25 November 2010, Volume 41 Issue 11
    

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    研究与开发
  • Enhanced the photoluminescent properties of BaMgSiO4:Eu2+ prepared in air by alkali carbonate
    You Pan-li
    . 2010, 41(11): 1-0.
    Abstract ( ) Knowledge map Save
    A serials of Eu2+-doped BaMgSiO4:Eu2+ phosphors were prepared in air by high temperature solid-state reaction. The effects of alkali carbonate on the PL properties of BaMgSiO4:Eu2+ prepared in air were investigated by X-ray diffraction (XRD), photoluminescence (PL) and scanning electron microscope (SEM). The results showed that Eu2+ ions located in Ba(1) and Ba(2) could be in favor of stable existence in air. The PL intensity of BaMgSiO4:Eu2+ prepared in air was increased by adding M2CO3 (M = Li, Na, K) flux, and the PL intensity of BaMgSiO4:Eu2+ phosphors containing 6% Na2CO3 prepared in air was the 91% of that prepared in reducing atmosphere.
  • Study on The Soft Magnetic Property of Fe/FeSiB Magnetic Core
    Zhenghou Zhu
    . 2010, 41(11): 3-0.
    Abstract ( ) Knowledge map Save
    Abstract: FeSiB amorphous magnetic cores were prepared by compression molding. The influence of annealing temperature, annealing time, granularity of amorphous powders，mixed rate of different granularity ，the amount of Fe powder added in were investigate to its performance. The results showed that when the cores were annealed from 200 to500 ℃, their μ increased and then decreased, reached at best at 375 ℃; the optimal annealing time found was 2 hours; Frequency stability was good at Frequency from 100KHz to 1MHz, and its center frequency found was about 500KHz; its performance get better as a increasing granularity of amorphous powders; the μ reached its maximum with the granularity rang from 60 to 100 mesh; its performance was best with a 60% of 60 to 100 mesh amorphous FeSiB when 60 to 100 mesh and 100 to 200 mesh amorphous FeSiB were composited; Its performance of soft magnetism with Fe composited had improved significantly, the μ could reach at 32 and Q at 33 with 30% Fe.
  • Experimental study on friction stir welded on thick plate of 7022 aluminium alloy
    WANG Hong feng; ;;
    . 2010, 41(11): 4-0.
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    Experimental study is carried out on the friction stir welding of 10mm thick 7022 aluminium alloy. The welded joint with smooth surface had been obtained. No welding crack and pore have been discovered by X-ray detection. The microstructure of friction welded joint is studied in different regions. The mechanical properties of welded joints are analyzed through tensile, impact and hardness tests. The results show that the organization of welded joint is small homogeneous isometric crystal. The tensile strength and yield strength of friction stir welded joints of 7022 aluminium alloy excess these of the base material when the rotating speed is 400rpm and the welding speed is 100mm/min. The impact toughness of welded joint is higher than the base material. The microhardness of welded joint is slightly lower than the base material. Welded joint has good mechanical properties.
  • Effect of sintering time at low temperature on the electrochemical dynamic performance of AB5 type hydrogen storage alloy
    Kai-Yu LIU
    . 2010, 41(11): 5-0.
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    AB5-type hydrogen storage alloy electrodes were sintered in flowing Ar atmosphere in tube-type resistance furnace at 573 K for different time (30min, 60min, 1h, 5h). Galvanostatic charge/discharge test, polarization curves and electrochemical impedance spectroscopy (EIS) have been performed to investigate the electrochemical performances of sintered electrode. The results indicate that the maximum discharge capacity of sintered electrodes in different time at the current density of 0.2C (60mAg-1) decrease with the sintering time increasing until 60min. The high rate dischargeablity (HRD) of sintered electrodes are better than the untreated electrode obviously, the longer the sintering time is, the higher the HRD is. The HRD of the sintered electrode for 60min increases 12.5% and 15% of sintered electrode for 5h when discharge at the current density of 1500mAg-1. The polarization resistance (Rp) and charge-transfer reaction resistance (Rct) of the sintered electrode decrease with the sintering time increase, while the exchange current density (I0), hydrogen diffusion coefficient D and limitting current density (IL) of the sintered electrodes increase significantly, the electrochemical dynamic performance of the alloy electrode is performed remarkably by sintering treatment at 573K.
  • Effect of pH Value on the Growth of the (100) Face of ADP Crystal
    . 2010, 41(11): 6-0.
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    Through investigating the growth rate of the (100) face of ammonium dihydrogen phosphate (ADP) crystal with different pH values at different supersaturations at 40℃, it is found that the growth rates of the (100) face improved noticeably after changing the pH value in the same supersaturations. The experimental results show that the growth of crystal is controlled by the dislocation mechanism at the lower supersaturations， and at the higher supersaturations, two-dimensional(2D) nucleation mechanism dominates the growth. Moreover, the growth mechanism transition from dislocation to 2D nucleation mechanism would occur at the lower supersaturations with the change of pH values. The edge free energy of the (100) face of ADP crystal with different pH values are calculated when the growth is controlled by 2D nucleation mechanism. Finally, the topography of the (100) surface of ADP crystal with different pH values at different supersaturations are observed by ex situ AFM. It is found that there are 2D nucleations appearing in the crystal surface with pH=2.5 and pH=5.0 at lower supersaturations compared with the normal pH.
  • Preparation and photocatalytic activity of Fe3+/Al3+- TiO2 composite photocatalyst and its the photocatalytic activity
    Fang Deng;yuexiang li
    . 2010, 41(11): 7-0.
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    Fe3+ and Al3+ co-doped TiO2 (Fe3+/Al3+-TiO2) composite photocatalysts were prepared by the sol-gel method using Ti(OC4H9)4 as precursor and characterized by X-ray diffraction (XRD) and UV-Vis. The effect of calcination temperature and salts in photocatalytic system on the photocatalytic activity of Fe3+/Al3+-TiO2 were investigated by photocatalytic degradation of methyl orange irradiated by sunlight. The photocatalytic activity of Fe3+/Al3+-TiO2 was enhanced with increasing temperature. HCO3- and NO2- decreased its photocatalytic activity.
  • Effect of Baking Temperature on Photocatalytic Properties of Titanium Calcium
    ;
    . 2010, 41(11): 8-0.
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    CaCO3 and TiO2 used as raw materials were baked to obtain CaTiO3 in the conditions that baking time is respectively 2,4,6,8 and 10h at 1500℃. The materials treated under high- temperature were characterized by XRD, SEM, FTIR, UV-Vis. The results show that baking time affects little on the synthesis of CaTiO3; with the time and temperature increasing, morphology of synthetic CaTiO3 changes into the smooth surface shape from irregular polygon-shape, and particles reunion phenomenon is increasingly apparent, and accumulation is dense among particles and size of particles increases. Baking time has little effect on the light absorption capacity of CaTiO3. With the extension of baking time in experiments of photocatalytic performance evaluation, the degradation rate and speed of methylene blue all reduces，and reaction rate constant can reduce the nearly 50%. The degradation of CaTiO3 on methylene blue solution is in line with a kinetic characteristic.
  • Function of nano-Si02 slurry for chemical mechanical polishing in alkaline media
    Xiaoyan Liu
    . 2010, 41(11): 9-0.
    Abstract ( ) Knowledge map Save
    Nano-SiO2 is a kind of functional material which has superior performance. In order to achieve a highly reliable CMP process it is necessary to examine the function of nano-Si02. However, at present the function of Nano-SiO2 for chemical mechanical polishing process in alkaline media is not well understood yet. A definitive understanding of the function is thus important to enhancement of the CMP process. There is a large number of hydroxyl, which react with alkaline forming silicate anion, on the nano-SiO2 sol surface due to the surface effect. Then silicate anion reacts with silicon in order to decrease nano-SiO2 surface energy. Meanwhile the silicon is removed. As described above, It is anticipated that the nano-SiO2 during CMP process not only function as abrasive but also take part in the chemical reaction. The reaction mechanism for nano-SiO2 is proposed based on the characteristic of nano-SiO2 for chemical mechanical polishing in alkaline media.
  • Preparation and Magnetic Properties of Fe3O4/wood Composite
    Hong-Lin GAOGuoyuan WU
    . 2010, 41(11): 10-0.
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    Abstract: Fe3O4/wood composites were prepared by the in-situ chemosynthesis method at room temperature with Yunnan fir wood as the matrix and mixed solution of FeCl3 and FeCl2 as the impregnating solution. The structure characterized by X-ray diffraction (XRD), and scanning electron microscopy (SEM) shows that the average particle size of Fe3O4 crystal is about 14 nm, but the particles settled in the hole of wood are aggregated with the size changed to 0.5~2.5 μm. Fourier transform infrared (FT-IR) analysis indicates that there exists interaction between Fe3O4 particles and the wood matrix, and the interaction influences the magnetic property of the composite. The magnetic feature was characterized by vibrating sample magnetometer (VSM). The results show that the concentration of impregnating solution and the wood fiber direction has some effects on the magnetization. It is found that the magnetization of the composite reaches to its maximum value with Fe ion concentration of 1.2 mol/L in the impregnating solution. Samples under the magnetic field with the same direction as their fiber directions have higher remain magnetization.
  • The study on technology for high corrosion-resistant SiNx thin film deposited by plasma enhanced chemical vapor deposition
    Liu Rui Wen;Jiao Bin bin ;
    . 2010, 41(11): 11-0.
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    The technology for high corrosion-resistant SiNx thin film deposited by plasma enhanced chemical vapor deposition (PECVD) was studied. The refractive index and film composition were studied by ellipsometer and X-ray photoelectron spectroscopy (XPS). Wet etching studies were conducted using alkaline solution. The results indicted that the deposition parameters have great influence on the performance of corrosion resistance. SiNx thin film with high corrosion-resistance has been deposited, the thin film can endure 12 hours in high-temperature alkaline solution (70 ℃, 33.3% KOH solution) without significant change, and accomplish self-supporting and full-hollow thin film finally.
  • Electrical Properties of Mixed Conductor Ba0.5Sr0.5Co0.8Fe0.2O3-δ
    ;;
    . 2010, 41(11): 12-0.
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    Abstract: In this paper, the total conductivity of Ba0.5Sr0.5Co0.8Fe0.2O3-δ（BSCF）was investigated by the DC four-probe measurement under the air and nitrogen atmospheres, the electronic blocking electrode measured ionic conductivity of BSCF under air atmosphere. The results showed that BSCF showed p-type semiconductor conductive characteristics, the total conductivity of BSCF increased with rising temperature and decreased with the decrease of oxygen partial pressure lower than 575℃; However, the total electrical conductivity dropped significantly due to escape of lattice oxygen of BSCF materia at 575 ℃~650 ℃. The relationship between temperature T and ionic conductivity σi measured by E-blocking electrode method is consistent with Arrhenius plot, and oxygen-ion conductance activation energy Ea = 140.7 kJ / mol. Oxygen ion conductivity calculated from Wagner formula is coincide with the value measured by electronic blocking method lower than 700℃; but oxygen ion conductivity is obviously lower than the value measured by electronic blocking method due to the exchange of gas and lattice oxygen of membrane surface of oxygen-rich side and the exchange of surface lattice oxygen and gas phase oxygen of hypoxia-side becoming the rate-limiting steps higher than 700℃, and the difference between them increased with rising temperature.
  • Study of Bi4Ti3O12 and Bi3.25La0.75Ti3O12 Ferroelectric Films With Si Substrate by Variable-energy Positron Beam
    ;;;
    . 2010, 41(11): 13-0.
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    A series Doppler broadening spectra of Bi4Ti3O12 and Bi3.25La0.75Ti3O12 ferroelectric films deposited on Silicon Substrate are measured by means of Variable-energy Positron Beam, the positron implantation energy dependence of shape parameter S are performed. The S(E) and W(E) data are analyzed dy plotting them in the S-W plane, the positron trapping states related to the structure of the samples are discussed. The results indicate that for the both samples the defects on the interface region between ferroelectric film and Si substrate are of multivacancy–Multioxygen complexes(VxOy) type. It also implys the doping of lanthanum is helpful to increase the diffusion resistance of the defects. Key Words: Variable-energy Positron Beam, Doppler broadening Spectrum,
  • Preparation of ZnFe2O4 by hydrolyzing Zn/Fe3O4 Nano-particles
    LI LAI QIANG;;
    . 2010, 41(11): 14-0.
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    Zn nano-particles were prepared by a dry roller vibration milling at room temperature, Fe3O4 nano-particles were prepared by chemical precipitation method, and then ZnFe2O4 nano-particles were manufactured by hydrolyzing Zn/ Fe3O4 nano-particles. TEM and XRD tests showed that Zn particles size milled 11 hour was the range between 10 and 20nm, Fe3O4 particles size was about 20nm and the solid product of the hydrolysis was also about 20nm with quadrate nano-flake morphology. The research indicated that it was optimal reaction condition for making ZnFe2O4 when reaction temperature was 300℃ and mol ratio (Zn: Fe3O4) equal to 1.5:1. It is obvious that Zn nano-particles milled 11 hour provided with excellent performances, which could make the chemical reaction complete rapidly in a lower temperature. The preparation method was comparative simpleness and prone to a batch production.
  • Effects of processing parameters on the structure and morphology of crystallized SrMoO4 films prepared by Chemical Solution Deposition
    ;
    . 2010, 41(11): 15-0.
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    Abstract: Under different processing conditions, crystallized SrMoO4 films with single scheelite-structure have been prepared on Si substrates via Chemical Solution Deposition. The films were characterized by X-ray diffraction (XRD) and scan electric micrograph (SEM) techniques. The effects of the processing parameters (including the contents of alcohol and acetic acid, solution concentration, and so on) on the structure and morphologies of the films have been systematically discussed. The research results indicated that all the prepared SrMoO4 films possess tetragonal phase with scheelite-structure and the growing characteristic of the films relied on the processing conditions except for the content of the alcohol. And also optimizing the processing conditions is very important for obtaining the dense and well-growth SrMoO4 thin films.
  • Preparation and photoelectrocatalytic activities of CdS/TiO2 nanotube arrays
    ling shi sheng
    . 2010, 41(11): 16-0.
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    The CdS particles modified TiO2 nanotube arrays (CdS/TiO2 NTs) were fabricated through anodization and electrodeposition. The morphology, phase structure, optical properties and photoelectric properties of CdS/TiO2 NTs were characterized by field emission scanning electron microscope(FE-SEM), X-ray diffraction(XRD), Diffuse Reflectance Spectroscopy(DRS) and Linear Sweep Voltammetry(LSV). The photoelectrocatalytic activity of CdS/TiO2 NTs was evaluated in degradation of methylene blue (MB) in aqueous solution. The results showed that CdS existed on the TiO2 NTs’ surface in particle form. CdS/TiO2 NTs exhibited higher photo absorption rate under visible light, bigger photocurrent (value) and improved photocatalytic activity ,compared with TiO2 NTs.
  • The biodegrades of porous ceramics of strontium substituted hydroxyapatite in vivo
    . 2010, 41(11): 17-0.
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    The Sr-HA（hydroxyapatite containing 5 at% Sr) porous ceramics and HA porous ceramics (as the positive contrast) with poriness of 31% were implanted into two side sacrospinal muscle of New Zealand rabbits. The interface between sample and muscle were observed with means of scanning electron microscopy and tetracycline fluorescent marker to evaluate the biodegradability and biologic capacity.The Results indicated that the quantity of crystal body were observed to degrade into structure as bone lacunae on the surface of Sr-HA at three months, while control group hadn’t much more appearance of degradation as time continued. Strong and bright fluorescent cingulum can be seen around Sr-HA at the six months. Sr-HA is a biomaterial with good biocompatibility and tissue conductivity. Sr-HA degrades faster and more completely than HA, and may induce bone matrix formation.
  • Hydrothermal synthesis, characterization and properties of single-crystal Sb2S3 nanoribbons
    ; ;
    . 2010, 41(11): 18-0.
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    Single-crystalline Sb2S3 nanoribbons have been successfully prepared by a simple hydrothermal method. It was found that CTAB plays a key role in the formation of the Sb2S3 nanoribbons. The morphology and structure of the obtained nanoribbons were characterized by XRD, SEM, TEM, and HRTEM in detail, indicating that the prepared Sb2S3 nanoribbons grows along the [001] crystal face. The widths of these nanoribbons are around 1 micrometer and lengths of tens of micrometers. The growth mechanism and optical properties of the obtained nanostructures were also discussed and measured.
  • Fluorescence Properties of 3-Pyridin-3-yl-indolizines in different pH condition
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    . 2010, 41(11): 19-0.
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    Abstract: Three compounds of 3-pyridin-3-yl-indolizines a, b and c were prepared. The fluorescence spectra of these compounds in different pH buffer solutions were studied. The results indicate that these three compounds all can emit strong blue fluorescent, and the fluorescence properties were affected apparently by the pH data. With the increasing of the pH, the fluorescent intensity of these three compounds all can be increased, and the emission wavelength were all red shifted , but the degrees of the increasing and red shift were obviously different. Among them, the fluorescent intensity of compounds c and a can be increased 200 and 150 fold, while the emission peaks of compounds b and a shifted by 49 and 30nm, respectively.
  • Organic chemistry template method of carbon nanotube/polyaniline hollow sphere composite
    . 2010, 41(11): 20-0.
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    In this paper, the four-iron oxide as a template, firstly the aniline was grafted on the surface of the carbon nanotubes (CNTs) by series of organic chemistry reactions. Then，the aniline grafted on the CNTs was polymerized to polyaniline (PANI) by in-situ chemical polymerization. At last, a hollow sphere nanometer composite named as the CNTs/PANI composite was obtained. The composition and the morphology of the obtained CNTs/PANI composite were characterized by the Fourier transform infrared spectroscopy and scanning electron microscope. And the electrochemical performances of the obtained materials were tested by the cyclic voltammograms, galvanostatic charging/discharging, and cycle life. The researching results showed that the obtained CNTs/PANI composite had high specific capacitance of 185F/g (in organic electrolyte), which was much more than those of the pure PANI, and CNTs/PANI composite by the organic chemistry metheds (about 65 F/g, 152 F/g). And this material appeared excellent application foreground in electrochemical energy field.
  • YAG: Ce3+ Phosphor Prepared by Spray Drying then Heat Treatment at High Temperature
    Shao-Yun CHEN
    . 2010, 41(11): 21-0.
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    YAG: Ce3+ phosphor was prepared by spray drying and then heat treatment at high temperature from a suspension including aluminum polycation. Effects of the heat treatment temperature and the suspension concentration on YAG phase formation, the particle morphology and the luminescence properties of the phosphor were analyzed by XRD, SEM and fluorescence spectra. Results showed that the particle size increased and the morphology tended to spherical when the suspension concentration increased from 0.03mol/L to 0.09mol/L. The relative brightness of phosphors increased when the heat treat temperature increased from 1300℃ to 1500℃ for 2h at the suspension concentration of 0.09mol/L. The YAG phase could be obtained after heat treatment at 900℃ for 2h. No hollow had been observed inside the particle of YAG: Ce3+ phosphor and the powder was low aggregation.
  • Synthesis and characterization of nanorods of polyaniline doped by sulfosalicylic acid
    Wang Xuezhi
    . 2010, 41(11): 22-0.
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    Nanorods of polyaniline(PANI) doped with sulfosalicylic acid has been synthesized via interfacial polymerization method using ammonium persulfate(APS) as oxidant. Polyaniline nanorods were characterized by FT-IR, UV-Vis, TEM and XRD. The results showed that SSA/AN and organic phase played the important roles in controlling the morphology of polyaniline. While the density of the organic phase is lower than water, the generated PANI had the better morphology, crystalline, yield and conductivity.
  • Microstructure evolution of Fe-3%Si in hot deformation process
    Feng-Hui AN
    . 2010, 41(11): 23-0.
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    Compression test of Fe-3%Si steel at the temperature 1173K with strain rate 0.01s-1 was carried out by Gleeble-1500 at different strain. EBSD was used to analysis the microstructure of deformed sample to discuss the mechanism of grain refinement. It was shown that well developed sub-grains had formed in the vicinity of grain boundary by progressive lattice rotation in the small strain stage, and with the strain increase, the misorientation in the vicinity of initial grain boundary increased, which led to the small angle grain boundaries became larger ones. In the large strain stage, the large grain boundaries new formed earlier contacted with each other, after then, the grain refinement will take place by geometric dynamic recrystallization though out the material. So, continuous dynamic recrystallization is the dominant mechanism for grain refinement for Fe-3%Si steel in the hot deformation process.
  • The Influence of Ultrasound on Coating Comprehensive Performance and density of diamond grid of Electroplated Diamond Tools
    . 2010, 41(11): 24-0.
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    The influence of the ultrasound on preparation of electroplated diamond tools has been studied. Electroplating was carried out from a conventional Watts bath with ultrasonic addition. Physical properties of the coating including microstructure, thickness and hardness were studied under the conditions of different ultrasonic power. The ultrasonic power was determined when the coatings get the best comprehensive performance. The microstructure and thickness of the coating was examined under a metallographic microscope, and hardness was tested by Micro Hardness Tester. Test showed that coating has a good comprehensive performance when ultrasonic power is 200 Watts. The impact of ultrasound on density of diamond grit in thickening process was studied with microscope for the preparation of electroplated diamond tools. It has laid the foundation for preparation of ultrasonic electroplated diamond tools.
  • A rapid，facile and efficient biomineralization approach for chitosan materials
    Lihua Li ;
    . 2010, 41(11): 25-0.
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    Mineralization of biopolymers is a hot topic and a promising method for tissue engineering. In this study, biomimetic mineralization of chitosan sponges was performed in a large quantity with a rapid and facile approach. The calcium phosphate apatite was co-precipitated as the precursor for the formation of hydroxyapatite in mixed water-ethanol solution. The component and morphology of the apatite and the nanocomposite hybrid sponges were measured with XRD, TEM, FTIR and ESEM. Results revealed that chitosan matrix improved the crystalline quality of hydroxyapatite (HAP) crystals. With elongation of mineralization time, the mineral layers on the outer surface and inner section of chitosan sponges increased. The chitosan sponge or the microenvironment around it promoted the crystallites quality of HAP phase. Furthermore, the compressive strength and modulus of the HAP-chitosan bio-composites increased to 0.55 MPa and 29.29± 1.25 MPa respectively. Such one-pot approach might be extended to the mineralization of other biopolymers and will have a very broad application in the future.
  • Design of novel microwave cavity for MPCVD diamond film
    . 2010, 41(11): 26-0.
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    New microwave cavity for diamond film deposition was proposed in this paper, the effective volume of cavity can be adjusted, ring shape quartz window is located under the substrate holder, which is far from the plasma, allowing to generate plasma with high temperature. Inner conductor is connected with the substrate holder, microwave power enters the chamber from the bottom of the cavity. Numerical simulations were performed to optimize the geometry by Finite Element Method (FEM), After optimization, the electric field in cavity exhibits one maximum and homogeneous distribution on substrate. Especially, it is very weak near the dielectric window, which satisfy the requirement of design. The calculation of the number density of electrons by Finite Difference Time Domain（FDTD) method, primary experiment was carried out ,the shape and position of plasma are consistent with numerical prediction.
  • The effect of temperature on the morphology of Ge/Si quantum dots grown by ion beam sputtering
    . 2010, 41(11): 27-0.
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    A serial of Ge quantum dot samples were grown by ion beam sputtering on Si(100) substrate at different temperature. The surface morphology and structure were studied with AFM and Raman spectra，Our results indicated that with temperature increasing，the density of quantum dots increased(At temperature of 750 ℃，the density of the quantum dots was up to 1.85×1010 cm-2)，the distribution of the quantum dots became more ordered，and the crystallinity became better. But the alloying processing was enhanced at the same time.
  • Fabrication of Nanostructured PZT Ferroelectric Thin Films and Their Characterization
    Xin hua Zhu ;;;;
    . 2010, 41(11): 28-0.
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    By using sol-gel spin coating method nanostructured Pb(Zr0.53Ti0.47)O3 (PZT) ferroelectric thin films were fabricated on the Si substrates coated by nanoporous alumina membranes with average pore sizes of 20 - 100 nm, in which metal (Au or Pt) nanowires were embedded as a part of the bottom electrode. The dielectric, ferroelectric properties and microstructure of the nanostructured PZT thin films were characterized. The dielectric measurements demonstrated that the dielectric constant of the PZT nanofilms with a thickness of 25 nm decreased quickly from 860 to 100 as increasing the frequency below 104 Hz, and then remained almost constant of 100 as further increasing the frequency up to 106 Hz. Such a fast decrease of the dielectric constant in the low frequency region was resulted from the dielectric relaxation of space charges accumulated at the interfaces between the nanofilm and the (bottom and top) metal electrodes. The dielectric loss peak observed near 4000 Hz was contributed from the resonant absorption effect of the space charges. The polarization-electric field hysteresis loops of the nanostructured PZT films with a thickness 100 nm showed that the remanent polarization of the PZT nanofilm was 50 mC/cm2 and coercive field of 500 kV/cm. Cross-sectional TEM images showed that the nanostructured PZT films contacted directly with the bottom electrode (metal nanowires), and the interface between them exhibited some degree of waviness. It was found that some Au nanowires became into branches at their ends after post-annealing the PZT nanofilms, whereas such a phenomenon was effectively prohibited by using Pt nanowires. A selection of proper post-annealing temperature was the critical processing parameter for fabricating nanostructured PZT ferroelectric thin films as making a trade-off between the ordered metal nanowires within the anoporous alumina membranes and the crystallinity of ferroelectric nanofilms.
  • Effects of atmospheres on reaction interface of Ag-Cu braze and oxygen-permeable membrane ceramics
    . 2010, 41(11): 29-0.
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    Ag-Cu braze was used to seal oxygen-permeable membrane ceramics and stainless steel support. Effects of atmospheres on reaction interface of Ag-Cu braze and oxygen-permeable membrane ceramics were investigated. The results show that a Cu-rich reaction layer on the membrane side has formed and the thickness of this reaction layer is about 310 μm. The thickness of the reaction layer keeps almost invariable in Ar and Ar+10%O2 for 100h, which indicates that the joining interface is stable in inert and oxidation-inert dual atmosphere environment at high temperature.
  • Quantitative Evaluation of H2O2 in Aqueous Suspensions of Zinc Oxides with Different Morphologies
    . 2010, 41(11): 30-0.
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    Hydrogen peroxide (H2O2) is considered as one of the primary factors in antibacterial mechanism of zinc oxide powder slurry. The H2O2 generated from the suspensions of zinc oxides with different morphologies under different light excitations were studied according to specified reaction followed by UV-Vis spectrophotometer. The results indicated that H2O2 was detected out from the three kinds of zinc oxide suspensions under simulated sunlight, darkness or UV-light. The productivities of H2O2 from the related three kinds of ZnOs were ranked as T-ZnO, n-ZnO and p-ZnO, whatever the light excited or not. There was no apparent proportional relationship between light conditions and the production of H2O2, and the morphology had more obvious effect than particle size and/or specific surface area.
  • Preparation and properties of two-colour interconversion electronic ink microcapsules
    . 2010, 41(11): 31-0.
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    The electronic ink microcapsules containing modified Phthalocyanine Green G and TiO2 particles were dispersed in Tetrachloroethylene (TCE) and prepared by complex coacervation with Gelatin-Gum acacia as wall materials. The size distribution of the unmodified and modified Phthalocyanine Green G was studied, the dispersing of the modified particles is better than the unmodified. The factors that affected the morphology of the electronic ink microcapsules were also discussed, and the response behavior of electronic ink microcapsules under the DC electric field was also studied. The results showed that the modified Phthalocyanine Green G and TiO2 nanoparticles have good dispersion behavior and reversibility under the electric field.
  • dielectric performances of graphene/PS intercalation composites
    yang cheng
    . 2010, 41(11): 32-0.
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    The single sheet graphite(graphene) was successfully obtained by concentrated acid treated and high temperature rapid thermal shocked. High resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) analysis confirmed the ordered graphene crystal structure. Prepared the graphene/polystyrene (PS) composite materials using the hot forming process. The dielectric performance measurement shown that the graphene/PS nanocomposites have very low percolation threshold (0.1 wt %), Such a low percolation threshold is help to the use of such materials development tend to minitype and weigh-light (when the content of grapheme < 0.1wt %). Future more, we found that the dielectric properties of graphene/PS nanocomposites have greatly different at with and without electric flied-induced.
  • Investigation into characterization of rhombus dodecahedron closed-cell cellular materials
    . 2010, 41(11): 33-0.
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    Abstract :Based on cell formed principle ,geometrical model which describes cellular materials closed-cell rhombus dodecahedron with thick edge is constructed .The dependence of relative density on microstructure and the unitary relation are also gained ;relative elastic modulus and Poisson’ ratio are calculated ,the influence of microstructure and relative density on above two material parameters are analysed. The results show that single-cell wall thickness is the secondary factor of relative density increment, wall-face connective curvature radius is the primary factor of relative density increment; the influence of increasing solid in wall-faces connective place on relative elastic modulus is same .These results can provide principle basis for cellular material parameters design.
  • Study on Static/Dynamic Mechanical Properties and Constitutive Relation of Multifunction cloth
    . 2010, 41(11): 34-0.
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    Tests via MTS and SHPB on the physical properties of multifunction cloth were carried out. Basic mechanical parameters and stress-strain curve of the cloth were obtained. The static and dynamic constitutive model was presented based on analysis of deformation behavior of materials, strain-rate-related effects and destruction properties. It provides bases for engineering applications of these materials and further improvement. Results show: under quasi-static loading and shock loading, strain rate effect is obvious with increasing strain rate and higher slope of stress-strain curve.
  • Preparation of functional polymeric nanofilm on AM60 magnesium alloy surface and its properties
    Ying-hui LIU;Zhi-Xin KANG;Gang FANG;Fen WANG;Yan LONG;Yuan-yuan LI
    . 2010, 41(11): 35-0.
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    The polymeric nanofilm on surface of AM60 magnesium alloy was fabricated by means of polymer plating with synthesized organic monomer of the triazine dithiol monosodium. The reaction mechanism during polymer plating was analyzed with cyclic voltammetry and X-ray photoelectron spectroscopy (XPS). The film thickness and wettability were respectively determined by spectroscopic ellipsometer and contact angle meter. The corrosion resistances of polymeric film were evaluated with polarization curve and electrochemical impedance spectroscopy. The experimental results show that the thickness of polymeric film belonged to the nanometer scale, and surface wettability was modified from hydrophilic into hydrophobic with fabricated nanofilm. The corrosion current density of polymer-plated magnesium alloy decreased to 540 nA?cm-2 as compared with 18 400 nA?cm-2 for the substrate, while the corrosion potential increased from -1.454 V to -1.340 V, and the charge transfer resistance raised from 2.24 kΩ?cm2 to 16.88 kΩ?cm2. Therefore, the anti-corrosion property for magnesium alloy was efficiently improved through polymer plating.
  • Effect of Electric Field Environment on the Process of Depositing Pure Cr Films by Magnetron Sputtering
    Li Hongtao
    . 2010, 41(11): 36-0.
    Abstract ( ) Knowledge map Save
    Pure Cr films were deposited under different electric field environment by magnetron sputtering ion plating system, and the effect of electric field environment on the micromorphology of pure Cr films were analyzed; Combining sputtering depositing principium with film growth principium, the essential impact of electric field environment on the process of depositing pure Cr films were revealed; Then prospective functions of magnetron sputtering ion plating technology in the process of the nano-engineering materials and amorphous materials were discussed. Based all above, it is expected to provide references for R&D nano-materials and the technical innovation of preparation.
  • Preparation of Y2O3:Eu3+ Luminescence Materials Chip by Micro-nano Dry Powder Pulse Jet Combustion Method
    Wang Yi;hou li ya
    . 2010, 41(11): 37-0.
    Abstract ( ) Knowledge map Save
    Y2O3:Eu3+ luminescence materials chip prepared by micro-nano dry powder pulse jet combustion method based on Technology of Digitalization of Microfluids, was tested by UV analyzer and fluorescence spectrometer. Different from the drop-on-demand inkjet delivery method, raw materials powder was jetted directly to prepare materials chip using powder-jet method, that micro-nano dry powder pulse jet method. Preparation of solution or suspension was unnecessary, so the materials chip preparation efficiency was raised. As the powder-jet technology is applicable to each kind of powder, it can be applied in new materials screening of electron, chemical industry, energy and many other fields.
  • Preparation and characterization of polypropylene/sepiolite composites and its mechanical properties
    ;hu xiao ping ;;
    . 2010, 41(11): 38-0.
    Abstract ( ) Knowledge map Save
    Organophilic sepiolite (OSEP) has been prepared by water exchange and absorption between hexadecyl trimethyl ammonium bromide (CTAB) and sepiolite, and the polypropylene(PP)/sepiolite composites were prepared by melt blend in a twin-screw extruder. The organic modification effect of sepiolite was confirmed by SEM、XRD、FT-IR、TG and CA, the results showed that CTAB has entered the channel of sepiolite, and some CTAB was adsorbed on the surface of SEP. The TG test indicated that the residue amount of OSEP increased by 17.63% compared with sepiolite at 800℃. The mechanical properties of composites were also investigated, it is indicated that the tensile and impact strengths of PP are improved effectively when the addition level of OSEP is 1.5%. The analysis of PP/OSEP composite using WAXD also show that the addition of OSEP results the reduction of β crytal and improvement of α crystal.
  • Preparation and characterization of cellulose/CdS nanocomposites
    . 2010, 41(11): 39-0.
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    Abstract： Nanocomposites of cadmium sulfide and microcrystalline cellulose (CdS/MCC) have been prepared from an aqueous solution of cadmium chloride and sodium sulfide by in-situ process using microcrystalline cellulose as substrate material. The influences of compounding conditions on the composition results were studied. The amount of the compounded cadmium sulfide particles depends on the composition conditions, such as Cd2+ concentration , Cd2+absorbing time, and ultrasonic powers. It is indicated that the content of compounded cadmium sulfide particles can be improved by properly increase Cd2+absorbing time and ultrasonic powers.The influences of Cd2+ concentration is significant. The structure and the properties of the composite (MCC/CdS) obtained were investigated by means of X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transformed infrared (FTIR) and photoluminescence (PL) spectrum. According to SEM images, the obtained CdS particles evenly distributed on the surface of microcrystalline cellulose. The PL spectrum of the CdS/MCC composite particles displayed peaks range from 510 nm to 540 nm with exited wavelength at 420 nm.
  • Synthesis of cryptomelane-type ion-sieve for potassium and its ionic exchange performance
    ;
    . 2010, 41(11): 40-0.
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    Cryptomelane-type manganese dioxide was prepared using manganese carbonate and potassium methoxide as the raw materials by high temperature solid-state method. A novel potassium ion-sieve (CRYMO-H) was obtained by acid-modification of CRYMO. The characterizations of the synthesized CRYMO-H were carried out by AAS, TG-DTA, BET, XRD and SEM. The effects of the Mn/K ratios of raw materials, calcined temperature and calcined time on crystal phase were investigated. The exchange capacities to K+, Ca2+, Mg2+, Na+, Li+ in single salt solution and the selectivities of CRYMO-H for the main cations in the seawater were measured. The results show that the chemical formula of the sample is K0.95Mn7.96O16.00 and its crystal phase belongs to α-MnO2 when prepared at the Mn/K ratio of 4:1, calcined temperature of 620℃ and calcined time of 12h. The sample is stable up to 650℃ and its morphology is virgulate-like. The exchange capacities of CRYMO-H to K+ in pure potassium solution and seawater are 126.78 and 29.11mg/g respectively, and its selectivity coefficients to K+ in the solution of K+/Na+ and K+/Li+ are 115.68 and 134.91 respectively, whereas it has no exchange capacity for Ca2+ and Mg2+. Therefore, the ion-sieve can be used to extract potash selectively from seawater. Key words: High temperature solid-state method; Cryptomelane-type manganese dioxide; Ionic sieve for potassium; Ion exchange performance
  • First principles study on the phase stability of CaNi2 and CaMgNi4
    . 2010, 41(11): 41-0.
    Abstract ( ) Knowledge map Save
    We performed first-principles calculations to the phase stability, ealstc properties and electronic structure of CaNi2 and CaMgNi4. The calculated results show that CaMgNi4 has the higher stability than CaNi2, duing to the relaxation of the stresses between atoms. The calculated bulk modulis show that CaMgNi4 has the larger bulk moduli than CaNi2. The melting temperature of CaNi2 and CaMgNi4 were calculated from elastic constants and bulk moduli, the results show that CaMgNi4 has the higher melting temperature(1379.6K or 1458.4K) than CaNi2 (1075.4K or 979.37K).
  • Research on interfacial characteristic of PDC prepared using nickel based alloy
    hongsheng jia
    . 2010, 41(11): 42-0.
    Abstract ( ) Knowledge map Save
    Abstract: Homogeneous D-D grown Polycrystalline Diamond Compact (PDC) was synthesized using infiltrating method with nickel based alloy as sintering solvent at high temperature and high pressure(HTHP, 5.2～6.0GPa , 1350～1450℃). Optical Microscope（OM）and Scanning Electron Microscopy (SEM) were used to observe the microcosmic morphology of PDC interface. The composition and the element distribution of PDC interface were investigated, the compound mechanism of interface growth was discussed by XRD and EDS. The results indicate that the original nickel based alloy symmetrically infiltrated the diamond layer and the WC foundation bed; The dense and interlaced microstructure with diamond-diamond (D-D) direct bonding has formed in the diamond layer of PDC; The transition layer exists in PDC.
  • Preparation of Bi0.75Er0.25O1.5 nanocrystalline solid electrolyte by SPS
    Rong LI; Michel Drache;;
    . 2010, 41(11): 43-0.
    Abstract ( ) Knowledge map Save
    Using analytical pure Bi2O3 and Er2O3 as raw materials, the precursor of Bi and Er can be precipitated by reverse titration co-precipitation method, and the adequate pH value for co-precipitation was also analyzed. Bi0.75Er0.25O1.5 nano-powder was obtained after calcining this precursor at 500oC for 3h. High temperature XRD results showed that this nanopowder was mainly in beta form, with an average grain size of 10nm calculated by Scherrer Equation, which transformed into delta form completely at 650oC. According to the thermodynamic calculation, the suitable temperature and partial pressure of oxygen was chose. Finally, dense delta-Bi0.75Er0.25O1.5 solid electrolyte was sintered at 500oC (measured temperature) for 1min, with a relative density of 96% and an average grain size of 18nm.
  • Effect of Plasma Stability on Growth of Convex Diamond Films
    Li Duosheng
    . 2010, 41(11): 44-0.
    Abstract ( ) Knowledge map Save
    Convex diamond films were prepared by direct current plasma jet chemical vapor deposition (DCPJCVD), and it was important to keep plasma stability on growth of convex diamond film. The results showed that, when convex diamond film grew in long time, anode usually accumulated graphite, and it hampered plasma moving, which caused quality of convex diamond film worse. Graphite is removed in good time, and it still can hold stabile plasma, stabile electron temperature Te and uniform active atom and radical density. Convex diamond film prepared was characterized by some techniques such as SEM and Raman. It was found that convex diamond film was compact and crystal size is homogeneous, and there is only diamond characteristic peak in diamond film. Thus, so high quality convex was prepared.
  • Preparation of Cd2+-doped TiO2 nanopaticle and influence mechanism of their energy level structure
    . 2010, 41(11): 45-0.
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    Abstract: Cd2+-doped TiO2 nanoparticles were prepared via sol-gel methods. These samples were characterized by X-ray diffraction(XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and UV–vis diffuse reflectance spectroscopy (DRS). The results indicate that all the resultant undoped TiO2 nanoparticles consist of anatase crystallites with a size of 20nm, which the mothology and size were not significantly affected by doping at low doping concentration. XPS results showed that Cd replaced Ti in the crystal lattice and formed Cd-O bong, and absorption edge of TiO2 nanoparticles exhibit obvious red shift with a reduced band gap because of doping Cd2+. First-principles based on the density functional theory(DFT) was employed to investigate influence mechanism for the energy level structure of Cd2+-dopd anatase TiO2. The theoretical results are identical to the experimental results.
  • A Coating Material of Adjust to Cohesive Force Between Polar Plate and Dust
    . 2010, 41(11): 46-0.
    Abstract ( ) Knowledge map Save
    In order to adjust cohesive force between Dust and polar plate, by setting up a mathematical model in the thesis, derive accept power thing of electricity medium due to electricity medium constant’s difference，educe electricity medium is pressed direction rule，calculate to select the appropriate coating materials, design the experimental equipment by myself ，through experiments approve coating’s adjust action for cohesive force.
  • Study on shielding properties of boron-containing iron ore concentrate powder/epoxy composite
    ;
    . 2010, 41(11): 47-0.
    Abstract ( ) Knowledge map Save
    A low cost shielding material using boron-containing iron ore concentrate and low viscosity epoxy E51 as starting materials was developed. Boron-containing iron ore concentrate was got after green ore containing boron dressing which is specific in China. Experiments were performed in order to determine the characteristics of the low cost composite, such as slow neutron and 60Coγ shielding performance. Confirmed the optimum mixture ratio of epoxy to boron-containing iron ore concentrate. Testified the feasibility of using boron-containing iron ore concentrate as starting material to prepare the shielding material. The results showed that slow neutron cross-section of three samples proportioning are all larger than lead-boron polyethylene shielding material B201, which cross-section is Σ=0.158cm-1 and loaded with B4C as neutron absorber. The largest cross-section among the samples is Σ=0.1882cm-1 and performs good slow neutron shielding ability. The 60Coγ shielding performance is between water and concrete, the largest linear attenuation coefficient of samples is μ=0.0772cm-1.
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