25 October 2010, Volume 41 Issue 10
    

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    研究与开发
  • Xie-Bin Zhu
    . 2010, 41(10): 1-0.
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    Abstract: By using microwave-assisted co-precipitation in aqueous phase, adding PEG-6000 into the mixture of InCl3 solution and SnCl4 solution, and adding the ammonia solution with the density (volume ratio) of 1:4, ITO precursor was prepared at the different reaction system temperatures of 35℃ to 75℃ , then ITO nano-powders was obtained after it was calcinated for 1 hour at the temperature of 800℃. ITO nano-powders’ morphology was characterized by SEM and its crystal structure, grain size and piling layers were characterized by XRD, and the matching granularity was determined by ZetaPlus2002. The effects of different temperature in microwave-assisted reaction system on ITO nano-powders’ morphology and its measurements were discussed, and its mechanism was also discussed. The Experimental results indicate that as the rise of reacting system temperature, the morphology of ITO particles is transformed from spherical to rod-like one with its crystal structure stable and its grain size or the matching granularity increased. And the rise of reacting system temperature that makes the grain size of ITO nano-crystallites in different crystal face and the numbers of crystal faces in different vertical direction varying increase is the basis of ITO nano-crystallites’ morphology transforming from spherical to rod-like one.
  • xiangyu hou;Jing Feng ;
    . 2010, 41(10): 2-0.
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    A hydrothermal route without any surfactant or template was suggested to synthesize nanofibre MnFe2O4. XRD, M?ssbauer, SEM and VSM were used to investigate the crystal structure, distribution of iron ions, morphologies and magnetic properties. Results showed that the products were pure phase spinel MnFe2O4 with a space group of Fd-3m. The distribution of iron ions on A and B sites were 41.3% and 58.7%. The morphology of MnFe2O4 was uniform nanofibre with diameter of about 20nm. The ratio of length to diameter was up to 50 and the surface was polish. The obtained MnFe2O4 could be magnetized easily and showed a soft magnetism at room temperature with a high saturation magnetization (Ms=62.07emu?g-1), low Mr and low Hc.
  • TAO Ya Ming ;;;
    . 2010, 41(10): 3-0.
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    Cu-doped ZnO (ZnO:Cu) films are prepared on glass and Si(100) substrates at different oxygen partial pressures by radio frequency reactive magnetron sputtering technique. The effect of various substrate and oxygen partial pressures on the crystalline and optical properties of ZnO:Cu thin films were investigated by the X-ray diffraction (XRD), atomic force microscopy(AFM) and fluorescence spectrophotometer. The results indicated that films deposited on Si substrates have a better C-axis preferred orientation than glass substrate. The films deposited on the various substrates have the same crystal law with increasing of oxygen partial pressure,and as the ratio of oxygen and argon is increased to 10:10, the C-axis growth orientation of films achieve the best at the same time. Study on Photoluminescence have shown that films prepared on the glass substrate have better light-emitting in poor oxygen environment, whereas films prepared on the Si substrate have better PL properties than on the glass substrate in rich oxygen environment.
  • . 2010, 41(10): 4-0.
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    PTFE-based composites filled with nanodiamond (ND) and PEEK were prepared by means of mold compressing and sintering. The tribological properties and microstructure of PTFE-based composites were investigated. The results showed that the wear resistance of PTFE-based composites was obviously improved with the increasing content of PEEK up to 20wt.%. By the addition of small amount of ND, the wear resistance of PTFE-based composite was found to be enhanced and the friction coefficient was decreased. Compared with the pure PTFE, the friction coefficient of the 1.0wt.%ND/20wt.% PEEK/PTFE composite was decreased by 20% and the wear resistance was increased about 120 times respectively. Atomic force microscopy (AFM) measurements indicated that ND particles were homogeneously dispersed in the matrix of PTFE-based composites.
  • Cui Hao;Fan He-Liang;;;
    . 2010, 41(10): 5-0.
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    An organometallic compound, [(C2H5)4N]2[Cu(dmit)2] (dmit2-=4,5-dithiolate-1,3-dithiole-2-thione), abbreviated as EtCu, is synthesized. Its nonlinear optical properties dissolved in acetonitrile with concentration of 1.0×10-3 mol/L are studied using the open-aperture Z-scan technique with 18 ns pulse width at 1053 nm. The results suggest that the sample shows optical limiting effect which is attributed to reverse saturable absorption of the material. This material may be a promising candidate for the optical limiting application.
  • LUO Lin ;;
    . 2010, 41(10): 6-0.
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    Etch pits on the (111) face of Hg3In2Te6 sample etched by modified Chen solution are investigated by means of scanning electron microscopy, scanning probe microscopy and electron backscatter diffraction instrument. The experimental results show that there are three basic etch pits: line shape, shuttle shape and date shape. In addition, black lines which are (111) plane projections of grooves in the latter two etch pits are oriented in three directions which are at 120° angles to one another. Further analyses show that the formation process of the three etch pits can be explained by the model of double cross-slip of screw dislocation.
  • MA su yun
    . 2010, 41(10): 7-0.
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    the ferrite powders/epoxy composite panels were prepared by molding method, which the ferrite powders Ba(Zn(1-x)Cox)2Fe16O27 were synthesized through chemical co-precipitation combining high temperature flux techniques. The electromagnetic parameters of the composite panels were investigated by coaxial cable method. Results showed that with increasing the content of Co, the main phase of the ferrite powders was transformed from BaZn2Fe16O27 to BaCo2Fe16O27 and corresponding the magnetic loss was increased gradually. The composite panels’ electromagnetic matching with air was relatively good when the frequency below 12.4_GHz. Furthermore, when connecting the ferrite powders/epoxy–based composite panels and M-glass fibers/epoxy-based composite panels together to form a multi-composite panels, there was a significant improvement in the electromagnetic matching performance. The specific results are as follows: when the thickness of the ferrite powders and the multi-composite panels absorbing layer were set to 2.0_mm (x=0.75) and 5.3_mm, respectively. Corresponding absolute values of the reflection coefficient of the multi-composite panels was over 4_dB at the frequency from 2 to 8_GHz, while over 10_dB at the frequency from 8 to 18_GHz.
  • . 2010, 41(10): 8-0.
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    Abstract : Thermoelectric materials of CaMnO3 doped with Sm3+ ion were synthesized by the sol-gel method and by sintering at 1000℃ in air with nitrales as starting materials. The phase composition and microstructure were carefully studied byTG-DTA, XRD, SEM. Thermoelectric properties such as the Seebeck coefficient, electrical resistivity and power factor of Ca1-x SmxMnO3 were carefully studied. The results showed that the samples of CaMnO3 doped with Sm3+ ion is single phase and have condensed microstructure. Sm3+ ion doped can improve the thermoelectric properties of CaMnO3, the highest power factor is 23×10-5wm-1k-2 at 600℃ for the sample of Sm0.05Ca0.95MnO3.
  • FU Chuan Qi
    . 2010, 41(10): 9-0.
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    The graphite/copper-ferrum matrix self-lubricating composites with various amounts of graphite additives were prepared by induction heating sintering method combined with the alloying of the copper-ferrum matrix with various metallic elements. As the temperature was increased from room temperature to 500℃, the mechanical properties of the composites were measured using the mechanical tester, while the friction and wear properties were evaluated by MRH-3 friction-wear tester. The worn surface morphologies of the composites were analyzed by means of scanning electron microscopy, and, the wear behaviors were investigated. It was found that the mechanical and friction/wear properties of the self-lubricating composites were related to the induction frequencies and the contents of the graphite as the solid lubricant. The increased graphite content resulted in reduced mechanical properties and increased friction/wear properties. The composites with proper graphite contents and induction frequencies have the lower the friction coefficients and wear volume loss at room temperature to 500℃. Meanwhile, wear mechanism of composites have been changed from abrasive wear to ploughing wear.
  • Yang Xiao
    . 2010, 41(10): 10-0.
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    Abstract:Organic aerogels were synthesized by sol-gel polycondensation of phlorogluctinol(P) with acetaldehyde(A) in a slightly alcohol solution,Na2CO3 as the base catalyst,followed by crosslink,solvent exchanging, drying with supercritical carbon dioxide. Pore structure and fact density of PA organic aerogelst can be modified upon variation of the phlorogluctinol to catalyst ratio and by varying the mass ratio of the reactants PhlorogluctInol and acetaldehyde in the sol.Here, series of PA organic aerogels have been produced with P/C 100, 300 and 500, each covering a wide density range. All samples were investigated using SEM and nitrogen adsorption. Surface area,total pore volume and average pore diameters of PA organic aerogelst can be modified upon monomer and catalyst concentration,but has less influence on microporosity.
  • hong wang;;;;
    . 2010, 41(10): 11-0.
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    Abstract :The degradation rate of BCP can be controlled by tri-calcium phosphate (TCP) content, porosity and micro-morphology. In this paper we regulated the degradation rate of BCP by changing the porosity. Through H2O2 foaming method we successfully obtained the BCP with porosity of 40%, 60%, 80%. Degradation test was performed by immersing the materials in Tris buffer and testing the released calcium (Ca) and phosphorus (P) concentrations. The degradation test shows that dissolution rate of BCP can be regulated effectively through the change of porosity. The enhanced bioactivity of BCP with higher porosity might due to both the structure and the increased Ca and P ions releasing.
  • ZHAO Xiao Feng ;
    . 2010, 41(10): 12-0.
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    Abstract: Nano polysilicon thin films were fabricated by low-pressure chemical vapor deposition (LPCVD) on p-type silicon <100> substrates at 620℃,which took SiH4 as gas source, the nano polysilicon thin films with different thicknesses were annealed in the case of vacuum and higher temperatures 700 ℃, 800 ℃ and 900 ℃ respectively. Through X-ray diffraction (XRD), Raman spectroscopy (Raman), field emission scanning electron microscopy (SEM) and atomic force microscope (AFM), the effect of thin films thicknesses and annealing temperatures on structure properties of oriented crystallization and surface appearance,etc.were researched. The result shows that orientation and polycrystalline characteristics are obvious with increasing thicknesses of the thin films, polycrystalline orientations of the deposited thin films are <111>, <220> and <311>, excellent orientation is <111>, Ranman spectrum TO mode is weakened and widened, grain sizes also increase. Intensity of X-ray diffraction crests increases with annealing temperature for the same thickness nano polysiocn thin films, Ranman spectrum TO mode strengthens.
  • . 2010, 41(10): 13-0.
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    It is meaningful for the cardiovascular implants how to adjust the behavior of platelets and endothelial cells (ECs) simultaneously. Surface topology and wettability are suggested as the important factors influencing cell modality and adhesion behavior. In this paper, the wettability of micro-patterned Ti-O thin film was altered by UV irradiation to adjust adhesion behavior of platelets and ECs in vitro.
  • Yao Fu
    . 2010, 41(10): 14-0.
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    The Zn2+-doped nanocrystalline anatase-type TiO2 film electrodes were prepared by sol-gel method. The effect of Zn2+ ion doping on the surface morphology and photoelectric properties of the electrodes were studied by X-ray diffraction (XRD), absorption spectra, atom force microscope and photocurrent action spectra. The results show that, the Zn2+ ion doping content shows no obvious effect on the phase composition and UV absorption strength of the films, but shows remarkable influence on the size and morphology of the grains in the films, this makes the photoelectric properties of the electrode vary significantly. When doping content increase to 0.1 mol%, the grain size of the film increases from 30 nm to 40 nm, and the shape of the grains also changes from near-spherical to prismatical structure. This special structure change significantly increases the surface area of the film, and remarkablely improves the transfer efficiency of the carriers on the solid-liquid interface, resulting in a 40% enhancement on electrode photocurrent density (PCD) compare with intrinsic electrode. However, as the doping content is increased, the grain size of the film increases gradually and the grain shape resumes to near-spherical, which make the electrode PCD decrease obviously. When the Zn2+ ion content increases to 5 mol%, the grain size rapidly increases to 130 nm, at the same time, the surface grains of the film melt and form a smooth surface, these lead to a rapid reduce on the electrode PCD.
  • 俊强 许
    . 2010, 41(10): 15-0.
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    The heterogeneous Fe-Al2O3 and Ce-Fe-Al2O3 materials were prepared by impregnation method. The structure and texture parameter was investigated by X-ray diffraction (XRD), N2 adsorption/desorption(BET). The high concentration coking wastewater was catalitically degradated using H2O2 as oxidant, Fe-Al2O3 and Ce-Fe-Al2O3 as catalyst. The results showed that the catalytic degradation performance of Fe-Al2O3 catalyst modified by Ce promoter could be enhanced. A series of reaction process parameters of 3%Ce-10%Fe- Al2O3 (20-40 mesh) was optimized as follow: the reaction temperature was 75 ℃, the mass quantity ratio of H2O2/ Ce-Fe-Al2O3 was m(H2O2)/m(Ce-Fe-Al2O3) =0.66/1, the pH value was 3, stirring speed was 500±50rpm. In this condition, the removal rate of CODCr value in coking water reached 96.3%.
  • . 2010, 41(10): 16-0.
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    Using ultrasonic technology, phenylmethylsilicone/organic montmorillonite (OMMT) nanocomposites were prepared by in-situ intercalative polymeriztion. The internal structure and morphology of the nanocomposites were characterized by X-ray diffraction (XRD), and transmission electron microscope (TEM). The effects of time for ultrasonic processing on the dispersing of MMT lamellar and on the thermal property of PLS nanocomposites were also studied. The intercalated and exfoliated phenylmethylsilicone /OMMT nanocomposites were successfully prepared by convenient process of changing ultrasonic time for 15 min and 30 min. The initial decomposition temperature of both intercalated and exfoliated PLS nanocomposites decreases with the adding of OMMT into silicone, while the rate of thermal weight loss changes slighter. The high temperature resistance of intercalated nanocomposite is higher than that of exfoliated nanocomposite. The thermal weight loss of intercalated nanocomposite is less than 10%, while those of the exfoliated nanocomposite and pure silicone are over 15% and 25%, respectively.
  • CHENG Xue-LianJin Wang; ;
    . 2010, 41(10): 17-0.
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    Abstract: layer-structured LiNi1/3Co1/3Mn1/3O2 cathode materials were prepared successfully by self-propagating solid-state metathesis, rheological phase method and self-propagating solid-state metathesis-rheological phase method, respectively. LiNi1/3Co1/3Mn1/3O2 materials prepared by different synthesis methods were studied by SEM, XRD and electrochemical tests. The results indicate the sample synthesized by self-propagating solid-state metathesis-rheological phase method has the best two-dimensional layered structure , cationic degree of order and uniform particle distribution. The initial specific discharge capacity obtained is 185.9,169.9,157.5和134.7 mAh/g between 2.8~4.3V at 0.2、 0.5、 1、2C respectively, showing favorable rate electrochemical performance . The cycle test at 0.5C shows capacity retention rate is 84.7% after 20 cycles. Increasing charge cut-off voltage could improve the previous discharge capacities .The initial discharge capacity is 197mAh/g in the voltage range of 2.8~4.6V, while the irreversible capacity presents increasing.
  • wang yanhang
    . 2010, 41(10): 18-0.
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    Tb3+ doped silicate glasses were successfully fabricated by high temperature melting process, and the effect of CeO2 on their luminescent properties and irradiation resistances was investigated. Results showed that excited energy of Tb3+ decreases due to part of absorption bands of Tb3+ overlap with those of Ce3+, which leads to quenching the luminescence of Tb3+ at 550nm. The afterglow life shortens for Tb3+ doped silicate glasses with the increase of CeO2 concentration. Irradiation resistance of Tb3+ doped silicate glasses can be effectively improved by CeO2 introduction because the valence change reaction takes place during irradiation: Ce4++e Ce3+. Taking the effect on luminescent properties and irradiation stability into account synthetically, the suitable CeO2 concentration for Tb3+ doped silicate glasses should be 0.4-0.8wt.%.
  • . 2010, 41(10): 19-0.
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    Al/Cr2O3 composite particles were prepared by coprecipitation method. The phase composition, morphologies and particle size distribution of the obtained Al/Cr2O3 composite particles were characterized by XRD, IR, SEM and laser particle analyzer. In addition, the infrared emissivity and the reflectivity at 1.06 μm wavelength of Al/Cr2O3 powders were tested. The results showed that the average sizes of composite particles with uniform thickness were bigger than the original aluminum powders. At the same time, the composite particles not only had low infrared emissivity of 0.66 but also had strong laser absorption with 0.41% reflectivity at 1.06μm wavelength. Moreover, the green of itself could also play a role in visible stealth.
  • LI Yu-Kun;;
    . 2010, 41(10): 20-0.
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    Phase change slurry (PCS) is a fluid for heat storage and transfer and it is advantageous in the field of the convective heat transfer enhancement. But traditional PCSs always have problems in application. In this paper, a phase change microemulsion is prepared to solve problems. Physical properties of phase change microemulsion were test and results show it has high latent heat and stability. It will be potential for application.
  • . 2010, 41(10): 21-0.
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    In the present work, Pt/TiO2 nano-Film was prepared by sol-gel method, and the photocatalytic decomposition of gaseous methanol on Pt/TiO2 nano-film was carried out in a continuous-flow reactor. The effect of various factors on the photocatalysis process was investigated, space velocity, illuminating time, methanol concentration, and also the photocatalytic activities of Pt/TiO2 nano-film was compared with TiO2 nano-film. The result shows that, Pt dispersed on TiO2 thin films are based on the existence of Pt0 Valence. The photocatalytic activity of Pt/TiO2 nano film was as 28 times as that of TiO2 nano film under the same condition. The effect of methanol concentration showed the maximum value of hydrogen production is 4.68 mmol/h when its concentration is 29%. The methanol conversion decreased with the increase of space velocity. The photocatalytic decomposition of methanol gas was first order reaction, and the activity energy is 26.19 kJ/mol. The reaction mechanism was deduced according to the kinetic and GC/MS analytical results.
  • ;
    . 2010, 41(10): 22-0.
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  • ;;
    . 2010, 41(10): 23-0.
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    A specific formula to calculate intensity of X-ray diffraction is deduced based on Thomson scattering theory, and the XRD pattern of orthorhombic BaSi2 is carried out, then the location, intensity and shape of peaks in the X-ray diffraction pattern have been studied.This method can be used to verify the reliability of XRD pattern in Powder Diffraction File database.
  • . 2010, 41(10): 24-0.
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    A bimodal mesoporous SiO2 was in-situ synthesized by using silica gel with macropore or mesopore as adding material. The prepared SiO2 powders were characterized by N2 adsorption-desorption measurements, X-ray diffaraction(XRD), scanning electron microscopy(SEM), and transmission electron microscopy(TEM) . The results showed that bimodal mesoporous SiO2 consist of small mesopore of ~2.8 nm and large mesopore of ~45 nm. The small mesopores have similar characters with MCM-41 and were formed on surface and pore wall of the silica gel, while large mesopores inherited from parent material silica gel were not blockage. The bimodal mesopore distribution of SiO2 and large mesopore diameter can be adjusted by changing the proportion of TEOS and silica gel or CTAB and TEOS.
  • ;Xian-Jin YANG;S.L. Zhu
    . 2010, 41(10): 25-0.
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    In the present paper, electrochemical method was used to build a porous surface on the Ti-based glassy alloy to improve its bioactivity. Bone-like apatite layer was successfully prepared on the porous surface. Morphology, phases, composition and chemical valence were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectrum (XPS). The results show: a homogenous porous surface can be built in 10% HNO3 under 2V potential for 1h at 60℃ on the Ti40Zr10Cu36Pd14 glassy alloy; Bone-like Ca/P layer can deposits rapidly on the glassy alloy with the porous surface in a simulated body fluid (SBF); the bone-like Ca/P layer is mainly composes of hydroxyapatite (HA).
  • Yi Zhang ;;;
    . 2010, 41(10): 26-0.
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    The effect of aging temperature and aging time on microstructure and properties of Cu-2.0Ni-0.5Si alloy were studied. The secondary phase was dispersive distribution in the alloy, the high hardness and electrical conductivity were obtained after the alloy was aged at different aging temperature and aging time. The transformation ratio of new phase in Cu-2.0Ni-0.5Si alloy was calculated when aging at 500℃ by measuring electrical conductivity, the relationship between the electrical conductivity and the quantity of new phase. Both the equation of Avrami phase transformation kinetics and the electrical conductivity equation were obtained at different aging temperature.The Orowan strengthening mechanism was operated in the aging progress.The calculated results by Orowan strengthening mechanism were closed to the actual results.
  • ;
    . 2010, 41(10): 27-0.
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    A series of PVDF/(PDMS-g-(PPO-PEO)) and PVDF-HFP/(PDMS-g-(PPO–P EO)) blend separators was prepared via phase inversion route in this work. After being activated with lithium electrolyte solution, the blend separators having proper porous structure were converted into corresponding lithium gel electrolyte membranes. By measuring the stability of electrolyte, electrochemical stability and ionic conductivity etc, the effects of PDMS-g-(PPO-PEO) on properties of lithium gel electrolyte membranes were investigated and discussed. The ionic conductivity of blend PVDF/PDMS-g-(PPO-PEO) and PVDF-HFP/PDMS-g-(PPO-PEO) lithium gel electrolyte membrane reached as high as 2.2mS/cm and 1.7mS/cm respectively. Together with its higher stability of electrolyte solution uptake, the PVDF/PDMS-g-(PPO-PEO) blend separator presented in this work should contribute the more proper matrix in gel electrolyte membrane used for lithium batteries.
  • ;
    . 2010, 41(10): 28-0.
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    A series of AlxGa1-xN films grown on sapphire were measured applying Spectroscopic Ellipsometry. The films thickness and optical constants in 245-1000 nm range are obtained by fitting. And Al composition is calculated by Effective-Medium-Approximation (EMA) model. With Al composition increasing, the refractive index n decreases, absorption edge shifts to shorter wavelength. The results are in good agreement with that of transmission spectrum.
  • . 2010, 41(10): 29-0.
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    The electrochemical corrosion behaviors of bulk amorphous Fe41Co7Cr15Mo14C15B6Y2 alloy was investigated in 0.5, 1, 2, 4 mol/L NaOH solutions by potentiodynamic polarization experiments and electrochemical impedance spectroscopy (EIS). The results of potentiodynamic polarization experiment show that the amorphous Fe41Co7Cr15Mo14C15B6Y2 alloy has excellent corrosion resistance in different concentration of NaOH solutions and its anodic reaction has a passive character. With the concentration of the NaOH solutions increasing, the corrosion resistance of the amorphous alloy decreases. EIS experimental results show that the Nyquist figures of amorphous alloy in different concentration solutions are composed of one single semi-circle in the state of open circuit potential. With the concentration of the NaOH solutions increasing, the semi-circle changed smaller and smaller. It demonstrates that the corrosion resistance of bulk amorphous Fe41Co7Cr15Mo14C15B6Y2 alloy changed weaker and weaker. This result is accord with that of potentiodynamic polarization.
  • ZHOU Yan Jun
    . 2010, 41(10): 30-0.
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    Abstract: By using reactive magnetron sputtering system and the sol-gel method, TiO2 thin films were fabricated onto quartz substrates, and then modified by Ge introduced with ion implantation method and sol-gel method. XRD, XPS and UV-vis were used to characterize the phase structure, the atomic chemical states and optical absorption of these composite TiO2 thin films. The results indicate that no diffraction peak of anatase is observed in implanted samples, even after an annealing process at 600℃. XPS result reveals that there is elemental Ge precipitation in the implanted thin films surface. More over, it is detected that there are anatase and Ge crystal in Ge doped films which prepared by sol-gel method, and Ge exists as elemental Ge and GeO2 in the films. The composite TiO2 thin films by ion implantation method and sol-gel method exhibits the absorption shift to visible region due to Ge doped TiO2 thin films.
  • ;
    . 2010, 41(10): 32-0.
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    Advanced composites will be successfully obtained via compounding the functional matrix and silicate minerals based on the structure and physico-chemical properties of silicate minerals. The main routes to compound the functional matrix and silicate minerals are emphasized, including surface loading, porous assembling and intercalation technology. The paper also summarizes the research status and prospect of the functional mineral-based composites in the field of ecological environment, catalysis, and optical, electrical, magnetic and absorbing materials, energy storage.
  • . 2010, 41(10): 33-0.
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    Chitosan(CS) and anion polyacrylamide(APAM) have been used to build up polyelectrolyte multilayers on recycled fibers based on the technology of layer-by-layer self-assembly. Scanning electron microscopy(SEM) was introduced to observe the morphology of the CS/APAM multilayers, zeta potential analyzer was adopted to monitor the dynamic features of pulp slurry during the polyelectrolyte multilayers build up, and FT-IR technique was used to investigate the formation mechanism. It was shown that chitosan(CS) and anion polyacrylamide(APAM) were alternately absorbed on negative fiber surface driven by electrostatic attraction. The fiber surface charge reversed due to the absorption of chitosan(CS) and anion polyacrylamide(APAM). The change of zeta potential of recycled fiber slurry can be believed as the indication of the process of layer-by-layer self-assembly. Strength measurements of the sheets including burst index and folding strength showed significant improvements ranging from 55 to 400%, which depend on the type of polyelectrolyte in the outer layer.
  • LIAO Yu Zhen
    . 2010, 41(10): 34-0.
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    Micropatterned Hyaluronic acid (HA) was fabricated by the method of soft-lithography on the surface of Titanium. Endothelial cells (ECs) were confined to a certain place due to the HA of high molecular weight with the resistance property of cell adhesion. Then, the the morphology and cytoskeletal conformation of ECs were investigated. The results indicated that micropatterned HA with microscale and with good edge definition were successfully formed on titanium substrates. ECs were confined to a certain place not covered with HA effectively and elongated, the cell’s actin was consistent with its morphology. The simple method made cells’ morphology changed could be used for both further research of cells’ function and endothelialization.
  • XU Ming Yao;;;
    . 2010, 41(10): 35-0.
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    The copper based catalysts were prepared by using a wetness impregnation and a pretreatment of H2 reduction for catalystic combustion of toluene, and then characterized separately by N2 adsorption-desorption, X–ray diffraction (XRD), temperature programmed reduction (H2-TPR) by H2 and CO-chemisorptions. Activity tests of the catalysts were carried out at atmospheric pressure in a fixed bed reactor. Results showed that the catalytic activity of the catalyst CuO/γ-Al2O3/HR treated with H2 reduction was much higher than that of the catalyst CuO/γ-Al2O3 treated without H2 reduction. The reducibility of CuO on the catalyst CuO/γ-Al2O3/HR was higher than that on the catalyst CuO/γ-Al2O3. Both the dispersion and metal area per gram of copper of the catalyst CuO/γ-Al2O3/HR were higher than that of the catalyst CuO/γ-Al2O3, and the partical sizes of Cu on the catalysts CuO/γ-Al2O3/HR and CuO/γ-Al2O were 11.9 and 31.1 nm separately. As a consequence of that, the catalytic activity of the catalyst CuO/γ-Al2O3/HR was greatly improved in comparison with the catalyst CuO/ γ-Al2O3 pretreated without H2 reduction.
  • Zhou Liang
    . 2010, 41(10): 36-0.
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    ZnO/Al2O3 composite coatings were prepared by plasma spray technology using ZnO powders, Al2O3 powders and PVA additives as starting materials. Phase compositions, microstructure of these coatings were analysised. And the influence of the content of ZnO in the absorbing coatings on dielectric property was investigated. The results indicate that new phase ZnAl2O4 generated in the progress of spraying, and by increasing the amount of ZnO, the counts of ZnAl2O4 increased. The density of coatings depends on the content of ZnO powders. The dielectric constant measurements revealed that when the content of ZnO increases from 60 mol.% to 70 mol.%, both the real part of permittivity and the loss change greatly over the frequency range 8.2–12.4 GHz. By the increase of frequency, the permittivity decrease when the ZnO content is 65 mol.%, which demonstrated the strong frequency dispersion.
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    . 2010, 41(10): 37-0.
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    Semiconductor ZnO porous nanospheres have been successfully obtained through microwave irradiating the precursor aqueous solution of Zn(CH3COO)2?2H2O and triethanolamine (TEA, C6H15NO3) for 5 min. The as-obtained powder was characterized by XRD, EDS, FESEM, TEM and HRTEM. The experimental results indicate that ZnO with hexagonal wurtzite structure are porous. The diameter of nanosphere is about 200~400 nm,and there are abound of cavities on the surface of nanospheres. The possible formation mechanism associated with TEA concentrations and microwave reaction time is discussed. The room temperature PL spectrum showed a strong exciton emission with peak located at 388 nm and a week broad yellow-green emission located at center of 550 nm respectively.
  • ;;;;
    . 2010, 41(10): 38-0.
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    In this paper, effect of process parameters on bonds structure of GeSi films prepared by hot-wire CVD with high hydrogen dilution ratio is studied. Raman spectroscopy and Fourier Transform Infrared spectroscopy are used to analyze the relative contents of nonpolar bonds (Ge-Ge, Ge-Si, Si-Si) and the relative contents of hydrogen bonds (Ge-H, Ge-H2, Si-H), respectively. It is found that effects of hot-wire temperature (Tw) and SiH4/GeH4 ratio (RS/G) on nonpolar bonds and hydrogen bonds are different. Tw and RS/G both have effects on relative content of nonpolar bonds. Relative contents of Ge-Si and Si-Si increase with Tw increasing. With RS/G increasing, relative content of Ge-Si increases but decreases when RS/G >1.4, while relative content of Si-Si increases all through. But Tw has no effects on relative contents of nonpolar bonds while RS/G affects obviously.
  • . 2010, 41(10): 39-0.
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    MgB2 superconducting materials were prepared with PIT (powder in tube) method. The Magnetic flux penetration depth (?’) of the MgB2 samples were measured in Campbell Method at the different additional alternating magnetic flux density (bac), and the critical current density in different magnetic fields were calculated. The error causations of the bac vs. ?’curves and the principle that the smooth parts in the curve are selected as availabe segments to calculate were briefly discussed. Characteristics that the integral microstructure of the sample influences the current is taken into consideration in this measure method, the critical current density obtained in this way is more correspond with reality.
  • . 2010, 41(10): 40-0.
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    In this paper,using hydrated calcium silicate powder as the filler prepared a kind of accelerator vulacnization silicone rubber.By examining the amount of filler and the vulacnizating process on the mechanical performance of siliicone rubber,a method of preparing this kind of silicone rubber is established.The results also show that hydrated calcium silicate powder can prefectlly accelerate cvulcanization and has good reinforcing effect.
  • ;;;
    . 2010, 41(10): 41-0.
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    Abstract To investigate the characteristics of porcine aorta fixed with oxidized sodium alginate (ADA) to provide the ideal biomaterials for constructing artificial organs. The porcine aortas were treated by ADA for 4h to 72h. The biological materials fixed with ADA were then examined with light microscope and SEM. Subsequently, the fixation index determination and biomechanics test were also performed. The experimental results indicated that the antigenicity of porcine aorta tissues could be diminished by ADA through getting rid of cell in the porcine aorta tissues or reducing the level of free amino groups in the porcine aorta tissues. The structural integrity of porcine aorta tissues can be preserved after treating with ADA. It was also found that the ADA-fixed porcine aorta tissues appeared more toughness and visco-elasticity, and should be promising biomaterials. Among the porcine aorta tissues fixed with ADA, the tissues that were fixed at pH 4.0, 15g/100ml initial fixative concentrations for 72h showed a more favorable characteristic.
  • . 2010, 41(10): 42-0.
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    Abstract: Different dimensions superparamagnetic Fe3O4 /BSA composite nanoparticles were synthesized by chemical liquid phase coprecipitation, which could be stably dispersed in solution for a long time. These particles showed better biological compatibility after being modified and coated proteins. An AC magnetic field (414kAm-1, 50Hz) was applied to record the change rate of turbidities of different particle sizes. The magnetic responsiveness of composite nanoparticles was obtained by using of turbidity-concentration fitting curves. The weight percentage of varied particles adsorbed on tube walls at the same time was semi-quantificationally calculated. Experimental results showed that the magnetic responsiveness of stable magnetic composite nanoparticles in the medium increases with the particles size. The particles size, 10nm, 108nm and 210nm were corresponded to the magnetic responsiveness 6%, 10% and 12%. After 30 seconds in additional magnetic field,the mass percentage of the magnetic composite nanoparticles with different dimension adsorbed on tube walls were 39.9%, 70.4% and 86.7%, respectively.
  • Li Yong You
    . 2010, 41(10): 43-0.
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    In order to improve the strength and impact toughness,adopt different heat treatment,watch the microstructure and analyse the composition by scanning electron microscopy(SEM) and analyse reasons.When using the reasonable relative composition design and heat treatment to control carbide structure and positions,solution anneal followed age-hardenable avoiding brittle phase,impact toughness are improved greatly.
  • . 2010, 41(10): 44-0.
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    The amorphous Fe78Si9B13 alloy was treated by low frequency pulse magnetic field (LFPMF). The temperature rise of specimens during the magneto-pulsing treatment was measured by a infrared non-touch-thermometer,The microstructural change of amorphous specimens after treatment were observed by M?ssbauer spectroscopy, XRD, TEM,etc. The results showed that nanocrystallization of amorphous specimens can occur at low temperature. The temperature rise is under 7℃. The volume content and grain size of nanocrystalline phase α-Fe(Si) are about 2.428%-6.992% and 10nm, Respectively. Compared with the as-quenched sample, the double- phase nanocrystalline alloy has obvious high mean hyperfine magnetic field. After the LFPMF treatment, this single-peak shifted to lower magnetic field and there was a sign of appearance of another single-peak at higher magnetic field. The peaks position varied with the pulse magnetic field parameters.
  • Xu-Li ZHU;
    . 2010, 41(10): 45-0.
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    When magnetic force between the particles in magnetorheological elastomers is estimated, the effects of the interactions of particle magnetization, particle structure and saturation of magnetization should be taken into account. In this paper, a particle unit model has been proposed for analyzing the local magnetic field of magnetorheological elastomers, which are composed by magnetic particles and non-magnetic polymer matrix, based on the principle of magnetism. The magnetization of particles is simplified based on the analysis of the particle unit, and a simple analytic formula for the magnetic force between the particles in magnetorheological elastomers has been obtained.
  • yao jin guang
    . 2010, 41(10): 46-0.
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    The surface modification of powdered carbonyl iron is necessary for the enhancement of its adhesion to silicon oil and MRF sedimentation stability by dispersion-polymerization. In this paper, Silane coupling agent was used for the surface modification of Carbonyl iron powder. The structure, morphologies and particle size of unmodified and modified carbonyl iron powder were characterized by fourier transform infrared spectroscopy, SEM as well as laser particle size analyzer. The results showed that carbonyl iron powder surface adsorbed coupling agent and particle size increased 2.4 times while there was good affinity with silicon oil. The modified carbonyl iron powders can be used for enhancement of MRF sedimentation stability. Adding coupling agent can strengthen MRF viscosity, but it effects weakly on rheological property.
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    . 2010, 41(10): 47-0.
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    PDMS membrane, PDMS/PTFE membrane and PP/PDMS membrane were prepared. The membranes were characterized by scanning electron microscopy (SEM), contact angle meter, thermo-gravimetric analysis (TGA) and Swelling test. Pervaporation experiments were carried out using these membranes to separate the mixtures of acetic acid/water. The results show that the selectivity and fluxes of membranes increase with increasing of feed concentration. With increasing temperature, fluxes increase and separation factors decrease. The separation factors change to some extent with increasing flow velocity of 14~38 L/h while fluxes change little. Support layer has significant influence to the pervaporation performance of membrane, the separation factors of 10 wt. % feed acetic acid concentration using PDMS, PDMS/PTFE and PDMS/PP membranes at 30 ℃ and 26 L/h are separately 2.51、2.74 and 2.15, and permeation fluxes are 35.29、42.09 and 40.84 g/(m2?h). All these observation would be helpful to provide a guideline for the selection of an optimum support layer and an optimum operating condition.
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    . 2010, 41(10): 48-0.
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    Melt-spinning speed has a significant effect on the microstructure and properties of melt-spinning Nd-Fe-B ribbons. In this paper, Nd10Fe81Co3B ribbons were prepared by melt-spinning method with different melt-spinning speeds, and the effects of melt-spinning speeds on the phase structure and crystallization procedure of Nd10Fe81Co3B ribbons were studied. The results show that there are great differences in the content of amorphous phases under different melt-spinning speeds. When the melt-spinning speed was increased, the content of amorphous phase was also increased. Moreover, the crystallization processes of ribbons melt-spun at different speeds are different. When the melt-spinning speed was low, there was a high degree of crystallization phase, whose crystallization annealing was controlled by disperse particle nucleus; With increasing the melt-spinning speed, there was high content of amorphous phase, whose crystallization annealing was gradually controlled by continuous crystallization model. With increasing melt-spinning speeds from 15m/s to 50m/s, the beginning crystallization temperature of all ribbons was at the range of 540-610 ℃.
  • . 2010, 41(10): 49-0.
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    Ti(C, N)-based cermets was obtained by the low pressure sintering technology. The microstructure ,phase of the Ti(C, N)-based cermets were studied by using scanning electron microscopy(SEM) and X-ray diffraction analysis(XRD), and compared the mechanical properties. The experiment results show that, the mainly microstructure of alloy was black core-white rim, there were only two phase existed are (Ti, W, Mo, Ta)(C, N) and Co/Ni ;with sintering temperature improved, the structure of alloy gradually uniformed , fracture toughness and hardness of Ti(C, N)-based cermets presented the trend of improving first and then reducing. Synthetical properties were best sintered at 1450℃, fracture toughness was 1774MPa, HV is 1628MPa.
  • Min Zhang
    . 2010, 41(10): 50-0.
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    Surface and fracture morphologies of carbon fibers prepared in Japan and China were observed by SEM. And the structure differences were analyzed. The results show that tensile strength of carbon fibers can be improved by descreasing the surface flaw, raising the internal compactness and reducing the size of axial micropores. The flaws of both inside and surface of homemade carbon fibers prepared by dry-jet wet spinning technology were minished, and it is beneficial to raise the tensile strength of carbon fibers. In addition, it is advantageous to lower the flaws in clean production condition and precision processing equipments.
  • . 2010, 41(10): 51-0.
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    A Langmuir-Blodgett (LB) inducing method was firstly used to prepare single layer and multilayer conducting composite PEDOT-PSS film. The film-forming ability of ionization ODA and ODA-SA monolayer spread on PEDOT-PSS nanoparticles subphase and the behavior of ODA/PEDOT-PSS assembly particles on pure water were firstly investigated. The results indicate that nanoparaticles in suphase pack the ionization monolayer and stable complex Langmuir film was formed at air/water interface. It has been found that the best film-forming conditions for composite film were as follows: molar ration of ODA to SA was 2:1, suphase temperature was 23 centigrade, concentration of PEDOT-PSS in subphse was about 1×10-3 M, compressing speed and deposition speed were 5 mm/min and 1 mm/min respectively. The SIMS and XRR investigation showed that this film exhibited well ordered layer structure.