On-line Preconcentration of Trace Nickel from Electrolytic Manganese Using Minicolumn Packed Activated Carbon for Electrothermal Atomic Absorption Spectrometry

1　IntroductionElectrolyticmanganeseisanimportantmetallurgicalproductthathasbeenregardedasakindofcombatreadi nessmaterialinseveralcountries[1] .Itisamainindustri alexportproductofXiangxiAutonomousRegionofChina .However,theimpuritycontentintheelectrolyticm…     

Adsorption of D113 resin for dysprosium(III)

The adsorption behavior and mechanism of D113 resin for Dy(III) was investigated by using the method of resin adsorption. Experimental results show that the optimum medium pH of adsorption of D113 resin for Dy³⁺ is pH=6.00 in the HAc-NaAc medium. The static adsorption capacity of D113 resin for Dy³⁺ is 292.7 mg·g⁻¹. The optimum eluant is 0.5 mol·L⁻¹ HCl. The adsorption rate constant is k ₂₉₈=6.8×10⁻⁶s⁻¹. The apparent activation energy of D113 resin for Dy(III) is 14.79 kJ·mol⁻¹. The adsorption behavior of D113 resin for Dy(III) obeys the Freundlich isotherm. The adsorption parameters of thermodynamic are ΔH=14.48 kJ·mol⁻¹, ΔS=54.69 J·mol⁻¹·K⁻¹, ΔG=−1.82 kJ·mol⁻¹.The adsorption mechanism of D113 resin for Dy³⁺ was confirmed by chemical analysis and IR spectra. Funded by the Natural Science Foundation of Zhejiang Province (No.201027), Foundation of Zhejiang Provincial Education Bureau (No.20040551) and Zhoushan Science Technology Bureau (No.04114)     

Adsorption of Macroporous Phosphonic Acid Resin for Nickel

1Introduction Thesynthesischaracterizationandadsorptionproper tyofpolymericmaterialshavebeenresearchedinrecent years[110].Macroporousphosphonicacidresin[11](PAR)isanovelpolymericmaterialwhichcontainsafunctional groupof[PO(OH)2].Ithasalotofadvantagessuchas…     

Simultaneous determination of adenine, uridine and adenosine in cordyceps sinensis and its substitutes by LC／ESI-MS

A simple, sensitive and reproducible high performance liquid chromatography-mass spectrometry coupled with electrospray ionization method for simultaneous separation and determination of adenine, adenosine and uridine was developed. The analytical column is a 2.0 mm× 150 mm Shimadzu VP-ODS column and volume fraction of the mobile phase is 86.5 %water, 12.0%methanol and 1.5%formic acid. 2-chloroadenosine was used as internal standard. Selective ion monitoring mode and selective ion monitoring ions at ratio of mass to electric charge of 136 for adenine, 268 for adenosine and 267 for uridine were chosen for quantitative analysis of the three active components. The results show that the regression equations and linear range are Y=0. 062X 0. 005 and 2.0 - 140.0μg · mL 1for adenine, Y=0. 049X 0. 004 and 4. 0 - 115.0 μg · mL-1 for uridine, Y=0. 154X 0. 014 and 1.0 - 125.0 μg · mL 1 for adenosine. The limits of detection are 0.6 μg · mL 1 for adenine, 1.0μg · mL-1 for uri dine and 0.2 μg · mL 1 for adenosine.The recoveries of the three constituents are from 96.6% to 103.2%.     

Water permeability parameters of dermal fibroblast employed in tissue engineering in subzero temperatures

In the construction of the tissue engineered dermal equivalent, the dermal fibroblast plays a crucial role[1]. While the fibroblasts need time to proliferate, synthesize, and se-crete extracellular matrix in the three-dimensional scaffold postseeding, a degradablescaffold commences disintegration over time. This may lead to an unusable product, if proper preservation does not conduct. Cryopreservation could solve this problem. The possibility of the long-term banking of cells and tissues would…     

Sorption Behavior and Mechanism of Indium（ Ⅲ ） onto Amino Methylene Phosphonic Acid Resin

The sorption behavior of amino methylene phosphonic acid resin (APAR) for In(III) was investigated. Experimental results show that In(III) adsorbed on APAR can be eluted with 2mol·L⁻¹ HCl. The apparent rate constant is k₂₉₈=1.50×10⁻⁵s⁻¹. The sorption behavior of APAR for In(III) obeys the Freundlich isotherm. The thermodynamic parameters of sorption, enthalpy change ΔH, free energy change ΔG and entropy change ΔS of sorption (APAR) for In(III) are 24.1kJ·mol⁻¹, −35.1kJ·mol⁻¹ and 200J·mol⁻¹·K⁻¹, respectively. The coordination molar ratio of the functional group of APAR to In(III) is 2∶1. The sorption mechanism of APAR for In(III) was examined by IR spectrometry. XIONG Chun-hua: Born in 1959 0 This project was supported by Foundation of Zhejiang Provincial Education Bureau(No.20010677) and Lishui Science and Technology Bureau(No.2001012).     

Experiments and reaction characteristics of liquid phase simultaneous removal of SO<Subscript>2</Subscript> and NO

Experiments of simultaneous removal of SO₂ and NO from simulated flue gas, using NaClO₂ solution as the absorbent, were carried out in a self-designed bubble reactor, and high simultaneous removal efficiencies of SO₂ and NO were obtained under the optimal experimental conditions. The mechanism of simultaneous removal based on NaClO₂ acid solutions was proposed by analyzing the removal products. Possibility and limitation of the desulfurization and denitrification using NaClO₂ acid solutions were calculated by thermodynamic methods. Experimental results of reaction kinetics for simultaneous desulfurization and denitrification indicated that the oxidation-absorption processes of SO₂ and NO were divided into two zones, namely the fast and slow reaction zones. In the slow reaction zones both were zero order reactions, and in the fast reaction zones, the reaction order, rate constant and activation energy of SO₂ reaction with absorbent were 1.4, 1.22 (mol·L⁻¹)^−0.4·s⁻¹ and 66.25 kJ·mol⁻¹, respectively, and 2, 3.15×10³ (mol·L⁻¹) ⁻¹·s⁻¹, and 42.50 kJ·mol⁻¹ for NO reaction, respectively. Supported by the National High-Tech Research and Development Program of China (“863” Project) (Grant No. 2007AA061803)     

Catalytic wave of cobalt and its analytical application in rapid determination of trace cobalt in complex zinc electrolyte solution

Ｂｅｃａｕｓｅｉｔｓｍｅｃｈａｎｉｓｍｉｓｒａｔｈｅｒｃｏｍｐｌｅｘ,ｔｈｅｐｏｌａｒｏｇｒａｐｈｉｃｗａｖｅｏｆｃｏｂａｌｔ(Ⅱ)ｄｉａｃｅｔｙｌｄｉｏｘｉｍｅ(ＤＭＧ)ｓｙｓｔｅｍｈａｓｂｅｅｎｅｘｐｌａｉｎｅｄａｓｃａｔａｌｙｔｉｃｈｙｄｒｏｇｅｎ[1～3],ｉｒｒｅｖｅｒｓｉｂｌｅｃｏｍｐｌｅｘａｄｓｏｒｐｔｉｏｎ[4,5],ｐａｒａｌｌｅｌｃａｔａｌｙｓｉｓ[6]ｗａｖｅｓａｎｄｓｏｏｎ[7].Ｂａｓｅｄｏｎｔｈｅｃａｔａｌｙｔｉｃｗａｖｅｏｆｔｈｅｓｙｓｔｅｍ,ｓｏｍｅｈｉｇｈｌｙｓｅｎｓｉｔｉｖｅｐｏｌａ…     

Preparation and properties of metal-PVA composite hydrophilic ultrafiltration membranes

1　INTRODUCTIONOrganicmembraneshavegoodflexibilityandse lectivitybutpoormechanicalstrength ,whileinorgan icmembraneshavegoodthermalandchemicalstabili ty ,andimmunetomicroorganism ,butpoorselectivi ty .Thus ,thecombinationofboththeirgoodproper tiesmaymakeanovelmembranewithexcellentprop erties .Metallicfibersinteredmembranehasthechar acteristicsofhighmechanicalstrength ,greatvoidfractionandlittleflowdragoffiltration ,soitiswide lyusedasfiltrationmedium ,butithastoobigholediameterandisdifficu…     

Synthesis of 3D ordered macroporous indium tin oxide using polymer colloidal crystal template

Three-dimensional (3D) ordered macroporous indium tin oxide (ITO) is pre- pared using a polymer colloidal crystal template that is formed by self-assembly of the monodisperse poly(methyl methacrylate) (PMMA) microspheres. The morphologies and BET surface area of the macroporous material is examined by scanning electron micro- scope, transmission electron microscopy and N2 adsorption/desorption. Results indicate that the macroporous material has highly ordered arrays of the uniform pores replicated from the PMMA colloidal crystal template when the polymer colloidal crystal template is removed by calcinations at 500℃. The pore diameter (about 450 nm) of macroporous ITO slightly shrank to the PMMA microspheres. The BET surface area and pore volume of the macroporous material are 389 m2·g-1 and 0.36 cm3·g-1, respectively. Moreover, the macroporous ITO, containing 5 mol% Sn and after annealing under vacuum, shows the minimum resistivity of ρ = 8.2×10-3 Ω· cm. The conductive mechanism of macroporous ITO is discussed, and it is believed that the oxygen vacancies are the major factor for excellent electrical properties.     

Adsorption of Pb^2＋ on macroporous weak acid adsorbent resin from aqueous solutions： Batch and column studies

The adsorption properties of a novel macroporous weak acid resin (D152) for Pb²⁺ were investigated with chemical methods. The optimal adsorption condition of D152 resin for Pb²⁺ is at pH 6.00 in HAc-NaAc medium. The statically saturated adsorption capacity is 527 mg/g at 298 K. Pb²⁺ adsorbed on D152 resin can be eluted with 0.05 mol/L HCl quantitatively. The adsorption rate constants determined under various temperatures are k _{288 K}=2.22×10⁻⁵ s^t-1, k _{298 K}=2.51×10⁻⁵ s⁻¹, and k _{308 K}= 2.95×10⁻⁵ s⁻¹, respectively. The apparent activation energy, E _a is 10.5 kJ/mol, and the adsorption parameters of thermodynamics are ΔH ^Θ=13.3 kJ/mol, ΔS ^Θ=119 J/(mol·K), and ΔG ^Θ 298 K =−22.2 kJ/mol, respectively. The adsorption behavior of D152 resin for Pb²⁺ follows Langmuir model. Foundation item: Project(2008F70059) supported by the Scientific and Technological Research Planning of Zhejiang Province, China     

Flow stress behavior of Cu13Zn alloy deformed at elevated temperature

Ｃｏｎｓｔｉｔｕｔｉｖｅｍｏｄｅｌｉｓａｍａｔｈｅｍａｔｉｃａｌｒｅｐｒｅｓｅｎｔａｔｉｏｎｏｆｔｈｅｄｅｆｏｒｍａｔｉｏｎｒｅｓｐｏｎｓｅｏｆａｍａｔｅｒｉａｌｔｏｅｘｔｅｒｎａｌｌｙａｐ ｐｌｉｅｄｌｏａｄｉｎｇ ,ｉｎｃｌｕｄｉｎｇｅｎｖｉｒｏｎｍｅｎｔａｌｆａｃｔｏｒｓ .Ｔｈｅｐｒｅ ｃｉｓｅｋｎｏｗｌｅｄｇｅｏｆｔｈｅｃｏｎｓｔｉｔｕｔｉｖｅｂｅｈａｖｉｏｒｏｆｔｈｅｍａｔｅｒｉａｌｉｓｔｈｅｆｏｕｎｄａｔｉｏｎｏｆｎｕｍｅｒｉｃａｌｓｉｍｕｌａｔｉｏｎｔｅｃｈｎｏｌｏｇｙｏｆｍａｔｅｒｉ…     

High Efficieney Synthesis of Isotaetie Polypropylene and Linear Polyethylene Using a New C2-symmetrie Carbon-bridged Zireonoeene Catalyst

Ansa-Cyclohexyl-bis（4,5,6,7-tertrahydro-l-indenyl） zirconium dichloride （5） was used as catalyst for propylene and ethylene polymerization together with methyl aluminoxane （MAO） as the cocatalyst. Isotactic polypropylene （PP） was obtained with the highest activity of 6.37× 107g PP （molZr）^-1h^-1. The mesomeso （mmmmm） pentads sequence content of PP was determined by 13C NMR spectroscopy. The dependence of the microstructure on the reaction temperature and the AI/Zr molar ratio was examined and the catalytic activity of complex 5 was compared with that of the similar ansa-zirconocene 3. The high activity of the new zirconocene 5 for propylene isospectic polymerization at high temperature （60℃） is the result of its unique bridged-group structure. Complex 5/MAO displays also high catalytic activity of 0.46× 10^6 to 9.87× 10^6g PE（molZr）^-h^-in the homo-polymerization of ethylene, The visometric molecular weight of PE ranges from 0.97×10^4 to 11.16×10^4 g.mol^- under the given conditions.^13C NMR spectroscopy analysis proves the PE to be linear polyethylene （LPE）.     

Measurement and Analysis of Density of Molten Ni-W Alloys

1IntroductionNi-based heat-resistant superalloys are widely usedto make critical components in gas-turbine engines,suchas bladeetc.But they are very hard and difficult to bemachined,the net-shape machining of these materials isveryimportant.Computer simul…     

Synthesis and characterization of arsenate antimonic acid AAAc(1 : 1)

The AAAc(1 : 1) was synthesized in water by As₂O₃ and Sb₂O₃ with molar ratio of 1 : 1. AAAc(1 : 1) was characterized by Raman, IR, TG/DTG, DSC, XPS and XRD. The results show that there are four peaks to v _s of As-OH, As-O-Sb, Sb-OH and Sb-O-Sb in Raman spectra of AAAc(1 : 1) at 100 – 1 000 cm⁻¹. The solution of AAAc(1 : 1) was also titrated with KOH solution. The titration results show that AAAc(1 : 1) is a hexabasic acid with dissociation constants of k ₁=3.62 × 10⁻², k ₂=3.05 × 10⁻³, k ₃=6.43 × 10⁻⁶, k ₄ =9.78 × 10⁻⁸, k ₅=1.32 × 10⁻¹¹, k ₆=3.87 × 10⁻¹². AAAc(1 : 1) has a good solubility and stability in water, its solid obtained by free volatilizing water from its solution under air at ambient temperature is amorphous. Chemical and thermal analysis show that the composition of AAAc(1 : 1) is As₂O₅ · Sb₂O₅ · 8H₂O in air at 25 °C. AAAc(1 : 1) has the structure of AsO(OH)₂-OH-Sb(OH)₄-O-Sb(OH)₄-OH-AsO(OH)₂ or As(OH)₃-O-Sb(OH)₄-O-Sb(OH)₄-O-As(OH)₃ (isomerism) through experimental determination and geometry optimization. Foundation item: Project(50274075) supported by the National Natural Science Foundation of China     

Structure and electrochemical properties of LiCoO2 synthesized by microwave heating

Microwave synthesis method was applied to the fast preparation of LiCoO₂. The structure of the synthesized oxides was analyzed by using X-ray diffraction. Only single-phase LiCoO₂ was obtained. Electrochemical behaviors of LiCoO₂ were investigated by charge-discharge cycling properties in the voltage range of 3.00 – 4.35 V (vs Li). The results show that the prepared LiCoO₂ powders calcinated at 900 °C for 120 min exhibit an initial charge and discharge capacity of 168 and 162 mA · h · g⁻¹ at 0.1C current rate, respectively, as compared to 159 and 154 mA · h · g⁻¹ of LiCoO₂ synthesized by conventional means. In addition, more than 95% of the capacity is retained even after 10 cycles. But with the increase of calcinating time, its electrochemical properties deteriorate. Compared with the conventional method, the microwave heating method is simple, fast, and with high energy efficiency.     

Upgrade and separation of Co from solution with low-grade Co

Ｆｉｎｅｌｉｎｎａｅｉｔｅ ,ｕｓｕａｌｌｙｗｉｔｈＣｏｃｏｎｔｅｎｔｆｒｏｍ0 .2 %ｔｏ 0 .3 % ,ｉｓｏｎｅｏｆｔｈｅｉｍｐｏｒｔａｎｔｍａｔｅｒｉａｌｓｕｓｅｄｔｏｕｐｇｒａｄｅＣｏｏｒｅｓ .Ｄｕｅｔｏｌｏｗ ｇｒａｄｅＣｏａｎｄｉｔｓｉｎｔｅｒｇｒｏｗｉｎｇｗｉｔｈｓｅｖｅｒａｌｍａｔｅｒｉａｌｓｓｕｃｈａｓＦｅ ,ＣｕａｎｄＮｉｅｔｃ .,ｉｔｓｕｐｇｒａｄｅａｎｄｓｅｐａｒａｔｉｏｎａｒｅｄｉｆｆｉｃｕｌｔ[1] .ＴｈｅｍｅｔｈｏｄｍａｉｎｌｙｕｓｅｄｉｎＣｈｉｎａａｎｄａｂｒｏａｄｉｓｔｏｒｏａｓ…     

Synthesis and characterization of Nd doped M-type hexagonal barium ferrite ultrafine powders

Ｂｅｃａｕｓｅｐｅｒｍａｎｅｎｔｂａｒｉｕｍｆｅｒｒｉｔｅｍａｔｅｒｉａｌｐｏｓｓｅｓｓｅｓｒｅｌａｔｉｖｅｌｙｈｉｇｈｓａｔｕｒａｔｉｏｎｍａｇｎｅｔｉｚａｔｉｏｎ ,ｇｒｅａｔｃｏｅｒｃｉｖｅｆｏｒｃｅａｎｄｈｉｇｈｍａｇｎｅｔｉｃａｎｉｓｏｔｒｏｐｙｆｉｅｌｄａｓｗｅｌｌａｓｅｘｃｅｌｌｅｎｔｃｈｅｍｉｃａｌｓｔａｂｉｌｉｔｙａｎｄｃｏｒｒｏｓｉｏｎｒｅｓｉｓｔａｎｃｅ ,ｉｔｈａｓｂｅｅｎｗｉｄｅｌｙｕｓｅｄａｓｔｒａｄｉｔｉｏｎａｌｐｅｒｍａｎｅｎｔｍａｇｎｅｔｓ,ｈｉｇｈ ｄｅｎｓｉｔｙｍ…     

Physical simulation of hot deformation of TiAI based alloy

In order to establish a model between the grain size and the process parameters, the hot deformation behaviors of Ti-49.5Al alloy was investigated by isothermal compressive tests at temperatures ranging from 800 to 1 100 ℃ with strain rates of 10^-3-10^-1 s^-1. Within this range, the deformation behavior obeys the power law relationship, which can be described using the kinetic rate equation. The stress exponent, n, has a value of about 5.0, and the apparent activation energy is about 320 J/mol, which fits well with the value estimated in previous investigations. The results show that, the dependence of flow stress on the recrystallized grain size can be expressed by the equation: σ = K1 drex^-0.56. The relationship between the deformed microstructure and the process control parameter can be expressed by the formula: lgdrex= -0.281 1gZ 3.908 1.     

Preparation and reaction mechanism of red mud based ceramic simple bricks

In order to utilize solid wastes,ceramic simple bricks with high performances were made from industrial solid wastes such as red mud,fly ash and poor clay shale as main raw materials in this paper.The phase compositions and microstructures were tested by XRD,SEM and EPMA.The experimental results show that the water absorption is 45.64%,the porosity is 58.91%,bulk density is 1.29 g·cm-3,compressive strength is 54.91 MPa,bending strength is 29.52 MPa,freeze-thaw resistance is 29.28 MPa,specific heat capacity at constant pressure is 1.31 J·g-1·K-1,thermal diffusivity is 5.89×10-3 cm2·s-1,and thermal conductivity is 1.15×10-2 W·cm-1·K-1.These effects of additives and preparation process to the properties and microstructures were discussed in detail.The reaction mechanism was also discussed.The results of the reaction mechanism show that there has wollastonite and feldspar generated during the process of firing while Ca gathered around the feldspar,and then Ca would displace K and generated cacoclasite.