基于卷积神经网络图像分类的轴承故障模式识别

针对传统的基于数据驱动的机械故障模式识别方法中需要人工构造算法提取特征以及人工构造特征提取算法繁琐的问题,结合卷积神经网络(CNN)在图像特征自动提取与图像分类识别中的广泛应用,提出了一种基于CNN图像分类的轴承故障模式识别方法。首先,利用集合经验模态分解(EEMD)方法对轴承振动信号进行自适应分解并用相关系数对得到的本征模函数分量进行筛选。其次,对筛选得到的本征模函数分量进行伪魏格纳-威利时频分析(PWVD)计算得到信号的时频分布图,并对时频图进行预处理。最后,将轴承15种不同工况预处理后的时频图利用CNN进行特征提取与分类识别。将该方法与同类方法进行了对比,分类正确率提高了4.26%。     

Photo- and thermoluminescence of BaGa2S4:Eu2+ and BaGa2S4:Eu2+,Ce3+ crystals

Data are presented on the photo- and thermoluminescence of polycrystalline BaGa₂S₄:Eu²⁺ and BaGa₂S₄:Eu²⁺, Ce³⁺ at temperatures from 77 to 300 K. The broad photoluminescence band at 505 nm in BaGa₂S₄:Eu²⁺ is shown to be due to the 4f ⁶5d → 4f ⁷ transition. The broad emission bands at 460 and 510 nm in BaGa₂S₄:Ce³⁺ arise from the 5D (² D _3/2) → 4f ²(² F _5/2) and 5D (² D _3/2) → 4f ²(² F _7/2) transitions. Codoping of BaGa₂S₄ with Eu²⁺ and Ce³⁺ increases the luminescence efficiency owing to energy transfer from Ce³⁺ to Eu²⁺. The thermoluminescence data were used to evaluate the energies of the traps involved: 0.26, 0.31, 0.42, 0.57, and 0.64 eV in BaGa₂S₄:Eu²⁺ and 0.28, 0.32, 0.54, 0.61, and 0.65 eV in BaGa₂S₄:Eu²⁺, Ce³⁺. Original Russian Text ? A.N. Georgobiani, B.G. Tagiev, S.A. Abushov, O.B. Tagiev, Zheng Xu, Suling Zhao, 2008, published in Neorganicheskie Materialy, 2008, Vol. 44, No. 2, pp. 151–155.     

Facile nano‐free electrochemiluminescence biosensor for detection of sulphamethoxazole via tris(2,2′‐bipyridyl)ruthenium(II) and N ‐methyl pyrrolidone recognition

The electrochemiluminescence (ECL) system based on the ruthenium complex has become a powerful tool in the field of analytical chemistry. However, the non‐aqueous ECL luminescence system, which does not involve complex nano‐modification, has not been widely used for the determination of analytes. In this study, N ‐methyl pyrrolidone was selected as the solvent, and it could also act as a co‐reactant of Rubpy32+. Based on this, a simple ECL system without nanomaterials was established. Strong ECL was generated. Furthermore, a quenching effect between the excited state of Rubpy32+ and sulphamethoxazole (SMZ) was observed. Based on this, a sensitive ECL sensor for detecting SMZ is constructed. A linear relationship between ECL signal quenching intensity (ΔI) and the logarithm of SMZ concentration (log C) in the concentration range of 1 × 10⁻⁷ –1 × 10⁻⁵ mol/l is obtained. The limit of detection is as low as 3.33 × 10⁻⁹ mol/l. The method has been applied to the detection of SMZ in tap water samples with different concentration levels with satisfactory results, and the recovery was 95.3–102.6%.Inspec keywords: biosensors, electrochemical sensors, electroluminescence, chemiluminescence, organic compounds, electrochemistryOther keywords: ruthenium complex, analytical chemistry, nonaqueous ECL luminescence system, complex nanomodification, quenching effect, ECL signal quenching intensity, ECL sensor system, nanofree electrochemiluminescence biosensor system, sulphamethoxazole detection, tris(2,2′‐bipyridyl)ruthenium(II), N‐methyl pyrrolidone recognition, analyte determination, nanomaterials, SMZ concentration detection     

Synthesis and Properties of Zn2TiO4–Zn2SnO4–ZnFe2O4 Solid Solutions

Zn₂TiO₄–Zn₂SnO₄–ZnFe₂O₄ mixed oxides are prepared by low-temperature hydrogen–oxygen plasma synthesis and solid-state reactions. Zn_{2 – x} (Ti _a Sn _b )_{1 – x} Fe_2x O₄ (a+ b = 1, x = 0–1.0) solid solutions are shown to have an inverted cubic spinel structure (sp. gr. Fd3m). The lattice parameter, electrical conductivity, band gap, and molar polarizability of about 100 samples are determined. With increasing Fe content, the lattice parameter, degree of spinel inversion, density, activation energy, and polarizability of the solid solutions decrease, while their conductivity rises.     

Self-doping Effects on the Superconducting Properties of Cu0.5Tl0.25M0.25Ba2Ca2Cu3O10−δ (M = Bi, Hg, Nb, Pd, Li, Na, K)

The effect of self-doping and substitution of elements of higher and lower electronegativity, such as Bi, Hg, Nb, Pd, Li, Na, K, on the superconducting properties of Cu_0.5Tl_0.5−x M _x Ba₂Ca₂Cu₃O_10−δ with x=0.25 is investigated. These experiments demonstrated that the elements of lower electronegativity such as Li, Na, and K can easily liberate their outer most s-electron that could be supplied to the conducting CuO₂ planes of Cu_0.5Tl_0.5−x M _x Ba₂Ca₂Cu₃O_10−δ superconductor, and as a result, we get enhanced superconducting properties. However, highly electro-negative elements hinder the transfer of carriers from charge reservoir layer to the conducting CuO₂ planes and promote inferior superconducting properties. In the present studies, we have investigated the effect of post-annealing in nitrogen and oxygen atmospheres for optimizing the carriers in conducting CuO₂ planes of Cu_0.5Tl_0.5−x M _x Ba₂Ca₂Cu₃O_10−δ (M=Bi,Hg,Nb,Pd,Li,Na,K) superconductor. These studies are important since the density of carriers in the conducting CuO₂ planes determines the Fermi-vector k _F and Fermi velocity v _F of the carriers, which ultimately brings about the final superconducting state of the system.      

Synthesis of biopolymeric particles loaded with phosphorus and potassium: characterisation and release tests

The authors synthesised nanoparticles (NPs) loaded with P and K from KH₂ PO₄ using gelatin type‐A and type‐B, and sodium alginate as carriers. Using type‐A and type‐B gelatin, quasi‐spherical particles were obtained, with average sizes of 682 and 856 nm, respectively; with sodium alginate, the resulting NPs exhibited spherical shapes and 600 nm particle average size. The authors found an interaction between KH₂ PO₄ and alginate via the hydrogen bonds existent among the carboxylic groups of the carbohydrate and the OH‐groups of the H₂ PO₄ ‐; interactions among gelatin types with the OH‐groups and the H₂ PO₄ ‐ion were also observed. Adding trypsin to the distilled water solutions of the NPs coated with type‐A gelatin increased the concentration of P in the solution by threefold, while increasing that of K increased by 2.6‐fold. Conversely, adding α ‐amylase to the water solutions with sodium alginate increased the P and K concentrations in the solution by nearly 1.3‐ and 1.1‐fold, respectively. Thus, sodium alginate resulted in NPs with smaller sizes and better spherical formations, though with a high polydispersity index and lower release rate of P and K. This low release rate represents an advantage since plants demand nutrients for long periods, and conventional fertilisers display low use efficiency.Inspec keywords: nanofabrication, nanoparticles, hydrogen bonds, gelatin, biomedical materials, particle size, enzymes, molecular biophysics, biochemistry, nanobiotechnology, polymer films, potassium compoundsOther keywords: sodium alginate, biopolymeric particles, release tests, type‐B gelatin, spherical shapes, carboxylic groups, OH‐groups, distilled water solutions, type‐A gelatin, quasi‐spherical particles, particle average size, hydrogen bonds, trypsin, spherical formations, high polydispersity index, plants, α‐amylase, size 682.0 nm, size 856.0 nm, size 600.0 nm, H₂ PO₄ , KH₂ PO₄      

Crystal structure and luminescent properties of europium-activated Ca10? x M x (PO4)6F2 (M = Pb, Mg) prepared via precipitation from aqueous solutions

Phase-pure polycrystalline fluorapatites with the general formula Ca_10−x M _x (PO₄)₆F₂:Eu³⁺(M = Pb, Mg) have been prepared by precipitation from aqueous solutions, and the effects of the Pb²⁺ and Mg²⁺ ions, differing markedly in ionic radius, on the structure, morphology, and luminescence spectra of the fluorapatites have been investigated. The Pb²⁺ and Mg²⁺ contents are shown to influence the Eu³⁺ distribution over inequivalent sites in the crystal structure of Ca_10−x M _x (PO₄)₆F₂. Original Russian Text ? N.V. Babayevskaya, Yu.N. Savvin, A.V. Tolmachev, 2007, published in Neorganicheskie Materialy, 2007, Vol. 43, No. 8, pp. 976–980.     

Synthesis of New Pb-Based 1222 Cuprates Containing Phosphorus, (Pb0.75P0.25)Sr2(RE2–x–y Ce x Sr y )Cu2O z (RE = Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, and Y)

New Pb-based 1222 cuprates containing phosphorus have been synthesized in the (Pb_0.75P_0.25)Sr₂- (RE_2–x–y Ce _x Sr _y )Cu₂O _z (RE = Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, and Y) systems. The almost-single phase samples are obtained for 0.5≤x≤1.0 and y=0.1 in the cases of RE = Nd, Dy, Ho, Er, Tm, Yb and Y, while for 0.3≤x≤1.0 and y=0.1 in the cases of RE = Sm, Eu and Gd. The samples crystallize in a tetragonal lattice, the lattice parameters a and c are decreasing with the decrease of the ionic radius of the RE element. Even after annealing under 143 atm O₂ atmosphere at 400 °C, almost all the samples with the common values x=0.5 and y=0.1 are semiconductors with a transport process followed by three-dimensional variable range hopping. However, the samples of RE = Sm, Eu and Gd, which are of almost single 1222 phase, even for x=0.3 and y=0.1, show superconductivity with the onsets at about 25 K, 20 K and 22 K, respectively. Through this study, we find very important procedure for discovery of new superconducting 1222 compound.     

Structural properties and kinetics of nitro-niobized steels

In the present study, structural characterization and kinetics of nitro-niobized AISI 1010, AISI D2, and AISI M2 steels by thermo-reactive deposition technique in the powder mixture consisting of ferro-niobium, ammonium chloride, and alumina at the temperatures of 1173, 1273, and 1373 K for 60–240 min were investigated. The thickness of the niobium nitride layers formed on the nitro-niobized AISI 1010, AISI D2, and AISI M2 steels are ranged from 2.80 ± 0.90 to 11.89 ± 1.10 μm, 3.16 ± 0.60 to 13.16 ± 1.51 μm, and 3.85 ± 0.91 to 16.77 ± 2.10 μm, respectively. The phases formed in the coating layer deposited on the surface of the steel substrates are NbN_0.95 and Nb₂CN. The hardness of the niobium nitride coating layers produced on AISI 1010, AISI D2, and AISI M2 steels are changing from 1151 ± 126 to 1446 ± 121 HV_0.005, 1359 ± 413 to 1594 ± 761 HV_0.005, and 1321 ± 51 to 1915 ± 134 HV_0.005, respectively. Diffusion constants of the coating layers were changing between 1.517 × 10⁻¹⁵ and 2.043 × 10⁻¹⁴ m²/s, depending on steel compositions, treatment time and temperatures, and activation energies of the AISI 1010, AISI D2, and AISI M2 steels for the process were calculated as 128.7, 123.8, and 132.5 kJ/mol, respectively. Moreover, an attempt was made to investigate the possibility of predicting the contour diagram of niobium nitride coating thickness variation, depending on process time and temperature.     

Thermally induced transformations in Ge x AsyTe100−x−y glasses

Chalcogenide glasses with compositions Ge_7.5As _y Te_92.5–y (y=20, 40, 45, 47.5, 50, 52.5, 55) and Ge₁₀As _y Te_90–y (y=15, 20, 22.5, 35, 40, 45, 50) have been prepared by the melt-quenching technique. The amorphous nature of these glasses has been confirmed by X-ray powder diffractometry. The thermal stability of these glasses has been studied using differential scanning calorimetry (DSC). The compositional dependence of the glass transition temperature,T _g, the crystallization temperatures,T _c1 andT _c2, and the melting temperature,T _m, are reported. The glass-forming tendency,K _gl, and the activation energy of crystallization,E, are calculated. The activation energy decreases with increasing tellurium content for both sets of glasses.     

Intense red-emitting phosphors for LED solid-state lighting

The phosphors Gd_2−xEu_x(MoO₄)₃ (x = 0.20, 0.40, 0.60, 0.80, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0), Gd_0.8−xY_xEu_1.2(MoO₄)₃ (x = 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8) and Gd_0.2Y_0.6−xEu_1.2Sm_x(MoO₄)₃ (x = 0.02, 0.024, 0.028, 0.032, 0.036, 0.04) were prepared by solid-state reaction technique at 950 °C. The presence of the Y³⁺ and Sm³⁺ ions strengthen and broaden the absorption of the phosphors at ∼400 nm. The intense red-emitting phosphor Gd_0.2Y_0.572Eu_1.2Sm_0.028(MoO₄)₃ with orthorhombic structure was obtained. Both Eu³⁺ and Sm³⁺ f-f transition absorptions are observed in the excitation spectra, the main emission line is at 616 nm (⁵D₀ → ⁷F₂ transition of Eu³⁺) and the chromaticity coordinates (x = 0.66, y = 0.33) is very close to the NTSC standard values (x = 0.67, y = 0.33). It is considered to be an efficient red-emitting phosphor for GaN-based light emitting diode (LED).     

Some evaluations of the elastic T-term using Eshelby's method

For some time now the elastic T-term has been proposed as a secondary biaxiality parameter, to be used in conjunction with the stress intensity factor, K _I, or the path independent integral J, as the primary parameter for the characterization of crack tip fracture states. At a recent conference a theorem due to Eshelby was presented [1]. The theorem provides a convenient method of calculating the T-term, obtained by evaluating appropriate J contour integrals. Examples of analytical, semi-analytical and numerical applications were included. Here, some additional finite element applications, using a fairly simple idealization, are presented in greater detail and comparison of the results of the different independent analyses available so far are made, giving further evidence of the practical utility of Eshelby's method. New results on double-edge notched specimens are also included.

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Résumé On a proposé depuis un certain temps déjà, que le terme T élastique soit considéré comme un paramètre de biaxialité secondaire, à utiliser de concert avec le factuer d'intensité de contraintes KI, on l'intégrale J, en tant que paramètre primaire, pour caractériser les états de la rupture à l'extrémité d'une fissure. Lors d'une conférence récente, on a présenté un théorème, dû à Eshelby, qui fournit une méthode commode pour calculer le terme T, obtenue par une évaluation des intégrales de contour J appropriées. On a inclu des exemples d'applications analytiques, semianalytiques et numériques. Dans la présente étude, on donne avec de plus amples détails quelques applications complémentaires des éléments finis, en utilisant une idéalisation assez simple, et l'on compare les résultats de diverses analyses disponibles jusqu'ici, ce qui convainc de l'utilité pratique de la méthode d'Eshelby.On inclut également des résultats nouveaux obtenus sur des éprouvettes à double entaille latérale.

     

Deposition of zirconium oxynitride films by reactive cathodic arc evaporation and investigation of physical properties

The area of metal oxynitrides is poorly explored, and understanding of the fundamental mechanism that explains structural, mechanical, electrical, and optical properties is still insufficient. Therefore, the purpose of the present investigation is to analyze structural, electrical, and optical properties of ZrN_xO_y films deposited by reactive cathodic arc evaporation.Depending on the oxygen flow, cubic ZrN:O, monoclinic ZrO₂:N, and tetragonal ZrO₂:N phases films were prepared. The sheet resistance and the optical transmittance very much depend on the oxygen flow. Optical transparent ZrN_xO_y films with transmittance of 86% at 650 nm, the sheet resistance 1.1 · 10³ Ω/sq, and the figure of merit 2 · 10^− 4 Ω^− 1 are deposited with the 60 sccm oxygen flow.     

Enhancing Superconductivity in Low-dimensional TlBa2Ca2Cu3O10?δ System

Mg-doped Tl(Ba_2?x Mg _x )Ca₂Cu₃O_10??? (x=0, 0.25, 0.50, 0.75, 1.0, 1.25, 1.5) superconductors are synthesized at the normal pressure and the possible mechanism of superconductivity in these compounds is studied. Tl(Ba_2?x Mg _x )Ca₂Cu₃O_10??? samples have shown an orthorhombic crystal structure and their c-axis length decreases up to Mg-doping of x=0.75 and then increases up to Mg-doping of x=1.50. In these studies we have investigated the role of decreased thickness of charge reservoir layer on the mechanism of superconductivity. The T _c (R=0) in as-prepared Tl(Ba_2?x Mg _x )Ca₂Cu₃O_10??? (x=0, 0.25, 0.5, 0.75, 1.0, 1.25) samples was 100, 98, 101, 102, 100, 96?K and in the oxygen post-annealed samples the T _c (R=0) is observed around 99, 98, 108, 127, 109, 97?K, respectively. The magnitude of the superconductivity after Mg-doping is improved in Tl(Ba_2?x Mg _x )Ca₂Cu₃O_10??? (x=0.25, 0.5, 0.75, 1.0, 1.25) samples. It was observed from the FTIR absorption measurements that the phonon modes related to CuO₂ planar oxygen atoms are hardened with the doping of Mg in the charge reservoir layer. These studies have shown that the thickness of charge reservoir layers decreases with Mg-doping, which most likely makes the charge transfer mechanism more efficient, which increases the magnitude of superconductivity in the final compound.     

Kationen-anionen-abstände in kupfer- und chrom-thiospinellen

The Cu- and Cr-thiospinels are divided in three groups on account of the cation-anion-distances. I. MeCr₂S₄ (Me = Cd, Co, Fe, Hg, Mn, Zn). II. CuMe₂S₄ (Me = Cr; Ti; V; Zr; Cr, Hf; Cr, Sn; Cr, Ti; Cr, Zr). III. CuMe₂S₄ (Me = Co, Rh). According to the model of Lotgering and van Stapele, these groups correspond to the valence distribution

$\text{+2+3+3}$

$\text{+1+3+4}$

$\text{+1+3+3?2?1}$

$\text{I. Me(CrCr)S}{}_4$

$\text{II. Cu(MeMe)S}{}_4$

$\text{III. Cu(MeMe)S}{}_3\text{S}$

     

Phase Relations in the Bi–Sr–Ca–Cu–M–O (M = Y, Dy, Ho, Er, Tm, Yb, Lu) Systems

The phase relations in the Bi–Sr–Ca–Cu–M–O (M = Y, Dy, Ho, Er, Tm, Yb, Lu) systems near Bi₂Sr₂CaCu₂O_{8+ x} (Bi-2212) were studied between 850 and 990°C. The results demonstrate that larger sized rare earths (Y, Dy, Ho, Er) substitute on the Ca site in Bi-2212, leading to the formation of CaO. Smaller sized rare earths (Tm, Yb, Lu) replace lesser amounts of Ca and form Sr₂MBiO₆phases. In the material of nominal composition Bi₂Sr₂Ca_0.85M_0.15Cu₂O_{8 + x} + 0.25Sr₂YBiO₆prepared via melt processing, a major fraction of the Y atoms substitute for Ca in Bi-2212, resulting in a low-T _cmultiphase superconductor. In the analogous Yb system, a Bi-2212–Sr₂YbBiO₆composite with T _c= 87 K is obtained.     

FSE–Ag complex NS: preparation and evaluation of antibacterial activity

Silver (Ag) complexes of drugs and their nanosystems have great potential as antibacterials. Recently, an Ag complex of furosemide (Ag–FSE) has shown to be a promising antimicrobial. However, poor solubility of Ag–FSE could hamper its introduction into clinics. Therefore, the authors developed a nanosuspension of Ag–FSE (Ag–FSE_NS) for its solubility and antibacterial activity enhancement. The aim of this study was to introduce a novel nanoantibiotic with enhanced antibacterial efficacy. Ag–FSE_NS was prepared by precipitation–ultrasonication technique. Size, polydispersity index (PI) and zeta potential (ZP) of prepared Ag–FSE_NS were measured by dynamic light scattering, whereas surface morphology was determined using scanning electron microscopy (SEM). In vitro antibacterial activity was evaluated against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa using broth microdilution method. Size, PI and ZP of optimised Ag–FSE_NS1 were 191.2 ± 19.34 nm, 0.465 ± 0.059 and −55.7 ± 8.18 mV, respectively. SEM revealed that Ag–FSE_NS1 particles were rod or needle‐like with smooth surfaces. Saturation solubility of Ag–FSE in NS increased eight‐fold than pure Ag–FSE. Ag–FSE_NS1 exhibited two‐fold and eight‐fold enhancements in activity against E. coli and S. aureus, respectively. The results obtained showed that developed Ag–FSE_NS1 holds a promise as a topical antibacterial.Inspec keywords: nanomedicine, nanofabrication, light scattering, surface morphology, silver, particle size, solubility, suspensions, scanning electron microscopy, electrokinetic effects, drugs, biomedical materials, antibacterial activity, microorganisms, nanoparticles, drug delivery systems, transmission electron microscopyOther keywords: saturation solubility, topical antibacterial, size 171.86 nm to 210.54 nm, voltage ‐47.52 mV to ‐63.88 mV, Ag, broth microdilution method, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, SEM, scanning electron microscopy, surface morphology, dynamic light scattering, particle size, polydispersity index, precipitation–ultrasonication technique, nanoantibiotic, nanosuspension, furosemide, nanosystems, drugs, Ag–FSE_NS preparation, in vitro antibacterial activity, pure Ag–FSE, Ag–FSE_NS1 particles, optimised Ag–FSE_NS1, zeta potential, enhanced antibacterial efficacy, antibacterials     

Electrical conductivity and dielectric permittivity of Bi5Nb3 ? 3 x M3 x O15 ? δ (M = Cr, Cu, Ni) solid solutions

Bi₅Nb_{3 − 3x} M_3x O_{15 − δ} (M — Cr, Cu, Ni) (M = Cr, Cu, Ni) layered perovskite-like solid solutions have been prepared by solid-state reactions. Increasing the solute content of the solid solutions gives rise to solute-dependent monoclinic distortion of their tetragonal cell. The electrical conductivity and dielectric permittivity of the Bi₅Nb_{3 − 3x} M_3x O_{15 − δ} solid solutions and bismuth niobate, Bi₅Nb₃O₁₅, have been measured at temperatures from 300 to 750 K and frequencies from 1 to 200 kHz. Original Russian Text ? N.A. Zhuk, I.V. Piir, 2008, published in Neorganicheskie Materialy, 2008, Vol. 44, No. 12, pp. 1504–1509.     

Superconductivity in transition metal-germanium systems

The variation in the superconducting properties of various binary alloys of the transition metal-germanium system was surveyed by studying sputter-deposited samples prepared under various conditions. Radiofrequency cosputtering was used to form samples of the form T _x Ge _1–x , where T represents a transition metal, Y, La, Ti, Zr, Hf, V, Nb, Ta, Mo, W, and Re. The primary interest has been to study the formation of A-15 compounds. While sputtered V ₃ Ge hadT _cs close to bulk sample values, Nb ₃ Ge (T _c=21.7 K) and Mo ₃ Ge (T _c=5.7 K) showed a considerable enhancement inT _c over the bulk values. The formation of the metastable A - 15 modification of Ta ₃ Ge, Ti ₃ Ge, Zr ₃ Ge, and Hf ₃ Ge was attempted, without success. Superconductivity was observed in samples of ZrGe ₂ , HfGe ₂ , YGe ₂ , and LaGe ₂ , the highestT _c being that of ZrGe ₂ (T _c=8.0 K). Annealing studies indicated that superconducting ZrGe₂ and HfGe₂ were metastable, depending on the conditions of synthesis. Superconductivity was also observed in mixtures of semiconducting Ge and metallic NbGe ₂ , the highestT _c observed being 16 K. Several explanations are considered to account for the observedT _cbehavior among the various alloys.Supported in part by the National Science Foundation.     

X-ray diffraction study of multicomponent oxides in the Zn2 ? x(TiaZrb)1 ? xFe2xO4 system

The multicomponent refractory oxide system Zn_{2 − x} (Ti _a Zr _b )_{1 − x} Fe_2x O₄ (a + b = 1; a: b = 1: 5, 1: 4, 1: 3, 1: 2, 1: 1, 2: 1, 3: 1, 4: 1; x = 0–1.0; Δx = 0.05) has been studied by X-ray diffraction, using samples prepared by melting appropriate metal oxide mixtures in a low-temperature hydrogen-oxygen plasma. Two phases, both with wide homogeneity ranges, have been identified: α-phase, with a cubic inverse spinel structure, and β-phase, with a tetragonal inverse spinel structure. The phase boundaries in the system have been determined. Structural data are presented for about 100 solid solutions.