH)P(CH)]PMoOwas stable during the reaction process and the oxidative product was dibenzothiophene sulfone(DBTO). Furthermore, the catalyst can be regenerated and recycled for four runs with little loss of activity.展开更多
A unique redox-coupled biomimetic system was developed, in which Fe-Anderson type polyoxometalates(POMs) were employed as electron transfer mediators(ETMs) and benzenesulfonic acid(BSA)-based deep eutectic solvents(DE...A unique redox-coupled biomimetic system was developed, in which Fe-Anderson type polyoxometalates(POMs) were employed as electron transfer mediators(ETMs) and benzenesulfonic acid(BSA)-based deep eutectic solvents(DESs) were used as electron-donors for aerobic oxidative desulfurization(AODS) of diesel fuel. Different compositions of DESs were used and the polyethylene glycol 2000(PEG2000)/2.5 BSA system showed the highest desulfurization activity, with the removal of dibenzothiophene(DBT) at 60 ℃ reaching 95% in 60 min. The excellent desulfurization activity of the system is due to the in situ formation of peroxysulfonate via a biomimetic process. By constructing a coupled redox system, Fe-Anderson type POMs as ETMs reduce the activation energy of oxygen-activated sulfonate. The physical characteristics of four different DESs were tested. The results show that the conductivity of DESs is correlated with the composition of BSA-based DESs. However, there is no similar trend in viscosity testing at the same temperature, and the maximum viscosity value is obtained for the PEG2000/2.5 BSA system at 60 ℃, which may be associated with the stronger hydrogen bonds. It is worth noting that the PEG2000/2.5 BSA system also possesses the best desulfurization activity, which suggests that the activity of the desulfurization system is related to the strength of the hydrogen bond in DESs. Finally, the biomimetic desulfurization system exhibits excellent performance and good stability under mild reaction conditions(60 ℃, atmospheric pressure, oxygen as the oxidant).展开更多
Al_(2)O_(3)-based eutectic ceramics are considered as promising candidates for ultra-high-temperature structural materials due to their exceptional thermal stability and mechanical properties.Nonetheless,several chall...Al_(2)O_(3)-based eutectic ceramics are considered as promising candidates for ultra-high-temperature structural materials due to their exceptional thermal stability and mechanical properties.Nonetheless,several challenges must be overcome before they can be widely used.This paper reviews in detail the tailoring of microstructure from the aspect of process parameters,the updated knowledge gained in microstructure(crystallographic orientation,high-resolution interfacial structures)and the latest means of optimizing eutectic microstructure(seed-induced method,introducing low-energy grain boundaries and high-entropy phase).Additionally,the paper explores future techniques for the fabrication of bulk ceramic materials and effective toughening approaches.This review highlights the achievements made especially in the last 15 years,current limitations in Al_(2)O_(3)-based eutectic ceramics,and offers comprehensive insights and strategic guidance for further mechanical breakthroughs.展开更多
A series of novel binary deep eutectic solvents(DESs)composed of choline chloride(ChCl)and formic acid(HCOOH)with different molar ratios have been successfully synthesized and applied in extractive desulfurization(EDS...A series of novel binary deep eutectic solvents(DESs)composed of choline chloride(ChCl)and formic acid(HCOOH)with different molar ratios have been successfully synthesized and applied in extractive desulfurization(EDS).Keggin-type polyoxometallate ionic liquid[TTPh]_(3)PW_(12)O_(40) was prepared and used as catalyst to enhance the EDS capacity by means of photocatalytic oxidative process.Both of the DESs and[TTPh]_(3)PW_(12)O_(40) ionic liquid catalyst were characterized in detail by Fourier transform infrared spectroscopy spectra(FT-IR),elemental analysis,and X-ray photoelectron spectroscopy(XPS).It was found that the molar ratios of Ch Cl:HCOOH had a major impact on desulfurization performance,and the optimal desulfurization capacity 96.5%was obtained by ChCl/5 HCOOH.Besides dibenzothiophene(DBT),the desulfurization efficiencies of 4-methylbenzothiophene(4-MDBT)and 4,6-dimethyldibenzothiophene(4,6-DMDBT),two kinds of DBT derivatives,were also investigated under the same experimental conditions.Moreover,the free radical scavenging experiments manifested that superoxide radical(·O_(2)^(-)) and hole(h^(+)) played important roles in the desulfurization system.After further analysis of the oxidation products by gas chromatography-mass spectrometry(GC–MS),the possible reaction mechanism was proposed.Thus,photocatalytic oxidative has been proved to be one of the efficient approaches for enhancing the extractive desulfurization performance in DES.展开更多
In lead-cooled fast reactor(LFR)systems,the liquid lead-bismuth eutectic(LBE)coolant provides a cor-rosive environment that damages the steel components during high-temperature operation.This study investigated the mi...In lead-cooled fast reactor(LFR)systems,the liquid lead-bismuth eutectic(LBE)coolant provides a cor-rosive environment that damages the steel components during high-temperature operation.This study investigated the microstructural deterioration of 9Cr ferritic/martensitic(F/M)steel under thermal aging at 550℃for 2,000,10,000,or 20,000 h and its effect on oxidation corrosion in an LBE environment using multiscale characterization techniques.The results indicated that the thickness of the internal oxidation zone(IOZ)increased significantly with extended thermal aging,whereas that of the spinel layer remained relatively constant.The abundant subgrain boundaries that emerged during extensive thermal aging facil-itated Fe diffusion,and the enlarged Cr-rich M23C6 carbides contributed to the formation of preferential oxidation regions,accelerating IOZ layer growth.The spinel layer formed from the IOZ was influenced by microstructural defects within the IOZ.A theoretical model describing the accelerated oxide layer growth due to thermal aging was developed.These findings support the advancement of LFR technology.展开更多
Developing efficient and durable non-noble-metal catalysts for the oxygen evolution reaction(OER)in acidic media remains a critical challenge for proton-exchange membrane water electrolysis.Here,we report a dual-phase...Developing efficient and durable non-noble-metal catalysts for the oxygen evolution reaction(OER)in acidic media remains a critical challenge for proton-exchange membrane water electrolysis.Here,we report a dual-phase Mn_(3)O_(4)-Co_(2)MnO_(4)hybrid oxide electrocatalyst synthesized via a sulfur-assisted coelectrodeposition strategy in a choline chloride/ethylene glycol-based deep eutectic solvent,followed by annealing.The incorporation of sulfur facilitates the formation of a cubic spinel Co_(2)MnO_(4)phase within the Mn_(3)O_(4)host,optimizing electronic conductivity and stabilizing the catalytic layer by strengthening Mn-O bonds.When supported on a corrosion-resistant Pt/Ti substrate,the composite electrode achieves a low overpotential of 317 mV at 10 mA cm^(-2)and sustains stable operation for over 100 h in 0.05 M H_(2)SO_(4)(pH=1),outperforming most MnO_(x)-based catalysts and approaching noble-metal benchmarks.Density functional theory calculations reveal that the Co_(2)MnO_(4)phase lowers the energy barrier for the rate-determining OOH^(*)→O_(2)step,while in-situ spectroscopic analyses confirm its structural integrity under acidic OER conditions.Furthermore,electrolyte dissociation kinetics significantly influences performance,with HClO_(4) exhibiting superior mass transfer due to its high proton conductivity.This work provides a rational design pathway for non-noble-metal acidic OER catalysts through phase engineering and electrolyte optimization,advancing sustainable hydrogen production technologies.展开更多
The effects of insoluble eutectic Si particles on the growth of anodic oxide films on ZL114A aluminum alloy substrates were in- vestigated by optical microscopy （OM） and scanning electron microscopy （SEM）. The ano...The effects of insoluble eutectic Si particles on the growth of anodic oxide films on ZL114A aluminum alloy substrates were in- vestigated by optical microscopy （OM） and scanning electron microscopy （SEM）. The anodic oxidation was performed at 25℃ and a con- stant voltage of 15 V in a solution containing 50 g/L sulfuric acid and 10 g/L adipic acid. The thickness of the formed anodic oxidation film was approximately 7.13 μm. The interpore distance and the diameters of the major pores in the porous layer of the film were within the ap- proximate ranges of 10~20 nm and 5-10 nm, respectively. Insoluble eutectic Si particles strongly influenced the morphology of the anodic oxidation films. The anodic oxidation films exhibited minimal defects and a uniform thickness on the ZL114A substrates; in contrast, when the front of the oxide oxidation films encountered eutectic Si particles, defects such as pits and non-uniform thickness were observed, and pits were observed in the films.展开更多
A series of Lewis-acid deep eutectic solvents (DESs) were synthesized by stirring phosphoric acid and zincchloride as raw materials at 80℃ to form H_(3)PO_(4)/nZnCl_(2) (n = 0.1, 0.25, 0.5, 0.75, 1). The DESs were ch...A series of Lewis-acid deep eutectic solvents (DESs) were synthesized by stirring phosphoric acid and zincchloride as raw materials at 80℃ to form H_(3)PO_(4)/nZnCl_(2) (n = 0.1, 0.25, 0.5, 0.75, 1). The DESs were characterized byFourier transform infrared spectrophotometry (FT-IR), thermogravimetry/differential thermogravimetry (TG/DTG), andelectron spray ionization mass spectrometry (ESI-MS). The DESs were used as both extractants and catalysts to removedibenzothiophene from fuels via oxidative desulfurization (ODS). Experiments were performed to investigated the influenceof factors such as composition of DES, temperature, oxidant dosage (molar ratio of O:S), DES dosage (volume ratio ofDES:oil), and number of cycles on desulfurization rate. The results indicated that the removal rate of dibenzothiophene (DBT)was affected by the Lewis acidic DESs, with that of H_(3)PO_(4)/0.25∙ZnCl_(2) reaching 96.4% under optimal conditions (Voil=5 mL,VDES=1 mL, an oxidant dosage of 6, T=50 ℃). After six cycles, the desulfurization rate of H_(3)PO_(4)/0.25∙ZnCl_(2) remained above94.1%. The apparent activation energy of dibenzothiophene (DBT) removal reaction was determined by a pseudo-first orderkinetic equation according to the Arrhenius equation to be 32.34 kJ/mol, as estimated. A reaction mechanism is proposedbased on the experimental data and characterization results.展开更多
Laser 3D printing based on melt growth has great potential in rapid preparation of Al_(2)O_(3)-based eutectic ce ramics.In this work,la rge-scale Al_(2)O_(3)/GdAlO_(3)/ZrO_(2)ternary eutectic ceramic rod with diameter...Laser 3D printing based on melt growth has great potential in rapid preparation of Al_(2)O_(3)-based eutectic ce ramics.In this work,la rge-scale Al_(2)O_(3)/GdAlO_(3)/ZrO_(2)ternary eutectic ceramic rod with diameter of 4-5 mm and height higher than 250 mm was additively manufactured by laser directed energy deposition.Especially,heat treatment was applied to eliminate the microstructure heterogeneity in the as-deposited eutectic ceramic,and the microstructure homogenization mechanism was studied in depth.The results indicate that colonies and banded structures completely disappear after the heat treatment,producing a homogeneous network eutectic structure.The microstructure homogenization is revealed to experience three stages of discontinuous coarsening,continuous coarsening and microstructure coalescence.Additionally,it is found that the eutectic spacing linearly increases with the heat treatment time,meaning that the coarsening behavior of the laser 3D-printed Al_(2)O_(3)/GdAlO_(3)/ZrO_(2)eutectic ceramic satisfies well with the Graham-Kraft model.展开更多
Distribution control and formation mechanism of gas inclusions formed in directionally solidified Al2O3-Er3Al5O12-ZrO2 eutectic ceramic rods are explored during laser floating zone melting. In atmospheric environment,...Distribution control and formation mechanism of gas inclusions formed in directionally solidified Al2O3-Er3Al5O12-ZrO2 eutectic ceramic rods are explored during laser floating zone melting. In atmospheric environment, highly-dense bubble-free eutectic rods are well fabricated at low solidification rate(<25μm/s). Gas inclusions form intermittently when the solidification rate is in the range of 25-50 μm/s,but produce continuously at higher solidification rates(100-200 μm/s). The gas inclusions exhibit an elongated finger-like pattern along the growth direction, which of the maximum value of diameter first increases and then decreases with increasing the solidification rate. Meanwhile, the volume fraction of gas inclusions increased gradually with the solidification rate. Based on the effect of surface tension gradient, heterogeneous nucleation of gas bubbles is evaluated to be the primary formation mechanism of gas inclusions.展开更多
Pb-Bi eutectic alloy has been receiving increasing attention as a heavy liquid metal coolant in accelerator driven systems and Generation IV fission reactors. Compatibility of structural materials with liquid PbBi eut...Pb-Bi eutectic alloy has been receiving increasing attention as a heavy liquid metal coolant in accelerator driven systems and Generation IV fission reactors. Compatibility of structural materials with liquid PbBi eutectic alloy at high temperature is one of the issues concerned. In the present study, corrosion tests of T91 steel in stagnant Pb-Bi eutectic alloy in saturated oxygen condition at 450 oC were carried out. After experiments, the thickness and compositional profile of the oxide layer on the specimen were analyzed using SEM and EDX. Analysis results show that the thickness of the oxide layer increases as the exposure time increases from 500 h to 1,000 h. The thickness of the oxide layer remains almost unchanged at 15 to 16 mm from 1,000 to 1,500 h. Formation of a thick and protective oxide layer at 450 oC prevents the penetration of liquid Pb-Bi eutectic alloy into the matrix of the T91 steel.展开更多
To solve the problems generally encountered during the plasma electrolytic oxidation(PEO) of Al alloys with high Si content, a pretreatment of chemical etching was applied before the process. The influence of such pre...To solve the problems generally encountered during the plasma electrolytic oxidation(PEO) of Al alloys with high Si content, a pretreatment of chemical etching was applied before the process. The influence of such pretreatment was studied by SEM, EDS and XRD. The pretreatment presents a significant effect on positive voltage at the beginning stage of PEO, leading to higher voltage over the whole process. The difference between the positive voltages of non-etched and etched specimens decreases gradually with the increase of processing time. The pretreatment exhibits much less influence on the negative voltage. For the sample with surface pretreatment, the average growth rate of PEO coating is increased from 0.50 to 0.84 μm·min-1and the energy consumption is decreased from 6.30 to 4.36 k W·h·μm-1·m-2. At the same time, both mullite and amorphous Si O2 contents are decreased in the coating.展开更多
The cavitation erosion of weld joint and base metal of China low activation martensitic（CLAM）steel in liquid lead-bismuth eutectic alloy（LBE）at 550°C was investigated to simulate the cavitation erosion of the...The cavitation erosion of weld joint and base metal of China low activation martensitic（CLAM）steel in liquid lead-bismuth eutectic alloy（LBE）at 550°C was investigated to simulate the cavitation erosion of the first wall and the nuclear main pump impeller in the accelerator driven sub-critical system（ADS）.A suit of ultrasonic cavitation facility was self-designed to study the cavitation erosion.By studying the surface micro topography,roughness and mean pit depth of the tested specimens,it was found that some crater clusters and large scale cracks appeared on the tested specimen surface after the formation of numerous single craters,and the base metal exhibited much better cavitation erosion resistance than the weld bead due to the difference in their mechanical properties and microstructures.In addition,by comparing the results of static corrosion and cavitation erosion,it could be concluded that the cavitation erosion and the dissolution and oxidation corrosion in liquid LBE would accelerate mutually.展开更多
基金financial support from the National Key R&D Program of China(No.2020YFA0405901)the National Natural Science Foundation of China(Nos.52375155 and 51875398).
文摘The study investigated the oxidation behavior of T91 steel modified with Al(T91-Al)and Si(T91-Si)in lead-bismuth eutectic(LBE)at 450℃under oxygen-saturated conditions(10^(−7)-10^(−8)wt.%)and oxygen-controlled conditions(3.2×10^(−4)wt.%).Advanced characterization techniques were employed to under-stand the thermodynamic and kinetic mechanisms of enhanced oxidation properties of the modified T91 steel.The results indicate that the oxidation resistance of the materials follows this order:T91<T91-Al<T91-Si.Noteworthy,the oxidation resistance of T91-Si material exhibited minimal correlation with dissolved oxygen.Under oxygen-controlled conditions,the oxide film of T91 and T91-Al was attacked and broken by LBE,with the former eventually peeling off.In contrast,both materials showed significant ox-ide film thickening,except T91-Si under oxygen-saturated conditions.The addition of Al improved the quality of the inner oxide film on T91-Al by generating Al_(2)O_(3),thereby slowing down the diffusion of Fe from the matrix and enhancing oxidation resistance.Conversely,Si actively participated in the oxidation process of T91-Si,slowing down the diffusion of Fe,and facilitating the diffusion of Cr,thereby strength-ening the oxide film protection.Consequently,the oxide thickness of T91-Si material was only 24%of T91 and 35%of T91-Al under saturated oxygen conditions.
基金Project(51764027)supported by the National Natural Science Foundation of ChinaProject(2014CB643404)supported by the National Basic Research Program of China
文摘Deep eutectic solvents(DESs)are a kind of potential lixiviant for selective metal processing due to their versatile complexation properties.In this study,we investigated the recovery of zinc from zinc oxide dust using choline chloride-ureaethylene glycol(ChCl-urea-EG)DESs.The zinc extraction efficiency can be up to 85.2%when the slurry concentration is 50 g/L,leaching temperature is 80°C and stirring speed is 600 r/min.The leaching process is controlled by the diffusion and the corresponding activation energy is 32.1 k J/mol.The resultant solution was directly used for the electrodeposition of zinc.The pure zinc deposit is obtained with a current efficiency of 82.6%.Furthermore,the ChCl-urea-EG DESs can be recycled.This approach is shown to be promising for the recycling of zinc from the zinc-containing dust.
基金supported by the National Natural Science Foundation of China(Nos.21822407,21675164)the CASPresident International Fellowship Initiative(No.2017PC0014)。
文摘Developing a new type of deep eutectic solvents(DESs)is indispensable for expanding their application in various fields.Here,we report a series of new highly basic DESs.FT-IR,quantitative 1 H NMR,MD simulation and physical properties show that these basic liquids are made up of hydroxide acceptor of alkali metal hydroxides in which the hydrogen bonding interactions coordinate the donor.These DESs can be played three roles as new solvents,template and reactant for facile and ultra-fast preparation of transition metal oxide nanomaterials such as NiCo2 O4,MnCo2 O4,NiMn2 O4,CoCu2 O4 and Co3 O4 under mild condition.This work shows one of the low energy-intensive methods for nanomaterial preparation.These initial findings of basic deep eutectic solvents provide a potential applicability around the systematic development of transition metal oxide nanosheets.
基金supported by the National Natural Science Foundation of China(Grant Nos.:82073605 and 81803287)the Natural Science Foundation of Hebei Province(Grant Nos.:B2018201270 and H2021201002)+3 种基金the Talent Engineering Training Foundation of Hebei Province(Grant No.:A201802002)the Research Project of Hebei Provincial Administration of Traditional Chinese Medicine(Grant No.:2021174)Post-graduate's Innovation Fund Project of Hebei University(Grant No.:HBU2021ss006)the Outstanding Doctoral Cultivation Project of Hebei University(Grant No.:YB201703).
文摘Indole-3-carbinol(I3C),an important anticancer compound found in broccoli,has attracted considerable attention.The rapid extraction and accurate analysis of I3C in the pharmaceutical industry in broccoli is challenging as I3C is unstable at low pH and high temperature.In this study,a rapid,accurate,and lowcost ultrasound-assisted dispersive-filter extraction(UADFE)technique based on poly(deep eutectic solvent)-graphene oxide(PDES-GO)adsorbent was developed for the isolation and analysis of I3C in broccoli for the first time.PDES-GO with multiple adsorption interactions and a fast mass transfer rate was synthesized to accelerate adsorption and desorption.UADFE was developed by combining dispersive solid-phase extraction(DSPE)and filter solid-phase extraction(FSPE)to realize rapid extraction and separation.Based on the above two strategies,the proposed PDES-GO-UADFE method coupled with high-performance liquid chromatography(HPLC)allowed the rapid(15-16 min),accurate(84.3%-96.4%),and low-cost(adsorbent:3.00 mg)analysis of I3C in broccoli and was superior to solid-phase extraction,DSPE,and FSPE methods.The proposed method showed remarkable linearity(r=0.9998;range:0.0840-48.0 mg/g),low limit of quantification(0.0840 mg/g),and high precision(relative standard deviation<5.6%).Therefore,the PDES-GO-UADFE-HPLC method shows significant potential in the field of pharmaceutical analysis for the separation and analysis of anti-cancer compounds in complex plant samples.
基金Project supported by the National Natural Science Foundation of China(51564015)
文摘Al-Cu-Y alloys were prepared by molten salt electrolysis in fluoride-oxide system composed of electrolyte（Na3 AlF6-AlF3-LiF-MgF2） and oxide（Al2 O3-CuO-Y2 O3）. Cathodic reduction process of Al2 O3,CuO and Y2 O3 were analyzed by cyclic voltammetry and chronoamperometry. Components and phase composition of alloy samples prepared by potentiostatic electrolysis were characterized by scanning electron microscopy and energy dispersive spectroscopy. The results show that the Al-Cu-Y alloy can be prepared in the AIF3-NaF-5 wt%LiF-5 wt%MgF2（NaF/AlF3 = 2.2, molecular ratio） eutectic system with mixed oxide（Al2 O3-CuO-Y2 O3） through 2 h at the conditions of a temperature of 1208 K, cell voltage3.0 V, cathode current density 0.7 A/cm^2. Al（Ⅲ） and Cu（Ⅱ） ions can be reduced to zero valence Al（0） and Cu（0） directly on carbonaceous electrode surface by instantaneous nucleation, respectively, the reduction process is controlled by diffusion. The reduction potential of Y（Ⅲ） ions is close to the active ions of fluoride melts, but strengthened phase AI3 Y can be formed through electrochemical reduction and alloyed process with active Al（Ⅲ） and Cu（Ⅱ） ions, meanwhile, the Al2 Cu and Al3 Y phases are distributed at the grain boundary of Al matrix.
基金Project(51101055)supported by the National Natural Science Foundation of China
文摘The isothermal oxidation behavior of NiAl-31Cr-2.9Mo-0.1Hf-0.05Ho directional eutectic alloy was investigated with the help of scanning electron microscopy and X-ray diffraction.The results revealed that a continuous Al2O3 scale was formed and owned excellent oxidation resistance in the temperature range of 900-1100°C.When the temperature was up to 1150°C,the continuous Al2O3 oxide film ruptured.Trace rare earth element Ho distributed uniformly in the alloy and relatively high level of Al in Cr（Mo）phase are beneficial to the formation of continuous and compact Al2O3 scale.During the oxidation,a phase transformation fromθ-Al2O3 toα-Al2O3 existed on the surface of oxidation film.It resulted in the abnormal oxidation mass gain happening when the alloy was oxidized at 1000°C or 1050°C.
基金financially supported by the National Natural Science Foundation of China (Nos. 21506080 and 21766007)Natural Science Foundation of Jiangsu Province (No. BK20150485)+1 种基金Advanced Talents of Jiangsu University (No. 15JDG053)A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Deep eutectic solvents(DESs) are a new class of green solvents analogous to ionic liquids due to their biodegradable capacity and low cost. However, the direct extractive desulfurization of diesel oil by DESs cannot meet the government’s standard. In this work, amphiphilic polyoxometalates were synthesized and characterized by FT-IR and mass spectrometry.The oxidative desulfurization results showed that benzothiophene(BT) could be completely removed by employing a [(CH)P(CH)]PMoO, DES(ChCl/2 Ac) and HOsystem. It was also found that the organic cation of catalysts played a positive role in oxidative desulfurization. The reaction conditions, such as reaction temperature and time, the amount of catalyst and DES and HO/S(O/S) molar ratio, were optimized. Different sulfides were tested to determine the desulfurization selectivity of the optimal reaction system, and it was found that 97.2% of dibenzothiophene(DBT) could be removed followed by 80.7% of 4-MDBT and 76.0% of 4,6-DMDBT. After reaction, the IR spectra showed that the catalyst [(CH)P(CH)]PMoOwas stable during the reaction process and the oxidative product was dibenzothiophene sulfone(DBTO). Furthermore, the catalyst can be regenerated and recycled for four runs with little loss of activity.
文摘A unique redox-coupled biomimetic system was developed, in which Fe-Anderson type polyoxometalates(POMs) were employed as electron transfer mediators(ETMs) and benzenesulfonic acid(BSA)-based deep eutectic solvents(DESs) were used as electron-donors for aerobic oxidative desulfurization(AODS) of diesel fuel. Different compositions of DESs were used and the polyethylene glycol 2000(PEG2000)/2.5 BSA system showed the highest desulfurization activity, with the removal of dibenzothiophene(DBT) at 60 ℃ reaching 95% in 60 min. The excellent desulfurization activity of the system is due to the in situ formation of peroxysulfonate via a biomimetic process. By constructing a coupled redox system, Fe-Anderson type POMs as ETMs reduce the activation energy of oxygen-activated sulfonate. The physical characteristics of four different DESs were tested. The results show that the conductivity of DESs is correlated with the composition of BSA-based DESs. However, there is no similar trend in viscosity testing at the same temperature, and the maximum viscosity value is obtained for the PEG2000/2.5 BSA system at 60 ℃, which may be associated with the stronger hydrogen bonds. It is worth noting that the PEG2000/2.5 BSA system also possesses the best desulfurization activity, which suggests that the activity of the desulfurization system is related to the strength of the hydrogen bond in DESs. Finally, the biomimetic desulfurization system exhibits excellent performance and good stability under mild reaction conditions(60 ℃, atmospheric pressure, oxygen as the oxidant).
基金financially supported by the National Natural Science Foundation of China(No.52171046)National Natural Science Foundation of China-key programme(No.52234010)the Fundamental Research Funds for the Central Universities and Shaanxi Provincial Key Science and Technology Innovation Team(No.2023-CX-TD-14).
文摘Al_(2)O_(3)-based eutectic ceramics are considered as promising candidates for ultra-high-temperature structural materials due to their exceptional thermal stability and mechanical properties.Nonetheless,several challenges must be overcome before they can be widely used.This paper reviews in detail the tailoring of microstructure from the aspect of process parameters,the updated knowledge gained in microstructure(crystallographic orientation,high-resolution interfacial structures)and the latest means of optimizing eutectic microstructure(seed-induced method,introducing low-energy grain boundaries and high-entropy phase).Additionally,the paper explores future techniques for the fabrication of bulk ceramic materials and effective toughening approaches.This review highlights the achievements made especially in the last 15 years,current limitations in Al_(2)O_(3)-based eutectic ceramics,and offers comprehensive insights and strategic guidance for further mechanical breakthroughs.
基金financially supported by the National Natural Science Foundation of China(No.21808091)Natural Science Foundation of Jiangsu Province(Nos.BK20200896,BK20190243)+2 种基金Key Laboratory of Tropical Medicinal Plant Chemistry of Ministry of Education,Hainan Normal University(20150376)China Postdoctoral Foundation(No.2020M671365)the Student Innovation and Entrepreneurship Training Program(202010299457X)。
文摘A series of novel binary deep eutectic solvents(DESs)composed of choline chloride(ChCl)and formic acid(HCOOH)with different molar ratios have been successfully synthesized and applied in extractive desulfurization(EDS).Keggin-type polyoxometallate ionic liquid[TTPh]_(3)PW_(12)O_(40) was prepared and used as catalyst to enhance the EDS capacity by means of photocatalytic oxidative process.Both of the DESs and[TTPh]_(3)PW_(12)O_(40) ionic liquid catalyst were characterized in detail by Fourier transform infrared spectroscopy spectra(FT-IR),elemental analysis,and X-ray photoelectron spectroscopy(XPS).It was found that the molar ratios of Ch Cl:HCOOH had a major impact on desulfurization performance,and the optimal desulfurization capacity 96.5%was obtained by ChCl/5 HCOOH.Besides dibenzothiophene(DBT),the desulfurization efficiencies of 4-methylbenzothiophene(4-MDBT)and 4,6-dimethyldibenzothiophene(4,6-DMDBT),two kinds of DBT derivatives,were also investigated under the same experimental conditions.Moreover,the free radical scavenging experiments manifested that superoxide radical(·O_(2)^(-)) and hole(h^(+)) played important roles in the desulfurization system.After further analysis of the oxidation products by gas chromatography-mass spectrometry(GC–MS),the possible reaction mechanism was proposed.Thus,photocatalytic oxidative has been proved to be one of the efficient approaches for enhancing the extractive desulfurization performance in DES.
基金supported by the Natural Science Foundation of Shandong Province with grant No.ZR2023ME196the Science and Technology Support Plan for Young Innovation of Colleges and Universities of Shandong Province with grant No.2022KJ273+1 种基金the Youth Innovation Promotion Association of the Chinese Academy of Sciences with grant No.2017486the Patent Navigation Project of Shandong Province with grant No.D202327.
文摘In lead-cooled fast reactor(LFR)systems,the liquid lead-bismuth eutectic(LBE)coolant provides a cor-rosive environment that damages the steel components during high-temperature operation.This study investigated the microstructural deterioration of 9Cr ferritic/martensitic(F/M)steel under thermal aging at 550℃for 2,000,10,000,or 20,000 h and its effect on oxidation corrosion in an LBE environment using multiscale characterization techniques.The results indicated that the thickness of the internal oxidation zone(IOZ)increased significantly with extended thermal aging,whereas that of the spinel layer remained relatively constant.The abundant subgrain boundaries that emerged during extensive thermal aging facil-itated Fe diffusion,and the enlarged Cr-rich M23C6 carbides contributed to the formation of preferential oxidation regions,accelerating IOZ layer growth.The spinel layer formed from the IOZ was influenced by microstructural defects within the IOZ.A theoretical model describing the accelerated oxide layer growth due to thermal aging was developed.These findings support the advancement of LFR technology.
基金financial support of the National Natural Science Foundation of China(52361039,21962008)Yunnan Ten Thousand Talents Plan Young&Elite Talents Project(YNWR-QN BJ-2018-346)。
文摘Developing efficient and durable non-noble-metal catalysts for the oxygen evolution reaction(OER)in acidic media remains a critical challenge for proton-exchange membrane water electrolysis.Here,we report a dual-phase Mn_(3)O_(4)-Co_(2)MnO_(4)hybrid oxide electrocatalyst synthesized via a sulfur-assisted coelectrodeposition strategy in a choline chloride/ethylene glycol-based deep eutectic solvent,followed by annealing.The incorporation of sulfur facilitates the formation of a cubic spinel Co_(2)MnO_(4)phase within the Mn_(3)O_(4)host,optimizing electronic conductivity and stabilizing the catalytic layer by strengthening Mn-O bonds.When supported on a corrosion-resistant Pt/Ti substrate,the composite electrode achieves a low overpotential of 317 mV at 10 mA cm^(-2)and sustains stable operation for over 100 h in 0.05 M H_(2)SO_(4)(pH=1),outperforming most MnO_(x)-based catalysts and approaching noble-metal benchmarks.Density functional theory calculations reveal that the Co_(2)MnO_(4)phase lowers the energy barrier for the rate-determining OOH^(*)→O_(2)step,while in-situ spectroscopic analyses confirm its structural integrity under acidic OER conditions.Furthermore,electrolyte dissociation kinetics significantly influences performance,with HClO_(4) exhibiting superior mass transfer due to its high proton conductivity.This work provides a rational design pathway for non-noble-metal acidic OER catalysts through phase engineering and electrolyte optimization,advancing sustainable hydrogen production technologies.
基金financially supported by the National Nature Science Foundation of China (No. 21371019)the Aero Science Foundation of China (No. 2011ZE51057)
文摘The effects of insoluble eutectic Si particles on the growth of anodic oxide films on ZL114A aluminum alloy substrates were in- vestigated by optical microscopy （OM） and scanning electron microscopy （SEM）. The anodic oxidation was performed at 25℃ and a con- stant voltage of 15 V in a solution containing 50 g/L sulfuric acid and 10 g/L adipic acid. The thickness of the formed anodic oxidation film was approximately 7.13 μm. The interpore distance and the diameters of the major pores in the porous layer of the film were within the ap- proximate ranges of 10~20 nm and 5-10 nm, respectively. Insoluble eutectic Si particles strongly influenced the morphology of the anodic oxidation films. The anodic oxidation films exhibited minimal defects and a uniform thickness on the ZL114A substrates; in contrast, when the front of the oxide oxidation films encountered eutectic Si particles, defects such as pits and non-uniform thickness were observed, and pits were observed in the films.
基金the College Student Innovation and Entrepreneurship Training Program Project of Liaoning Province(202310148016)Doctoral Fund of Liaoning Province(201501105).
文摘A series of Lewis-acid deep eutectic solvents (DESs) were synthesized by stirring phosphoric acid and zincchloride as raw materials at 80℃ to form H_(3)PO_(4)/nZnCl_(2) (n = 0.1, 0.25, 0.5, 0.75, 1). The DESs were characterized byFourier transform infrared spectrophotometry (FT-IR), thermogravimetry/differential thermogravimetry (TG/DTG), andelectron spray ionization mass spectrometry (ESI-MS). The DESs were used as both extractants and catalysts to removedibenzothiophene from fuels via oxidative desulfurization (ODS). Experiments were performed to investigated the influenceof factors such as composition of DES, temperature, oxidant dosage (molar ratio of O:S), DES dosage (volume ratio ofDES:oil), and number of cycles on desulfurization rate. The results indicated that the removal rate of dibenzothiophene (DBT)was affected by the Lewis acidic DESs, with that of H_(3)PO_(4)/0.25∙ZnCl_(2) reaching 96.4% under optimal conditions (Voil=5 mL,VDES=1 mL, an oxidant dosage of 6, T=50 ℃). After six cycles, the desulfurization rate of H_(3)PO_(4)/0.25∙ZnCl_(2) remained above94.1%. The apparent activation energy of dibenzothiophene (DBT) removal reaction was determined by a pseudo-first orderkinetic equation according to the Arrhenius equation to be 32.34 kJ/mol, as estimated. A reaction mechanism is proposedbased on the experimental data and characterization results.
基金financially supported by the National Key R&D Program of China(Nos.2018YFB1106600 and 2017YFB1103500)Science,Technology and Innovation Commission of Shenzhen Municipality(No.JCYJ20180306171121424)+4 种基金National Natural Science Foundation of China(Nos.51822405,51472200)Aeronautics Power Foundation(No.6141B09050337)Key R&D Program of Shaan Xi Province(No.2018ZDCXL-GY-09-04)Joint Research Funds of the Department of Science&Technology of Shaanxi Province and NPU(No.2020GXLH-Z-024)Research Fund of the State Key Laboratory of Solidification Processing(NPU)(No.2019QZ-02)。
文摘Laser 3D printing based on melt growth has great potential in rapid preparation of Al_(2)O_(3)-based eutectic ce ramics.In this work,la rge-scale Al_(2)O_(3)/GdAlO_(3)/ZrO_(2)ternary eutectic ceramic rod with diameter of 4-5 mm and height higher than 250 mm was additively manufactured by laser directed energy deposition.Especially,heat treatment was applied to eliminate the microstructure heterogeneity in the as-deposited eutectic ceramic,and the microstructure homogenization mechanism was studied in depth.The results indicate that colonies and banded structures completely disappear after the heat treatment,producing a homogeneous network eutectic structure.The microstructure homogenization is revealed to experience three stages of discontinuous coarsening,continuous coarsening and microstructure coalescence.Additionally,it is found that the eutectic spacing linearly increases with the heat treatment time,meaning that the coarsening behavior of the laser 3D-printed Al_(2)O_(3)/GdAlO_(3)/ZrO_(2)eutectic ceramic satisfies well with the Graham-Kraft model.
基金supported financially by the Science, Technology and Innovation Commission of Shenzhen Municipality (No. JCYJ20180306171121424)the National Key R&D Program of China (Nos. 2018YFB1106600 and 2017YFB1103500)+5 种基金the National Natural Science Foundation of China (Nos. 51822405 and 51472200)the Aeronautics Power Foundation (No. 6141B09050337)the Research Fund of Equipment Development Department (No. 61409230402)the Key R&D Program of ShaanXi Province (No. 2018ZDCXL-GY-0904)the Innovation Fund of the Zhejiang Kechuang New Materials Research Institute (No. ZKN-18-P04)the Research Fund of the State Key Laboratory of Solidification Processing (NPU) (No. 2019QZ-02)。
文摘Distribution control and formation mechanism of gas inclusions formed in directionally solidified Al2O3-Er3Al5O12-ZrO2 eutectic ceramic rods are explored during laser floating zone melting. In atmospheric environment, highly-dense bubble-free eutectic rods are well fabricated at low solidification rate(<25μm/s). Gas inclusions form intermittently when the solidification rate is in the range of 25-50 μm/s,but produce continuously at higher solidification rates(100-200 μm/s). The gas inclusions exhibit an elongated finger-like pattern along the growth direction, which of the maximum value of diameter first increases and then decreases with increasing the solidification rate. Meanwhile, the volume fraction of gas inclusions increased gradually with the solidification rate. Based on the effect of surface tension gradient, heterogeneous nucleation of gas bubbles is evaluated to be the primary formation mechanism of gas inclusions.
基金financially supported by the Strategic Priority Research Program CAS under Grant No.XDA03010304the National Science Foundation of China under Grant No.91226204the Youth Innovation Promotion Association CAS
文摘Pb-Bi eutectic alloy has been receiving increasing attention as a heavy liquid metal coolant in accelerator driven systems and Generation IV fission reactors. Compatibility of structural materials with liquid PbBi eutectic alloy at high temperature is one of the issues concerned. In the present study, corrosion tests of T91 steel in stagnant Pb-Bi eutectic alloy in saturated oxygen condition at 450 oC were carried out. After experiments, the thickness and compositional profile of the oxide layer on the specimen were analyzed using SEM and EDX. Analysis results show that the thickness of the oxide layer increases as the exposure time increases from 500 h to 1,000 h. The thickness of the oxide layer remains almost unchanged at 15 to 16 mm from 1,000 to 1,500 h. Formation of a thick and protective oxide layer at 450 oC prevents the penetration of liquid Pb-Bi eutectic alloy into the matrix of the T91 steel.
基金Supported by the Natural Science Foundation of Guangdong Province,China(S2013010015211)
文摘To solve the problems generally encountered during the plasma electrolytic oxidation(PEO) of Al alloys with high Si content, a pretreatment of chemical etching was applied before the process. The influence of such pretreatment was studied by SEM, EDS and XRD. The pretreatment presents a significant effect on positive voltage at the beginning stage of PEO, leading to higher voltage over the whole process. The difference between the positive voltages of non-etched and etched specimens decreases gradually with the increase of processing time. The pretreatment exhibits much less influence on the negative voltage. For the sample with surface pretreatment, the average growth rate of PEO coating is increased from 0.50 to 0.84 μm·min-1and the energy consumption is decreased from 6.30 to 4.36 k W·h·μm-1·m-2. At the same time, both mullite and amorphous Si O2 contents are decreased in the coating.
基金supported by the National Natural Science Foundation of China with Grant Nos.51375216 and 51505197the Open-Fund Research of State Key Lab of Advanced Welding and Joining with Grant No.AWJ-16-M07the Fusion Digital Simulation(FDS)Team for support the CLAM steel
文摘The cavitation erosion of weld joint and base metal of China low activation martensitic（CLAM）steel in liquid lead-bismuth eutectic alloy（LBE）at 550°C was investigated to simulate the cavitation erosion of the first wall and the nuclear main pump impeller in the accelerator driven sub-critical system（ADS）.A suit of ultrasonic cavitation facility was self-designed to study the cavitation erosion.By studying the surface micro topography,roughness and mean pit depth of the tested specimens,it was found that some crater clusters and large scale cracks appeared on the tested specimen surface after the formation of numerous single craters,and the base metal exhibited much better cavitation erosion resistance than the weld bead due to the difference in their mechanical properties and microstructures.In addition,by comparing the results of static corrosion and cavitation erosion,it could be concluded that the cavitation erosion and the dissolution and oxidation corrosion in liquid LBE would accelerate mutually.
