Critical Systematic Evaluation and Thermodynamic Optimization of the Fe-RE System: RE = Gd,Tb, Dy,Ho, Er,Tm, Lu,and Y

As the second part of the thermodynamic study of binary Fe-RE system, critical evaluations and optimizations of all available phase diagrams and thermodynamic data for the Fe-heavy RE (heavy RE = Gd, Tb, Dy, Ho, Er, Tm, Lu, and Y) systems were conducted to obtain reliable thermodynamic functions of all the phases in the systems. In the thermodynamic modeling of the heavy RE systems, systematic variations in the phase diagrams and thermodynamic properties such as the enthalpy of mixing in the liquid state and enthalpy of formation of solid compounds with the atomic number of lanthanide series were observed. These systematic trends were incorporated in the optimization of the Fe-heavy RE system to resolve inconsistencies between available experimental data and to estimate unknown thermodynamic properties. The systematic trends in thermodynamic properties of solid and liquid phases and phase diagram of the entire Fe-RE systems were summarized.     

Cleavage nature,electrokinetics,aggregation and dispersion of kaolinite

1　INTRODUCTIONKaoliniteiscurrentlyusedinceramics ,papermanufacturing ,medicalapplications ,agriculturalchemicals ,chemicalengineering ,refractorymaterialanddefenseindustrybecausekaolinitehasmanyhighprocessingpropertiesasanindustrialmineralduetoitssurfaceproperties[1,2 ] .Inreverseflotationofdi asporicbauxite ,whichisveryimportantforthein dustryofaluminumoxideproduction ,kaoliniteisneededtoberemoved .Therefore ,Itisusefultoun derstandthecrystalstructure ,cleavagenature ,sur faceelectrokin…     

Thermodynamic properties and mixing thermodynamic parameters of Ba-Al, Mg-Al, Sr-Al and Cu-Al metallic melts

Application of equations of mixing thermodynamic parameters formulated on the basis of the coexistence theory of metallic melts in Ba-Al, Mg-Al, Sr-Al and Cu-Al melts leads to fruitful results that not only the evaluated mass action concentrations agree well with the measured activities, but also the calculated mixing thermodynamic parameters are quite coincident with the experimental values. Moreover, the calculated mass action concentrations strictly obey the mass action law. The evaluated mixing thermodynamic parameters have very fine regularity: the mixing free energy is composed of standard free formation energies of all compounds and chemical potentials of all structural units at equilibrium; the mixing enthalpy consists of standard formation enthalpies of all compounds; the mixing entropy is composed of standard entropies of all compounds and configuration entropies of all structural units at equilibrium. As the equations of mixing thermodynamic parameters formulated are widely applicable to metallic melts involving compound formation, they can be used as the second practical criterion to determine whether thermodynamic models of metallic melts are correctly formulated.     

Syntheses, characteristics, and fluorescence properties of complexes of europium with benzoic acid and its derivatives

The binary complexes of europium with benzoic acid and its derivatives (phthalic acid, m-phthalic acid,o-aminobenzoic acid, salicylic acid, and sulfosalicylic acid) were synthesized and their compositions were identified by elemental analyses. UV and IR of the complexes have been investigated. The UV spectra indicated that the complexes‘ ultraviolet absorption were mainly the ligands‘ absorption. The IR spectra showed that the IR spectra of complexes are different from those of free ligands. The fluorescence properties of them were investigated by using luminescence spectroscopy, the results showed that only three complexes appear as better luminescence, they were Eu-benzoic acid,Eu-m-phthalic acid and Eu-phthalic acid, while the others exhibited the ligands‘ wideband emission.     

Tantalum—processing,properties and applications

Tantalum— the Earth’s 49th most abundant element— is frequently produced as a by-product of tin smelting. The metal is also extracted from concentrates by reduction with sodium or fused-salt electrolysis; tantalum carbide is produced by carburization of Ta₂O₅ or tantalum hydride. Sintering, electric-arc melting and electron-beam melting are used to refine and purify raw tantalum. Tantalum’s unique properties make it suitable for a number of diverse applications, including capacitors, chemical equipment, hard-metal tooling and alloys. Tantalum consumption is expected to increase in the capacitor market, because of the demand for electronics equipment.     

Synthesis, characterization, and biological activities of Pt(Ⅱ) and Pd(Ⅱ2'''',3'''',4'''',5,7-pentahydroxy flavone

Pt(Ⅱ) and Pd(Ⅱ) complexes with 2',3',4',5,7-pentahydroxy-flavone were synthesized and characterized by elemental analysis, molar conductance, IR, 1HNMR, TG-DTA, UV-Vis spectroscopic techniques, and fluorescence analysis. The scavenging effect on the superoxide radical (O2- ) and the inhibitory effect on lipid peroxides were also investigated. Both the ligand and the complexes exhibit scavenging effect on superoxide radicals, and the effect of the complexes is greater than that of the ligand. The Pt(Ⅱ) complex exhibits the strongest scavenging efficiency. Both Pt(Ⅱ) and Pd(Ⅱ) complexes have the inhibitory effect on lipid peroxides, and the effect of the complexes is greater than that of the ligand, but the Pt(Ⅱ) complex has a high effect of promoting lipid peroxides.     

Electronic structures and physical properties of pure Cr,Mo and W

1　INTRODUCTIONIntheframeworkofthemetallicmaterialssys tematicscience[1] ,therearethreescientifictheorysystems :puremetalsystematicscience ,alloysphysicsandchemistry ,andalloysstatisticalthermodynamics .Thecoreofthepuremetalsystema ticscienceistheoneatomtheory (OA ) [2 5] ,andthatofthealloysphysicsandchemistryandalloysstatisticalthermody namicsisthecharacteristiccrystaltheory(CC) .Inordertomakethematerialsdesignstepfromempiricaltoscientificundertheguidanceofthemetallicmateri alssystemati…     

Synthesis of NiMoO4 nanoparticles by sol–gel method and their structural,morphological, optical,magnetic and photocatlytic properties

Nickel molybdate (NiMoO₄) nanoparticles (NPs) were synthesized by sol–gel method. Utilizing water as solvent provides crystalline nanostructures. These nanocrystals were structurally characterized by X-ray diffraction, energy dispersive X-ray analysis (EDX), and Fourier transform infrared spectra. Compositional stoichiometry was confirmed by EDX technique. The size and shape were observed by scanning electron microscopy (SEM) and transmission electron microscope (TEM). It was found that the obtained NPs were pure and single phase crystalline with monoclinic structure. The optical properties were studied by ultraviolet–visible diffuse reflectance spectroscopy (UV–Vis–DRS) and photoluminescence (PL) measurements at room temperature. The magnetic properties were studied by vibrating sample magnetometer (VSM) and results showed superparamagnetic behavior of the obtained nanoparticles. Photocatalytic activity of NiMoO₄ was studied. The photocatalytic activity of NiMoO₄ was enhanced with the addition of TiO₂. The catalysts NiMoO₄, TiO₂ and NiMoO₄–TiO₂ nanocomposites (NC) were tested for photocatalytic degradation (PCD) of 4-chlorophenol (4-CP). It was found that PCD efficiency of NiMoO₄–TiO₂ NC was higher than that of pure NiMoO₄ and TiO₂.     

Investigation of Nanometer- and Submicron-Size Dispersed Phases in Titanium Pseudo- β -Alloys using Scattering and Diffraction of Neutrons,Electrons, and X-Ray Radiation

Metal Science and Heat Treatment - The size and volume fraction of fine particles of secondary β -phase formed during hardening heat treatment of pseudo-β-titanium alloy VT22 are...     

Synthesis,structure, and properties of a bentonite–magnetite composite

A bentonite–magnetite composite is obtained by means of bentonite intercalation with iron oxide Fe₃O₄. Using the methods of electron microscopy, low-temperature nitrogen vapor adsorption–desorption, and XRD phase analysis, the composite morphology, structure, and texture have been investigated. It is shown that the synthesized bentonite–magnetite composite can be used as a sorbent for wastewater purification from organic pollutants.     

Recent progress in the determination of gallium, indium, and thallium

This mini-review covers the literatures of the determination of gallium, indium, and thallium by instrumental analysis with computer-assisted searching over the period of 1994 to 2003. Some papers appearing in the early of 2004 are also included. Because the rapid progress in the instnLment has been made, these new papers are prioritized in selection in the similar papers. The contents are considered to be separation and preconcentration, spectrophotometry, spectrofluorimetry,electroanalyses, atomic absorption spectrometry, inductively coupled plasma-atomic emission spectrometry, inductively coupled plasma-mass spectrometry and so forth.     

Thermodynamic Assessments of Ternary Ga-As-P,Ga-P-Sb,In-As-P and In-P-Sb Systems

1 ＩｎｔｒｏｄｕｃｔｉｏｎＭｕｃｈａｔｔｅｎｔｉｏｎｈａｓｂｅｅｎｐａｉｄｔｏⅢ Ⅴｓｅｍｉｃｏｎｄｕｃｔｏｒｃｏｍｐｏｕｎｄｓｆｏｒｄｅｃａｄｅｓｂｅｃａｕｓｅｏｆｔｈｅｉｒｉｍｐｏｒｔａｎｔａｐｐｌｉｃａｔｉｏｎｓｉｎｏｐｔｏｅｌｅｃｔｒｏｎｉｃａｎｄｈｉｇｈｓｐｅｅｄｅｌｅｃｔｒｏｎｉｃｄｅ ｖｉｃｅｓ .Ｔｈｅｍａｔｅｒｉａｌｓｏｒｄｅｖｉｃｅｓｃａｎｂｅｇｒｏｗｎｂｙｌｉｑｕｉｄｐｈａｓｅｅｐｉｔａｘｙ (ＬＰＥ ) ,ｃｈｅｍｉｃａｌｖａｐｏｒｄｅｐｏｓｉｔｉｏｎ(ＣＶＤ) ,ｍｏｌｅｃｕ ｌａｒ…     

Structure,nitridation efficiency and magnetic properties of SmFe powders and its nitrides

The effect of annealing temperature(TA) at600-900℃ on structure and magnetic properties of the melt-spun Sm_8.6Fe_85.9Co_4.3Zr_1.2 alloys and its nitrides was investigated.Results show that the melt-spun powder is TbCu7-type SmFe₉ single phase.X-ray diffractometer(XRD) Rietveld refinement shows that the lattice parameter a increases,c and c/a decrease with the increase in T_A at600-700℃.This is due to the tendency of nitrogen entering ...     

Heat Treatment and Properties of Nitrogen Alloyed, Martensitic, Corrosion-resistant Steels

This paper gives a short introduction to the typical process route and material properties of these steels in comparison to standard martensitic corrosiun-resistant steels. The typical response of these steels to various heat treatment parameters is shown and explained using the three grades M333, N360 and M340 (all made by Boehler Edelstahl GmbH) as examples, and the physical metallurgy of these steels and its consequences for practical heat treatment is explained. The correlation between tempering parameters and their effect on the toughness and corrosion properties is explained in particular detail, showing that these new steels not only offer far better properly combinations under the usual heat treatment parameters than standard martensitic corrosion-resistant steels, but that they also open the door to extending heat treatment combinations and properties.     

Texture and stretch formability of rolled Mg-Zn-RE （Y, Ce, and Gd） alloys at room temperature

To develop a new magnesium alloy with excellent formability at room temperature, the effect of Y, Ce, and Gd addition on texture and stretch formability of Mg-1.5Zn alloys was carried out. The result shows that Y, Ce, and Gd addition in Mg-1.5Zn alloys can effectively weaken and modify the basal plane texture, characterized by TD-split texture in which the position of basal is titled from normal direction （ND） toward transverse direction （TD）. When Mg-1.5Zn alloy with Gd addition appears low texture intensity and TD-split texture, where the position of basal poles is tilted by about 4-35° from ND toward to TD, the largest Erichsen value of 7.0 and the elongation rate reaches 29.1% in TD direction. However, Y and Ce addition in Mg-1.5Zn alloys promote a large number of second phase particles, which cancel the contribution of the unique basal texture to stretch formability and ductility.     

Structural, elastic and electronic properties for M2XC （M--Ti and Cr, X--Ga and A1） phases from ab initio calculations

The first-principles study of the structural, elastic and electronic properties of the M 2 XC phases depending on the type of M transition metal (M are Ti and Cr) and on X (X are Ga and Al) was reported. The calculations are performed using the pseudo-potential plane-wave approach in both the local density and generalized gradient approximations. The elastic constants are calculated using the static finite strain technique. Features such as structural and elastic parameters, Debye temperature, sound velocities and their pressure dependence have been investigated. In agreement with experimental and previous theoretical findings, it is found that the compressibility along a and c axis depends on the valence electron concentration (VEC). Correlations revealing the governing role of the X and M elements on the machinability indices of the material have been examined. The electronic properties have been discussed in terms of chemical bonding showing that bonding is due to Md-Cp and Md-Xp hybridizations. M-C bonds are stiffer than M-X ones and Al-Ti (Cr-C) bonds are stiffer than those corresponding to Ti-C (Al-Cr). It is shown that the stiffness of the M-X and M-C bonds increases with increasing the number of VEC.     

Synthesis,luminescent properties,and theoretical study of novel Sm~(3+) and Dy~(3+) complexes containing β-diketone and 1,10-phenanthroline

Two new ternary complexes of 1-(2-thienyl)-3-(p-phenylethynylphenyl)-1,3-propanedione (HTPP) and 1,10-phenanthroline (phen) with Sm³⁺ and Dy³⁺ were synthesized. The composition of the ternary complexes was characterized as Sm(TPP)₃phen and Dy(TPP)₃phen, respectively, by infrared (IR) spectra, chemical analysis, elemental analysis, and thermodynamic analysis. At room temperature, under UV light excitation, the Sm³⁺ and Dy³⁺ complexes exhibit characteristic emissions of the central ions. It is found that the fluorescence intensity of Sm(TPP)₃phen is stronger than that of Dy(TPP)₃phen. In order to explain this phenomenon, an accurate quantum chemistry calculation was carried out, and the result is in good agreement with the experiment data.     

The Friction and Wear Properties of CrN, Graphit-iC and Dymon-iC Coatings in Air and under Oil-lubrication.

NITRIDE COATINGS have always been the popularchoice for increasing the wear lifetime for industrialcomponents.TiN is the most widely accepted butrecently CrN has been gaining more interest due itsthermal stability and good performance in corrosiveenvironments.Knowledge of the tribologicalperformance of CrN coatings in dry and lubricatedconditions is still quite limited[1,2].Many authorshave studied the properties of diamond like carbon(DLC)films and how they perform in dry conditions[…     

Characteristics of Tungsten,Titanium,Rare-Earths and Antimony Mineral Resources of China

Large area of old basements ofmetamorphic volcanic series,andmagmatic and sedimentary rocks of differ-ent ages are existing in China.They are lo-cated at the junction of plates.Especially,China is rich in Mesozoic granite rockswhich are closely related to nonferrousmetals ore deposits,and favourable for theformation of tungsten,titanium,rare—earths and antimony ore deposits.Tungsten and antimony ores of Chinaare world famous.Titanium andrare—earths ores have now caught up andsuroassed the two firsts.Geological pros-     

Review Recent progress in the determination of gallium, indium, and thallium

This mini-review covers the literatures of the determination of galliumindiumand thallium by instrumental analysis with computer-assisted searching over the period of 1994 to 2003. Some papers appearing in the early of 2004 are also included because the rapid progress i nthe instrument has beeen made these new papers are peioritized in selecton in the simiar papers the contents sre considered to be separation and preconcentra sepectrophotomaetry electroanalyses atomic absorption spectrometry inductively coupled plasma-atomic emission spectrometry inductively coupled plasma-mass spectrometry and so forth