METASTABLE EXTENSION OF SOLID SOLUBILITY OF RARE-EARTH ELEMENTS IN Al

The splat folis of Al-RE(RE=Y,La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Er and Yb) binary alloys of 0.04—0.06 mm thickness were made by are-melting and hammer-anvil technique,the.cooling rate is in 10~6 K/s order of magnitude.The metastable extended solid solubilities of these RE elements have been evaluated by measurements of the lattice spacings of the rapidly solidified(RS)Al-RE alloys,they are 0.4,0.15,0.21,0.21,0.3, 0.5,0.1,0.6,0.65,0.7,0.75,0.2 at.-% for above individual RE clements,respectively.The secondary phase in RS Al-RE alloys were identified to be Al_4RE for alloys containing light RE and Eu elements and Al_3 RE for alloys containing heavy RE and Y elements. Some factors influencing the extension of solid solubility of Al-RE alloy were discussed.

Experimental Determination of Solid Solubility of Ce、La、Nd、Sm in Fe or Ni

The solid solubility of Ce、La、Sm and Nd in Fe or N i at various temperature was determined by means of a diffusion-couple method with the aid of an electron probe microanalyzer.Two methods,namely area method and whole range method,were proposed for data processing in the present paper.The principle and re- lated problems in the experimental determination of the solid solubility of rare-earth elements in Fe or Ni by use of the above mentioned methods were also discussed.

Solid Solubility and Age Hardening of Rapidly Solidified Al-Er Alloys

The metastable extension of solid solubility and age hardening of rapidly solidified Al-Er alloy were inves- tigated.The splat foils(0.04～0.06 mm in thickness)and spun ribbons(0.02～0.04 mm in thickness)of Al-Er alloys were prepared by melt hammer-anvil and melt spinning techniques,respectively.The cooling rate was about 10~6～10~7 K/s.The metastable extended solid solubility of Er in Al evaluated by measurements of lat- tice parameters of rapidly solidified alloys was 0.75 at%.An age hardening response was observed in the quenched and aged specimen.The precipitate responsible for age hardening was identified to be Cu_3Au type cubic Al_3Er.

Solid solubility and photoluminescence of Y_3Al_5O_(12):Ce^(3+)prepared by using(Y_(1-x)Ce_x)_2O_3 as precursor

Trivalent cerium-doped yttrium aluminum garnet （YAG：Ce3＋） phosphors are synthesized by solid-state reaction method through using （Yl-xCex）203 solid solutions as precursors. Solid solubility limits of Ce3＋ replacing y3＋ in Y203 and YAG are determined to be 40% and 7.5%, respectively, based on the relationship between the lattice param- eter and chemical composition. Using （Y1-xCex）203 as precursors we synthesize YAG：Ce3＋single phase at 1450 ~C and N2 atmosphere. However, under the same conditions using CeO2 there exists a second phase YA103 as impurity. The photoluminescence intensity of YAG：Ce3＋ increases monotonically with the increase of Ce concentration until it reaches a maximum at solid solubility limits of Ce3＋ in YAG.

MICROSTRUCTURE AND EXTENDED SOLID SOLUBILITY OF Tb IN RAPIDLY SOLIDIFIED Ag-Tb ALLOY

The 0,05—0.08 mm thick splat foils of Ag-Tb alloy,containing Tb up to 10 at.-%,were made by the hammer-anvil technique.The cooling rate was in order of 10~6 K/s.The metastable extension of solid solubility of Tb in the alloy was measured to be up to 5 at.-% by lattice parameter method.The secondary phase in metastable eutectic structure was identi- fied as Ag_3Tb from diffraction pattern.The microstructure and micro-defect in as-quenched Ag-Tb splat foil were also observed.

FACTORS INFLUENCING SOLID SOLUBILITIES OFRARE-EARTHS IN Pd

A parameter describing the solid solubilities of mre-earths in Pd, Nf/aX(TR - rPd),was proposed, where N is the fshell filled electron nutnben △X the electronegativity dtherence between Palladium and rare-earths, rR the atotnic radii of rare-earth elementand rPd of Pd. The marimum solid solubilities are linear relation to this parnmeterexcept La, Nd and Ce.

RELATIONSHIP BETWEEN METASTABLE EXTENSION OF SOLID SOLUBITY OF EUTECTIC SYSTEMS AND PHASE DIAGRAM

A criterion of the metastable extension of solid solubility was proposed.When the eutectic concentration arm ratio parameter of an alloy,J>10,the hypereutectic extension and the metastable solid solubility limit beyond eutectic concentration may be obtained.When J≤10, the hypoeutectic extension may be obtained.The extension parameter,C_(eq)~s/C_(cu),is directly proportional to the parameter J.Thus,it seems easy to predict the tendency of the solid solu- hility extension under rapid solidification on the basis of the eutectic phase diagram.

Description and Prediction of the Solid Solubilities of Binary Alloys Based on the Actinide Metals

The solid solubilities of 207 binary alloys based on the three actinide metals (Th, U and Pu) at room tem- perature are studied with the two theoretical schemes suggested by one of the present authors (ZBW).The re- sults show that the soluble elements can be distinguished from the insoluble ones by a parabola y_1=a--bx^2 or an ellipse (x_2,-m)~2/c^2+(y_2-n)~2/d^2=l with the total reliabilities of 87.9% and 92.3% respectively for the 207 binary alloys. The contants a and b in the parabola equation, and c, d, m and n in the ellipse equation can be related to some appropriate parameters for each host metal respectively. The reasons are discussed. From the theories the soluble elements in these actinide host metals that have not been measured yet can be predicted in the accuracies of the schemes.

Application Fourier transform near infrared spectrometer in rapid estimation of soluble solids content of intact citrus fruits

Nondestructive method of measuring soluble solids content (SSC) of citrus fruits was developed using Fourier transform near infrared reflectance (FT-NIR) measurements collected through optics fiber. The models describing the relationship between SSC and the NIR spectra of citrus fruits were developed and evaluated. Different spectra correction algorithms (standard normal variate (SNV), multiplicative signal correction (MSC)) were used in this study. The relationship between laboratory SSC and FT-NIR spectra of citrus fruits was analyzed via principle component regression (PCR) and partial least squares (PLS) re- gression method. Models based on the different spectral ranges were compared in this research. The first derivative and second derivative were applied to all spectra to reduce the effects of sample size, light scattering, instrument noise, etc. Different baseline correction methods were applied to improve the spectral data quality. Among them the second derivative method after baseline correction produced best noise removing capability and yielded optimal calibration models. A total of 170 NIR spectra were acquired; 135 NIR spectra were used to develop the calibration model; the remaining spectra were used to validate the model. The developed PLS model describing the relationship between SSC and NIR reflectance spectra could predict SSC of 35 samples with correlation coefficient of 0.995 and RMSEP of 0.79 °Brix.

Measurement of soluble solids content in watermelon by Vis/NIR diffuse transmittance technique

Watermelon is a popular fruit in the world with soluble solids content （SSC） being one of the major characteristics used for assessing its quality. This study was aimed at obtaining a method for nondestructive SSC detection of watermelons by means of visible/near infrared （Vis/NIR） diffuse transmittance technique. Vis/NIR transmittance spectra of intact watermelons were acquired using a low-cost commercially available spectrometer operating over the range 350-1000 nm. Spectra data were analyzed by two multivariate calibration techniques： partial least squares （PLS） and principal component regression （PCR） methods. Two experiments were designed for two varieties of watermelons [Qilin （QL）, Zaochunhongyu （ZC）], which have different skin thickness range and shape dimensions. The influences of different data preprocessing and spectra treatments were also investigated. Performance of different models was assessed in terms of root mean square errors of calibration （RMSEC）, root mean square errors of prediction （RMSEP） and correlation coefficient （r） between the predicted and measured parameter values. Results showed that spectra data preprocessing influenced the performance of the calibration models. The first derivative spectra showed the best results with high correlation coefficient of determination [r=0.918 （QL）; r=0.954 （ZC）], low RMSEP [0.65 °Brix （QL）; 0.58 °Brix （ZC）], low RMSEC [0.48 °Brix （QL）; 0.34°Brix （ZC）] and small difference between the＇RMSEP and the RMSEC by PLS method. The nondestructive Vis/NIR measurements provided good estimates of SSC index of watermelon, and the predicted values were highly correlated with destructively measured values for SSC. The models based on smoothing spectra （Savitzky-Golay filter smoothing method） did not enhance the performance of calibration models obviously. The results indicated the feasibility of Vis/NIR diffuse transmittance spectral analysis for predicting watermelon SSC in a nondestructive way.

Experimental measurement and thermodynamic modeling of binary and ternary solid–liquid phase equilibrium for the systems formed by L-arabinose,D-xylose and water

Solid–liquid phase equilibrium data for binary(L-arabinose–water) and(D-xylose–water) systems at temperatures from(269.85–298.05) K and ternary(L-arabinose–D-xylose–water) system at temperatures of 273.85 K,278.85 K and 284.45 K were measured at atmospheric pressure.The ternary phase diagrams of the systems were constructed on the base of the measured solubility.Two pure solid phases were formed at given temperatures,including pure L-arabinose and pure D-xylose,which were con firmed and determined by the method of Schreinemakers' wet residue.At the same temperature,the crystallization region of L-arabinose was larger than D-xylose's.The acquired solubility data were then correlated using the NRTL model,Wilson model and Xu model.The calculated solubility with the three models agreed well with the experimental values.

Nondestructive determination of soluble solids and firmness in mix-cultivar melon using near-infrared CCD spectroscopy

Nondestructive evaluation of melon quality is in great need of comprehensive study.Soluble solids content(SSC)and firmness are the two indicators of melon internal quality that mostly a®ect consumer acceptance.To provide guidance for fruit classification,internal quality standards was preliminarily established through sensory test,as:Melon with SSC over 12
Brix,firmness 4–5.5 kgf·cm^(-2)2 were considered as satisfactory class sample;and SSC over 10
Brix,¯rmness 3.5–6.5 kgf·cm^(-2) as average class sample.The near infrared(NIR)nondestructive detection program was set as spectra collected from the stylar-end,Brix expressed by the average SSC of inner and outer mesocarp,each cultivar of melon was detected with its own optimum integration time,and the second derivative algorithm was used to equalize them.Using wavelength selected by genetic algorithms(GA),a robust SSC model of mix-cultivar melon was established,the root mean standard error of cross-validation(RMSECV)was 0.99 and the ratio performance deviation(RPD)nearly reached 3.0,which almost could meet the accuracy requirement of 1.5
Brix.Firmness model of mix-cultivar melon was acceptable but inferior.

Online quantitative analysis of soluble solids content in navel oranges using visible-nearinfrared spectroscopy and variable selection methods

Variable selection is applied widely for visible-near infrared(Vis-NIR)spectroscopy analysis of internal quality in fruits.Different spectral variable selection methods were compared for online quantitative analysis of soluble solids content(SSC)in navel oranges.Moving window partial least squares(MW-PLS),Monte Carlo uninformative variables elimination(MC-UVE)and wavelet transform(WT)combined with the MC-UVE method were used to select the spectral variables and develop the calibration models of online analysis of SSC in navel oranges.The performances of these methods were compared for modeling the Vis NIR data sets of navel orange samples.Results show that the WT-MC-UVE methods gave better calibration models with the higher correlation cofficient(r)of 0.89 and lower root mean square error of prediction(RMSEP)of 0.54 at 5 fruits per second.It concluded that Vis NIR spectroscopy coupled with WT-MC-UVE may be a fast and efective tool for online quantitative analysis of SSC in navel oranges.

Organic Manures Improved the Phenolic Content, Antioxidant Capacity and Soluble Solids in Pepper

The aim of this research was to determine the effect of three organic manures (vermicompost, simple compost, compost with gypsum) with four different levels, as sources of fertilization, and mixed with river sand, this was used as an inert material, on the phenolic content, antioxidant capacity and total soluble solids of bell peppers (Capsicum annuum L.). The 12 mixtures formulated, with eight replications, were distributed in a completely randomized design. Data were statistically analyzed by analysis of variance and means were compared by test Tukey5%. All variables were significantly affected (p ≤ 0.001). Fruits with highest phenolic content were developed in the mixtures M2, M5 and M6 with 538.76, 541.54 and 565.04 mg GAE·100 kg-1 DW, respectively. Antioxidant capacity of fruits was increased with mixtures M2, M5, M6 and M7 with values of 934.48, 942.04, 921.69 and 924.17 μM TEAC·g-1 DW, respectively. The soluble solids content was higher in mixtures M1 and M2 with values of 4.93 and 4.97 °Brix, respectively. It was concluded that the variables studied were favored when applying, as sources of fertilization, mixtures of these organic manures with river sand, which could represent a suitable alternative for food production with quality nutraceutical.

Effect of compound treatment of rotating magnetic field and Al-5Ti-1B refiner on microstructure and properties of Al-5Cu alloy

The Al-5Cu alloys were prepared by different treatment methods,including adding a refiner Al-5Ti-1B,exerting a rotating magnetic field(RMF),and compound treatment of both refiner and RMF.The effects of treatment methods on the microstructure,properties,and solid solubility of the Al-5Cu alloy were investigated.The optimal magnetic field parameters and addition amount of refiner were confirmed by experiment.Results show that either RMF or adding refiner Al-5Ti-1B alone can refine the grain size,and the refining effect can be further improved by a compound refining treatment with optimized magnetic field parameters(120 A current and 8 Hz frequency) and 1.0wt.% Al-5Ti-1B refiner(RMF*+Al-5Ti-1B*).The average grain size is decreased to 68.1 μm,which is 60.8%,21.1%,and 83.5% lower than that of the alloy treated by the optimized rotating magnetic field,the Al-5Ti-1B refiner,and the alloy without any treatment,respectively.The tensile strength and elongation of the alloy reach 232.5 MPa and 18.6%,respectively,which are obviously higher than those of the alloys treated by rotating magnetic field,Al-5Ti-1B refiner,and the alloy without any treatment,respectively.Additionally,the solid solubility of the alloy is also obviously improved compared to the alloys treated by other methods.

Improved microwave dielectric properties of MgAl_(2)O_(4)spinel ceramics through(Li_(1/3)Ti_(2/3))^(3+)doping

A series of nominal compositions MgAl_(2-x)(Li_(1/3)Ti_(2/3))_(x)O_(4)(x=0,0.04,0.08,0.12,0.16,and 0.20)ceramics were successfully prepared via the conventional solid-state reaction route.The phase compositions,microstructures,and microwave dielectric properties were investigated.The results of x-ray diffraction(XRD)and scanning electron microscopy(SEM)showed that a single phase of MgAl_(2-x)(Li_(1/3)Ti_(2/3))_(x)O_(4)ceramics with a spinel structure was obtained at x≤0.12,whereas the second phase of MgTi_(2)O_(5)appeared when x>0.12.The cell parameters were obtained by XRD refinement.As the x values increased,the unit cell volume kept expanding.This phenomenon could be attributed to the partial substitution of(Li_(1/3)Ti_(2/3))^(3+)for Al^(3+).Results showed that(Li_(1/3)Ti_(2/3))^(3+)doping into MgAl_(2)O_(4)spinel ceramics effectively reduced the sintering temperature and improved the quality factor(Q_f)values.Good microwave dielectric properties were achieved for a sample at x=0.20 sintering at 1500℃in air for 4 h:dielectric constantε_(r)=8.78,temperature coefficient of resonant frequencyτ_(f)=-85 ppm/℃,and Q_(f)=62300 GHz.The Q_(f)value of the x=0.20 sample was about 2 times higher than that of pure MgAl_(2)O_(4)ceramics(31600 GHz).Thus,MgAl_(2-x)(Li_(1/3)Ti_(2/3))_(x)O_(4)ceramics with excellent microwave dielectric properties can be applied to 5G communications.

Influence of high magnetic field on as-cast structure of Cu-25wt.%Ag alloys

To investigate the influence of high magnetic field (HMF) on the solidification microstructure of Cu-25wt.%Ag alloy, the Cu-25wt.%Ag alloy was prepared under HMF of 12 T, and for comparison, the alloy solidified without HMF was also fabricated. Macro and microstructures of the alloys were observed using the stereomicroscope, and scanning electron microscope, field emission scanning electron microscopy. The weight percentages of the pro-eutectic and eutectic, Cu phase and Ag phase in eutectic, and precipitates of Ag phase in pro-eutectic were analyzed by using of IPP software. Results show that the morphology of the column dendrites changes into cellular dendrites and the grains are refined under HMF of 12 T. Meanwhile, the thickness of the eutectic wall increases, but the sizes of Cu phase and Ag phase and the eutectic lamellar spacings are decreased. The Ag precipitates in the Cu matrix become coarser and sparser. The weight percentage variation of the phases in the microstructure and the Cu-Ag binary phase diagram reveals that the eutectic point moves to the left of the eutectic point in the equilibrium condition and the supersaturated solid solubility of Ag decreases under HMF.

Effects of Mechanical Alloying Parameters on the Microstructures of Nanocrystalline Cu-5 wt% Cr Alloy

Nanocrystalline Cu-5 wt%Cr alloy powders were fabricated by mechanical alloying （MA）, The effects of MA processing parameters on the crystallite size, solid solubility, and microstructures of the Cu- 5 wt%Cr alloys were investigated including type and size distribution of the grinding medium and ball-topowder weight ratio （BPR）. The results show that the crystallites were refined effectively and solid solubility of Cr in Cu was extended when heavier ball and higher BPR were adopted. The maximum solubility is extended up to 5.6 at% （namely 4.6 wt%） Cr in Cu by use of a combination of large and small size WC-Co balls with BPR of 30：1. A Cn-5 wt%Cr supersaturated solid solution alloy bulk is obtained by spark plasma sintering the as-milled powders at 900 ℃ for 5 min.

Mechanical Alloying of Ag-Cu Immiscible Alloy System

Mechanical alloying has been performed in Ag-Cu immiscible alloy system with five different compositions. X-ray diffraction analysis was carried out to determine the structural characterization of the milled powders. Lattice constants of the milled powders were determined and the solubility for Ag in Cu was calculated. The results demonstrated that MA indeed produced a face center cubic (f.c.c.). Cu-based Cu-Ag solid solution and the solid solubility has been extended to x(Ag)=30% for Ag in Cu when the grain size of Cu-based Cu-Ag solid solution is about 10 nm after MA. There is a three-phases co-existence during the process of MA in this alloy system which agrees well with other experimental and theoretical results. Based on the experimental results a formation model was proposed in this paper to understand the formation of Ag-Cu solid solution during MA.

Coupling physics in machine learning to investigate the solution behavior of binary Mg alloys

The solution behavior of a second element in the primary phase(α(Mg))is important in the design of high-performance alloys.In this work,three sets of features have been collected:a)interaction features of solutes and Mg obtained from first-principles calculation,b)intrinsic physical properties of the pure elements and c)structural features.Based on the maximum solid solubility values,the solution behavior of elements inα(Mg)are classified into four types,e.g.,miscible,soluble,sparingly-soluble and slightly-soluble.The machine learning approach,including random forest and decision tree algorithm methods,is performed and it has been found that four features,e.g.,formation energy,electronegativity,non-bonded atomic radius,and work function,can together determine the classification of the solution behavior of an element inα(Mg).The mathematical correlations,as well as the physical relationships among the selected features have been analyzed.This model can also be applied to other systems following minor modifications of the defined features,if required.