The microstructures and thermodynamic properties of mixed systems comprising pyridinium ionic liquid[HPy][BF_(4)]and acetonitrile at different mole fractions were studied using molecular dynamics simulation in this wo...The microstructures and thermodynamic properties of mixed systems comprising pyridinium ionic liquid[HPy][BF_(4)]and acetonitrile at different mole fractions were studied using molecular dynamics simulation in this work.The following properties were determined:density,self-diffusion coefficient,excess molar volume,and radial distribution function.The results show that with an increase in the mole fraction of[HPy][BF_(4)],the self-diffusion coefficient decreases.Additionally,the excess molar volume initially decreases,reaches a minimum,and then increases.The rules of radial distribution functions(RDFs)of characteristic atoms are different.With increasing the mole fraction of[HPy][BF_(4)],the first peak of the RDFs of HA1-F decreases,while that of CT6-CT6 rises at first and then decreases.This indicates that the solvent molecules affect the polar and non-polar regions of[HPy][BF_(4)]differently.展开更多
We introduce our state-of-the art of“vacuum consistent electrochemistry”to an investigation of the interfaces between oxides and ionic liquid(IL).Pulsed laser deposition(PLD)has been one of the powerful and sophisti...We introduce our state-of-the art of“vacuum consistent electrochemistry”to an investigation of the interfaces between oxides and ionic liquid(IL).Pulsed laser deposition(PLD)has been one of the powerful and sophisticated techniques to realize nanoscale preparation of high-quality epitaxial oxide thin films.On the other hand,electrochemistry is a simple,very sensitive,and non-destructive analysis technique for solid-liquid interfaces.To ensure the reproducibility in experiment of the interfaces of such epitaxial oxide films,as well as bulk oxide single-crystals,with IL,we employ a home-built PLD-electrochemical(EC)system with IL as an electrolyte.The system allows one to perform all-in-vacuum experiments during the preparation of well-defined oxide electrode surfaces to their electrochemical analyses.The topics include electrochemical evaluations of the oxide’s own properties,such as carrier density and relative permittivity,and the interfacial properties of oxides in contact with IL,such as flat band potential and electric double layer(EDL)capacitance,ending with future perspectives in all-solid-state electrochemistry.展开更多
The memory behavior in liquid crystals(LCs)that is characterized by low cost,large area,high speed,and high-density memory has evolved from a mere scientific curiosity to a technology that is being applied in a variet...The memory behavior in liquid crystals(LCs)that is characterized by low cost,large area,high speed,and high-density memory has evolved from a mere scientific curiosity to a technology that is being applied in a variety of commodities.In this study,we utilized molybdenum disulfide(MoS_(2))nanoflakes as the guest in a homotropic LCs host to modulate the overall memory effect of the hybrid.It was found that the MoS₂nanoflakes within the LCs host formed agglomerates,which in turn resulted in an accelerated response of the hybrids to the external electric field.However,this process also resulted in a slight decrease in the threshold voltage.Additionally,it was observed that MoS₂nanoflakes in a LCs host tend to align homeotropically under an external electric field,thereby accelerating the refreshment of the memory behavior.The incorporation of a mass fraction of 0.1%2μm MoS₂nanoflakes into the LCs host was found to significantly reduce the refreshing memory behavior in the hybrid to 94.0 s under an external voltage of 5 V.These findings illustrate the efficacy of regulating the rate of memory behavior for a variety of potential applications.展开更多
The development of highly active catalyst in pH-neutral media for oxygen evolution reaction(OER)is critical in the field of renewable energy storage and conversion.Nevertheless,the slow kinetics of proton-coupled elec...The development of highly active catalyst in pH-neutral media for oxygen evolution reaction(OER)is critical in the field of renewable energy storage and conversion.Nevertheless,the slow kinetics of proton-coupled electron transfer(PCET)hinders the overall OER efficiency.Herein,we report an ionic liquid(IL)modified CoSn(OH)_(6)nanocubes(denoted as CoS-n(OH)_(6)-IL),which could be prepared through a facile strategy.The modified IL would not change the structural character-istics of CoSn(OH)_(6),but could effectively regulate the local proton activity near the active sites.The CoSn(OH)_(6)-IL exhibited higher intrinsic OER performances than the pristine CoSn(OH)_(6)in neutral media.For example,the current density of CoS-n(OH)_(6)-IL at 1.8 V versus reversible hydrogen electrode(RHE)was about 4 times higher than that of CoSn(OH)_(6).According to the pH-dependent kinetic investigations,operando electrochemical impedance spectroscopic,chemical probe tests,and deuterium kinetic isotope effects,the interfacial layer of IL could be utilized as a proton transfer mediator to promote the proton transfer,which enhances the surface coverage of OER intermediates and reduces the activation barrier.Consequent-ly,the sluggish OER kinetics would be efficiently accelerated.This study provides a facile and effective strategy to facilitate the PCET processes and is beneficial to guide the rational design of OER electrocatalysts.展开更多
Ultrathin 2D niobium oxide dichloride(NbOCl_(2))is an emerging member of the 2D ferroelectric material family with extensive potential to provide multifunctionality in electronic devices and nanophotonics elements.It ...Ultrathin 2D niobium oxide dichloride(NbOCl_(2))is an emerging member of the 2D ferroelectric material family with extensive potential to provide multifunctionality in electronic devices and nanophotonics elements.It exhibits negligible interlayer electronic coupling and significant excitonic behavior in the bulk state.Here we substantiate that NbOCl_(2) nanosheets can be exfoliated and effectively size-selected using controlled centrifugation techniques by the liquid phase exfoliation(LPE)method.Spectroscopic measurements displayed that the variations in dispersion were highly dependent on the nanosheet dimensions.The nanosheets seemed to be comparatively defect-free which will be further corroborated by high resolution transmission electron microscopy(HRTEM)and Raman analysis.The size selected nanosheets are unanticipated stable in isopropyl alcohol(IPA),possibly owing to the protective influence of a solvation shell.Additionally,the photothermal conversion response and photothermal stability of nanosized NbOCl_(2) were investigated.Our finding revealed that NbOCl_(2) possesses a robust photothermal agent property,boasting a photothermal conversion efficiency of more than 30%.This underscores its promising potential for various photothermal applications in different fields such as photothermal therapy and thermal energy conversion.展开更多
Flammable ionic liquids exhibit high conductivity and a broad electrochemical window,enabling the generation of combustible gases for combustion via electrochemical decomposition and thermal decomposition.This charact...Flammable ionic liquids exhibit high conductivity and a broad electrochemical window,enabling the generation of combustible gases for combustion via electrochemical decomposition and thermal decomposition.This characteristic holds significant implications in the realm of novel satellite propulsion.Introducing a fraction of the electrical energy into energetic ionic liquid fuels,the thermal decomposition process is facilitated by reducing the apparent activation energy required,and electrical energy can trigger the electrochemical decomposition of ionic liquids,presenting a promising approach to enhance combustion efficiency and energy release.This study applied an external voltage during the thermal decomposition of 1-ethyl-3-methylimidazole nitrate([EMIm]NO_(3)),revealing the effective alteration of the activation energy of[EMIm]NO_(3).The pyrolysis,electrochemical decomposition,and electron assisted enhancement products were identified through Thermogravimetry-Differential scanning calorimetry-Fourier transform infrared-Mass spectrometry(TG-DSC-FTIR-MS)and gas chromatography(GC)analyses,elucidating the degradation mechanism of[EMIm]NO_(3).Furthermore,an external voltage was introduced during the combustion of[EMIm]NO_(3),demonstrating the impact of voltage on the combustion process.展开更多
In this work,tensile mechanical behavior of 316L steels fabricated by three different processing methods(casting,powder extrusion printing(PEP)and laser powder bed fusion(LPBF))was studied in the presence of liquid le...In this work,tensile mechanical behavior of 316L steels fabricated by three different processing methods(casting,powder extrusion printing(PEP)and laser powder bed fusion(LPBF))was studied in the presence of liquid lead-bismuth eutectic(LBE)and air at 350℃.The results show that all three steels tested in LBE are not subjected to evident degradation of tensile elongation to failure and strength compared to those tested in air,suggesting that LME does not occur regardless of the processing methods.The LPBF 316L steel exhibits the highest yield strength(420-435 MPa),followed by casting 316 L(~242 MPa)and PEP 316L(146-165 MPa).Ultimate tensile strength of three steels is comparable and ranges from 427 to 485 MPa.The PEP and casting 316L steels have similar total elongation to failure(i.e.,40.0%-43.8%),whereas this property decreases markedly to 18.6%-19.5% for the LPBF 316 L steel.The superior strength and relatively low ductility of the LPBF 316L steel can be attributed to nanosized dislocations trapped at cell structures which can produce a remarkable strengthening effect to the steel matrix.By contrast,due to massive residual micropores,the PEP 316L steel has the lowest strength.展开更多
The geological structure of coal seams in China is remarkably varied and complex,with coalbed methane reservoirs marked by significant heterogeneity and low permeability,creating substantial technical challenges for e...The geological structure of coal seams in China is remarkably varied and complex,with coalbed methane reservoirs marked by significant heterogeneity and low permeability,creating substantial technical challenges for efficient extraction.This study systematically investigates the impact of liquid nitrogen immersion(LNI)on the coal’s pore structure and its mechanism of enhancing permeability with a combination of quantitative nuclear magnetic resonance(NMR)analysis,nitrogen adsorption experiments,and fractal dimension calculations.The results demonstrate that LNI can damage the coal’s pore structure and promote fracture expansion through thermal stress induction and moisture phase transformation,thereby enhancing the permeability of coal seams.The T_(2)peak area in the NMR experiments on coal samples subjected to LNI treatment shows a significant increase,the Brunauer-Emmett-Teller(BET)specific surface area decreases to 6.02 m^(2)/g,and the Barrett-Joyner-Halenda(BJH)total pore volume increases to 14.99 mm^(3)/g.Furthermore,changes in fractal dimensions(D_(1)rising from 2.804 to 2.837,and D_(2)falling from 2.757 to 2.594)indicate a notable enhancement in the complexity of the pore structure.With increasing LNI cycles,the adsorption capacity of the coal samples diminishes,suggesting a significant optimization of the pore structure.This optimization is particularly evident in the reconstruction of the micropore structure,which in turn greatly enhances the complexity and connectivity of the sample’s pore network.In summary,the study concludes that LNI technology can effectively improve the permeability of coal seams and the extraction efficiency of coalbed methane by optimizing the micropore structure and enhancing pore connectivity,which offers a potential method for enhancing the permeability of gas-bearing coal seams and facilitating the development and utilization of coalbed methane.展开更多
For the determination of salicylaldoxime in environmental water samples,a stable and rapid method with low detection was proposed and established,based on the liquid-liquid extraction-high performance liquid chromatog...For the determination of salicylaldoxime in environmental water samples,a stable and rapid method with low detection was proposed and established,based on the liquid-liquid extraction-high performance liquid chromatography with ultraviolet detector.Parameters including extraction solvent,ionic strength,solution pH,and extraction pattern were discussed for the optimal quantification of salicylaldoxime-spiked water.When the described method was applied to four spiked water samples,the obtained average extraction recovery rate was found between 87%–107%and relative standard deviation was below 6%.At the same time,good linear relationships were observed for spiked water samples from 0.01 to 10μg/mL(R2=0.9993).In addition,the detection limit of salicylaldoxime was revealed between 0.003–0.008μg/mL,which is two orders of magnitude lower than previously reported results.Thus,the presented method may be advantageous for the high-efficiency determination of salicylaldoxime in water samples.展开更多
A systematic investigation on the mechanism of dynamic liquid dispersing process via theoretical and experimental approach is presented.The experiments include weak and strong constrained scenarios using the high-spee...A systematic investigation on the mechanism of dynamic liquid dispersing process via theoretical and experimental approach is presented.The experiments include weak and strong constrained scenarios using the high-speed camera technique and the flash X-ray radiography technique.Based on dynamic analysis,one-dimensional characteristics analysis and some numerical simulations on the propagating processes of blast waves before the container shell rupturing,further and detailed analyses of the experimental results are presented.The effects of the liquid viscosity on the dynamic dispersing flow are also analyzed,and the spall fracture mechanism is explored.Thus,the dominating forces determining the dispersing liquid flow are revealed,that is,the stretching and shearing action due to the interaction of two reflecting rarefaction waves in opposite propagating directions.The influence of container shell strength on the dispersing liquid flow is also investigated,and the characters of cavitation layered in liquid before shell rupturing are uncovered.Results revealed that different shell material results in different cavitating layers.Then the different cavitating layers drive the different dynamic liquid dispersing process coming into being.The metastable liquid states caused by pressure drop and cavitation generation are discussed.展开更多
The physical stability of solid-liquid fuel is a factor that needs to be considered for fuel product practicability for storage and transportation. To determine the Influence of liquid bridge force on physical stabili...The physical stability of solid-liquid fuel is a factor that needs to be considered for fuel product practicability for storage and transportation. To determine the Influence of liquid bridge force on physical stability, two detection devices were designed. The laws obtained from microscopic experiments are used to verify the physical stability of fuel under different component ratios. The liquid bridge force is found to increase with the droplet volume. Multiliquid bridges above one critical saturation can generate significant resultant forces compared to single-liquid bridges of the same volume. There exist four states of solid-liquid mixed fuel with increasing liquid saturation rate. The liquid bridge force between the solid and liquid plays a dominant role in the physical stability of the first three states. There may be two stages involved in the stratification process for state 4 fuel, and the liquid viscosity is another factor that cannot be ignored. In the process of selecting a fuel ratio, a larger liquid bridge force between the components can be obtained by properly improving the wetting effect so that the fuel shows better physical stability.展开更多
In order to study the action mechanism of Sacha Inchi polypeptide in liquid crystal emulsion,oil-in-water liquid crystal emulsions with Sacha Inchi fermented polypeptide as the active component were prepared.The micro...In order to study the action mechanism of Sacha Inchi polypeptide in liquid crystal emulsion,oil-in-water liquid crystal emulsions with Sacha Inchi fermented polypeptide as the active component were prepared.The microstructures,particle sizes,stabilities,thermodynamic properties,and rheological properties of liquid crystal emulsions with different concentrations of the fermentation products were observed by Polarizing microscope,Particle size meter,Thermogravimetric differential thermal synchronous measurement system,and Rheometer,respectively.The results showed that the average particle size of fermented peptide liquid crystal emulsion was(25.7±2.8)μm,and the liquid crystal structure was complete and stable.The content of bound water and liquid crystal in the emulsion with 1%Sacha Inchi polypeptide were higher than those in the blank emulsion and the emulsions with 3%and 5%Sacha Inchi polypeptide.Rheological results indicated that the viscosity of liquid crystal emulsion with the change curve of shear rate registered the shear thinning phenomenon,which belongs to non-Newtonian fluid.The hysteresis area,energy storage modulus,and loss modulus of the 1%additive amount of liquid crystal emulsion were larger than those of the blank emulsion and the emulsions with 3%and 5%Sacha Inchi polypeptide,indicating greater thixotropy and stronger shear resistance.The hydrophilic amino acid residues of the peptide in the 1%additive amount of the emulsion were combined with the water phase,while the hydrophobic amino acid residues of the peptide entered the oil phase,which formed a viscoelastic film at the oil-water interface,so that the liquid crystal emulsion had a more stable gel network structure.展开更多
The measurement of urine catecholamine and metanephrine concentrations is important for biochemical screening and diagnosis of pheochromocytoma.The goal of this work was to develop a simple liquid chromatography-tande...The measurement of urine catecholamine and metanephrine concentrations is important for biochemical screening and diagnosis of pheochromocytoma.The goal of this work was to develop a simple liquid chromatography-tandem mass spectrometry(LC-MS/MS)method for determining catecholamines and metanephrines in urine to replace an existing liquid chromatographic method using electrochemical detection.Urine samples were prepared using Oasis weak-cation-exchange cartridges.The eluate was analyzed on an Agilent ZORBAX Eclipse Plus Phenyl-Hexyl column in 3 min.Adrenaline,noradrenaline,dopamine,metanephrine,normetanephrine,and their deuterated internal standards were monitored in positive electrospray ionization mode by multiple reaction monitoring(MRM).No evidence of ion suppression was observed.The assay was linear up to 5μmol/L for adrenaline,5μmol/L for noradrenaline,6.1μmol/L for dopamine,5.6μmol/L for metanephrine,and 34.6μmol/L for normetanephrine,with lower limits of quantification of 5,5,12,6 and 7nmol/L,respectively.The intra-day and inter-day precisions for all analytes ranged from 0.59%to 4.64%and1.98%to 4.80%,respectively.External quality assurance samples were assayed and showed excellent agreement with the target values.This simple method provides an improved assay for determining urine catecholamines and metanephrines.展开更多
In order to study the instability propagation characteristics of the liquid kerosene rotating detonation wave(RDW),a series of experimental tests were carried out on the rotating detonation combustor(RDC)with air-heat...In order to study the instability propagation characteristics of the liquid kerosene rotating detonation wave(RDW),a series of experimental tests were carried out on the rotating detonation combustor(RDC)with air-heater.The fuel and oxidizer are room-temperature liquid kerosene and preheated oxygenenriched air,respectively.The experimental tests keep the equivalence ratio of 0.81 and the oxygen mass fraction of 35%unchanged,and the total mass flow rate is maintained at about 1000 g/s,changing the total temperature of the oxygen-enriched air from 620 K to 860 K.Three different types of instability were observed in the experiments:temporal and spatial instability,mode transition and re-initiation.The interaction between RDW and supply plenum may be the main reason for the fluctuations of detonation wave velocity and pressure peaks with time.Moreover,the inconsistent mixing of fuel and oxidizer at different circumferential positions is related to RDW oscillate spatially.The phenomenon of single-double-single wave transition is analyzed.During the transition,the initial RDW weakens until disappears,and the compression wave strengthens until it becomes a new RDWand propagates steadily.The increased deflagration between the detonation products and the fresh gas layer caused by excessively high temperature is one of the reasons for the RDC quenching and re-initiation.展开更多
Through laboratory test, the relationships among change of compactibility, liquid/plastic limit, free swell, swell ratio without load, california bearing ratio (CBR) and soakage (after being soaked in water), and mix-...Through laboratory test, the relationships among change of compactibility, liquid/plastic limit, free swell, swell ratio without load, california bearing ratio (CBR) and soakage (after being soaked in water), and mix-ratio of quick lime and time were studied. The results show that optimum water content, plastic limit and CBR of high liquid limit clay improved by quick lime increase with the increase of mix-ratio of quick lime, while the maximum dry density, liquid limit, plasticity index, soakage (after being immersed in water), free swell, and swell ratio without load decrease with the increase of mix-ratio of quick lime. Plastic limit of high liquid clay improved by quick lime gradually increases with time, while the liquid limit, plasticity index, free swell and swell ratio without load gradually decrease with time. When the mix-ratio of quick lime exceeds 2%, after 14 d, swell ratio without load of the improved clay is zero, its free swell is about 30% of that of untreated soil, and its plasticity index is less than 26 for sub-grade material, satisfying the requirement by 'Specifications for Design of Highway Subgrade'.展开更多
In research of the characteristics of the cavity evolution, the pressure, and the liquid spurt in hydrodynamic ram, the experiment of the high-velocity fragment impacting the water-filled container had been conducted....In research of the characteristics of the cavity evolution, the pressure, and the liquid spurt in hydrodynamic ram, the experiment of the high-velocity fragment impacting the water-filled container had been conducted. The relationships between the above three characteristics have been researched. The evolution of the cavity can be divided into three processes according to its shape characteristics. The first liquid spurt occurred in Process Ⅱ and the rest of it occurred in Process Ⅲ. The duration of the second liquid spurt is longer than the first liquid spurt. When the impact velocity of the fragment is less than996 m/s, the velocity of the second liquid spurt is the highest. When the velocity of the fragment is greater than 996 m/s, the velocity of the first liquid spurt is the highest. The maximum velocities of the first and second liquid spurt are 111 m/s and 94 m/s respectively. The pressure fluctuated sharply in Processes Ⅰ and Ⅲ. The maximum peak pressures in the shock and the cavity oscillation phases are15.51 MPa and 7.96 MPa respectively. The time interval of the two adjacent pressure pulses increases with the increase of the fragment velocity.展开更多
CeO2 nanorods were synthesized by a hydrothermal method at 160℃ from CeC16-6H20 and NH3.H20 in the presence of an ionic liquid 1-butyl-3-methyl-imidazolium chloride （[Bmim]C1）. The phase and morphology of the resul...CeO2 nanorods were synthesized by a hydrothermal method at 160℃ from CeC16-6H20 and NH3.H20 in the presence of an ionic liquid 1-butyl-3-methyl-imidazolium chloride （[Bmim]C1）. The phase and morphology of the result- ing products were characterized by X-ray diffraction （XRD） and high-resolution transmission electron microscopy （HRTEM）, respectively. The results reveal that morphology of CeO2 prepared in the presence of the ionic liquid is nano- rod while it changes to irregular nanoparticle without ionic liquid. The resulting nanorods are about 13-25 nm in diameter and 200-500 nm in length. With the increase of ionic concentration, nanorods were disappeared gradually and nanoparticles were obtained. Moreover, increasing the hydrothermal temperature to 180℃, nanospheres at size of 19-24 nm could be synthesized by aggregation of-2 nm nanocrystals.展开更多
Development of effective chromatographic or electrophoretic separation involves judicious deciding of selection of optimal experimental conditions that can provide an adequate resolution at a reasonable run time for t...Development of effective chromatographic or electrophoretic separation involves judicious deciding of selection of optimal experimental conditions that can provide an adequate resolution at a reasonable run time for the separation of interested components. Box-Behnken factorial design was effectively applied for the separation optimization of eight structurally related sulfonamides using capillary zone electrophorosis and reverse high performance liquid chromatography. Optimum values for volume ratio of THF to H2O in eluent, column temperature and flow rate of eluent are found as 12 to 88, 35℃ and 1.0 mL/min, respectively. Box-Behnken modified optimization model is extended to separation by capillary electrophoresis (CE). While using CE, a satisfactory separation is achieved with a minimum resolution larger than 1.0 for a separation time less than 10 min.展开更多
文摘The microstructures and thermodynamic properties of mixed systems comprising pyridinium ionic liquid[HPy][BF_(4)]and acetonitrile at different mole fractions were studied using molecular dynamics simulation in this work.The following properties were determined:density,self-diffusion coefficient,excess molar volume,and radial distribution function.The results show that with an increase in the mole fraction of[HPy][BF_(4)],the self-diffusion coefficient decreases.Additionally,the excess molar volume initially decreases,reaches a minimum,and then increases.The rules of radial distribution functions(RDFs)of characteristic atoms are different.With increasing the mole fraction of[HPy][BF_(4)],the first peak of the RDFs of HA1-F decreases,while that of CT6-CT6 rises at first and then decreases.This indicates that the solvent molecules affect the polar and non-polar regions of[HPy][BF_(4)]differently.
文摘We introduce our state-of-the art of“vacuum consistent electrochemistry”to an investigation of the interfaces between oxides and ionic liquid(IL).Pulsed laser deposition(PLD)has been one of the powerful and sophisticated techniques to realize nanoscale preparation of high-quality epitaxial oxide thin films.On the other hand,electrochemistry is a simple,very sensitive,and non-destructive analysis technique for solid-liquid interfaces.To ensure the reproducibility in experiment of the interfaces of such epitaxial oxide films,as well as bulk oxide single-crystals,with IL,we employ a home-built PLD-electrochemical(EC)system with IL as an electrolyte.The system allows one to perform all-in-vacuum experiments during the preparation of well-defined oxide electrode surfaces to their electrochemical analyses.The topics include electrochemical evaluations of the oxide’s own properties,such as carrier density and relative permittivity,and the interfacial properties of oxides in contact with IL,such as flat band potential and electric double layer(EDL)capacitance,ending with future perspectives in all-solid-state electrochemistry.
文摘The memory behavior in liquid crystals(LCs)that is characterized by low cost,large area,high speed,and high-density memory has evolved from a mere scientific curiosity to a technology that is being applied in a variety of commodities.In this study,we utilized molybdenum disulfide(MoS_(2))nanoflakes as the guest in a homotropic LCs host to modulate the overall memory effect of the hybrid.It was found that the MoS₂nanoflakes within the LCs host formed agglomerates,which in turn resulted in an accelerated response of the hybrids to the external electric field.However,this process also resulted in a slight decrease in the threshold voltage.Additionally,it was observed that MoS₂nanoflakes in a LCs host tend to align homeotropically under an external electric field,thereby accelerating the refreshment of the memory behavior.The incorporation of a mass fraction of 0.1%2μm MoS₂nanoflakes into the LCs host was found to significantly reduce the refreshing memory behavior in the hybrid to 94.0 s under an external voltage of 5 V.These findings illustrate the efficacy of regulating the rate of memory behavior for a variety of potential applications.
基金supported by the National Natural Science Foundation of China(22209040,22202063).
文摘The development of highly active catalyst in pH-neutral media for oxygen evolution reaction(OER)is critical in the field of renewable energy storage and conversion.Nevertheless,the slow kinetics of proton-coupled electron transfer(PCET)hinders the overall OER efficiency.Herein,we report an ionic liquid(IL)modified CoSn(OH)_(6)nanocubes(denoted as CoS-n(OH)_(6)-IL),which could be prepared through a facile strategy.The modified IL would not change the structural character-istics of CoSn(OH)_(6),but could effectively regulate the local proton activity near the active sites.The CoSn(OH)_(6)-IL exhibited higher intrinsic OER performances than the pristine CoSn(OH)_(6)in neutral media.For example,the current density of CoS-n(OH)_(6)-IL at 1.8 V versus reversible hydrogen electrode(RHE)was about 4 times higher than that of CoSn(OH)_(6).According to the pH-dependent kinetic investigations,operando electrochemical impedance spectroscopic,chemical probe tests,and deuterium kinetic isotope effects,the interfacial layer of IL could be utilized as a proton transfer mediator to promote the proton transfer,which enhances the surface coverage of OER intermediates and reduces the activation barrier.Consequent-ly,the sluggish OER kinetics would be efficiently accelerated.This study provides a facile and effective strategy to facilitate the PCET processes and is beneficial to guide the rational design of OER electrocatalysts.
基金Projects(62275275,11904239)supported by the National Natural Science Foundation of ChinaProjects(2021JJ40709,2022JJ20080)supported by the Natural Science Foundation of Hunan Province,China。
文摘Ultrathin 2D niobium oxide dichloride(NbOCl_(2))is an emerging member of the 2D ferroelectric material family with extensive potential to provide multifunctionality in electronic devices and nanophotonics elements.It exhibits negligible interlayer electronic coupling and significant excitonic behavior in the bulk state.Here we substantiate that NbOCl_(2) nanosheets can be exfoliated and effectively size-selected using controlled centrifugation techniques by the liquid phase exfoliation(LPE)method.Spectroscopic measurements displayed that the variations in dispersion were highly dependent on the nanosheet dimensions.The nanosheets seemed to be comparatively defect-free which will be further corroborated by high resolution transmission electron microscopy(HRTEM)and Raman analysis.The size selected nanosheets are unanticipated stable in isopropyl alcohol(IPA),possibly owing to the protective influence of a solvation shell.Additionally,the photothermal conversion response and photothermal stability of nanosized NbOCl_(2) were investigated.Our finding revealed that NbOCl_(2) possesses a robust photothermal agent property,boasting a photothermal conversion efficiency of more than 30%.This underscores its promising potential for various photothermal applications in different fields such as photothermal therapy and thermal energy conversion.
基金supported by the National Natural Science Foundation of China(Grant No.52206165)。
文摘Flammable ionic liquids exhibit high conductivity and a broad electrochemical window,enabling the generation of combustible gases for combustion via electrochemical decomposition and thermal decomposition.This characteristic holds significant implications in the realm of novel satellite propulsion.Introducing a fraction of the electrical energy into energetic ionic liquid fuels,the thermal decomposition process is facilitated by reducing the apparent activation energy required,and electrical energy can trigger the electrochemical decomposition of ionic liquids,presenting a promising approach to enhance combustion efficiency and energy release.This study applied an external voltage during the thermal decomposition of 1-ethyl-3-methylimidazole nitrate([EMIm]NO_(3)),revealing the effective alteration of the activation energy of[EMIm]NO_(3).The pyrolysis,electrochemical decomposition,and electron assisted enhancement products were identified through Thermogravimetry-Differential scanning calorimetry-Fourier transform infrared-Mass spectrometry(TG-DSC-FTIR-MS)and gas chromatography(GC)analyses,elucidating the degradation mechanism of[EMIm]NO_(3).Furthermore,an external voltage was introduced during the combustion of[EMIm]NO_(3),demonstrating the impact of voltage on the combustion process.
基金Project(2024YFB4608600)supported by the National Key Research and Development Program of ChinaProjects(52271063,U21B2066,U24B2024)supported by the National Natural Science Foundation of China+3 种基金Project(JSGG20210713091539014)supported by the Shenzhen Science and Technology Innovation Commission Key Technical Project,ChinaProject(HNGD2025040)supported by the Overseas High-Level Talents Introduction of Henan Province,ChinaProject(240621041)supported by the Fundamental Research Funds of Henan Academy of Sciences,ChinaProject(20231120233925001)supported by Stabilization Support Program for Higher Education Institutions of Shenzhen,China。
文摘In this work,tensile mechanical behavior of 316L steels fabricated by three different processing methods(casting,powder extrusion printing(PEP)and laser powder bed fusion(LPBF))was studied in the presence of liquid lead-bismuth eutectic(LBE)and air at 350℃.The results show that all three steels tested in LBE are not subjected to evident degradation of tensile elongation to failure and strength compared to those tested in air,suggesting that LME does not occur regardless of the processing methods.The LPBF 316L steel exhibits the highest yield strength(420-435 MPa),followed by casting 316 L(~242 MPa)and PEP 316L(146-165 MPa).Ultimate tensile strength of three steels is comparable and ranges from 427 to 485 MPa.The PEP and casting 316L steels have similar total elongation to failure(i.e.,40.0%-43.8%),whereas this property decreases markedly to 18.6%-19.5% for the LPBF 316 L steel.The superior strength and relatively low ductility of the LPBF 316L steel can be attributed to nanosized dislocations trapped at cell structures which can produce a remarkable strengthening effect to the steel matrix.By contrast,due to massive residual micropores,the PEP 316L steel has the lowest strength.
基金Projects(52204226,52104204,52474276)supported by the National Natural Science Foundation of ChinaProject(tsqnz20221140)supported by the Taishan Scholars Project of China+1 种基金Projects(ZR2022QE243,ZR2024ME097)supported by the Natural Science Foundation of Shandong Province of ChinaProject(252300421010)supported by the Excellent Youth Foundation of Henan Scientific Committee,China。
文摘The geological structure of coal seams in China is remarkably varied and complex,with coalbed methane reservoirs marked by significant heterogeneity and low permeability,creating substantial technical challenges for efficient extraction.This study systematically investigates the impact of liquid nitrogen immersion(LNI)on the coal’s pore structure and its mechanism of enhancing permeability with a combination of quantitative nuclear magnetic resonance(NMR)analysis,nitrogen adsorption experiments,and fractal dimension calculations.The results demonstrate that LNI can damage the coal’s pore structure and promote fracture expansion through thermal stress induction and moisture phase transformation,thereby enhancing the permeability of coal seams.The T_(2)peak area in the NMR experiments on coal samples subjected to LNI treatment shows a significant increase,the Brunauer-Emmett-Teller(BET)specific surface area decreases to 6.02 m^(2)/g,and the Barrett-Joyner-Halenda(BJH)total pore volume increases to 14.99 mm^(3)/g.Furthermore,changes in fractal dimensions(D_(1)rising from 2.804 to 2.837,and D_(2)falling from 2.757 to 2.594)indicate a notable enhancement in the complexity of the pore structure.With increasing LNI cycles,the adsorption capacity of the coal samples diminishes,suggesting a significant optimization of the pore structure.This optimization is particularly evident in the reconstruction of the micropore structure,which in turn greatly enhances the complexity and connectivity of the sample’s pore network.In summary,the study concludes that LNI technology can effectively improve the permeability of coal seams and the extraction efficiency of coalbed methane by optimizing the micropore structure and enhancing pore connectivity,which offers a potential method for enhancing the permeability of gas-bearing coal seams and facilitating the development and utilization of coalbed methane.
基金Project(201309052)supported by the National Special Fund for Scientific Research in the Public InterestProject(2013FJ2003)supported by the Science and Technology Planning Project of Hunan Province of China
文摘For the determination of salicylaldoxime in environmental water samples,a stable and rapid method with low detection was proposed and established,based on the liquid-liquid extraction-high performance liquid chromatography with ultraviolet detector.Parameters including extraction solvent,ionic strength,solution pH,and extraction pattern were discussed for the optimal quantification of salicylaldoxime-spiked water.When the described method was applied to four spiked water samples,the obtained average extraction recovery rate was found between 87%–107%and relative standard deviation was below 6%.At the same time,good linear relationships were observed for spiked water samples from 0.01 to 10μg/mL(R2=0.9993).In addition,the detection limit of salicylaldoxime was revealed between 0.003–0.008μg/mL,which is two orders of magnitude lower than previously reported results.Thus,the presented method may be advantageous for the high-efficiency determination of salicylaldoxime in water samples.
基金the support of National Nature Science Foundation of China, the support numbers are No. 10572149 and No.10676120the National Key Research and Development program of China (subject no. 2017YFC0209901) for its support to the work of this paper
文摘A systematic investigation on the mechanism of dynamic liquid dispersing process via theoretical and experimental approach is presented.The experiments include weak and strong constrained scenarios using the high-speed camera technique and the flash X-ray radiography technique.Based on dynamic analysis,one-dimensional characteristics analysis and some numerical simulations on the propagating processes of blast waves before the container shell rupturing,further and detailed analyses of the experimental results are presented.The effects of the liquid viscosity on the dynamic dispersing flow are also analyzed,and the spall fracture mechanism is explored.Thus,the dominating forces determining the dispersing liquid flow are revealed,that is,the stretching and shearing action due to the interaction of two reflecting rarefaction waves in opposite propagating directions.The influence of container shell strength on the dispersing liquid flow is also investigated,and the characters of cavitation layered in liquid before shell rupturing are uncovered.Results revealed that different shell material results in different cavitating layers.Then the different cavitating layers drive the different dynamic liquid dispersing process coming into being.The metastable liquid states caused by pressure drop and cavitation generation are discussed.
基金financial support from National Natural Science Foundation of China (Grant No. 12102197)。
文摘The physical stability of solid-liquid fuel is a factor that needs to be considered for fuel product practicability for storage and transportation. To determine the Influence of liquid bridge force on physical stability, two detection devices were designed. The laws obtained from microscopic experiments are used to verify the physical stability of fuel under different component ratios. The liquid bridge force is found to increase with the droplet volume. Multiliquid bridges above one critical saturation can generate significant resultant forces compared to single-liquid bridges of the same volume. There exist four states of solid-liquid mixed fuel with increasing liquid saturation rate. The liquid bridge force between the solid and liquid plays a dominant role in the physical stability of the first three states. There may be two stages involved in the stratification process for state 4 fuel, and the liquid viscosity is another factor that cannot be ignored. In the process of selecting a fuel ratio, a larger liquid bridge force between the components can be obtained by properly improving the wetting effect so that the fuel shows better physical stability.
文摘In order to study the action mechanism of Sacha Inchi polypeptide in liquid crystal emulsion,oil-in-water liquid crystal emulsions with Sacha Inchi fermented polypeptide as the active component were prepared.The microstructures,particle sizes,stabilities,thermodynamic properties,and rheological properties of liquid crystal emulsions with different concentrations of the fermentation products were observed by Polarizing microscope,Particle size meter,Thermogravimetric differential thermal synchronous measurement system,and Rheometer,respectively.The results showed that the average particle size of fermented peptide liquid crystal emulsion was(25.7±2.8)μm,and the liquid crystal structure was complete and stable.The content of bound water and liquid crystal in the emulsion with 1%Sacha Inchi polypeptide were higher than those in the blank emulsion and the emulsions with 3%and 5%Sacha Inchi polypeptide.Rheological results indicated that the viscosity of liquid crystal emulsion with the change curve of shear rate registered the shear thinning phenomenon,which belongs to non-Newtonian fluid.The hysteresis area,energy storage modulus,and loss modulus of the 1%additive amount of liquid crystal emulsion were larger than those of the blank emulsion and the emulsions with 3%and 5%Sacha Inchi polypeptide,indicating greater thixotropy and stronger shear resistance.The hydrophilic amino acid residues of the peptide in the 1%additive amount of the emulsion were combined with the water phase,while the hydrophobic amino acid residues of the peptide entered the oil phase,which formed a viscoelastic film at the oil-water interface,so that the liquid crystal emulsion had a more stable gel network structure.
文摘The measurement of urine catecholamine and metanephrine concentrations is important for biochemical screening and diagnosis of pheochromocytoma.The goal of this work was to develop a simple liquid chromatography-tandem mass spectrometry(LC-MS/MS)method for determining catecholamines and metanephrines in urine to replace an existing liquid chromatographic method using electrochemical detection.Urine samples were prepared using Oasis weak-cation-exchange cartridges.The eluate was analyzed on an Agilent ZORBAX Eclipse Plus Phenyl-Hexyl column in 3 min.Adrenaline,noradrenaline,dopamine,metanephrine,normetanephrine,and their deuterated internal standards were monitored in positive electrospray ionization mode by multiple reaction monitoring(MRM).No evidence of ion suppression was observed.The assay was linear up to 5μmol/L for adrenaline,5μmol/L for noradrenaline,6.1μmol/L for dopamine,5.6μmol/L for metanephrine,and 34.6μmol/L for normetanephrine,with lower limits of quantification of 5,5,12,6 and 7nmol/L,respectively.The intra-day and inter-day precisions for all analytes ranged from 0.59%to 4.64%and1.98%to 4.80%,respectively.External quality assurance samples were assayed and showed excellent agreement with the target values.This simple method provides an improved assay for determining urine catecholamines and metanephrines.
基金supported by the National Natural Science Foundation of China(Grant No.11802137,11702143 and 11802039)the Fundamental Research Funds for the Central Universities(No.30919011259).
文摘In order to study the instability propagation characteristics of the liquid kerosene rotating detonation wave(RDW),a series of experimental tests were carried out on the rotating detonation combustor(RDC)with air-heater.The fuel and oxidizer are room-temperature liquid kerosene and preheated oxygenenriched air,respectively.The experimental tests keep the equivalence ratio of 0.81 and the oxygen mass fraction of 35%unchanged,and the total mass flow rate is maintained at about 1000 g/s,changing the total temperature of the oxygen-enriched air from 620 K to 860 K.Three different types of instability were observed in the experiments:temporal and spatial instability,mode transition and re-initiation.The interaction between RDW and supply plenum may be the main reason for the fluctuations of detonation wave velocity and pressure peaks with time.Moreover,the inconsistent mixing of fuel and oxidizer at different circumferential positions is related to RDW oscillate spatially.The phenomenon of single-double-single wave transition is analyzed.During the transition,the initial RDW weakens until disappears,and the compression wave strengthens until it becomes a new RDWand propagates steadily.The increased deflagration between the detonation products and the fresh gas layer caused by excessively high temperature is one of the reasons for the RDC quenching and re-initiation.
文摘Through laboratory test, the relationships among change of compactibility, liquid/plastic limit, free swell, swell ratio without load, california bearing ratio (CBR) and soakage (after being soaked in water), and mix-ratio of quick lime and time were studied. The results show that optimum water content, plastic limit and CBR of high liquid limit clay improved by quick lime increase with the increase of mix-ratio of quick lime, while the maximum dry density, liquid limit, plasticity index, soakage (after being immersed in water), free swell, and swell ratio without load decrease with the increase of mix-ratio of quick lime. Plastic limit of high liquid clay improved by quick lime gradually increases with time, while the liquid limit, plasticity index, free swell and swell ratio without load gradually decrease with time. When the mix-ratio of quick lime exceeds 2%, after 14 d, swell ratio without load of the improved clay is zero, its free swell is about 30% of that of untreated soil, and its plasticity index is less than 26 for sub-grade material, satisfying the requirement by 'Specifications for Design of Highway Subgrade'.
基金the National Natural Science Foundation of China(Grant No.11572159)the National Defense Science and Technology Foundational Enhancement Program Technology Field Foundation(No.2020-JCJQ-JJ-401)for providing the financial support for this study.
文摘In research of the characteristics of the cavity evolution, the pressure, and the liquid spurt in hydrodynamic ram, the experiment of the high-velocity fragment impacting the water-filled container had been conducted. The relationships between the above three characteristics have been researched. The evolution of the cavity can be divided into three processes according to its shape characteristics. The first liquid spurt occurred in Process Ⅱ and the rest of it occurred in Process Ⅲ. The duration of the second liquid spurt is longer than the first liquid spurt. When the impact velocity of the fragment is less than996 m/s, the velocity of the second liquid spurt is the highest. When the velocity of the fragment is greater than 996 m/s, the velocity of the first liquid spurt is the highest. The maximum velocities of the first and second liquid spurt are 111 m/s and 94 m/s respectively. The pressure fluctuated sharply in Processes Ⅰ and Ⅲ. The maximum peak pressures in the shock and the cavity oscillation phases are15.51 MPa and 7.96 MPa respectively. The time interval of the two adjacent pressure pulses increases with the increase of the fragment velocity.
文摘CeO2 nanorods were synthesized by a hydrothermal method at 160℃ from CeC16-6H20 and NH3.H20 in the presence of an ionic liquid 1-butyl-3-methyl-imidazolium chloride （[Bmim]C1）. The phase and morphology of the result- ing products were characterized by X-ray diffraction （XRD） and high-resolution transmission electron microscopy （HRTEM）, respectively. The results reveal that morphology of CeO2 prepared in the presence of the ionic liquid is nano- rod while it changes to irregular nanoparticle without ionic liquid. The resulting nanorods are about 13-25 nm in diameter and 200-500 nm in length. With the increase of ionic concentration, nanorods were disappeared gradually and nanoparticles were obtained. Moreover, increasing the hydrothermal temperature to 180℃, nanospheres at size of 19-24 nm could be synthesized by aggregation of-2 nm nanocrystals.
基金Project(20235010) support by the NSFC-KOSEF Scientific Cooperation ProgramProject supported by the Program for New Century Talents of University in Henan ProvinceProgram for Backbone Teacher in Henan Province, China
文摘Development of effective chromatographic or electrophoretic separation involves judicious deciding of selection of optimal experimental conditions that can provide an adequate resolution at a reasonable run time for the separation of interested components. Box-Behnken factorial design was effectively applied for the separation optimization of eight structurally related sulfonamides using capillary zone electrophorosis and reverse high performance liquid chromatography. Optimum values for volume ratio of THF to H2O in eluent, column temperature and flow rate of eluent are found as 12 to 88, 35℃ and 1.0 mL/min, respectively. Box-Behnken modified optimization model is extended to separation by capillary electrophoresis (CE). While using CE, a satisfactory separation is achieved with a minimum resolution larger than 1.0 for a separation time less than 10 min.
