Due to their high-entropy effects,the high-entropy(HE)MAX-phase materials improve the comprehen-sive performance of MAX phases,opening up more possibilities for practical engineering applications.However,it is still c...Due to their high-entropy effects,the high-entropy(HE)MAX-phase materials improve the comprehen-sive performance of MAX phases,opening up more possibilities for practical engineering applications.However,it is still challenging to obtain S-containing high-entropy MAX phases because of the high volatilization behavior of sulfur,suffering from issues such as high reaction temperature and long re-action time of traditional synthesis methods.This paper proposes a novel process named as liquid metal assistant self-propagating high-temperature synthesis(LMA-SHS)for efficient synthesis of high-purity S-containing high-entropy MAX-phase materials.Low-melting-point metal(Sn or In)has been introduced into the raw mixture and melted into a liquid phase during the early stage of the SHS reaction.By serv-ing as a“binder”between transition metal atoms of the M-site due to the negative mixing enthalpy,this liquid phase can accelerate mass and heat transfer during the SHS process,ensuring a uniform solid solution of each element and realizing the synthesis of high-purity(TiNbVZr)_(2)SC in an extremely short time.The synthesis method for high-entropy MAX-phase materials developed in this study,i.e.,LMA-SHS,showing very short reaction time,low energy consumption,high yield,and low cost,has the promise to be a general energy-and resource-efficient route towards high-purity HE materials.展开更多
The preparation of dispersible MFI-type zeolite nanoparticles with open micropores is challenging.Herein,a rapid and effective ultrasound-assisted liquid-phase exfoliation method along with a freezedrying process for ...The preparation of dispersible MFI-type zeolite nanoparticles with open micropores is challenging.Herein,a rapid and effective ultrasound-assisted liquid-phase exfoliation method along with a freezedrying process for redispersion of calcined silicalite-1(S-1)zeolite nanoparticle aggregates using 3-aminopropanol as an exfoliating agent is demonstrated.The exfoliation of S-1 zeolite nanoparticles is characterized by X-ray diffraction,scanning electron microscopy and DLS particle size analysis.The effects of drying methods of as-synthesized zeolite nanoparticle suspension,zeolite contents in frozen nanoparticle suspension,exfoliating agent concentrations,and zeolite doses in ultrasonic suspension on exfoliation efficiency are systematically investigated.It is found that the S-1 zeolite nanoparticle(~70 nm)achieves a yield up to 95%through a 30 min ultrasonic exfoliation in a 3-aminopropanol solution along with a freeze-drying process.The proposed exfoliation mechanism involves two primary stages:vip molecule insertion followed by water expansion,both substantially enhanced by tip sonication.This work offers a comprehensive understanding of the exfoliation process,provides valuable insights into the dispersion of sintered zeolite nanoparticles.展开更多
An ionic liquid assisted hydrogel modified silica was synthesized using a one-pot polymerization and physical coating technique and subsequently applied to mixed-mode liquid chromatography.Analytical techniques,includ...An ionic liquid assisted hydrogel modified silica was synthesized using a one-pot polymerization and physical coating technique and subsequently applied to mixed-mode liquid chromatography.Analytical techniques,including Fourier transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),and elemental analysis,etc.,confirmed the successful prepared of this innovative stationary phase.The unique combination of amide,long alkyl chain,and imidazole ring in the hydrogel coating enables the stationary phase to function effectively in hydrophilic/reversed-phase/ion exchange liquid chromatography.Notably,the stationary phase exhibited superior separation performance owing to the synergistic effect of the ionic liquid and hydrogel.This was particularly evident when analyzing various analytes such as organic acids,nucleosides/bases,polycyclic aromatic hydrocarbons(PAHs)and anions.Furthermore,under our operating conditions,an excellent column efficiency of 53,642.9 plates/m was achieved for theobromine.In summary,we have proposed a straightforward strategy to enhance the separation performance of hydrogel coatings in liquid chromatography,thereby broadening the potential applications of hydrogels in the field of separation.展开更多
The enrichment of low-grade phosphate rock is an important process to realize sustainable support of phosphorus resources. An aqueous solution containing Ca(NO_(3))_(2) and Mg(NO_(3))_(2) is produced during the enrich...The enrichment of low-grade phosphate rock is an important process to realize sustainable support of phosphorus resources. An aqueous solution containing Ca(NO_(3))_(2) and Mg(NO_(3))_(2) is produced during the enrichment of low-grade phosphate rock by leaching of HNO_(3) or calcination coupling with leaching of NH_(4)NO_(3) solution. Preparation liquid fertilizer is a preferential way to utilize it. The liquid−solid phase diagrams of Ca(NO_(3))_(2)-Mg(NO_(3))_(2)-H_(2)O, KNO_(3)-Mg(NO_(3))_(2)-H_(2)O, KNO_(3)-Ca(NO_(3))_(2)-H_(2)O and KNO_(3)-Ca(NO_(3))_(2)-Mg(NO_(3))_(2)-H_(2)O systems at 313.15 K were studied by isothermal dissolution equilibrium method. Two crystallization regions of Ca(NO_(3))_(2)·4H_(2)O and Mg(NO_(3))_(2)·6H_(2)O were observed in the phase diagram of the ternary system Ca(NO_(3))_(2)-Mg(NO_(3))_(2)-H_(2)O, a liquid fertilizer with a maximal total nutrient content of 27.46% and a nutrients ratio of N:Ca:Mg = 8.40:10.37:1 can be formed. A homogenous solution can be formed by mixing Ca(NO_(3))_(2)·4H_(2)O and Mg(NO_(3))_(2)·6H_(2)O. In the ternary system KNO_(3)-Mg(NO_(3))_(2)-H_(2)O, the crystallization regions of KNO_(3), Mg(NO_(3))_(2)·6H_(2)O and the co-crystallization region of KNO_(3) and Mg(NO_(3))_(2)·6H_(2)O were observed. The obtained maximal total nutrient content of liquid fertilizer is 23.32% with the ratio of N:K_(2)O = 1:3.39. In the ternary system KNO_(3)-Ca(NO_(3))_(2)-H_(2)O, the crystallization regions of Ca(NO_(3))_(2)·4H_(2)O and KNO_(3) were observed. The obtained maximal total nutrient content of liquid fertilizer is 38.41% with the ratio of N:K_(2)O:Ca = 1.05:1.18:1. A homogenous solution can also be formed by mixing Ca(NO_(3))_(2)·4H_(2)O and KNO_(3) directly. In the quaternary system KNO_(3)-Ca(NO_(3))_(2)-Mg(NO_(3))_(2)-H_(2)O, the crystallization regions of Ca(NO_(3))_(2)·4H_(2)O, Mg(NO_(3))_(2)·6H_(2)O and KNO_(3) and the co-crystallization region of KNO_(3) and Mg(NO_(3))_(2)·6H_(2)O were observed. The obtained maximal total nutrient content of liquid fertilizer is 38.41% with the ratio of N:K_(2)O:Ca = 1.05:1.18:1. The modified BET model was successfully used to fit the solubility curves. The results can provide a guidance for the formulation of water-soluble fertilizers of N-(K, Ca, Mg).展开更多
Covalent organic frameworks(COFs)have demonstrated great potential in chromatographic separation because of unique structure and superior performance.Herein,single-crystal three-dimensional(3D)COFs with regular morpho...Covalent organic frameworks(COFs)have demonstrated great potential in chromatographic separation because of unique structure and superior performance.Herein,single-crystal three-dimensional(3D)COFs with regular morphology,good monodispersity and high specific surface area,were used as a stationary phase for high-performance liquid chromatography(HPLC).The single-crystal 3D COFs packed column not only exhibits high efficiency in separating hydrophobic molecules involving substituted benzenes,halogenated benzenes,halogenated nitrobenzenes,aromatic amines,aromatic hydrocarbons(PAHs)and phthalate esters(PAEs),but also achieves baseline separation of acenaphthene and acenaphthylene with similar physical and chemical properties as well as environmental pollutants,which cannot be quickly separated on commercial C18 column and a polycrystalline 3D COFs packed column.Especially,the column efficiency of 17303-24255 plates/m was obtained for PAEs,and the resolution values for acenaphthene and acenaphthylene,and carbamazepine(CBZ)and carbamazepine-10,11-epoxide(CBZEP)were 1.7and 2.2,respectively.This successful application not only confirmed the great potential of the singlecrystal 3D COFs in HPLC separation of the organic molecules,but also facilitates the application of COFs in separation science.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
The crystallization of ionic crystals has traditionally been explained by Gibbs's classical nucleation theory.However,recent observations of intermediate phases during nucleation suggest that the process may be mo...The crystallization of ionic crystals has traditionally been explained by Gibbs's classical nucleation theory.However,recent observations of intermediate phases during nucleation suggest that the process may be more complex,necessitating new theoretical frameworks,though key empirical evidence remains elusive.In this study,we used microdroplets to investigate the crystallization of sodium halides(NaCl,NaBr,and NaI)under homogeneous nucleation conditions across a wide range of supersaturations.In the evaporating droplet,NaCl follows the classical nucleation pathway,whereas NaBr and NaI exhibit the formation of an intermediate phase prior to the nucleation of anhydrous and hydrous single crystals,respectively.Optical and computational analyses indicate that these intermediate phases are liquid crystal phases composed of contact ion pairs.These findings establish a new theoretical framework for crystal nucleation and growth and offer methods to control nucleation pathways,enabling us to achieve desired crystals regardless of specific conditions.展开更多
The remarkable power of chemistry over description and trans-formation of matters has been significantly enhanced through the development of dynamic chemistry and condensed matter chemistry[1].This progress has furthe...The remarkable power of chemistry over description and trans-formation of matters has been significantly enhanced through the development of dynamic chemistry and condensed matter chemistry[1].This progress has further elevated chemistry to a creative science and a thriving industry.The development of dynamic chemistry,span-ning from supramolecular chemistry to constitutional dynamic chem-istry,has witnessed significant advancements towards adaptive chemistry,which is characterized primarily by its self-adaption to external stimuli.This is particularly achieved in two-or three-dimensional dynamic frameworks.Meanwhile,the multi-phase evolution resulting from the emerging of solid-to-liquid transition plat-form is assuming an increasingly crucial role in condensed matter chemistry[2].展开更多
The authors regret the following changes to the paper:1.The following author is added to this article:Agnieszka Chmielewska-Wysockaa 2.Section 2.1:●“An aqueous binder”should be changed to“A solvent binder”.●Repl...The authors regret the following changes to the paper:1.The following author is added to this article:Agnieszka Chmielewska-Wysockaa 2.Section 2.1:●“An aqueous binder”should be changed to“A solvent binder”.●Replace“a composition of ethylene glycol monobutyl ether and ethylene glycol”by“50% binder saturation”.展开更多
Developing a chiral material as versatile and universal chiral stationary phase(CSP) for chiral separation in diverse chromatographic techniques simultaneously is of great significance.In this study,we demonstrated fo...Developing a chiral material as versatile and universal chiral stationary phase(CSP) for chiral separation in diverse chromatographic techniques simultaneously is of great significance.In this study,we demonstrated for the first time that a chiral metal-organic cage(MOC),[Zn_(6)M_(4)],as a universal chiral recognition material for both multi-mode high-performance liquid chromatography(HPLC) and capillary gas chromatography(GC) enantioseparation.Two novel HPLC CSPs with different bonding arms(CSP-A with a cationic imidazolium bonding arm and CSP-B with an alkyl chain bonding arm) were prepared by clicking of functionalized chiral MOC [Zn_(6)M_(4)] onto thiolated silica via thiol-ene click chemistry.Meanwhile,a capillary GC column statically coated with the chiral MOC [Zn_(6)M_(4)] was also fabricated.The results showed that the chiral MOC exhibits excellent enantioselectivity not only in normal phase HPLC(NP-HPLC) and reversed phase(RP-HPLC) but also in GC,and various racemates were well separated,including alcohols,diols,esters,ketones,ethers,amines,and epoxides.Importantly,CSP-A and CSP-B are complementary to commercially available Chiralcel OD-H and Chiralpak AD-H columns in enantioseparation,which can separate some racemates that could not be or could not well be separated by the two widely used commercial columns,suggesting the great potential of the two prepared CSPs in enantioseparation.This work reveals that the chiral MOC is potential versatile chiral recognition materials for both HPLC and GC,and also paves the way to expand the potential applications of MOCs.展开更多
The formation and evolution characteristics of bcc phase during the isothermal relaxation processes for supercooled-liquid and amorphous Pb were investigated by molecular dynamics simulation and cluster-type index met...The formation and evolution characteristics of bcc phase during the isothermal relaxation processes for supercooled-liquid and amorphous Pb were investigated by molecular dynamics simulation and cluster-type index method （CTIM）. It is found that during the relaxation process, the formation and evolution of bcc phase are closely dependent on the initial temperature and structure. During the simulation time scale, when the initial temperature is in the range of supercooled liquid region, the bcc phase can be formed and kept a long time; while it is in the range of glassy region, the bcc phase can be formed at first and then partially transformed into hcp phase; when it decreases to the lower one, the hcp and fcc phases can be directly transformed from the glassy structure without undergoing the metastable bcc phase. The Ostwald＇s ＂step rule＂ is impactful during the isothermal relaxation process of the supercooled and glassy Pb, and the metastable bcc phase plays an important role in the precursor of crystallization.展开更多
A thin layer of TiO2 film was deposited on ITO surface via the liquid phase deposition （LPD） process. The photocurrent and electrochemical impedance spectroscopy （EIS） measurements indicated that the as-prepared L...A thin layer of TiO2 film was deposited on ITO surface via the liquid phase deposition （LPD） process. The photocurrent and electrochemical impedance spectroscopy （EIS） measurements indicated that the as-prepared LPD TiO2/ITO film had an excellent photoelectrochemical performance, which showed a sensitive and rapid response to the UV irradiation. The photogenerated electron-hole pairs could be effectively separated by applying an external bias to the TiO2 film electrode. The LPD TiO2/ITO film was employed to study the photoelectrocatalytic （PEC） degradation of 4-aminoantipyrine. Compared with other techniques, the PEC technique based on such a LPD film electrode had a synergetic effect for 4-aminoantipyrine degradation. When the applied bias potential was＋0.8 V and the supporting electrolyte concentration of Na2SO4 was 0.1 mol/L, the highest degradation efficiency within 120 min could reach 95%for 0.1 mmol/L 4-aminoantipyrine solution at pH 2.0.展开更多
The carbon-coated monoclinic Li3V2(PO4)3(LVP) cathode materials were successfully synthesized by liquid phase method using PEG as reducing agent and carbon source. The effects of relative molecular mass of PEG on the ...The carbon-coated monoclinic Li3V2(PO4)3(LVP) cathode materials were successfully synthesized by liquid phase method using PEG as reducing agent and carbon source. The effects of relative molecular mass of PEG on the properties of Li3V2(PO4)3/C were evaluated by X-ray diffraction(XRD), scanning electron microscope(SEM) and electrochemical performance tests. The SEM images show that smaller size particles are obtained by adding larger and smaller PEGs. The electrochemical cycling of Li3V2(PO4)3/C prepared by both PEG200 and PEG20 k has a high initial discharge capacity of 131.1 mA·h/g at 0.1C during 3.0-4.2 V, and delivers a reversible discharge capacity of 123.6 m A·h/g over 30 cycles, which is better than that of other samples. The improvement in electrochemical performance is caused by its improved lithium ion diffusion coefficient for the macroporous morphology, which is verified by cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS).展开更多
Transient liquid phase（TLP） bonding of IN738 LC superalloy was carried out using a rapidly solidified MBF-15 Ni-based foil. The effects of bonding temperature（1130–1170 °C） and time（5–120 min） as well as ...Transient liquid phase（TLP） bonding of IN738 LC superalloy was carried out using a rapidly solidified MBF-15 Ni-based foil. The effects of bonding temperature（1130–1170 °C） and time（5–120 min） as well as foil thickness（35–140 μm） were studied on the microstructure of joint region and its mechanical properties. The solidification sequence in the joint region was found to be（i） formation of γ solid solution in the isothermally solidified zone, followed by（ii） ternary eutectic of γ ＋ Ni3 B ＋ Cr B, and finally（iii） binary eutectic of γ ＋ Ni3 Si in the athermally solidified zone. Fine Ni3 Si particles were also formed via a solid state transformation within the γ matrix in the vicinity of eutectic products. A deviation of isothermal solidification kinetics from the standard parabolic TLP model was observed by increasing the bonding temperature to 1170 °C, which resulted in the formation of eutectic constituents at the joint centerline.The analysis of mechanical and fractographic test results revealed that the samples with complete isothermal solidification exhibit the highest shear strength, whereas the hard eutectic constituents act as preferential failure sites and lead to a significant reduction in the joint shear strength in samples with incomplete isothermal solidification.展开更多
Gangue existing states largely affect the high-temperature characteristics of iron ores. Using a micro-sintering method and scan- ning electron microscopy, the effects of gangue content, gangue type, and gangue size o...Gangue existing states largely affect the high-temperature characteristics of iron ores. Using a micro-sintering method and scan- ning electron microscopy, the effects of gangue content, gangue type, and gangue size on the assimilation characteristics and fluidity of liquid phase of five different iron ores were analyzed in this study. Next, the mechanism based on the reaction between gangues and sintering mate- dais was unraveled. The results show that, as the SiO2 levels increase in the iron ores, the lowest assimilation temperature （LAT） decreases, whereas the index of fluidity of liquid phase （IFL） increases. Below 1.5wt%, Al2O3 benefits the assimilation reaction, but higher concentra- tions proved detrimental. Larger quartz particles increase the SiO2 levels at the local reaction interface between the iron ore and CaO, thereby reducing the LAT. Quartz-gibbsite is more conductive to assimilation than kaolin. Quartz-gibbsite and kaolin gangues encourage the forma- tion of liquid-phase low-Al2O3-SFCA with high IFL and high-Al2O3-SFCA with low IFL, respectively.展开更多
Ultra-high molecular weight polyethylene (UHMWPE) with a microporous structure was prepared via thermally induced phase separation (TIPS).Liquid paraffin (LP) was used as a diluent in the preparation of microporous UH...Ultra-high molecular weight polyethylene (UHMWPE) with a microporous structure was prepared via thermally induced phase separation (TIPS).Liquid paraffin (LP) was used as a diluent in the preparation of microporous UHMWPE. Small angle laser light scattering (SALLS) and differential scanning calorimetry (DSC) were used to determine the phase separation temperatures,i.e.the cloud points and the dynamic crystallization temperatures,respectively.It was found that the cloudI points were coincident with the cryst...展开更多
The kinetic characteristics of W grain growth operated by diffusion controlled Oswald ripening （DOR） during liquid phase sintering were studied. A liquid phase sintering of W-15wt%Cu was carried out by pushing compa...The kinetic characteristics of W grain growth operated by diffusion controlled Oswald ripening （DOR） during liquid phase sintering were studied. A liquid phase sintering of W-15wt%Cu was carried out by pushing compacts into a furnace at the moment when the temperature increased to 1340℃ for different sintering times. The results show that liquid phase sintering produces the compacts with considerably low relative density and inversely, rather high homogeneity. On the basis of the data extracted from the SEM images, the kinetic equation of W grain growth, G^n = G0^n ＋ kt, is determined in which the grain growth exponent n is 3 and the grain growth rate constant k is 0.15 μm^3/s. The cumulative normalized grain size distributions produced by different sintering times show self-similar. The cumulative distribution function is extracted from the curves by non-linear fitting. In addition, the sintering kinetic characteristics of W-15wt%Cu compacts were also investigated.展开更多
Velocities of solid phase and liquid phase in debris flow are one key problem to research on impact and abrasion mechanism of banks and control structures under action of debris flow. Debris flow was simplified as two...Velocities of solid phase and liquid phase in debris flow are one key problem to research on impact and abrasion mechanism of banks and control structures under action of debris flow. Debris flow was simplified as two-phase liquid composed of solid phase with the same diameter particles and liquid phase with the same mechanical features. Assume debris flow was one-dimension two-phase liquid moving to one direction, then general equations of velocities of solid phase and liquid phase were founded in two-phase theory. Methods to calculate average pressures, volume forces and surface forces of debris flow control volume were established. Specially, surface forces were ascertained using Bingham＇s rheology equation of liquid phase and Bagnold＇s testing results about interaction between particles of solid phase. Proportional coefficient of velocities between liquid phase and solid phase was put forward, meanwhile, divergent coefficient between theoretical velocity and real velocity of solid phase was provided too. To state succinctly before, method to calculate velocities of solid phase and liquid phase was obtained through solution to general equations. The method is suitable for both viscous debris flow and thin debris flow. Additionally, velocities every phase can be identified through analyzing deposits in-situ after occurring of debris flow. It is obvious from engineering case the result in the method is consistent to that in real-time field observation.展开更多
The effect of Sm-rich liquid phase （Sm2Co3） on magnetic properties and microstructure of 2：17-type Sin-Co magnet was studied. Three phases existed in liquid phase ingot, and took on white, dark grey and grey, respe...The effect of Sm-rich liquid phase （Sm2Co3） on magnetic properties and microstructure of 2：17-type Sin-Co magnet was studied. Three phases existed in liquid phase ingot, and took on white, dark grey and grey, respectively. It was found that the composition of the grey area was similar to the nominal one. Our results indicated that the optimal composition was obtained at 3 wt.% liquid phase added, and the magnetic properties were B^I 1.58 kGs, Hci〉26 kOe, （BH）m=29.51 MGOe. Br increased by 3%, Hci was 13 times larger, and （B/-/）m was 6 times bigger than none liquid phase magnets. Moreover, with the aging time decreasing from 20 to 8 h, the squareness of the demagnetization curves got better, while the coercivity of the samples decreased. It revealed that Sm（Co,Cu）5 phase also precipitated at particle boundaries. It maybe also enhanced the coercivity.展开更多
A single-drop liquid phase micro-extraction procedure using 1-butyl-3-methylimidazolium hexafluorophosphate （[C4MIM][PF6]） was demonstrated for the sensitive determination of four phenols in water samples. Under the...A single-drop liquid phase micro-extraction procedure using 1-butyl-3-methylimidazolium hexafluorophosphate （[C4MIM][PF6]） was demonstrated for the sensitive determination of four phenols in water samples. Under the optimized conditions, the linear range of proposed method was excellent in the range of 0.5-100 μg·L^-1, the reproducibility （RSD, n=6） were in the range 5.4%-8.9% and detection limits （S/N=3） were 0.3, 0.3, 0.5 and 0.5 μg·L^-1 for 2, 4-dichlorophenol, 2-naphthol, 2-nitrophenol and 4-chlorophenol, respectively. The experimental results indicated that the effect of complex matrices natural water samples could be resolved with addition of sodium ethylene diamine tetracetate （EDTA） into the samples. Excellent spiked recoveries were achieved for these four phenols ranged from 86.2%-114.9 %. All these facts demonstrated that the proposed method with merits of low cost, simplicity and easy operating would be a competitive alternative procedure for the determination of such compounds at trace level.展开更多
基金supported by the Shanghai Local Capacity Building Program(No.23010500700)the Project of Shanghai Municipal Science and Technology Commission(No.22DZ2291100)the Qinglan Project of Jiangsu Province,and the Open Project of Jiangsu Provincial Key Laboratory of Eco-Environmental Materials.
文摘Due to their high-entropy effects,the high-entropy(HE)MAX-phase materials improve the comprehen-sive performance of MAX phases,opening up more possibilities for practical engineering applications.However,it is still challenging to obtain S-containing high-entropy MAX phases because of the high volatilization behavior of sulfur,suffering from issues such as high reaction temperature and long re-action time of traditional synthesis methods.This paper proposes a novel process named as liquid metal assistant self-propagating high-temperature synthesis(LMA-SHS)for efficient synthesis of high-purity S-containing high-entropy MAX-phase materials.Low-melting-point metal(Sn or In)has been introduced into the raw mixture and melted into a liquid phase during the early stage of the SHS reaction.By serv-ing as a“binder”between transition metal atoms of the M-site due to the negative mixing enthalpy,this liquid phase can accelerate mass and heat transfer during the SHS process,ensuring a uniform solid solution of each element and realizing the synthesis of high-purity(TiNbVZr)_(2)SC in an extremely short time.The synthesis method for high-entropy MAX-phase materials developed in this study,i.e.,LMA-SHS,showing very short reaction time,low energy consumption,high yield,and low cost,has the promise to be a general energy-and resource-efficient route towards high-purity HE materials.
基金supported by the Natural Science Foundation of Zhejiang Province,China(LD24B060002)National Key Research and Development Program of China(2021YFB3801102)the Fundamental Research Funds for the Central Universities(226-2024-00060).
文摘The preparation of dispersible MFI-type zeolite nanoparticles with open micropores is challenging.Herein,a rapid and effective ultrasound-assisted liquid-phase exfoliation method along with a freezedrying process for redispersion of calcined silicalite-1(S-1)zeolite nanoparticle aggregates using 3-aminopropanol as an exfoliating agent is demonstrated.The exfoliation of S-1 zeolite nanoparticles is characterized by X-ray diffraction,scanning electron microscopy and DLS particle size analysis.The effects of drying methods of as-synthesized zeolite nanoparticle suspension,zeolite contents in frozen nanoparticle suspension,exfoliating agent concentrations,and zeolite doses in ultrasonic suspension on exfoliation efficiency are systematically investigated.It is found that the S-1 zeolite nanoparticle(~70 nm)achieves a yield up to 95%through a 30 min ultrasonic exfoliation in a 3-aminopropanol solution along with a freeze-drying process.The proposed exfoliation mechanism involves two primary stages:vip molecule insertion followed by water expansion,both substantially enhanced by tip sonication.This work offers a comprehensive understanding of the exfoliation process,provides valuable insights into the dispersion of sintered zeolite nanoparticles.
基金Innovation Groups of Basic Research in Gansu Province(No.23JRRA570)。
文摘An ionic liquid assisted hydrogel modified silica was synthesized using a one-pot polymerization and physical coating technique and subsequently applied to mixed-mode liquid chromatography.Analytical techniques,including Fourier transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),and elemental analysis,etc.,confirmed the successful prepared of this innovative stationary phase.The unique combination of amide,long alkyl chain,and imidazole ring in the hydrogel coating enables the stationary phase to function effectively in hydrophilic/reversed-phase/ion exchange liquid chromatography.Notably,the stationary phase exhibited superior separation performance owing to the synergistic effect of the ionic liquid and hydrogel.This was particularly evident when analyzing various analytes such as organic acids,nucleosides/bases,polycyclic aromatic hydrocarbons(PAHs)and anions.Furthermore,under our operating conditions,an excellent column efficiency of 53,642.9 plates/m was achieved for theobromine.In summary,we have proposed a straightforward strategy to enhance the separation performance of hydrogel coatings in liquid chromatography,thereby broadening the potential applications of hydrogels in the field of separation.
基金support from the National Key Research and Development Program of China(2022YFC2904704)the Fundamental Research Funds for the Central Universities(SCU2024D009)。
文摘The enrichment of low-grade phosphate rock is an important process to realize sustainable support of phosphorus resources. An aqueous solution containing Ca(NO_(3))_(2) and Mg(NO_(3))_(2) is produced during the enrichment of low-grade phosphate rock by leaching of HNO_(3) or calcination coupling with leaching of NH_(4)NO_(3) solution. Preparation liquid fertilizer is a preferential way to utilize it. The liquid−solid phase diagrams of Ca(NO_(3))_(2)-Mg(NO_(3))_(2)-H_(2)O, KNO_(3)-Mg(NO_(3))_(2)-H_(2)O, KNO_(3)-Ca(NO_(3))_(2)-H_(2)O and KNO_(3)-Ca(NO_(3))_(2)-Mg(NO_(3))_(2)-H_(2)O systems at 313.15 K were studied by isothermal dissolution equilibrium method. Two crystallization regions of Ca(NO_(3))_(2)·4H_(2)O and Mg(NO_(3))_(2)·6H_(2)O were observed in the phase diagram of the ternary system Ca(NO_(3))_(2)-Mg(NO_(3))_(2)-H_(2)O, a liquid fertilizer with a maximal total nutrient content of 27.46% and a nutrients ratio of N:Ca:Mg = 8.40:10.37:1 can be formed. A homogenous solution can be formed by mixing Ca(NO_(3))_(2)·4H_(2)O and Mg(NO_(3))_(2)·6H_(2)O. In the ternary system KNO_(3)-Mg(NO_(3))_(2)-H_(2)O, the crystallization regions of KNO_(3), Mg(NO_(3))_(2)·6H_(2)O and the co-crystallization region of KNO_(3) and Mg(NO_(3))_(2)·6H_(2)O were observed. The obtained maximal total nutrient content of liquid fertilizer is 23.32% with the ratio of N:K_(2)O = 1:3.39. In the ternary system KNO_(3)-Ca(NO_(3))_(2)-H_(2)O, the crystallization regions of Ca(NO_(3))_(2)·4H_(2)O and KNO_(3) were observed. The obtained maximal total nutrient content of liquid fertilizer is 38.41% with the ratio of N:K_(2)O:Ca = 1.05:1.18:1. A homogenous solution can also be formed by mixing Ca(NO_(3))_(2)·4H_(2)O and KNO_(3) directly. In the quaternary system KNO_(3)-Ca(NO_(3))_(2)-Mg(NO_(3))_(2)-H_(2)O, the crystallization regions of Ca(NO_(3))_(2)·4H_(2)O, Mg(NO_(3))_(2)·6H_(2)O and KNO_(3) and the co-crystallization region of KNO_(3) and Mg(NO_(3))_(2)·6H_(2)O were observed. The obtained maximal total nutrient content of liquid fertilizer is 38.41% with the ratio of N:K_(2)O:Ca = 1.05:1.18:1. The modified BET model was successfully used to fit the solubility curves. The results can provide a guidance for the formulation of water-soluble fertilizers of N-(K, Ca, Mg).
基金the National Natural Science Foundation of China(No.22274021)Natural Science Foundation of Fujian Province(No.2022J01535)for financial support。
文摘Covalent organic frameworks(COFs)have demonstrated great potential in chromatographic separation because of unique structure and superior performance.Herein,single-crystal three-dimensional(3D)COFs with regular morphology,good monodispersity and high specific surface area,were used as a stationary phase for high-performance liquid chromatography(HPLC).The single-crystal 3D COFs packed column not only exhibits high efficiency in separating hydrophobic molecules involving substituted benzenes,halogenated benzenes,halogenated nitrobenzenes,aromatic amines,aromatic hydrocarbons(PAHs)and phthalate esters(PAEs),but also achieves baseline separation of acenaphthene and acenaphthylene with similar physical and chemical properties as well as environmental pollutants,which cannot be quickly separated on commercial C18 column and a polycrystalline 3D COFs packed column.Especially,the column efficiency of 17303-24255 plates/m was obtained for PAEs,and the resolution values for acenaphthene and acenaphthylene,and carbamazepine(CBZ)and carbamazepine-10,11-epoxide(CBZEP)were 1.7and 2.2,respectively.This successful application not only confirmed the great potential of the singlecrystal 3D COFs in HPLC separation of the organic molecules,but also facilitates the application of COFs in separation science.
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 Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.2021R1C1C2006535)supported by the Korea Basic Science Institute(National Research Facilities and Equipment Center)grant funded by the Korea government(MSIT)(No.RS-2024-00403164)supported by the National Research Foundation of Korea grant funded by the Korea government,Ministry of Science and ICT(Development of Nanofiber Yarn Based Compound Sensor as a Comprehensive Wearable Healthcare Solution)(Grant No.RS-2024-00357296).
文摘The crystallization of ionic crystals has traditionally been explained by Gibbs's classical nucleation theory.However,recent observations of intermediate phases during nucleation suggest that the process may be more complex,necessitating new theoretical frameworks,though key empirical evidence remains elusive.In this study,we used microdroplets to investigate the crystallization of sodium halides(NaCl,NaBr,and NaI)under homogeneous nucleation conditions across a wide range of supersaturations.In the evaporating droplet,NaCl follows the classical nucleation pathway,whereas NaBr and NaI exhibit the formation of an intermediate phase prior to the nucleation of anhydrous and hydrous single crystals,respectively.Optical and computational analyses indicate that these intermediate phases are liquid crystal phases composed of contact ion pairs.These findings establish a new theoretical framework for crystal nucleation and growth and offer methods to control nucleation pathways,enabling us to achieve desired crystals regardless of specific conditions.
基金the BAGUI talent program(No.2019AC26001)the National Natural Science Foundation of China(Nos.U23A2080,22371173,22171075).
文摘The remarkable power of chemistry over description and trans-formation of matters has been significantly enhanced through the development of dynamic chemistry and condensed matter chemistry[1].This progress has further elevated chemistry to a creative science and a thriving industry.The development of dynamic chemistry,span-ning from supramolecular chemistry to constitutional dynamic chem-istry,has witnessed significant advancements towards adaptive chemistry,which is characterized primarily by its self-adaption to external stimuli.This is particularly achieved in two-or three-dimensional dynamic frameworks.Meanwhile,the multi-phase evolution resulting from the emerging of solid-to-liquid transition plat-form is assuming an increasingly crucial role in condensed matter chemistry[2].
文摘The authors regret the following changes to the paper:1.The following author is added to this article:Agnieszka Chmielewska-Wysockaa 2.Section 2.1:●“An aqueous binder”should be changed to“A solvent binder”.●Replace“a composition of ethylene glycol monobutyl ether and ethylene glycol”by“50% binder saturation”.
基金supported by the National Natural Science Foundation of China (Nos.22064020,22364022,and 22174125)the Applied Basic Research Foundation of Yunnan Province (Nos.202101AT070101 and 202201AT070029)。
文摘Developing a chiral material as versatile and universal chiral stationary phase(CSP) for chiral separation in diverse chromatographic techniques simultaneously is of great significance.In this study,we demonstrated for the first time that a chiral metal-organic cage(MOC),[Zn_(6)M_(4)],as a universal chiral recognition material for both multi-mode high-performance liquid chromatography(HPLC) and capillary gas chromatography(GC) enantioseparation.Two novel HPLC CSPs with different bonding arms(CSP-A with a cationic imidazolium bonding arm and CSP-B with an alkyl chain bonding arm) were prepared by clicking of functionalized chiral MOC [Zn_(6)M_(4)] onto thiolated silica via thiol-ene click chemistry.Meanwhile,a capillary GC column statically coated with the chiral MOC [Zn_(6)M_(4)] was also fabricated.The results showed that the chiral MOC exhibits excellent enantioselectivity not only in normal phase HPLC(NP-HPLC) and reversed phase(RP-HPLC) but also in GC,and various racemates were well separated,including alcohols,diols,esters,ketones,ethers,amines,and epoxides.Importantly,CSP-A and CSP-B are complementary to commercially available Chiralcel OD-H and Chiralpak AD-H columns in enantioseparation,which can separate some racemates that could not be or could not well be separated by the two widely used commercial columns,suggesting the great potential of the two prepared CSPs in enantioseparation.This work reveals that the chiral MOC is potential versatile chiral recognition materials for both HPLC and GC,and also paves the way to expand the potential applications of MOCs.
基金Projects (50831003, 50571037) supported by the National Natural Science Foundation of China
文摘The formation and evolution characteristics of bcc phase during the isothermal relaxation processes for supercooled-liquid and amorphous Pb were investigated by molecular dynamics simulation and cluster-type index method （CTIM）. It is found that during the relaxation process, the formation and evolution of bcc phase are closely dependent on the initial temperature and structure. During the simulation time scale, when the initial temperature is in the range of supercooled liquid region, the bcc phase can be formed and kept a long time; while it is in the range of glassy region, the bcc phase can be formed at first and then partially transformed into hcp phase; when it decreases to the lower one, the hcp and fcc phases can be directly transformed from the glassy structure without undergoing the metastable bcc phase. The Ostwald＇s ＂step rule＂ is impactful during the isothermal relaxation process of the supercooled and glassy Pb, and the metastable bcc phase plays an important role in the precursor of crystallization.
基金Projects(12JJ3013,11JJ5010,10JJ5002)supported by the Natural Science Foundation of Hunan Province,ChinaProject(2013CL04)supported by the Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation,Changsha University of Science and Technology,ChinaProject(2011RS4069)supported by the Planned Science and Technology Program of Hunan Province,China
文摘A thin layer of TiO2 film was deposited on ITO surface via the liquid phase deposition （LPD） process. The photocurrent and electrochemical impedance spectroscopy （EIS） measurements indicated that the as-prepared LPD TiO2/ITO film had an excellent photoelectrochemical performance, which showed a sensitive and rapid response to the UV irradiation. The photogenerated electron-hole pairs could be effectively separated by applying an external bias to the TiO2 film electrode. The LPD TiO2/ITO film was employed to study the photoelectrocatalytic （PEC） degradation of 4-aminoantipyrine. Compared with other techniques, the PEC technique based on such a LPD film electrode had a synergetic effect for 4-aminoantipyrine degradation. When the applied bias potential was＋0.8 V and the supporting electrolyte concentration of Na2SO4 was 0.1 mol/L, the highest degradation efficiency within 120 min could reach 95%for 0.1 mmol/L 4-aminoantipyrine solution at pH 2.0.
基金Project(2014CB643406)supported by the National Basic Research Program of China
文摘The carbon-coated monoclinic Li3V2(PO4)3(LVP) cathode materials were successfully synthesized by liquid phase method using PEG as reducing agent and carbon source. The effects of relative molecular mass of PEG on the properties of Li3V2(PO4)3/C were evaluated by X-ray diffraction(XRD), scanning electron microscope(SEM) and electrochemical performance tests. The SEM images show that smaller size particles are obtained by adding larger and smaller PEGs. The electrochemical cycling of Li3V2(PO4)3/C prepared by both PEG200 and PEG20 k has a high initial discharge capacity of 131.1 mA·h/g at 0.1C during 3.0-4.2 V, and delivers a reversible discharge capacity of 123.6 m A·h/g over 30 cycles, which is better than that of other samples. The improvement in electrochemical performance is caused by its improved lithium ion diffusion coefficient for the macroporous morphology, which is verified by cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS).
文摘Transient liquid phase（TLP） bonding of IN738 LC superalloy was carried out using a rapidly solidified MBF-15 Ni-based foil. The effects of bonding temperature（1130–1170 °C） and time（5–120 min） as well as foil thickness（35–140 μm） were studied on the microstructure of joint region and its mechanical properties. The solidification sequence in the joint region was found to be（i） formation of γ solid solution in the isothermally solidified zone, followed by（ii） ternary eutectic of γ ＋ Ni3 B ＋ Cr B, and finally（iii） binary eutectic of γ ＋ Ni3 Si in the athermally solidified zone. Fine Ni3 Si particles were also formed via a solid state transformation within the γ matrix in the vicinity of eutectic products. A deviation of isothermal solidification kinetics from the standard parabolic TLP model was observed by increasing the bonding temperature to 1170 °C, which resulted in the formation of eutectic constituents at the joint centerline.The analysis of mechanical and fractographic test results revealed that the samples with complete isothermal solidification exhibit the highest shear strength, whereas the hard eutectic constituents act as preferential failure sites and lead to a significant reduction in the joint shear strength in samples with incomplete isothermal solidification.
基金financially supported by the Fundamental Research Funds for the Central Universities of China(No.FRF-MP-12-003B)
文摘Gangue existing states largely affect the high-temperature characteristics of iron ores. Using a micro-sintering method and scan- ning electron microscopy, the effects of gangue content, gangue type, and gangue size on the assimilation characteristics and fluidity of liquid phase of five different iron ores were analyzed in this study. Next, the mechanism based on the reaction between gangues and sintering mate- dais was unraveled. The results show that, as the SiO2 levels increase in the iron ores, the lowest assimilation temperature （LAT） decreases, whereas the index of fluidity of liquid phase （IFL） increases. Below 1.5wt%, Al2O3 benefits the assimilation reaction, but higher concentra- tions proved detrimental. Larger quartz particles increase the SiO2 levels at the local reaction interface between the iron ore and CaO, thereby reducing the LAT. Quartz-gibbsite is more conductive to assimilation than kaolin. Quartz-gibbsite and kaolin gangues encourage the forma- tion of liquid-phase low-Al2O3-SFCA with high IFL and high-Al2O3-SFCA with low IFL, respectively.
基金supported by Special Funds for Major State Basic Research Projects,China (No.2003CB615705).
文摘Ultra-high molecular weight polyethylene (UHMWPE) with a microporous structure was prepared via thermally induced phase separation (TIPS).Liquid paraffin (LP) was used as a diluent in the preparation of microporous UHMWPE. Small angle laser light scattering (SALLS) and differential scanning calorimetry (DSC) were used to determine the phase separation temperatures,i.e.the cloud points and the dynamic crystallization temperatures,respectively.It was found that the cloudI points were coincident with the cryst...
基金This work was financially supported by the National Natural Science Foundation of China (No. 50174007).
文摘The kinetic characteristics of W grain growth operated by diffusion controlled Oswald ripening （DOR） during liquid phase sintering were studied. A liquid phase sintering of W-15wt%Cu was carried out by pushing compacts into a furnace at the moment when the temperature increased to 1340℃ for different sintering times. The results show that liquid phase sintering produces the compacts with considerably low relative density and inversely, rather high homogeneity. On the basis of the data extracted from the SEM images, the kinetic equation of W grain growth, G^n = G0^n ＋ kt, is determined in which the grain growth exponent n is 3 and the grain growth rate constant k is 0.15 μm^3/s. The cumulative normalized grain size distributions produced by different sintering times show self-similar. The cumulative distribution function is extracted from the curves by non-linear fitting. In addition, the sintering kinetic characteristics of W-15wt%Cu compacts were also investigated.
基金Project supported by the Talent Fund of the Ministry of Communication of China(No.95050508) the Fund of Western Communication of China(No.200332822047) the Key Science Fund of the Ministry of Communication of China(No.95060233)
文摘Velocities of solid phase and liquid phase in debris flow are one key problem to research on impact and abrasion mechanism of banks and control structures under action of debris flow. Debris flow was simplified as two-phase liquid composed of solid phase with the same diameter particles and liquid phase with the same mechanical features. Assume debris flow was one-dimension two-phase liquid moving to one direction, then general equations of velocities of solid phase and liquid phase were founded in two-phase theory. Methods to calculate average pressures, volume forces and surface forces of debris flow control volume were established. Specially, surface forces were ascertained using Bingham＇s rheology equation of liquid phase and Bagnold＇s testing results about interaction between particles of solid phase. Proportional coefficient of velocities between liquid phase and solid phase was put forward, meanwhile, divergent coefficient between theoretical velocity and real velocity of solid phase was provided too. To state succinctly before, method to calculate velocities of solid phase and liquid phase was obtained through solution to general equations. The method is suitable for both viscous debris flow and thin debris flow. Additionally, velocities every phase can be identified through analyzing deposits in-situ after occurring of debris flow. It is obvious from engineering case the result in the method is consistent to that in real-time field observation.
基金supported by the National Natural Science Foundation of China (50871032)National High Technology Research and Development Program of ChinaProgram of Beijing Municipal Science & Technology
文摘The effect of Sm-rich liquid phase （Sm2Co3） on magnetic properties and microstructure of 2：17-type Sin-Co magnet was studied. Three phases existed in liquid phase ingot, and took on white, dark grey and grey, respectively. It was found that the composition of the grey area was similar to the nominal one. Our results indicated that the optimal composition was obtained at 3 wt.% liquid phase added, and the magnetic properties were B^I 1.58 kGs, Hci〉26 kOe, （BH）m=29.51 MGOe. Br increased by 3%, Hci was 13 times larger, and （B/-/）m was 6 times bigger than none liquid phase magnets. Moreover, with the aging time decreasing from 20 to 8 h, the squareness of the demagnetization curves got better, while the coercivity of the samples decreased. It revealed that Sm（Co,Cu）5 phase also precipitated at particle boundaries. It maybe also enhanced the coercivity.
文摘A single-drop liquid phase micro-extraction procedure using 1-butyl-3-methylimidazolium hexafluorophosphate （[C4MIM][PF6]） was demonstrated for the sensitive determination of four phenols in water samples. Under the optimized conditions, the linear range of proposed method was excellent in the range of 0.5-100 μg·L^-1, the reproducibility （RSD, n=6） were in the range 5.4%-8.9% and detection limits （S/N=3） were 0.3, 0.3, 0.5 and 0.5 μg·L^-1 for 2, 4-dichlorophenol, 2-naphthol, 2-nitrophenol and 4-chlorophenol, respectively. The experimental results indicated that the effect of complex matrices natural water samples could be resolved with addition of sodium ethylene diamine tetracetate （EDTA） into the samples. Excellent spiked recoveries were achieved for these four phenols ranged from 86.2%-114.9 %. All these facts demonstrated that the proposed method with merits of low cost, simplicity and easy operating would be a competitive alternative procedure for the determination of such compounds at trace level.
