Preparation of FeCoNi medium entropy alloy from Fe^(3+)-Co^(2+)-Ni^(2+)solution system

In recent years,medium entropy alloys have become a research hotspot due to their excellent physical and chemical performances.By controlling reasonable elemental composition and processing parameters,the medium entropy alloys can exhibit similar properties to high entropy alloys and have lower costs.In this paper,a FeCoNi medium entropy alloy precursor was prepared via sol-gel and coprecipitation methods,respectively,and FeCoNi medium entropy alloys were prepared by carbothermal and hydrogen reduction.The phases and magnetic properties of FeCoNi medium entropy alloy were investigated.Results showed that FeCoNi medium entropy alloy was produced by carbothermal and hydrogen reduction at 1500℃.Some carbon was detected in the FeCoNi medium entropy alloy prepared by carbothermal reduction.The alloy prepared by hydrogen reduction was uniform and showed a relatively high purity.Moreover,the hydrogen reduction product exhibited better saturation magnetization and lower coercivity.

Effects of iron oxide on crystallization behavior and spatial distribution of spinel in stainless steel slag

Chromium plays a vital role in stainless steel due to its ability to improve the corrosion resistance of the latter.However,the re-lease of chromium from stainless steel slag(SSS)during SSS stockpiling causes detrimental environmental issues.To prevent chromium pollution,the effects of iron oxide on crystallization behavior and spatial distribution of spinel were investigated in this work.The results revealed that FeO was more conducive to the growth of spinels compared with Fe2O3 and Fe3O4.Spinels were found to be mainly distrib-uted at the top and bottom of slag.The amount of spinel phase at the bottom decreased with the increasing FeO content,while that at the top increased.The average particle size of spinel in the slag with 18wt%FeO content was 12.8μm.Meanwhile,no notable structural changes were observed with a further increase in FeO content.In other words,the spatial distribution of spinel changed when the content of iron oxide varied in the range of 8wt%to 18wt%.Finally,less spinel was found at the bottom of slag with a FeO content of 23wt%.

Hydrothermal synthesis of calcium sulfate whisker from flue gas desulfurization gypsum

Plenty of flue gas desulfurization(FGD) gypsum generated from coal-fired power plants for sulfur dioxide sequestration caused many environmental issues. Preparing calcium sulfate whisker(CSW) from FGD gypsum by hydrothermal synthesis is considered to be a promising approach to solve this troublesome problem and utilize calcium sulfate in a high-value-added way. The effects of particle size of FGD gypsum, slurry concentration,and additives on CSW were investigated in this work. The results indicated that fine particle size of FGD gypsum and moderately high slurry concentration were beneficial for crystal nucleation and growth. Three additives of magnesium chloride, citric acid, and sodium dodecyl benzene sulfonate(SDBS) were employed in this study. It was found that mean length and aspect ratio of CSW were both decreased by the usage of magnesium chloride,while a small quantity of citric acid or SDBS could improve the CSW morphology. When multi-additives of citric acid-SDBS were employed, the mean length and aspect ratio increased more than 20%. Moreover, surface morphology of CSW went better, and the particle size and crystal shape became more uniform.

Effect of Ca/Mg molar ratio on the calcium-based sorbents

Steelmaking industry faces urgent demands for both steel slag utilization and CO_(2)abatement.Ca and Mg of steel slag can be extracted by acid solution and used to prepare sorbents for CO_(2)capture.In this work,the calcium-based sorbents were prepared from stainless steel slag leachate by co-precipitation,and the initial CO_(2)chemisorption capacity of the calcium-based sorbent prepared from steel slag with the Ca and Mg molar ratio of 3.64:1 was 0.40 g/g.Moreover,the effect of Ca/Mg molar ratio on the morphology,structure,and CO_(2)chemisorption capacity of the calcium-based sorbents were investigated.The results show that the optimal Ca/Mg molar ratio of sorbent for CO_(2)capture was4.2:1,and the skeleton support effect of MgO in calcium-based sorbents was determined.Meanwhile,the chemisorption kinetics of the sorbents was studied using the Avrami-Erofeev model.There were two processes of CO_(2)chemisorption,and the activation energy of the first stage(reaction control)was found to be lower than that of the second stage(diffusion control).

The principal moments of inertia calculated with the hydrostatic equilibrium figure of the Earth

As an indication of the Earth＇s mass distribution, the principal moments of inertia （PMOI, i.e., A, B, C） of the Earth are the basic parameters in studies of the global dynamics of the earth, like earth nutation, and the geophysics. From the aspect of observation, the PMOI can be calculated from the spherical coefficients of observed gravity field. In this paper, the PMOI are calculated directly according to its definition with the figures of the Earth＇s interior derived by a generalized theory of the hydrostatic equilibrium figure of the Earth. We obtain that the angle between the principal axis of the maximum moment of PMOI and the rotational axis is 0.184~, which means that the other two principal axes are very closely in the equatorial plane. Meanwhile, B-A is 1.60 x 10-5 MR2, and the global dynamical flattening （H） is calculated to be 3.29587 ~ 10-3, which is 0.67% different from the latest observation derived value Hobs（3.273795 × 10 ^-3） （Petit and Luzum, 2010）, and this is a significant improvement from the 1.1% difference between the value of H derived from traditional theories of the figure of the Earth and the value of Hobs. It shows that we can calculate the PMOI and H with an appropriate accuracy by a gener- alized theory of the hydrostatic equilibrium figure of the Earth.

稀土对重轨钢组织转变的影响

通过在真空感应炉熔炼、锻造加工和轧制准备洁净重轨钢，采用热模拟仪、金相显微镜和扫描电镜研究了稀土（RE）对重轨钢的相转变和组织影响。热模拟试验结果表明，RE将珠光体转变的C曲线向右下方移动，延长了珠光体的孕育期并且提高了过冷奥氏体的稳定性。通过稀土使珠光体转变的最小孕育期从24s增加到30s，而且稀土能减少珠光体转变的临界冷却速度，从1℃·s-1减少到0．5℃·S-1，淬火的临界冷却速率从15℃·s-1减少到13℃·S-1。除此之外，稀土可明显细化退火和正火珠光体。添加稀土的重轨钢珠光体层状距离分别减少了12．9％（退火）和13．3％（正火）。

Detrital Zircon Geochronology of Early Triassic Strata in the West Qinling Orogen:Implications for the Tectonic Evolution of the Paleo-Tethyan Ocean

The West Qinling Orogen(WQO)is located in the western part of the Qinling Orogen and in the transition zone of Qilian Orogen,Songpan-Garze Orogen and Yangtze Block,and also the key position of Triassic collision orogenic event.The study of the Early Triassic strata in the WQO is contributed to analyze the closure process of the paleo-Tethys.We conducted LA-ICP-MS U-Pb dating studies on detrital zircons to determine the provenance,depositional age,and tectonic setting of the Early Triassic Longwuhe Formation in the Lintan area of the WQO.The results show that the majority of the detrital zircons in the Longwuhe Formation are mainly magmatic origin and have characteristic of crust source zircon.The lowest limit of sedimentation of the Longwuhe Formation is constrained to the Early Triassic,with the youngest detrital zircon age of 253±3 Ma.The ages can be divided into five age groups:3346–1636 Ma,with two peak ages of ca.2495 and ca.1885 Ma;1585–1010 Ma,with a peak age at ca.1084 Ma;992–554 Ma,with a peak age at ca.939 Ma;521–421 Ma,with a peak age at ca.445 Ma;418–253 Ma,with a peak age at ca.280 Ma.Apparently,the sources of the Longwuhe Formation include the northern margin of the WQO,the Qilian Orogen(QLO)and the basement of the southern margin of the North China Block(NCB),of which the ancient basement of the southern margin of the NCB is the main source area of the Longwuhe Formation.Combined with previous studies,we propose that the Longwuhe Formation was formed in a fore-arc basin,which is related to the closure of the A’nyemaqen-Mianlüe Ocean from the Early Permian to Early–Middle Triassic due to the northward subduction-collision of the Yangtze Block(YZB).This also indicates that the A’nyemaqen-Mianlüe Ocean has flat subduction characteristics.

Vickrey-Clark-Groves-based Method for Eradicating Deceptive Behaviors in Demand Response Transactions

Demand response transactions between electric consumers,load aggregators,and the distribution network manager based on the"combination of price and incentive"are feasible and efficient.However,the incentive payment of demand re-sponse is quantified based on private information,which gives the electric consumers and load aggregators the possibility of defrauding illegitimate interests by declaring false information.This paper proposes a method based on Vickrey-Clark-Groves(VCG)theory to prevent electric consumers and load aggregators from taking illegitimate interests through deceptive behaviors in the demand response transactions.Firstly,a demand response transaction framework with the price-and-incentive com-bined mode is established to illustrate the deceptive behaviors in the demand response transactions.Then,the idea for eradi-cating deceptive behaviors based on VCG theory is given,and a detailed VCG-based mathematical model is constructed follow-ing the demand response transaction framework.Further,the proofs of incentive compatibility,individual rationality,cost minimization,and budget balance of the proposed VCG-based method are given.Finally,a modified IEEE 33-node system and a modified IEEE 123-node system are used to illustrate and validate the proposed method.

Evolution and deformability of inclusions in Al-killed steel with rare earth-alkali metals(Ca or Mg) combined treatment

The quality of stainless steel is closely related to the deformability of inclusions,which is significantly affected by their compositions.The present study first inve stigated the evolution of inclusion compositions in AI-killed steel with rare earth-alkali metals(Ca or Mg)combined treatme nt through four laboratory-scale experiments.The Ce contents in the final steel are 0.0080 wt%,0.015 wt%,0.016 wt%and 0.010 wt%,respectively.The Mg content is 0.0014 wt%in Ce-Mg combined treated steel,and the Ca content is0.0015 wt%in Ce-Ca combined treated steel.The deformability of inclusions in both Ce_(2)O_(3)-Al_(2)O_(3)-CaO and Ce_(2)O_(3)-Al_(2)O_(3)-MgO systems was subsequently evaluated by calculating their Young's modulus at low temperature.The results show that irregular Al_(2)O_(3)and MgAl_(2)O_(4)with poor deformability are modified to CeAlO_(3)and Ce_(2)O_(3)by Ce treatment,resulting in the decrease of Young's modulus of inclusions.The deformability of inclusions is further improved due to the transformation from lumped-like CeAlO_(3)to spherical CaO-Al_(2)O_(3)-Ce_(2)O_(3)caused by Ca treatment,and some of these inclusions are the ones with low liquidus temperature.Thermodynamic analysis was used to discuss the control condition of the formation and evolution of inclusions.Accordingly,the appropriate addition amounts of Al,Mg,Ce,and Ca are expected to control inclusion compositions and properties,including deformability and liquidus temperature,thereby improving the steel performance.

Phosphorus fixation capacity of CaO-SiO_(2)-Al_(2)O_(3)-MnO-Ce_(2)O_(3) slag based on structural considerations

The phosphorus fixation capacity of some slag systems,such as Ce_(2)O_(3)-containing slag,has hardly been investigated from a thermodynamics view due to the lack of relevant thermodynamic data.Since the macroscopic properties are primarily determined by the microscopic structure,the correlation between phosphorus fixation capacity and slag structure was explored by spectroscopy(XPS),Raman spectroscopy,and ferromanganese dephosphorization experiments.The results show that the predominant species of P^(5+)are Q_(P)^(0)(PO_(4)^(3-))and Q_(P)^(1)(P_(2)O_(7)^(4-))units in the CaO^(-)SiO_(2)-Al_(2)O_(3)-MnO^(-)Ce_(2)O_(3)-P_(2)O_(5)quenched slag,and the phosphorus fixation capacity increases with the Q_(P)^(1)(P_(2)O_(7)^(4-))unit to Q_(P)^(0)(PO_(4)^(3-))unit transformation(the P-O^(0) bond to P-O^(-)bond transformation)since the electron cloud density between P and O atoms increases and the average radius of P-O bonds decreases.Especially,CaO or Ce_(2)O_(3) as a network modifier can release the O_(2)-and promote the P-O^(0) bond to P-O^(-)bond(connected to Ca^(2+),/Ce^(3+))transformation in the quenched slag.Furthermore,the phosphorus enrichment phases in the slow cooling slag are confirmed as nCa_(2)SiO_(3)-Ca_(3)P_(2)O_(8)(nC_(2)S-C3P)and CePO_(4) solid solutions by the scan electron microscopy(SEM),transmission electron microscopy(TEM),and energy-dispersive spectrometer(EDS)methods.The re sults show Ce_(2)O_(3) can depolymerize the polyphosphate structure partially replacing CaO after introducing Ce_(2)O_(3) into CaO based slag because of its strong ability to donate electrons.The above results not only help to understand the dependence of phosphorus fixation capacity on slag composition from a structural view,but also provide the theoretical guidance for optimizing the composition of Ce_(2)O_(3)-containing dephosphorization slag.

Phase equilibria in low basicity region of CaO-SiO2-Nb2O5-（5 wt%,10 wt%,15 wt%） La2O3 system

The lack of thermodynamic information,such as primary phase fields and liquidus temperatures,in the CaO-SiO2-Nb2O5-La2O3 quaternary system phase diagram has restricted the comprehensive utilization of the niobium(Nb) and rare earth(RE) resources.In this work,the phase equilibria in low basicity region(w(CaO)/w(SiO2)<1) of CaO-SiO2-Nb2O5-(0-15 wt%)La2O3 system at 1373-1873 K were experimentally studied by thermodynamic equilibrium experiment,and then,the results were analyzed by X-ray diffraction(XRD),scanning electron microscopy(SEM),and energy dispersive spectrometry(EDS).Additionally,an optimized method was proposed to process the compositions of equilibrium liquid phases at different temperatures.According to the experimental results,the univariate line between CaNb2O6,SiO2 and LaNbO4 primary phase fields,interface between CaNb2O6 and SiO2 primary phase fields and isothermal liquidus surfaces in SiO2 primary phase field were determined.Finally,the spatial phase diagram of CaO-SiO2-Nb2O5-La2O3 within specific region was constructed,and furthermore,the phase diagram was also presented in CaO-SiO2-Nb2O5 pseudo-ternary system with w(La2O3)=5 wt%,10 wt% and 15 wt%.The research results have guiding significance for the improvement of related phase diagram and the comprehensive utilization of Nb and RE resources.

Digital literacy and financial market participation of middle-aged and elderly adults in China

Digital literacy has become increasingly important for individuals to participate in regular economic activities,including employment,consumption,and investment.This paper quantitatively defines digital literacy with recently released household survey data in China and describes the digital divide across regions and ages.We further show that digital literacy increases risky asset ownership in the financial market among the middle-aged and elderly population.In this sense,this paper identifies a novel factor that affects financial investment.These findings imply that the digital divide may lead to the asset divide and wealth inequality.Family and social assistance to improve the digital literacy of disadvantaged population groups may increase financial inclusion as well.