Deep eutectic solvents for separation and purification applications in critical metal metallurgy:Recent advances and perspectives

Solvent extraction,a separation and purification technology,is crucial in critical metal metallurgy.Organic solvents commonly used in solvent extraction exhibit disadvantages,such as high volatility,high toxicity,and flammability,causing a spectrum of hazards to human health and environmental safety.Neoteric solvents have been recognized as potential alternatives to these harmful organic solvents.In the past two decades,several neoteric solvents have been proposed,including ionic liquids(ILs)and deep eutectic solvents(DESs).DESs have gradually become the focus of green solvents owing to several advantages,namely,low toxicity,degradability,and low cost.In this critical review,their classification,formation mechanisms,preparation methods,characterization technologies,and special physicochemical properties based on the most recent advancements in research have been systematically described.Subsequently,the major separation and purification applications of DESs in critical metal metallurgy were comprehensively summarized.Finally,future opportunities and challenges of DESs were explored in the current research area.In conclusion,this review provides valuable insights for improving our overall understanding of DESs,and it holds important potential for expanding separation and purification applications in critical metal metallurgy.

Critical behaviours and magnetic properties of three-dimensional bond and anisotropy dilution Blume-Capel model in the presence of an applied field

This paper studies the critical behaviours and magnetic properties of three-dimensional bond and anisotropy dilution Blume-Capel model （BCM） in the presence of an applied field within the effective field theory. The trajectory of tricritical point, reentrant transitions and degenerate patterns of anisotropy are obtained both for the bond and the anisotropy dilutions. The global phase diagrams demonstrate unusually reentrant phenomena. The temperature dependences of magnetization curves undergo remarkable spin glass behaviour at low temperatures, and transform from ferromagnetism to paramagnetism at high temperature in applied fields. Temperature dependence of magnetic susceptibility curve is in qualitative agreement with experimental result.

A New Group-Contribution Method for Critical Properties

In the paper, an estimating method for critical properties in group-contribution method is presented.For eliminating the influence of adjacent group and distinguishing isomers, the new method including first-level group-contribution method and second-level group-contribution method is proposed. The new method demonstrates significant improvement in accuracy.

Micromechanical analysis on tensile properties prediction of discontinuous randomized zalacca fibre/high-density polyethylene composites under critical fibre length

In this research,the tensile properties'performance of compression moulded discontinuous randomized zalacca fibre/high-density polyethylene under critical fibre length was analysed by means of experimental method and micromechanical models.These investigations were used to verify the tensile properties models toward the effect of fibre length and volume fraction on the composites.The experimental results showed that the tensile properties of composites had significantly increased due to the enhancement of fibre length.On the contrary,a decline in the tensile properties was observed with the increase of volume fraction.A comparison was made between the available experimental results and the performances of Tsai-Pagano,Christensen and Cox-Krechel models in their prediction of composites elastic modulus.The results showed that the consideration of fibre's elastic anisotropy in the Cox-Krenchel model had yielded a good prediction of the composites modulus,nevertheless the models could not accurately predict the composites modulus for fibre length study.

Theoretical Studies on Critical Properties of Binary System with Supercritical Carbon Dioxide

A new expression of mixing rule is suggested according to the Mayson′s mixing rule in this paper, which adopts the Redlich Kwong cubic equation of state and the modified Chueh Prausnitz method to calculate the experiment critical points of six binary mixtures CO 2+toluene, CO 2+cyclohexane, CO 2+ n butanal, CO 2+ i butanal , CO 2+methanol, CO 2+ethanol. The coefficients of interaction parameter in the expression of mixing rule were optimized from experimental data. The calculated results of critical temperature and critical pressure meet the experiment data well. The maximum relative errors of temperature and pressure between the calculation results and experiment data are 1 493% and 5 2236% respectively, indicating that the proposed expression of mixing rule is reasonable. This may provide a fundamental method for studying and predicting the properties of supercritical fluids.

Critical Properties of Mixed Ising Spin System with Different Trimodal Transverse Fields in the Presence of Single-Ion Anisotropy

Within the framework of an effective field approximation, the effects of single-ion anisotropy and different trimodal transverse fields of two sublattices on the critical properties of the mixed spin-1/2 and spin-1 Ising system are investigated on the simple cubic lattice. A smaller single-lon anisotropy can magnify magnetic ordering phases and a larger one can depress magnetic ordering phase for T-Ω1/2 space at low temperatures, while a smaller single-ion anisotropy can hardly change the value of critical transverse field for T-Ω1 space. On the other hand, influences of two different trimodal transverse fields concentrations on tricritical points and magnetic ordering phases take on some interesting results in T-D space. The main reason comes from the common action of single-ion anisotropy, different transverse fields and two trimodal distributions.

Critical temperatures and pressures of reacting mixture in synthesis of dimethyl carbonate with methanol and carbon dioxide

Critical temperatures and pressures of nominal reacting mixture in synthesis of dimethyl carbonate （DMC） from methanol and carbon dioxide （quaternary mixture of carbon dioxide ＋ methanol ＋ water ＋ DMC） were measured using a high-pressure view cell. The results suggested that the critical properties of the reacting mixture depended on the reaction extent as well as its initial composition （initial ratio of carbon dioxide to methanol）. Such information is essential for determining the reaction conditions when one intends to carry out the synthesis of DMC with CO2 and methanol under supercritical conditions.

Phase Equilibrium of Isobutanol in Supercritical CO2

Vapor-liquid phase equilibrium data including composition,densities,molar volume and equilibrium constant of isobutanol in supercritical carbon dioxide from 313.2K to 353.2K were measured in a variable-volume visual cell.The properties of critical point were obtained by extrapolation.The results showed that critical temperature,critical pressure and critical compressibility factor of CO2-isobutanol system decreased with the increase of critical CO2 content.The phase equilibrium model was established by Peng-Robinson equation of state and van der Waals-2 mixing regulation,and model parameters were determined by optimization calculation of nonlinear least square method.The correlation between calculated values and the experimental data showed good agreement.

CORRELATION OF CRITICAL LOCI FOR FLUID MIXTURES

The hard-sphere three-parameter equation of state proposed in our previous investigation was applied to correlate binary critical loci of alkane-alkane, aromatic-aromatic, hydrocarbon-inorganic gas and systems containing oxygenated hydrocarbons including those exhibiting type Ⅲ behaviors as classified by van Konynenberg and Scott. A new procedure was also presented which simplified mathematical manipulations and permitted the reduction of the computation time.Results were compared with those obtained by Patel-Teja equation with temperature-dependent binary interaction parameters. Significant improvements were achieved by the proposed equation with temperature-dependent parameters.In addition parameters obtained from the critical locus calculations were used to predict vapor-liquid equilibria of hydrogen-carbon monoxide and hydrogen-carbon dioxide systems. Prediction accuracies were found to be very satisfactory.

Simulation of critical behaviour on damage evolution

Based on a damage evolution equation and a critical damage function model, this paper has completed the numerical simulation of ductile spall fracture. The free-surface velocity and damage distribution have been used to determine jointly the physical parameters D1 （the critical linking damage）, Df （the critical fracturing damage） and k （the softening rate of critical damage function model） of the critical damage function model, which are 0.11, 0.51 and 0.57 respectively. Results indicate that the parameters determined by any of shots could be applicable to the rest of other shots, which is convincing proof for the universal property of critical damage function. In our experiments, the shock pressure is about 1 GPa to 2.5 CPa. For the reason of limited pressure range, there are still some limitations in the methods of present analysis. Moreover, according to the damage evolution characteristic of pure aluminum obtained by experiments, two critical damages are obtained, which are 0.11 and 0.51 respectively. The results are coincident with the experimental ones, which indicate that the critical growth behaviour of damage occurs in the plastic metal under dynamic loading.

Measurements of the Critical Temperature and Pressure of Ethylene+Benzene+Ethylbenzene Mixture

Critical temperature (Tc) and critical pressure (pc) of the ternary mixture of ethylene+benzene+ethylbenzene (the mole ratio of ethylbenzene to benzene was fixed at 0.95:0.05) were measured by using a high=pressure view cell with direct visual observation.The interaction coefficients obtained from the critical properties of the relevant binary systems were used to predict the critical properties (Tc,pc) of the ternary mixture.The agreement between the prediction and experiments is satisfactory.

Study on the Critic Ablation Property of 2D Carbon Reinforced Silicon Carbide (C/SiC) Laminated Composites via CVI Process

Two dimensions (2D) C/SiC laminated composites is the material with isotropic properties in laminated sheets, which is considered as a promising thermal skin for aircrafts. There are intense thermal flux and thermal impact at the local interference region during the flight of the aircrafts. Therefore, mastering ablation and mechanical properties of 2D C/SiC laminated composite under extreme environments become the guild lines for the designs of the flight corridor and the aircraft security. This paper presents the experimental results of the ablation and thermal impact of C/SiC composites under different thermal environments (thermal flux ~5 MW/m2), which were carried out with the equipments of free-jets and conduct pipes. The effects on the ablation and mechanical properties of the C/SiC composites are studied, including gas pressure, thermal temperature, and the rates of temperature increasing and decreasing. The results show that the active oxidation and ablation behaviors of 2D C/SiC laminated composites under the thermal flux 5 MW/m2 consist with that of theoretical simulations. The critical failure conditions of 2D C/SiC laminated composite is also provided for the enveloping designs of the whole composites lightweight aircrafts.

Correlation of Critical Micelle Concentration of Sodium Alkyl Benzenesulfonates with MolecularDescriptors

The hydrophobic-hydrophilic segment geometries of 36 sodium alkyl benzenesulfonates were fully optimized and calculated by abinitio RHF/6-31G（d）, quantum chemical data such as the charge density, the energy of molecular orbital and the dipole moment were obtained. Based on two topological descriptors and one quantum chemical descriptor, a significant quantitative structure-property relationship （QSPR） model for the critical micelle concentration （Cmc） of sodium alkyl benzenesulfonate surfactants was obtained by using the multiple linear regression technique. The good correlation coefficient of Re （0. 980） and cross-validation correlation coefficient Rcv^2 （0. 974） indicate the excellent capability and stability of the regression equation developed. In addition, linear relationships between logarithm of Cmc and the dipole moment of surfaetant hydrophobic hydrophilic segments for each homologous series have also been established with high correlation coefficient.

Effect of powder feeding rate and size on critical velocity and mechanical properties of cold sprayed Al_(2)O_(3)/2024 deposit

The particle acceleration behavior and deposition mechanism of cold spraying aluminum matrix composites(Al_(2)O_(3)/2024)are complicated by the addition of ceramic particles.The effects of different feeding rates and particle diameters on critical velocity and mechanical properties were studied by numerical simulation and experiment.The results indicate that as the powder feeding rate increases,the impact velocity of gas and particles gradually decreases,and the temperature of gas and particles increases,resulting in an increase in the difference between particle impact velocity and critical velocity.The highest tensile strength of the deposit is achieved at a powder feeding rate of 1 r/min,which is 343 MPa.As the powder feeding rate increases,the performance of the deposits decreases,but it significantly saves time and cost.As the particle diameter increases,the impact temperature first increases and then decreases,resulting in the critical velocity first decreasing and then increasing,and the mechanical performance first increasing and then decreasing.To some extent,the best performance of the deposit is achieved when the size of the metal particle is close to that of the ceramic particle.

Iso-propyl caprylate and iso-propyl linolenate synthetic fluids as novel alternatives in deep-water drilling operations:Critical fluid properties and aerobic biodegradability assessments

Present drilling fluids for deep water wells have severe degenerative effect on the environment with high operational and disposal costs.Thus,making them less desirable in recent times.Ester synthetic drilling fluid provides a novel environmentally friendly alternative but conventional ester-based drilling fluids exhibit high viscosities in deep-water wells causing excessive equivalent circulating density(ECD)and increased risk of lost circulation owing to narrow mud density window.This study experimentally investigates the critical fluid properties and aerobic biodegradability potentials of two newly developed deep-water synthetic ester drilling fluids namely:iso-propyl caprylate(COIPE)and iso-propyl linolenate(LOIPE)synthetic fluids and their comparison with synthetic-paraffin(SP-SBF)and isomerized-olefin(IOSBF)synthetic hydrocarbon fluids.The esters of iso-propyl caprylate and iso-propyl linolenate were produced from the isolation of ester mixtures that were obtained from the homogeneous catalytic transesterification of coconut and linseed plant oil biomass respectively.The COIPE was isolated from the coconut oil iso-propyl ester mixture by low-pressure fractional distillation technique.While fractional distillation and crystallization were used to isolate the LOIPE ester from the linseed oil iso-propyl ester mixture.Meanwhile,the aerobic biodegradation investigation was conducted by a modified oxygen consumption respirometry technique.The GC-MS analysis of the COIPE and LOIPE showed that the former contains essentially of lower saturated carbon compounds(C8).Whereas the latter contains higher molecular weight and unsaturated carbon compounds(C18+).The COIPE and LOIPE kinematic viscosity values are in good agreement with that of the reference synthetic hydrocarbon fluid samples(SP-SBF and IO-SBF).Although,the COIPE synthetic ester has lower viscosity value owing to the presence of shorter chain and saturated carbon atoms(C8 esters).Similarly,the linolenic oil iso-propyl ester has excellent cold flow characteristics for deep-water well drilling owing to lower values of cloud and pour points as a result of higher concentration of poly-unsaturated linolenic esters.The iso-propyl caprylate and the iso-propyl linolenate ester synthetic fluids are readily biodegradable in the sea water inoculum under aerobic condition.However,the iso-propyl caprylate is inherently biodegradable because its degradation level and that of the reference chemical sample were already above 60%during the 10-day window period.The SP-SBF and the IO-SBF synthetic fluids have lower aerobic biodegradation values because they contain little quantity of poly aromatic hydrocarbons as evident in their GC-MS profiles.Finally,esters and unsaturated synthetic-based fluid are more rapidly biodegradable than paraffinic synthetic fluids and the rate of biodegradation of organic compounds decreases as molecular weight increases.

基于AHP-CRITIC法的清炒白术物性参数与有效成分相关性研究

目的探究白术饮片清炒炮制过程中物性参数与有效成分的相关性及炮制温度和炮制时间对白术有效成分含量的影响。方法以不同的炮制温度和时间对白术饮片进行炮制,制备炒白术、焦白术、白术炭,探究炒白术、焦白术、白术炭中有效成分含量随温度和时间的变化规律,运用均匀设计法制备不同炮制程度的清炒白术饮片,测定饮片的物性参数(色度值、pH值、相对密度、氧化值和吸湿率),紫外分光光度法测定多糖含量,HPLC法测定5-HMF、白术内酯Ⅰ、Ⅱ、Ⅲ和苍术酮含量,运用SPSS 25.0软件进行物性参数与有效成分的相关性分析,并建立相应的回归模型,采用AHP-CRITIC法对白术不同程度炮制饮片进行多指标综合评价。结果随着炮制温度的升高和炮制时间的增加,5-HMF在初炒到炒黄阶段基本没有产生,在炒焦阶段含量大幅增加,炒炭阶段含量开始下降,并趋于稳定;白术内酯Ⅰ、Ⅱ、Ⅲ在炒焦阶段达到最大值;苍术酮在炒黄阶段时含量最高,随着炮制程度的加深,含量呈下降趋势,至炒炭后趋于稳定;多糖含量随着炮制程度的加深不断下降。经相关性分析,5-HMF含量与H、I值和pH值具有极显著负相关;白术内酯Ⅲ、苍术酮含量与H、I、pH值具有显著正相关;多糖含量与pH值和相对密度具有显著正相关,与氧化值呈极显著负相关;白术内酯Ⅰ含量与S具有极显著正相关;白术内酯Ⅱ含量与H具有显著正相关。分析建立的7个回归模型P值均小于0.05,具有统计学意义,可用物性参数依据定量模型预测有效成分含量,分别在89.1%、90.2%程度上根据H值、I值和pH值预测分析5-HMF和苍术酮含量,在74.7%程度上依据pH值、相对密度和氧化值预测分析多糖含量,在73.7%程度上根据饱和度S预测分析白术内酯Ⅰ含量,在84.3%、42.7%程度上根据色调H预测白术内酯Ⅱ和白术内酯Ⅲ含量,在35.1%程度上可以根据5-HMF含量预测分析饮片整体质量。结论白术不同程度炮制品物性参数与有效成分含量具有显著相关性,物性参数与有效成分的回归模型可分析预测物性参数与有效成分含量之间的关系,为规范化白术的炮制工艺和提高白术饮片质量提供科学依据。

AHP-CRITIC权重分析法综合优选玉竹全粉改性工艺

为改善玉竹全粉产品的功能特性,提升玉竹应用价值,考察不同改性方法对玉竹全粉品质的影响。以玉竹全粉(QO)为原料,探究超微粉碎(WO)、湿热处理结合冷冻干燥(RL)、湿热处理结合热风干燥(RR)及复合酶解(MO)等改性工艺对玉竹全粉物性、有效成分和体外抗氧化能力的影响,并运用AHP-CRITIC权重分析法对玉竹全粉固体饮料进行综合评价,优选符合特定应用的玉竹全粉改性工艺。湿热改性玉竹全粉的流动性及冲调性均有显著改善(P<0.05),但色泽较差,各有效成分含量及体外抗氧化能力均有显著增加(P<0.05);复合酶改性玉竹全粉的冲调性及吸湿性显著改善(P<0.05),产品色泽较好,各有效成分含量及·OH清除能力均有显著增加(P<0.05);超微粉碎玉竹全粉的冲调性、黏度及吸湿性均显著降低,但色泽较好,总多糖含量、Fe^(3+)还原能力及DPPH自由基清除能力显著提高(P<0.05)。AHP-CRITIC权重分析法综合评分显示RL对玉竹全粉改性效果较佳,其次为MO和RR。高温高压湿热改性对玉竹全粉综合品质具有良好的改善效果,运用AHP-CRITIC权重分析法综合优选玉竹全粉改性工艺具有一定的科学合理性,适用于涉及多指标产品及工艺的综合评价。

Investigation on the Dielectric Properties of CO2 and CO2-Based Gases Based on the Boltzmann Equation Analysis

In this paper, the dielectric properties of CO2, CO2/air, CO2/O2, CO2/N2, CO2/CF4, CO2/CH4, CO2/He, C02/H2, CO2/NH3 and CO2/CO were investigated based on the Boltzmann equation analysis, in which the reduced critical electric field strength （E/N）cr of the gases was derived from the calculated electron energy distribution function （EEDF） by solv- ing the Boltzmann transport equation. In this work, it should be noted that the fundamental data were carefully selected by the published experimental results and calculations to ensure the validity of the calculation. The results indicate that if He, H2, N2 and CH4, in which there axe high ionization coefficients or a lack of attachment reactions, are added into CO2, the dielectric properties will decrease. On the other hand, air, O2, NH3 and CFa （ranked in terms of （E/N）cr value in increasing order） have the potential to improve the dielectric property of CO2 at room temperature.

Influence of the gassing materials on the dielectric properties of air

Influence of the gassing materials, such as PA6, PMMA, and POM on the dielectric properties of air are investigated. In this work, the fundamental electron collision cross section data were carefully selected and validated. Then the species compositions of the air–organic vapor mixtures were calculated based on the Gibbs free energy minimization. Finally, the Townsend ionization coefficient, the Townsend electron attachment coefficient and the critical reduced electric field strength were derived from the calculated electron energy distribution function by solving the Boltzmann transport equation. The calculation results indicated that H;O with large attachment cross sections has a great impact on the critical reduced electric field strength of the air–organic vapor mixtures. On the other hand, the vaporization of gassing materials can help to increase the dielectric properties of air circuit breakers to some degree.

GALVANOMAGNETIC PROPERTIES OF METALS ATBOILING OF LIQUID HELIUM

Galvanomagnetic properties of metals at boiling point of liquid helium and some prob-lems relating to Joule heating in cylinder conductors are investigated by the method of voltage current characteristics. Radial current under an external coaxial magnetic field is used to get high magnetoresistance of conductor. High level of magnetore-sistance in this geometry offers the possibility to investigate a wide range of heat generation. The stabilization of voltage observed in definite current range is discussed in terms of analysis of heat aspects of problem when a heat genemtion function and heat elimination they are regarded at helium temperuture. An electric temperature ordering of system is proposed as a factor responsible for voltage stabilization when the presence of more heated and less heated sections along conductor radius is connected with negativity of derivative of heat elimination function with respect to temperature between first and second boiling crisis.