25 December 2010, Volume 41 Issue 12
    

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    研究与开发
  • The effect of different matrixs on microstructure and shielding effectiveness of composite coating
    JIN Chuan-gui
    . 2010, 41(12): 1-0.
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    The conductivity (ρ) and shielding effectiveness (SE) of eectromagnetic interference (EMI) shielding coating materials of acrylic resin matrix, alkyd paint and phenolic paint using polyaniline adoped by camphor sulfonic acid (PAn-CSA) and nickle powders as conductive fillers, KH-550 as coupling agent were measured and analyzed. The results show that the ρacrylic resin＞ρalkyd paint＞ρphenolic paint, SEacrylic resin＞SEalkyd paint＞SEphenolic paint. The surface morphologies of them were observed and analyzed. Observation results show that the dispersive uniformity of conductive fillers in matrix is acrylic resin＞alkyd paint＞phenolic paint, which is agreement those of conductivity and shielding effectiveness measured.
  • Steady rheological behaviors of collagen solution and mathematical simulation
    ;
    . 2010, 41(12): 2-0.
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    The steady rheological behaviors of collagen solution were studied by coaxial viscometer. The effects of concentration and temperature on the flow curve of collagen solution were discussed. The experimental data showed that viscosity decreased with increasing shear rate，indicating that collagen solution was pseudo-plastic. At the same shear rate， the viscosity of collagen solution decreased with increasing temperature but increased with increasing concentration. Ostwald-de wale model, Carreau model and Cross model were used to fit the experimental data. The results indicated that Ostwald-de wale model，Carreau model and Cross model could all accurately describe the flow curve of collagen solution. The values of consistency index K and flow behavior index n，obtained from Ostwald-de wale model，could accurately reflect the changes of pseudo-plastic behavior. Compared with Ostwald-de wale model，Carreau model and Cross model had more parameters and were more accurate to coincide with the experimental data，however, both the zero-shear rate viscosity and the infinite-shear rate viscosity of Carreau model and Cross model were inexact on the experimental conditions.
  • Microstructure distribution of the micro-arc oxidizing coating on magnesium alloy
    . 2010, 41(12): 3-0.
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    An extensive study was made of the microstructure distribution of the ceramic coating formed on AZ91 magnesium alloy substrate by micro-arc oxidation(MAO).The coating was prepared in an alkaline electrolytic solution composed of 5-20g/l of NaH2PO4/Na2SiO3/NaAlO2, 1-5g/l of NaOH, 5-8g/l of KF; 0.5-2g/l of Na3C6H5O7, and 0.5-2g/l of EDTA, employing a constant-current controlled AC power supply with a current density of 20A/dm2; and the microstructure of the coatings was characterized using scanning electron microscopy(SEM), optical microscopy and X-RAY diffraction instrument(XRD). It was found that: (1) The microstructure prepared in an alkaline electrolytic solution was best than in aluminate or phosphate electrolytic solution; (2) The ceramic coating had both structures, and the dense inner sublayer made of most of the thickness, about 75％～85％; (3) The elements made of coatings, such as Si, Al or P, distributed in the outer sublayer, and the compositions of the dense inner sublayer were Mg and O; the phase compositions corresponding to the three electrolytic solutions, such as MgSiO3, MgAl2O4 or Mg3(PO4)2 distributed in the outer sublayer, and it was MgO in the dense inner sublayer。
  • Superhydrophilicity antifogging modification of poly(methyl methacrylate) via static electronic self-assembly on the surface
    LUO Xiang;ZHAO Jian-Hao
    . 2010, 41(12): 4-0.
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    A superhydrophilicity antifogging modification of poly(methyl methacrylate)(PMMA) plate was studied by static electronic self-assembly of poly(acryllamine hycrochloride) and SiO2 nano-particles on PMMA plate surface. The water contact angle analysis showed that the hydrophilicity of PMMA plate was greatly improved with increasing the number of electric bilayers, and a super hydrophilic surface was achieved while coating 20 bilayers. The Atomic Force Microscope observation showed that the super hydrophilic surface maybe resulted from the regular arrangement nanoporous structure which was in favor of the formation of water layer. A good antifogging performance was further obtained in PMMA plate with 20 coating bilayers via an antifogging test. In addition, the visible light transmission of self-assembly coating modified PMMA plates was not decreased but increased a little bit because of the reflection reduction on the surface.
  • Synthesis Of a Novel TPA Material With Multibranch Structure
    . 2010, 41(12): 5-0.
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    A novel TPA material with multibranch structure 1,3,5-Tris[4-[2-(3-pyridyl)ethenyl]phenyl] benzene was synthesized．The structure of the compound had been characterized by elemental analysis， electron-spray mass spectra， 1H NMR， and IR spectra. Uv.Vis absorption，one-photon induced fluorescence and two-photon induced fluorescence were experimentally studied. The two-photon absorption cross-section is as high as 763?10?50cm4 ?s? photon?1. A pulse duration of 200 fs and repetition rate of 76 MHz, mode-locked Ti:sapphire laser was used for two-photon microfabrication. Some three dimensional lattices were created by two-photon polymerization of an acrylic eater oligomer using this initiator. The lattice fabricated was observed through a polarization microscope (Olympus, BX-51). It is a potential TPA material.
  • Study on structural changes in porous silicon during high-temperature annealing
    Cai Hong
    . 2010, 41(12): 6-0.
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    Porous silicon film samples with different pore sizes were prepared by electrochemical anodization, and then were annealed at 1050 ℃.The structure of porous silicon before and after annealing was observed by scanning electron microscopy and Raman spectrometry. The mechanism of pore size changes were analyzed according to nucleation theory, and its microscopic mechanism were discussed from the thermodynamic point of view. Experimental and theoretical results confirmed the existence of a critical radius above which the pore size increases and below which the pore size decreases during high temperature annealing.
  • Performances of Sn Films as Lithium Ion Insertion Electrodes Prepared by Radio Frequency Frequency Magnetron Sputtering
    LI Chang Ming
    . 2010, 41(12): 7-0.
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    Tin film was deposited onto copper foil by radio frequency(RF) magnetron sputtering. Two kinds of films as negative materials for lithium-ion batteries was prepared with different RF power(200W and 350W). Their structures and performances were studied with X-ray diffraction (XRD), electronic probe, scanning electron microscopy(SEM) and charging-discharge experiments. The results show that the tin-copper alloy was formed with RF power at 350W, the binding force between the layers is enhanced due to the forming of alloy and it has more excellent cycle performance. its shows better discharge capacity and cyclic stability than that was prepared by power of 200W: the discharge capacity of the RF power 350W electrode is 707mAh/g for the first cycle and keeps 643 mAh/g after 30 cycles.
  • Low temperature electrical-resistivity of CuZrNb bulk metallic glass
    zhi xin wang
    . 2010, 41(12): 9-0.
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    The glass-forming ability (GFA) of Cu60Zr40-xNbx (x=2,5,8) alloys are studied by means of differential scanning calorimeter (DSC) and x-ray diffraction (XRD). The electrical-resistivity ratio measurements between 1.8K and 298K are performed by means of physical property measurement system (PPMS). The experimental results demonstrate that the content modification changes the GFA and electrical-resistivity ratios of CuZrNb alloys. Compared with Cu60Zr35Nb5 bulk metallic glass with part superconductivity, electrical-resistivity ratio of the crystallized sample decreases and become superconductive alloy.
  • Effect of Asymmetrical Rolling Process on Microstructures and Mechanical Property of Steel/Aluminum Cladding Plate
    ;;
    . 2010, 41(12): 10-0.
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    The microstructure and mechanical properties of Al/steel cladding plate prepared by the asynchronous rolling process were investigated using OM, SEM and the material stretch test machine. The effect of asynchronous speed ratio on the interfacial shear strength of cladding plate was discussed. The results showed that the asynchronous rolling process allows for initial bonding effectively in the presence of the critical reduction of 30%, and the initial bonding strength is higher than that of cladding plate made via the synchronous rolling process. The shear strength firstly increases and subsequently decreases with the increase of asynchronous speed ratio. The range of the optimum asynchronous speed ratio is from 1.2 to 1.25. The asynchronous rolling process results in breaking of coarse columnar crystals and grain refining of steel body. The ideal softening of steel is achieved through annealing at 450℃ for 1h, avoiding the formation of bristle intermetallic compounds on the bonding interface for the sample prepared by the synchronous rolling process when the annealing temperature is beyond 500℃. The bending number of the cladding plate is 10 times higher.
  • Investigation of ion transport and its effect on the photovoltaic performance in dye-sensitized nanocrystalline TiO2 solar cells
    Shengjun Li ;
    . 2010, 41(12): 11-0.
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    The diffusion behaviour of was investigated in the thin film structure cell. The diffusion velocity slow down rapidly after the coating of TiO2 film. To improve the transport performance in TiO2 film, sphere pores were introduced through the using of polystyrene sphere. The short circuit current of the TiO2 electrode was investigated at various light intensities. The result showed that the photoelectric performance was enhanced through the introduction of sphere pores to TiO2 film.
  • Influence of texture on magnetic aging of cold rolling non-oriented silicon steel sheets
    xu lingfeng
    . 2010, 41(12): 12-0.
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    The relationship between magnetic aging and texture of non-oriented silicon steel 50W700 with ~30ppm carbon was investigated. The 24h aging treatment at 200oC showed that the carbide precipitated in the form of fine cementite particles from supersaturated ferrite during aging and Cementite particles precipitated from ferrite during aging inhibited the movement of magnetic domain walls and subsequently increased the core loss of non-oriented silicon steel. The driving force to move the 180o stripe domain walls during magnetization is influenced by the texture of steel sheet. The sheet texture of <100> parallel to the magnetizing field will reduce coreloss increment induced by the magnetic aging.
  • Synthesis and Pyrolytic Conversion of a Hyperbranched Liquid Polycarbosilane with Low Oxygen Content
    ;ma-tai DING; ;;
    . 2010, 41(12): 13-0.
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    A hyperbranched liquid polycarbosilane(HBPCS) with a low oxygen content was prepared by Grignard coupling of partially methoxylated chloromethyltrichlorosilane, followed by reduction with lithium aluminum hydride. The as-synthesized HBPCS was characterized by gel permeation chromatography (GPC), nuclear magnetic resonance (NMR) spectroscopy and elemental analysis. It is suggested that side reactions of THF and chlorosilanes can be avoided with the increase of methoxylation ratio. Less oxygen is expected in the precursors. Pyrolysis behavior of the HBPCS and crystallization behavior of the resultant ceramic were studied by means of thermal gravimetric analysis (TGA) and X-ray diffraction (XRD), respectively.
  • Superconducting critical current measurement methods and principles
    . 2010, 41(12): 14-0.
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    The critical current characteristic of superconducting material is one of the main characteristics of this kind of materials. The critical current is defined and identified in different modes in the engineering survey were summarized, and the distinguishing parameters were given. The current five superconducting critical current measurement methods and principles were introduced. The applicable material types，measuring conditions, measuring parameters, measuring results, measuring precision and measurement process can get the material′s other informations of the five measurement methods were discussed briefly. The five methods were compared together, it is can be used to choose the aptitude way to measure the superconductor critical current.
  • Effects of High Pressure and High Strain Rate on Dynamic Compressive Strength of Alumina
    Liu Zhan-fangXiao-Wei FENG;;
    . 2010, 41(12): 15-0.
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    Critical value which transforms from elastic deformation to inelastic deformation is corresponding with the compression strength of the material under the plane impact compression. Hydrostatic pressure and high strain-rate influenced material strength seriously. In this paper, we establish a non-elastic deformation of the dynamic yield condition Based on the viscoplastic material law Analogy, and introduce the Drucker-Prager static yield criterion to consider the effect of hydrostatic pressure and high strain-rate. We give a new representation of Hugoniot elastic limit. The shock compression experiments of alumina ceramics were carried out under 1D strain state one-stage gas gun and free surface velocity histories of particles in alumina were measured by VISAR. The experimental determination of the dynamic strength of alumina was discussed and open problems were clarified.
  • Synthesis and Photoluminescence of Gd2O2SO4:Dy3+ nano-phosphors by a co-precipitation method
    . 2010, 41(12): 16-0.
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    Abstract Gd2O2SO4:Dy3+ nano-phosphors were synthesized by a co-precipitation method from Gd2O3, Dy2O3, H2SO4 and NaOH starting materials. The characterizations of Gd2O2SO4:Dy3+ nano-phosphors were investigated by means of XRD, TEM and PL spectra. XRD analysis shows that the precursor can be transformed into pure Gd2O2SO4:Dy3+ nano-phosphor by calcining at 900 ℃ for 2 h in air. TEM observation shows that the Gd2O2SO4:Dy3+ phosphor particles are quasi-spherical in shape and well dispersed, with a mean particle size of about 20-40 nm. Photoluminescence (PL) spectroscopy reveals that the main and second emission peaks are located at 575 nm and 485 nm under 277 nm UV light excitation, which corresponds to the 4F9/2→6H13/2 and the 4F9/2→6H15/2 transitions of Dy3+ ions，respectively. The quenching concentration of Dy3+ ions is 2 mol% and the concentration quenching mechanism is exchange interaction among the Dy3+ ions. Decay study reveals that the 4F9/2→6H13/2 and 4F9/2→6H15/2 transitions of Dy3+ ions have a single exponential decay behavior with a corresponding lifetime of 0.468 ms and 0.462 ms, respectively.
  • Vapor-liquid-solid massive growth of hexagonal indium nitride nanowires
    . 2010, 41(12): 17-0.
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    Uniform indium nitride nanowires were grown at a large scale via vapor-liquid-solid growth mechanism. Scanning electron microscopy imaged that smooth indium nitride nanowires have an average diameter of 65 nm and average length of 15 micron. Transmission electron microscopy and energy dispersive spectra showed that nanowires featured tips on one of their ends of Au-In alloy. High-resolution transmission electron microscopy, selected-area electron diffraction and micro-Raman measurements consistently revealed that indium nitride nanowires have the nature of single crystal with a hexagonal wurtzite structure. In addition, photoluminescence spectrum presented a dominant active luminescent peak at 1.89 eV.
  • The influence of sectional curve on electromagnetic properties of C-shaped SiC fibers
    . 2010, 41(12): 18-0.
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    C-shaped SiC fibers with different sectional curve were prepared, and electromagnetic parameters as well as microwave absorbing properties of those fibers were studied. C-shaped SiC fiber is electric loss material. When the sectional radian of C-shaped fibers increases, electric permittivity and loss decrease, while the fibers with radian of 240° have biggest real part of permittivity. Microwave absorbing peak moves to high frequency along with increase of sectional radian, while the peak value and absorbing width at high frequency increase.
  • Effect of 17(Cu-Ni) Doping on Sintering Atmosphere and Properties of 18NiO-NiFe2O4 Composite Ceramics
    ;Guang-chun Yao;;;;
    . 2010, 41(12): 19-0.
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    The 17(Cu-Ni) doped 18NiO-NiFe2O4 composite ceramics were prepared with the powder metallurgy technology, the effects of doping 17(Cu-Ni) on the sintering atmosphere, phase composition, morphology, relative density and bending strength were studied. The results show that, the sintering atmosphere plays a very important role in the process of sintering composite ceramics, if the partial pressure of oxygen is too low, the ceramic phase Fe2O3 is decomposed into Fe3O4 and O2; the partial pressure of oxygen is too high, the metal phase of Ni is oxidized to NiO. With doping 17(Cu-Ni) the composition of composite ceramics change NiO and NiFe2O4 into NiFe2O4 (NixFe3-xO4), NiO and Cu3-xNix by sintering in the controlled atmosphere. When sintered at 1473K, the relative density of the specimens increases from 83.28% to 99.04%, the bending strength increases from 31.93MPa to 53.41MPa, the grain size increases from 2μm~3μm to 20μm~30μm, the fracture mode varied from intergranular fracture to transgranular fracture.
  • CONDUCTION BEHAVIOR OF SILVER-COATED FLY ASH CENOSPHERES/ SILICONE RUBBER COMPOSITES UNDER MICRO-LOAD
    ;;
    . 2010, 41(12): 20-0.
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    Resistance change of silver-coated fly ash cenospheres/methyl vinyl silicone rubber conductive composites were simultaneously measuremented with a dynamic mechanical thermal analyzer (DMA) and a bench-type digital multimeter under quasi-static micro-loading, transient micro-loading, alternating micro-loading and temperature field. The morphologies of the stretching sections of the test pieces were studied with scanning electron microscopy (SEM). The results showed that, the resistance of the conductive composites depends on the tensile frequency under the alternating micro-load and the temperature field. Especially, the resistance of the composites begins to decrease then to increase with increaing temperature when the tensile frequency is 1Hz. The resistance response of the conductive composites appears viscoelastic propertie with stress relaxation (transient micro-loading) and greep (quasi-static micro-loading) to a certain extent, likes the polymer materials’ mechanical relaxation behaviors, due to the conductibility between the interpenetrating polymer matrix network and the conductive filler network.
  • Effect of V substitution for Nb on the crystallization kinetics of FINEMET amorphous alloys
    . 2010, 41(12): 21-0.
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    Amorphous ribbons Fe73.5Si13.5B9Cu1Nb3-xVx (x=1 and 2) were prepared by the standard single copper wheel melt spinning technique in the air atmosphere. The primary crystallization kinetics of amorphous ribbons have been calculated by non-isothermal Differential Scanning Calorimetry (DSC) measurements. The crystallization activation energies of amorphous ribbons have been calculated by using Kissinger plot method and their values were 302 kJ/mol and 364 kJ/mol for x=1 and 2, respectively. The calculated Avrami exponents n were 2.35 and 1.61 for x=1 and 2, respectively. The values of the Avrami exponents showed that the crystallization mechanism in the non-isothermal primary crystallization of amorphous ribbons was all shapes growing from small dimensions controlled by diffusion at decreasing nucleation rate. The isothermal annealing was carried out at 793 K, 823 K and 853 K for 1 h in a vacuum furnace to induce the formation of nanocrystallite in amorphous ribbons. The X-ray diffraction (XRD) analyses showed that the average sizes of α-Fe (Si) grains for the alloy of x=1 are 12.8 nm, 14.0 nm and those for the alloy of x=2 are 13.3 nm, 14.2 nm when annealed at 823 K and 853 K, respectively.
  • Fabrication of Graded Density SiO2 Aerogel via Layer-by-layer Gelation and Its Interface Research
    Jia-Yin GUI;; ;;;
    . 2010, 41(12): 22-0.
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    Graded density silica aerogel was derived from a layer-by-layer gelation technic with tetraethoxysilane (TEOS) as the organic precursor and supercritical drying process, whose density ranges from 50 mg / cm3 ~ 200 mg / cm3. SEM, X-ray phase contrast method were used to characterize the graded density silica aerogel prepared, especially its layer interface structure. It can be found that the practical packing tightness was different between adjacent layer and there exist diffusion in the interface. Moreover, the gradient density aerogel was expected to be fabricated in this paper.
  • Growth kinetics of phase in nanophase composite alloys
    . 2010, 41(12): 23-0.
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    In this paper, the growth kinetics of phase in nanophase composite alloys is overviewed, the grain growth kinetic theory in single phase materials is also addressed, with focus on growth kinetic theories of the small volume fraction phase and matrix phase in nanophase composite alloys. The growth of the small volume fraction phase follows the classical ripening theory described by LSW equation. But the growth of matrix phase is deserved to research in detail.
  • Research on sensing characteristics of continuous corbon fiber reinforced cement-base composite
    . 2010, 41(12): 24-0.
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    The patched and reinforced existing concrete structure requires efficient means to monitor and assess its safe condition. In this paper, the variation law between resistance and distortion of continuous carbon fiber reinforced cement-base composite three-point-bending beam has been researched in different loading modes; the sensing characteristics of continuous carbon fiber reinforced cement-base composite have also been probed into. The results show that the strain-resistance sensitivity of the samples of continuous carbon fiber reinforced cement-base composite is higher than the electric resistance strain gauge; their linearity and hysteresis are better; their creep age is small and their stability is better. Thereafter, continuous carbon fiber reinforced cement-base composite can be used to make sensors with damaged sensory structure, so as to achieve the online health monitoring of the large-scale civil structures. If continuous carbon fiber reinforced cement-base composite is used as patching material, while it is used to patch and reinforce the damaged structures, its strain-resistance sensitivity can also be made full use of to monitor online the damage of the structures and their patching quality long-termly and dynamically.
  • Preparation and photocatalytic property of ZnO-TiO2 nanocomposites
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    . 2010, 41(12): 25-0.
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  • Preparation and application of Brucite Matrix Organic-Inorganic composite Flame Retardant
    ;;;
    . 2010, 41(12): 26-0.
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    Abstract: Core-shell brucite matrix organic-inorganic composite flame retardant were obtained by means of grafting aminepolyphosphate onto the surface of microparticle adopted brucite, polyphosphoric acid and laurylamine as material. Chemical phase and morphology of the obtained composite particles were characterized by XRD, FTIR, TGA, SEM. Suspension experiment indicates that the surface of brucite matrix composite flame retardant is hydrophobicity and it can greatly improve the compatibility. The results showed that the EVA product filled with the composite flame retardant at the value of 40% had the utmost limit oxygen index of 32.0%、 tensile strength of 10.03MPa and elongation at break of 719.0% that can be in accordance with the level of UL94-V0.
  • Photoluminescence study of ZnO films prepared by the oxidation of the different orientation Zn films
    Shuyang Ren ;
    . 2010, 41(12): 27-0.
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    Zinc oxide (ZnO) films were synthesized by thermal oxidation of (101) and (002) orientation zinc films which were prepared by resistance heating vacuum evaporation. The structural and optical properties of ZnO films were investigated using XRD, SEM, UV-Vis absorption spectra and photoluminescence (PL) analysis. The annealing samples show mixed patterns of Zn and ZnO peaks from XRD results. Photoluminescence (PL) spectra at room temperature of the ZnO films display predominant excitonic ultraviolet (UV) emission and weak deep level visible emission. It is observed that the ZnO films prepared by (101) orientation zinc films have more stronger UV emission intensity than the samples prepared by (002) orientation zinc films. The excellent UV emission from the annealing films is attributed to the certain effect of Zn doping and a strong UV absorption.
  • A porous carbon prepared by template method using a natural zeolite mineral as template and its electrochemical performance
    Guiyang LiuGUO Jun-ming;
    . 2010, 41(12): 28-0.
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    To decrease the cost of templated carbon, a natural zeolite mineral was used as template to prepare a porous carbon. XRD, N2 adsorption and cyclic voltammetry are used to analyze the phase composition, pore structure and electrochemical performance. Investigation indicates that the specific surface area of this carbon is only 411m2/g, but most of its pores are meso-pores and macro-pores, and its pore size distribution is wide. Cyclic voltammetry study indicates that, in 1M H2SO4 media, the specific capacitance of the carbon is 185F/g at a scan rate of 1mV/s/, and the capacitance retains 72% when scan rate increases from 1 to 500mV/s. It is much better than that of 23% retaining of a commercial activated micro-porous carbon with specific surface area of 2322 m2/g in the same conditions. The shape of cyclic voltammograms of the as-prepared carbon also keeps better at high scan rate.
  • Chemical silver plating on the copper alloy wires for high density optical pickup
    Hai-cheng Wang;Zhan-shuang Gong;Lan-ying Wu;Li-jin Wang
    . 2010, 41(12): 29-0.
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    Copper alloy wires with silver coating were prepared by chemical liquid plating. In this study, the effect of coating composition, main salt concentration and reaction time on the property of suspension wire were investigated. It was found that the resistivity of suspension wire firstly decreases and thereafter increases with the increase of silver nitrate, glucose concentration. The thickness of silver increases and the resistivity decrease with increasing plating time. When the concentration of silver nitrate is about 30 g/L, the concentration of glucose is about 40 g/L and the reaction time is 20 minutes, the thickness of silver gets 1.3 μm and the resistivity of sample reaches to 7.0×10-6 ( .cm). The conductivity has got about 20 percent increase compared with the sample without silver plating. The morphology, thickness, composition were characterized by Physics Properties Measurement System (PPMS，Quantum Design) and field emission-scanning electron microscope (FE-SEM). The results show that the coating composition is pure silver without oxide. The binding force between the silver coating and the substrate is perfect and there are no defects such as crack, stripping，and so on. The suspension wires obtained from this method is suitable for the application at the optical actuator for high density optical storage.
  • Effect of air bubbles on damping behavior of fiber concretes
    LIU TIE-JUN
    . 2010, 41(12): 30-0.
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    Damping property of 4 kinds’ fiber reinforced concrete with various contents of air-entraining agent is measured by self-designed 3-point flexure beam damping measurement instrument. The effects of various contents of air-entraining agent on pore structure of fiber concrete are investigated by the air contained instrument and the mercury intrusion porosimetry, and the micro-structures of fiber concrete with various pores are observed by the scanning electron microscopy. The experiment results show that the increase of the contents of air-entraining agent in the fiber concrete results the enhancement of damping ability of the fiber concrete, but the enhancement of damping ability is not obvious when the content is up to a certain value. The plentiful pores and air bubbles like soft cushion which induced by the certain content of air-entraining agent contributed to the damping ability of fiber concrete when the concrete suffered by the external vibration.
  • STUDY OF BENZOTRIAZOLE AS CORROSION INHIBITOR OF REINFORCING STEEL IN SIMULATED CONCRETE PORE SOLUTION
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    . 2010, 41(12): 31-0.
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    The inhibiting efficiency of benzotriazole (BTA) on reinforcing steel in simulated concrete pore solution with 0.25mol/L NaCl was studied by means of linear polarization resistance (LPR), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP). The results indicate that the corrosion inhibiting efficiency is good when 0.25mol/L BTA was added in simulated concrete pore solution (saturated Ca(OH)2 with pH about 12.5). It was proved that the corrosion inhibiting efficiency of BTA is better than that of the well-known nitrite by electrochemical methods, and multilayer organic protective films were formed on the steel surface from the SEM images which may prevent the attack from chloride ions. To sum up, BTA may be an attractive inhibitor for inhibiting corrosion of reinforcing steel in reinforced concrete structures.
  • Preparation and swelling property of pH-sensitive calcium alginate porous hydrogel microsphere
    ; ;
    . 2010, 41(12): 32-0.
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    Sodium alginate was used to prepare a kind of porous pH-sensitive hydrogel microsphere. Optimum preparation conditions, 2wt% sodium alginate, 3wt% calcium chloride, gelling temperature of 60℃ and heat preservation time for 40min, were obtained by orthogonal experiment. The swelling ratio of the gel microsphere was 21.8 in pH 7.4 buffer solution (colon pH value environment) for 30 min, while it was only 1.5 in deionized water (pH value 6) or pH 1.2 buffer solution (gastric pH value environment) for the same time. The swelling response rate was increased significantly after adding pore former, such as PEG200 and NaCl. The time to swell to the biggest swelling ratio of the gel microsphere was 30 min without pore former in pH 7.4 buffer solution, while the time was 10 min and 15min respectively with appropriate PEG200 and NaCl.
  • Preparation and properties of silver dendritic nanostructures array
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    . 2010, 41(12): 33-0.
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    Fabrication of nanocrystals with tailored morphologies and geometries has been attracting vast interest in the field of nanotechnology. The ability for shape control and functionalization of nanomaterials during synthesis plays a crucial role in their application potential. Herein, silver dendritic nanoparticles have been prepared by aqueous chemical approach in the presence of sodium polyacrylate, and then assembled on glass substrate by self-assembly process. Morphology of the dendrites array was examined by scanning electron microscopy. The optical measurements indicate that the samples exhibit undee pass-bands at optical frequencies. This method might be used effectively in preparing silver dendritic nanostructure.
  • Effect of width on magneto-impedance of (Fe1-xCox)76.9Cu0.6Nb2.5Si11B9 （x = 0.1）amorphous ribbons
    . 2010, 41(12): 34-0.
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    The effect of width on magneto-impedance (MI) of (Fe1-xCox)76.9Cu0.6Nb2.5Si11B9 （x = 0.1）amorphous ribbons was studied. The ribbons used for the MI measurements were 40 mm long, 8 mm and 4.4 mm wide respectively. The as cast 4.4-mm-wide ribbons exhibit a larger MI compared with the 8-mm-wide ribbons, at all frequencies. The MI attains a maximum value of 28% for 4.4-mm-wide ribbon at 3.75 MHz, and 17% for 8-mm-wide ribbons at 4.34 MHz.The maximum MI of (Fe1-xCox)76.9Cu0.6Nb2.5Si11B9 （x = 0.1）amorphous ribbons is much higher than Co68Fe5Si12B15 amorphous ribbons.
  • Femtosecond laser on the surface of PTFE
    Ming Zong Huang;Zhou Ming
    . 2010, 41(12): 35-0.
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    This paper describes a new method of processing PTFE surface. Application of femtosecond laser on surface modification of polytetrafluoroethylene obtained with nanometer - micrometer scale expanded structures, and their optical properties and surface wettability were studied further. Which shows the femtosecond laser is extremely convenient, efficient, green machining tools at processing of PTFE, and can make the PTFE surface to superhydrophobic properties.
  • TiO2-Nanotube-Arrays-Based Electrode Dye-Sensitized Solar Cells
    Leng Li Min;PANG Qi
    . 2010, 41(12): 36-0.
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    Highly ordered TiO2 nanotube arrays were fabricated via electrochemical anodization of pure Titanium Foil. The morphology, crystal structure of the TiO2 samples were characterized by SEM, XRD. The photovoltaic performances of TiO2 nanotube arrays were sensitized with ruthenium-based dye N719 were evaluated by means of the Linear Sweep voltammetry measurement. The results showed that the pore-size and length of TiO2 nanotube arrays increased with the increases of anodization voltage and time. At the same time, the samples calcined at 450 ℃ have a perfect anatase phase crystal structure and showed the highest light conversion efficiency was 2.1%.
  • Preparation and Photocatalytic Property of Ag-doped TiO2
    ZHANG Li Yuan;;;
    . 2010, 41(12): 37-0.
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    Ag-doped TiO2 was prepared by sol-gel process. The characteristics of TiO2 powder were investigated by SEM、XPS、XRD、UV-Vis. The results indicated that the diameter of undoped TiO2 particles was 80~100 nm and that of Ag-doped TiO2 particles was 40~50 nm, Ag was successfully doped into crystal lattice and the content of Ag was 0.67at%. The Crystal forms of Ag-doped and undoped TiO2 were almost the same after annealing at 400℃. However, transform from anatase to rutile could be restrainted after annealing at 600℃. The absorption profile of TiO2 was shifted to longer wavelength by doping.The optimal doping quantity was 0.5% and the optimal annealing temperature was 600℃. Methyl orange was used as the degradable agent in photocatalytic experiment. The results indicated that methyl orange could be degraded 97.9 % by Ag-doped TiO2 under the optimal conditions after 120 minutes.
  • Study of the photoluminescence of SiC/ZnO/Si complex film
    . 2010, 41(12): 38-0.
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    Abstract: 　Nano-crystalline SiC/ZnO/Si films was prepared by radio frequency (RF) magnetron co-sputtering， and adopting subsequent high temperature annealing. Analyzed the photoluminescence (PL) of the film, observed that the anneal temperature higher, the intensity enhanced, the main reason is the increasing of luminescent centers .the new summit of photoluminescence means that there are new luminescent centers appeared in the complex film, and the PL of sample under conditions of different annealing temperatures can also proved that.
  • Synthesis and Electrochemical Properties of Li4Ti5O12/C Composites by Sol-gel Method
    Jin Wang; ;
    . 2010, 41(12): 39-0.
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    In situ carbon-coated Li4Ti5O12 composites were prepared by sol-gel route using citric acid and lauric acid as chelate agent and also carbon sources. The crystal structure, microstructure and electrochemical properties of samples were characterized by XRD, SEM, TEM, TG-DSC and galvanostatically charge-discharge experiments. The effects of the content of carbon sources on the phase structure, the microstructure and electrochemical properties were studied to optimize process. The sample prepared with citric acid to titanium molar ratio CTR=1:6 and lauric acid to titanium molar ratio LTR=1:20 was coated with a carbon layer of 5~10nm, exhibiting the best electrochemical performance. The carbon content of the sample was about 2.3 wt%. Its discharge capacity at 1C rates can reach 151.1mAh/g, respectively. After 50 cycles, fairly stable cycling performance was achieved without obvious capacity fade.
  • Synthesis of ZrWMoO8-containing ceramic composites with controllable thermal expansion using wet chemical route
    . 2010, 41(12): 40-0.
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    These controlled expansion composites can be used in high precision optical mirrors, fiber optic systems, electronic devices or as a thermal package for fiber Bragg gratings. A serious of β-ZrWMoO8 ceramic composites with controllable thermal expansion were successfully synthesized by wet chemical method using zirconium nitrate (ZrO(NO3)2?5H2O), ammonium tungstate (H40N10O41W12?xH2O) and ammonium molybdenum (N6H24Mo7O24?4H2O) as raw materials. The crystallization process of the precursor was studied by the thermogravimetric and differential scanning calorimetry (TG-DSC). The crystal structure, section morphology and thermal expansion property were investigated by X-ray diffraction (XRD), scanning electronic microscopy (SEM) and dilatometry, respectively. The results indicate that the composition of all of the obtained composites is ZrO2 and β-ZrWMoO8, and these composites exhibit linear thermal expansion property during the temperature range from 30 to 600℃. The average thermal expansion coefficient of ZrO2/β-ZrWMoO8 composites will decrease with increasing mass fraction of β-ZrWMoO8. Among all the samples, the ZrO2/50%ZrWMoO8 composite with an average thermal expansion coefficient of -0.61×10-6K-1 shows almost zero thermal expansion property.
  • Application of positively charged nanofiltration membrane in waste-water drained from the production of sodium alginate
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    . 2010, 41(12): 41-0.
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    Based on Wastewater Recycling, a positively charged composite nanoflitration membrane prepared by ourselves is applied in the treatment of waste-water drained from the production of sodium alginate. These factors affecting nanofiltration process including operating pressure、cross-flow rate and the cleaning membrane are investigated. And the removal of total solubility solid, Salinity and CODcr, etc through this membrane are determined. The results suggest that the after waste water is treated through nanofiltration, the concentration of CODcr in the effluent is 21.4mg/L, and the removals of CODcr and rigidity reach 93.0% and 88.3%, respectively, which realizes the desalination of waste-water and the removal of organic substances , the effluent may be reused for process technology.
  • Preparation of MMT modified gelatin/PEG composite spinning solutions and study on their rheological behavior
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    . 2010, 41(12): 42-0.
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    The gelatin/PEG composite spinning solutions with different amounts of MMT have been prepared, and their rheological behaviors have been investigated. The results indicate that the composite spinning solutions behave as bulging plastic fluid. The viscosity of the gelatin/PEG-MMT solution decreases with increasing temperature, and meanwhile, it increases first and then decreases with the increase of MMT content. This study shows that proper amount of MMT disperses well in gelatin/PEG solution and hence increases the viscosity of the solutions as a crosslinker between polymer chains. However, excess MMT may cause the aggregation of polymers. TEM observation further confirms the conclusion above.
  • Adsorption of sulfur - containing compounds on CuCl/SBA-15 molecular sieve prepared by the thermal diffusion method
    Jia-Hui SHAN;Xiao-Qin LIU
    . 2010, 41(12): 43-0.
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    The adsorbent CuCl/SBA-15 was prepared with the thermal diffusion method, the dispersions of CuCl on SBA-15 were studied by XRD, and adsorptive performance of the adsorbents for thiophene was investigated via static adsorption experiments. The effects of CeO2 added into the adsorbent and toluene content in model fuel on thiophene removal were also studied. The results showed that: CuCl dispersed uniformly on SBA-15 surface when CuCl loading was lower than the threshold, 0.3502 g CuCl/g SBA-15 measured by XRD method. When the CuCl loading amount was 0.33 gCuCl/gSBA-15, the adsorbent had the best desulfurization performance and it′s adsorption capacity was high to 0.8767 mmol/g, indicating the threshold effect. With the addition of CeO2, the adsorption capacity improved 7.3 %, and the best quality ratio was mCe/mCu = 0.3. There was dramatic decrease in the capacity on CuCl/SBA-15 for thiophene removal in model fuel with a small toluene content, but toluene had a less effect on thiophene adsorption over CuCl/SBA-15 with CeO2.
  • Effect of sputtering current on the structure and properties of CrNx films deposited by magnetron sputtering
    . 2010, 41(12): 44-0.
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    CrNx films were deposited on stainless steel and Si wafer substrates via unbalanced magnetron sputtering technique. The microstructure and mechanical properties of the as-deposited films were investigated by means of field emission scanning electron microscope (FESEM) , X-ray diffraction (XRD) , energy dispersive X-ray analysis (EDS) and nanoindentation. With the sputtering current increasing, the N/Cr ratio decreased , the phase changed from CrN (200) to Cr2N (111) , the grain size became smaller , and the microstructure became denser as accompanied with the transformation from a columnar morphology to a featureless morphology. The hardness increased monotonously with the increase of sputtering current due to the formation of hard Cr2N phase and dense structure at high sputtering currents. As a result , the film deposited at 21 A exhibited the highest hardness of 21 GPa.
  • Study on preparation and blood compatibility in vitro of CTS/PHB/PEG multivariate blend films
    mengxiaorong ;;
    . 2010, 41(12): 45-0.
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    Abstract: For improving the blood compatibility of CTS materials, CTS/ PHB/ PEG multivariate blend composites were prepared in acetic acid solution system. The fundamental physico-chemical properties of these composites were characterized and analyzed by means of FT-IR, WAXD, SEM and swelling property. The evaluation of blood compatibility was carried out on CTS/PHB/PEG compound materials in vitro. The results indicat that there are stated chemistry among ingredients of compound materials. The crystallization of blend films are controlled by CTS. Adding PHB and PEG have biggish effect on surface appearance and hydrophilia of CTS materials. The blood compatibility of composite membranes materials including haemolysis ratio, plasma recalcification time and dynamic clotting time curve are improved compare with CTS. and membranes which reduce platelet adhesion on materials surface display excellent antithtromboic property.
  • Room-temperature electrical conductivity property of Si3N4/TiN multiphase ceramics
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    . 2010, 41(12): 46-0.
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    Room-temperature electrical conductivity property of Si3N4/TiN multiphase ceramics fabricated by Si3N4 powders from iron ore tailing and high titanium slag was investigated. Si3N4/TiN multiphase ceramics were machined by electrical discharge machining. The results show that the minimum amount of TiO2 in initial raw materials is about 20wt% for the formation of electroconductive network in the composites, of which the electric resistivity is 4.25×10-2 ??cm. The electric resistivity decreases slightly with increasing the sintering temperature. Surface roughness increases significantly with the increase of speed of the electrical discharge machining.
  • Electrolytic Corrosion of NiFe2O4 Based Cermet Inert Anode in Aluminum Electrolysis
    Youguo Huang ;
    . 2010, 41(12): 47-0.
    Abstract ( ) Knowledge map Save
    The 5Cu/(NiFe2O4-10NiO) cermet inert anode was developed by classical powder metallurgical technique. The corrosion behaviors of NiFe2O4-based inert anodes in Na3AlF6-AlF3-Al2O3 melts were investigated at 20℃ and 40℃ superheat respectively. The results show that the increase of superheat has no significant effect on anode appearance. The anodes edge are corroded, but the Inner Structure of anode keeps intact at different superheat. The cell voltage is larger in low electrolysis temperature than that in traditional electrolysis temperature. The fluctuation of cell voltage decreases during the increase of superheat. The equilibrium concentration of Fe, Ni, and Cu are 140ppm, 35ppm, and 44ppm in 20℃ superheat and 142ppm, 36 ppm, and 34ppm in 40℃ respectively. The increase of superheat has no significant effect on the equilibrium concentration of corrosion constituent in electrolyte and the decrease of electrolysis temperature results in the decrease of the equilibrium concentration of corrosion constituent in electrolyte.
  • Studies on Degradability of Poly( L-lactide) /Surface-Grafting Silica Nanocomposites
    CAI YAN HUA ;
    . 2010, 41(12): 48-0.
    Abstract ( ) Knowledge map Save
    In order to investigate effection of the silica nanoparticles surface-grafted with L-lactic acid oligomer (g-SiO2) to degradability of Poly( L-lactide)(PLLA). PLLA/ g-SiO2 nanocomposites were prepared by melt blending. Degradation behavior of PLLA/g-SiO2 nanocomposites and PLLA in PBS buffer solution was investigated by the apparent morphology, water absorption, weight loss, the result showed that g-SiO2 can increase degradation rate of PLLA, and degradation rate of PLLA had accelerated noticeably with increasing content of g-SiO2. DSC analysis showed that Tg of PLLA/ g-SiO2 composites decreased with prolongation of degradation time.
  • The Micro-dispersion Research of Nano-augmented Injection Microemulsion
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    . 2010, 41(12): 49-0.
    Abstract ( ) Knowledge map Save
    Abstract: A new nano-augmented injection agent was prepared by a cheap source of surfactant, diesel and nano-SiO2, and can be used in low permeability oil field. This nano-augmented injection agent can disperse diesel into micro droplets in water to make a steady O/W microemulsion. The nano-SiO2 and the microemulsion were characterized by the Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), Nano-particle Size and Potentionmetric Meter, High Resolution Optical Microscope and other test methods. The results showed that the average size of the nano-SiO2 and the microemulsion droplets is about 20nm and 150nm, so there are several nano-SiO2 particles in one diesel micro droplet. The theoretical calculation proved that the average number is six. The experimental results and theoretical calculation results are good in completely agreement.
  • Research of dielectric coatings for 0Cr18Ni9 stainless steel substrate prepared by BaO-Al2O3-SiO2 glass-ceramics
    LU YU Feng
    . 2010, 41(12): 50-0.
    Abstract ( ) Knowledge map Save
    The nonstoichiometric BAS glass-ceramics doped with ZrO2 were employed to prepare thick film dielectric coatings on 0Cr18Ni9 stainless steel substrate. MgO and CaO is able to decrease the sintering temperature as well as increase the crystallization temperature of the BAS glass-ceramics, and thus restrain the crystallization. As a result, the sintering processability is obviously modified. The binding ability between 0Cr18Ni9 stainless steel substrate and dielectric coating can bear 10 times mechanical shocks based on GB2633. The coating can meet the requirement of thick film circuit for multilayer co-firing technology after 3 sintering cycles, with coating thickness higher than 100 μm, breakdown voltage higher than 2.1 V and leakage current less than 0.01 mA. Some results from the present work have been applied into production of the cooperating company.
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