Separation and determination of sulfur with different valance in polysulfide mixture

Ｔｈｅｐｏｌｙｓｕｌｆｉｄｅｍｉｘｔｕｒｅ ,ａｃｏｍｐｌｅｘｓｙｓｔｅｍｏｆｔｅｎｐｒｅｓｅｎｔｓｉｎｔｈｅａｑｕｅｏｕｓｃｏｎｄｅｎｓａｔｅｓｆｒｏｍｃｏａｌｌｉｑｕｅｆａｃｔｉｏｎｐｒｏｃｅｓｓｅｓ[1] ,ｓｕｃｈａｓｔｈｅｃｏｋｅｏｖｅｎａｍｍｏｎｉａｃａｌｌｉｑｕｏｒｓ ,Ｋｒａｆｔｐａｐｅｒｐｕｌｐｉｎｇｌｉｑｕｏｒｓ ,ａｎｄｓｕｌｆｉｄｅｅｌｅｃｔｒｏｌｙｔｅ[2 ] .Ａｎａｌｙｔｉｃａｌｄｅｔｅｒｍｉｎａｔｉｏｎｏｆｉｎｄｉｖｉｄｕａｌｐｏｌｙｓｕｌｆｉｄｅｓｐｅｃｉｅｓｉｎａｑｕｅｏｕｓ…     

Quantitative and comparative analysis of hyperspectral data fusion performance

0　ＩＮＴＲＯＤＵＣＴＩＯＮＨｙｐｅｒｓｐｅｃｔｒａｌｄａｔａａｎａｌｙｓｉｓｉｓｏｆｇｒｏｗｉｎｇｉｎｔｅｒｅｓｔａｓａｎａｐｐｒｏａｃｈｔｏｍｅｔｅｏｒｏｌｏｇｙ ,ｇｅｏｌｏｇｙ ,ｅａｒｔｈｒｅｍｏｔｅｓｅｎｓｉｎｇａｎｄｍｉｌｉｔａｒｙｓｕｒｖｅｉｌｌａｎｃｅ[1～ 5] .Ｃｏｍｐａｒｅｄｗｉｔｈｍｕｌｔｉｓｐｅｃ ｔｒａｌｉｍａｇｅｓ ,ｈｙｐｅｒｓｐｅｃｔｒａｌｉｍａｇｅｓｈａｖｅｈｕｎｄｒｅｄｓｏｆｂａｎｄｓ ,ｗｉｔｈａｖｅｒｙｓｍａｌｌｉｎｃｒｅｍｅｎｔｉｎｗａｖｅｌｅｎｇｔｈａｎｄｈｉｇ…     

Stress field analysis of extra-height forging die using finite element method

ＴｈｅｅｘｔｒａｈｅｉｇｈｔｆｏｒｇｉｎｇｄｉｅｉｎＳｏｕｔｈｅｗｅｓｔＡｌｕｍｉｎｉｕｍＦａｂｒｉｃａｔｉｏｎＰｌａｎｔｉｓａｓｐｅｃｉａｌｄｉｅｆｏｒｍａｋｉｎｇａｒｍａｍｅｎｔａｎｄｓｐｅｃｉａｌｃｉｖｉｌｐｒｏｄｕｃｔｓｉｎＣｈｉｎａ．Ａ...     

Dielectric mechanism in complex perovskite

Ｃｏｍｐｌｅｘｐｅｒｏｖｓｋｉｔｅｒｅｌａｘｏｒｆｅｒｒｏｅｌｅｃｔｒｉｃｓｉｓａｋｉｎｄｏｆｓｐｅｃｉａｌｄｉｅｌｅｃｔｒｉｃｍａｔｅｒｉａｌ.Ｃｏｍｐａｒｅｄｗｉｔｈｎｏｒｍａｌｆｅｒｒｏｅｌｅｃｔｒｉｃｓ,ｉｔｈａｓｓｐｅｃｉａｌｄｉｅｌｅｃｔｒｉｃｐｒｏｐｅｒｔｉｅｓ,ｅ.ｇ.ｔｈｅｄｉｆｆｕｓｅｐｈａｓｅｔｒａｎｓｉｔｉｏｎ(ＤＰＴ),ａｓｔｒｏｎｇｆｒｅｑｕｅｎｃｙｄｉｓｐｅｒｓｉｏｎｏｆｔｈｅｄｉｅｌｅｃｔｒｉｃｃｏｎｓｔａｎｔ,ｐｏｌａｒｉｚａｔｉｏｎｃｈａｎｇｉｎｇｗｉｔｈｔｅｍｐｅｒ…     

Sol-Gel Synthesis of Normal Spinel LiMn_2O_4 and Its Characteristics

1　ＩｎｔｒｏｄｕｃｔｉｏｎＮｏｒｍａｌｓｐｉｎｅｌＬｉＭｎ2 Ｏ4 ｐｏｓｓｅｓｓｅｓｓｐｅｃｉｆｉｃｍｅｍｏｒｙｅｆｆｅｃｔｆｏｒｌｉｔｈｉｕｍｉｏｎ .Ｍａｎｇａｎｅｓｅｉｓｒｉｃｈｉｎｎａｔｕｒａｌｒｅ ｓｏｕｒｃｅｓａｎｄｈａｓｎｏｐｏｌｌｕｔｉｏｎｔｏｔｈｅｅｎｖｉｒｏｎｍｅｎｔ .Ｅｘｔｒａｃ ｔｉｏｎｏｆｍｉｃｒｏ ｌｉｔｈｉｕｍｆｒｏｍｓｅａｗａｔｅｒａｎｄｓａｌｔ ｌａｋｅｂｒｉｎｅｂｙｌｉｔｈｉｕｍｍａｎｇａｎｅｓｅｏｘｉｄｅｉｓｒｅｇａｒｄｅｄａｓｔｈｅｍｏｓｔｐｒｏｓｐｅｃ ｔｉｖｅ…     

Ultraviolet-visible spectral properties of nanometer zinc oxide colloidal solution

1　ＩＮＴＲＯＤＵＣＴＩＯＮＳｉｎｃｅｔｈｅｅｎｄｏｆｌａｓｔｃｅｎｔｕｒｙ ,ｓｔｕｄｉｅｓｏｎｔｈｅ ｐｒｅｐａｒａｔｉｏｎａｎｄ ｐｒｏｐｅｒｔｉｅｓｏｆｎａｎｏｍｅｔｅｒｐａｒｔｉｃｌｅｓｈａｖｅａｔｔｒａｃｔｅｄａｌｏｔｏｆａｔｔｅｎｔｉｏｎ .Ｎａｎｏｍｅｔｅｒｚｉｎｃｏｘｉｄｅｗｉｔｈｓｏｍｅｓｐｅｃｉａｌｐｒｏｐ ｅｒｔｉｅｓｃｏｕｌｄｂｅｗｉｄｅｌｙｕｓｅｄｉｎｍａｎｙａｓｐｅｃｔｓ,ｓｕｃｈａｓａｕｔｏｍｏｂｉｌｅｉｎｄｕｓｔｒｙ ,ｓｕｎ ｐｒｏｏｆｃｏｓｍｅｔ ｉｃｓ,ｐｈｏｔｏｓｅｎ…     

Analysis of diffusion bond interface of TiAl base alloy with Ti, TC4 alloy and 40Cr steel

0　ＩＮＴＲＯＤＵＣＴＩＯＮＴｉＡｌｂａｓｅａｌｌｏｙｈａｓｓｕｃｈｇｏｏｄｆｅａｔｕｒｅｓａｓｌｉｇｈｔｓｐｅｃｉｆｉｃｇｒａｖｉｔｙ(ａｂｏｕｔ3.8ｇ/ｃｍ3),ｈｉｇｈｓｐｅｃｉｆｉｃｓｔｒｅｎｇｔｈ,ｇｏｏｄｓｔｉｆｆｎｅｓｓ,ｇｏｏｄｈｉｇｈｔｅｍｐｅｒａｔｕｒｅｍｅｃｈａｎｉｃａｌｐｒｏｐｅｒｔｉｅｓａｎｄｏｘｉｄａｔｉｏｎｒｅｓｉｓｔａｎｃｅ,ａｎｄｉｓｃｏｎｓｉｄｅｒｅｄｔｏｂｅａｎｉｄｅａｌｎｅｗｈｉｇｈｔｅｍｐｅｒａｔｕｒｅｓｔｒｕｃｔｕｒｅｍａｔｅｒｉａｌｗｉｔｈｐｏｔｅｎｔｉａｌａ…     

Characterization of 3D surface topography with spectral moments

0　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｓｔｏｃｈａｓｔｉｃｖａｒｉａｂｌｅｓ ,ｓｕｃｈａｓｐｏｗｅｒｓｐｅｃｔｒｕｍ ,ａｕｔｏ ｃｏｒｒｅｌａｔｉｏｎｆｕｎｃｔｉｏｎ ,ｓｔｒｕｃｔｕｒｅｆｕｎｃｔｉｏｎ ,ｓｐｅｃｔｒａｌｍｏ ｍｅｎｔａｎｄｓｏｏｎ ,ｈａｖｅｅｖｅｒｐｌａｙｅｄｋｅｙｒｏｌｅｓｉｎｃｈａｒａｃｔｅｒｉ ｚａｔｉｏｎｏｆｓｕｒｆａｃｅｒｏｕｇｈｎｅｓｓ[1,2 ] .Ｗｉｔｈｔｈｅａｒｅａｌｉｚａｔｉｏｎｏｆｓｕｒｆａｃｅｃｈａｒａｃｔｅｒａｎｄｔｈｅｅｍｅｒｇｅｎｃｅｏｆｍｉｃｒｏ ｎａｎｏｓｕ…     

An exploration of futurological architecture

1　ＦＵＴＵＲＯＬＯＧＹＦｕｔｕｒｏｌｏｇｙｓｔｕｄｉｅｓｔｈｅｅｆｆｅｃｔｏｆｍｏｄｅｒｎｉｎｄｕｓｔｒｙ ,ｓｃｉ ｅｎｃｅａｎｄｔｅｃｈｎｏｌｏｇｙａｎｄｉｎｆｏｒｍａｔｉｚａｔｉｏｎｏｆｓｏｃｉｅｔｙｏｎｖａｒｉ ｏｕｓａｓｐｅｃｔｓｏｆｔｈｅｓｏｃｉｅｔｙｉｎｔｈｅｆｕｔｕｒｅ .Ｉｔｉｓｕｓｅｄｔｏａｎａ ｌｙｚｅａｎｄｍａｋｅｐｒｅｄｉｃｔｉｏｎｓａｂｏｕｔｔｈｅｄｉｒｅｃｔｉｏｎｓｏｆｄｅｖｅｌｏｐ ｍｅｎｔｏｆｖａｒｉｏｕｓａｓｐｅｃｔｓｏｆｓｏｃｉｅｔｙａｎｄｌａｗｓｆｏｒｓｕｃｈｄ…     

Synthesis of Lithium-cobalt Oxides by Sol-gel Method and their Cathodical Discharge Behavior at 500 ℃

Ｌｉａｌｌｏｙｓ/ＦｅＳ2(ｏｒＣｏＳ2)ｔｈｅｒｍａｌｂａｔｔｅｒｉｅｓｈａｖｅｂｅｅｎｔｈｅｍｏｓｔｗｉｄｅｌｙｕｓｅｄｅｌｅｃｔｒｏｃｈｅｍｉｃａｌｓｙｓｔｅｍ,ｂｕｔｔｈｅｉｒｌｏｗｄｉｓｃｈａｒｇｅｖｏｌｔａｇｅ(ａｂｏｕｔ2.0Ｖ)ｄｅｔｅｒｉｏｒａｔｅｓｔｈｅｉｒｓｐｅｃｉｆｉｃｃａｐａｃｉｔｙａｎｄｓｐｅｃｉｆｉｃｅｎｅｒｇｙ.ＴｈｅｐｏｔｅｎｔｉａｌｏｆＬｉａｌｌｏｙｓａｎｏｄｅｓｕｃｈａｓＬｉＢａｌｌｏｙｓ[1,2]ｉｓａｌｍｏｓｔｅｑｕａｌｔｏｔｈａｔｏｆｐｕｒｅｌｉｔｈｉｕｍ,ｔｈｅｒｅｆ…     

Micro-inhomogeneous structure of liquid Al-Fe alloys

ＢｏｔｈｔｈｅＦｅｒｉｃｈａｌｌｏｙｓａｎｄｔｈｅＡｌｒｉｃｈａｌｌｏｙｓａｒｅｉｍｐｏｒｔａｎｔｉｎｐｒａｃｔｉｃｅ.ＴｈｅｒｅａｒｅｓｅｖｅｒａｌｉｎｔｅｒｍｅｔａｌｌｉｃｃｏｍｐｏｕｎｄｓｉｎｔｈｅＡｌＦｅｓｙｓｔｅｍ,ｓｕｃｈａｓＦｅ3Ａｌ,Ａｌ3ＦｅａｎｄＡｌ5Ｆｅ2.ＭｕｃｈａｔｔｅｎｔｉｏｎｈａｓｂｅｅｎｐａｉｄｔｏＦｅ3Ａｌ[1];Ａｌ3Ｆｅｉｓａｐｈａｓｅｔｈａｔａｆｆｅｃｔｓｔｈｅｐｒｏｐｅｒｔｉｅｓｏｆｔｈｅｍａｔｒｉｘｓｔｒｏｎｇｌｙ[2].Ｔｈｅｓｔｕｄｙｏｆｔｈｅｍｅｌｔｓｔｒｕｃｔｕ…     

The electronic structure and grain boundary segregation by boron addition

The electronic structure and grain boundary segregation caused by boron addition to Ni₃Al have been studied by X-ray photoelectron spectroscopy and Auger electron spectroscopy, respectively. The obtained results show that the Ni2p_3/2 electron binding energy rises gradually in the sequence of pure Ni<Ni₇₆Al₂₄<Ni₇₄Al₂₆<Ni₇₅Al₂₅, while it reduces monotonously with an increase in boron addition to Ni₃Al. Besides, it is found that the grain boundary segregation of boron occurring in Ni₃Al is a combined equilibrium and non-equilibrium type in nature. Based on the concept of the bonding environmental inhomogeneity, measured by the shift in Ni2p_3/2 electron binding energy from the nickel atoms in the simple substance nickel to those in the intermetallic compound Ni₃Al (ΔE _B), being responsible for the brittle behavior of the alloy, a binding energy shifting criterion for the brittle-ductile fracture transition in Ni₃Al is presented; when ΔE _B>0, the brittle failure occurs in Ni₃Al; when δE _B<0, the ductile one appears. Combined with the above experimental rules, the criterion predicts that pure Ni₃Al is brittle, and there exist the stoichiometric effect and concentration effect in the ductilization process for Ni₃Al by boron addition. Hence the criterion can be taken as a theoretical guide to alloy design in developing ductile intermetallics. Project supported by the National Natural Science Foundation of China.     

Microscopic phase-field simulation of Cr atom substitution character during formation of Ll2 and DO22 phases in Ni-Cr-Al alloy

The simulations of Cr atom substitution character during the formation of L12 and DO22 phases in Ni-Cr-Al alloy were performed at 873 K based on microscopic phase-field model. It is found that the substitution of Cr is affected by Cr and Al contents and limits of occupation probabilities of Cr atom in L12 phase are present. The precipitate is single L12 phase when the component is less than the limit, Cr atoms substitute the Al sublattices in Ll2 phase, and both of atoms Al and Cr occupy the β-sites and complex phases Ni3（Al1-xCrx） are formed; Cr atoms enter Ni sites when Al and Cr contents exceed the limit, and substitute β-sites or both of α- and β-sites. The DO22 phase is formed at the boundary of Ll2 phase.     

Environmental embrittlement of intermetallic compounds in Fe-Al alloys

First,it is proposed that hydrogen atoms occupy the interstitial sites in Fe3Al and FeAl.Then the environmental embrittlement of intermetallic compounds in Fe-Al alloys is studied in the light of calculated valence electron structures and bond energy of Fe3Al and FeAl containing hydrogen atoms.From the analyses it is found that the states of metal atoms will change,in which more lattice electrons will become covalent electrons to bond with hydrogen atoms when the atomic hydrogen diffuses into the intermetallic compounds in Fe-Al alloys,which will result in the decrease of local metallicity in Fe3Al and FeAl.Meanwhile,it is found that the crystal will easily cleave since solute hydrogen bonds with metal atoms and severely anisotropic bonds form.As a conclusion,these factors result in the environmental embrittlement of Fe3Al and FeAl.     

Effect of matrix composition on physical properties of Al<Subscript>3</Subscript>CON in-situ reaction reinforced corundum composite

60% white corundum used for aggregate, 5% aluminium powder for fixed additions and 35% various additives for matrix were prepared for specimens 1#,2#,3#. They were mixed uniformly with the suitable resin as a binder and pressed under pressure of 315 ton forging press, then dried at 200℃ for 24 h. Effects of various additives on 1500 ℃×2 h creep properties of Al3CON reinforced corundum composite were researched. The experimenal results show that creep coefficients of specimens 1#,2#,3# at 1500 ℃×2 h are 1.4×10^- 4, -9.4×10^-4, -22.6×10^-4, respectively. Crushing strength of the slide plate added with suitable additive A after fired at 1500 ℃ ×3 h reaches to 225 MPa, the creep rate is positive all the time from 0% to 0.014% at 1500 ℃ for 2 h. The microstructure result analysis shows that reinforced phases of Al3CON fiber composite have been formed after fired with Al powder in coke at high temperatures for specimen 1#, and the strength of the composite is increased. The hot modulus of rupture is up to 59 MPa at 1400 ℃ and the RUL is obviously higher than that at 1700 ℃. Its service life is two times as that of Al2O3-C slide plate when used in the process of pouring steel. The mechanism of creep rate resistance of the composites can be discovered by means of SEM and EDAX analysis. It is concluded that the active Al3CON and Al2O3 multiphases that were formed by N2 in gas, C, Al and Al2O3 inside the matrix of the composites during in-situ reaction,which gives the composites outstanding creep rate resistance for the dense zone resuiting from Al3CON oxidation that inhibits contraction at the high temperature. Besides, the matrix will turn into the multiphase with high refractoriness, N content and its Al3CON reinforced fiber will further increase accordingly. In addition, Al3CON formed by Al2O3 and C, Al in the matrix with N2 in gas will inhibit the creep rate and also greatly improve the creep rate resistance of the composites.     

Preparation of Al2O3-SiO2-TiO2-ZrO2 Composite Ceramic Membranes by Sol-Gel Method

Al2O3-SiO2- TiO2-ZrO2 supported membranes were prepared by Sol-Gel method. These composite ceramic membranes are level, even and no macro crack. There exist several crystalline phases such as Al2O3, TiO2 ( anatase ), Al2 SiO5 , and ZrO2 in these membranes. Changing the molar ratio of Al:Si: Ti : Zr ,the kinds and content of crystal phases of composite membranes could be different, which may lend to a variety of microstructure of membranes. The surface nanoscale topography and microstructure of membranes were investigated by XRD, SEM, AFM, EPMA. The effects of additives and heat treatments on the surface nanoscale topography and microstracture of composite ceramic membranes were also analyzed.     

Kinetics of Fe3O4 formation by air oxidation

The kinetics of Fe₃O₄ formation by air oxidation of slightly acidic suspension of Fe(OH)₂ was studied. The effects of initial concentration of Fe(II), temperature, partial pressure of oxygen, air flow rate and stirring rate on the oxidation rate were investigated. The results show that Fe₃O₄ formation is composed of two-step reaction, the first step is the formation of Fe(OH) ₂ ⁺ by oxidation of Fe(OH)⁺ complex ions, the second step is the formation of magnetite by dehydration and deprotonation of Fe(OH)⁺ and Fe(OH) ₂ ⁺ . The oxidation reaction is zero-order with respect to the concentration of Fe(II) and around 0.5-order with respect to partial pressure of oxygen, and oxygen transfer process is rate-limiting step of oxidation reaction with apparent activation energy of 2.74 kJ · mol⁻¹.     

Effect of Fe(III) impurity on the electrochemical performance of LiFePO<Subscript>4</Subscript> prepared by hydrothermal process

Lithium iron phosphate (LiFePO₄) was synthesized from LiOH, FeSO₄ and H₃PO₄ by a hydrothermal process at 180°C. The samples were characterized by X-ray diffraction, scanning electron microscopy and chemical analysis. Electrochemical performance of the samples was tested in terms of charge-discharge capacity and cycling behavior. The results indicated that Fe(III) impurity had obviously effect on the electrochemical properties of LiFePO₄, and the formation of Fe³⁺ was caused by the oxidation of Fe²⁺ in the dissolving and feeding processes accompanying the increase of pH value. It was found that the precipitation separation was effective in decreasing the content of Fe³⁺ in the solution of FeSO₄ and the sealed feeding was useful in preventing the conversion of Fe²⁺ to Fe³⁺. When the content of Fe³⁺ < 0.5 wt%, the hydrothermally synthesized LiFePO₄ calcined at 750°C with sucrose as carbon source exhibited an initial discharge capacity of 154.9 mAh·g⁻¹ at the rate of 0.1 C (1 C = 150 mA·g⁻¹) and the cycling retention rate could reach 98% after 50 cycles at room temperature.     

Chemical reaction of in-situ processing of NiAl/Al2O3 composite by using thermite reaction

NiAl/Al₂O₃ composite were synthesized by thermite reaction of nickel oxide and aluminum powder mixtures. The phase, the microstructure of the composite, as well as the thermite reaction mechanism, were investigated by X-ray diffractometry (XRD), scanning electron microscopy (SEM) combined with differential scanning calorimetry (DSC). The experimental results show that the thermite reaction leads to the interpenetrating network structure of NiAl/Al₂O₃ at 1223K for 60 min and the chemical reaction apparent activation energy is E_ap=166.960±13.496 kJ·mol⁻¹ in the NiO/Al system. Funded by the Younger Teacher Foundation of High School of Anhui Province (No. 2003jq158)     

Moessbauer spectra of MnFe2-2x Al2xO4 （0 ≤x≤ 0.4） ferrites

The effect of non-magnetic Al³⁺ ion doping on the magnetic properties of MnFe_2−2x Al_2x O₄ (0≼x≼0.4) spinel ferrites was studied using M?ssbauer spectroscopy measurements at room temperature. From the M?ssbauer study, it is observed that the resolved hyperfine sextets are due to the distribution of Fe ions on the two sublattices of the spinel ferrites. The value of the isomer shift obtained from the fitting of the M?ssbauer spectra indicates that Fe ions are in +3 state. A paramagnetic doublet is observed at degree of inversion x=0.4, superimposed on the hyperfine sextets, indicating that the super-exchange interaction A–B decreases due to the dilution of sublattice by Al³⁺ ions. The hyperfine magnetic field decreases at both interstitial sites of tetrahedral (A) and octahedral (B) with the increase in Al concentration.