25 April 2011, Volume 42 Issue 04
    

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    研究与开发
  • Yan Dong
    . 2011, 42(04): 1-0.
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    Abstracts: Mg doped BaAl12O19:Mn2+ green phosphor for PDP with the particle size of 1~2μm was synthesized by the chemical co-precipitation method, the phase transition and particle growth process of the phosphor during the baking process were investigated, and the screen coating experiment was made by spraying the phosphor. The results show that, the phase transition is extremely complicated, the transition phases include BaCO3, γ-Al2O3, BaF2, BaAl2O4 and two phases contain Mn, no ?-Al2O3 phase appears during the entire process; The formation temperature of BaAl12O19 phase by the co-precipitation method is approximately 1200℃, which is significantly lower than that by the high temperature solid state reaction method. A well dispersed Mg doped BaAl12O19:Mn2+ green phosphor with small particle size and hexagonal flaky shape can be prepared by this method. The result of the screen coating experiment showed that, the phosphor layer sprayed with the phosphor is dense and with a flat surface, which is beneficial to obtain a larger discharge space.
  • Fan-Guang Zeng
    . 2011, 42(04): 2-0.
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    Carbon nanotube (CNT) film was directly grown on silicon substrate by pyrolysis of FePc. The characteristics of directly grown CNT film in the way of intensity pulsed electron emission was investigated. When the electron emission was performed in the mode of single pulse, pulsed peak emission current and the corresponding current density under a macro electric field of 11.7V/μm are 109.4A and 5.57A/cm2, respectively. In the mode of double pulse, for the first pulse, the peak current and the corresponding current density under a macro electric field of 8.6V/μm are 117.2A and 5.97A/cm2, respectively. For the second pulse, the peak current and the corresponding current density under a macro electric field of 5.4V/μm are 720.8A and 36.7A/cm2, respectively. Current magnifying effect with a magnification of 6.15 was found in the second pulse.
  • De-yuan ZhanLi Xiang;Hua-wei Chen;Yuan-yue Li
    . 2011, 42(04): 3-0.
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    The long-chain polymers have been applied to drag reduction of pipeline and obtained remarkable effect, but the effective acting time of its coating is very short for being applied to drag reduction of watercraft. In order to solve the problem of long-chain polymers, the polyacrylamide long-chain molecules were fixed to water-borne epoxy substrate by graft copolymerization for synthesizing long-acting long-chain grafting drag-reducing film. To verify the practicability of the long-chain film for drag reduction of watercraft, the properties of long-chain film such as water resistance、drag reduction effect and effective acting time were researched. The results show that the long-chain film can keep the surface smooth and undamaged after being washed for a long time, and keep a large number of polyacrylamide molecules fixing to the film surface. The long-chain film has significant drag reduction effect in the flow velocity range between 3.6~10m/s, and the average drag reduction efficiency reaches 9.1%, while the effective drag reduction time exceeds 3 hours, so that the long-chain film has the ability of prolonged drag reduction.
  • ;
    . 2011, 42(04): 4-0.
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    calcium carbonate nanoparticle was synthesized in the additives–Ca (OH)2–CO2–H2O multiphase system using the carbonation. The effect of the citric acid and sucrose concentrations, mass ratio of citric acid to sucrose and adding process on the morphology of the calcium carbonate nanoparticle was studied. The products were characterized by the transmission electron microscopy (TEM) and X-ray powder diffraction (XRD).The results indicated that the nano-sized calcium carbonate cuboids with diameter of 60 nm can be synthesized by controlling the sucrose concentration. The rod-like calcium carbonate nanoparticles can be synthesized by controlling the citric acid concentration. The rod-like calcium carbonate nanoparticles with different aspect ratios were prepared for the first time by using additives complex of citric acid and sucrose.
  • Yanghuan Zhang ;;;;
    . 2011, 42(04): 5-0.
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    The Mg2Ni-type Mg2Ni1-xMnx (x = 0, 0.1, 0.2, 0.3, 0.4) alloys with a nanocrystalline and amorphous structure are synthesized by melt-spinning technique. The as-spun alloy ribbons with a continuous length, a thickness of about 30 μm and a width of about 25 mm are obtained. The structures of the as-spun alloy ribbons were characterized by XRD and HRTEM. The electrochemical characteristics as well as the electrochemical impedance spectrums (EIS) of the as-spun alloy ribbons are measured. The semilogarithmic curves of anodic current versus time responses of the alloy were plotted by an electrochemical workstation, and the hydrogen diffusion coefficients (D) in the alloys were obtained by virtue of potential-step method. The results show that all the as-spun alloys (x=0) hold typical nanocrystalline structure, whereas the as-spun alloy (x=0.4) displays a nanocrystalline and amorphous structure, confirming that the substitution of Mn for Ni facilitates the glass formation in the Mg2Ni-type alloy. The substitution of Mn for Ni significantly improves the electrochemical performances of the alloys, involving the discharge capacity and the electrochemical cycle stability. The high rate dischargeability (HRD) of the alloy monotonously grows with increasing the spinning rate, but it obtains a maximum value with the variation in the percent of Mn substitution.
  • ;Zheng Ying ;;
    . 2011, 42(04): 6-0.
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    Using P123 as a template and TEOS as a silica resource, Ce-silica mesoporous SBA-15-type material was synthesized rapidly via microwave technique and characterized by XRD, FT-IR, low temperature N2 adsorption-desorption and DRS measurements. The results showed that there exist two coordination states of cerium in Ce-SBA-15 which synthesized when the pH value of gel system ranged from 2 to 7. The obtained Ce-SBA-15 possess the highest surface area when the acidity condition was adjusted at pH=2.
  • ;
    . 2011, 42(04): 7-0.
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    Abstract: With tantalum as substrate and diboron trioxide as boron source, boron-doped diamond thin-film was prepared by hot filament chemical vapor deposition technique. Chitosan was used to modify BDD thin-film electrode by the method of covalent-band reaction and used in the determination of Cu2+ in the Na2HPO4 buffer solution(0.1mol/L, PH=4). The results showed that a good linear range for Cu2+ was from 4.0×10-7 to 1.0×10-3. The detection limit was 7.0×10-8 mol/L and correlation coefficient was 0.9916. Comparing the test results of Cu2+ by different enrichment mode. While use the unmodified electrode and chitosan modified electrode to detect the same concentration of copper ions, the reductive peak current increased and reductive potential changed. It showed that the chemically modified BDD thin-film electrode can detect Cu2+ sensitively and accurately. Besides, it proved that chitosan had been modified successfully on BDD thin-film electrode.
  • Cheng SHEN ;;
    . 2011, 42(04): 8-0.
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    A two-electrode cell has been utilized to anodize Ti foils for obtaining highly oriented TiO2 nanotube (NT) arrays. The morphology and composition of the TiO2 NT arrays were characterized by scanning electron microscope (SEM) and energy dispersive spectra (EDS). Depending upon the anodization time (8-20h), the lengths and diameters of TiO2 NT arrays was arranged from 6.7 to 19.5 μm, and 90 to 110 nm, respectively. As confirmed by X-ray diffraction (XRD) and selected area electron diffraction (SAED), the as-anodized TiO2 NTs were amorphous but transformed into anatase phase after thermal annealing at 450℃ for 3h. Reflectance spectrum of TiO2 NT arrays showed that the layer with longer NTs can lower the reflectance in the visible spectrum, thus enhancing light harvesting for dye-sensitized solar cells (DSSC). The photocurrent density-voltage (J-V) characteristics of TiO2 NT-based DSSCs showed that higher energy conversion efficiencies can be achieved with longer TiO2 NT lengths.
  • . 2011, 42(04): 9-0.
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    Using lipophilic TiO2 and Fe3O4 as display particles, SDS, span80 as emulsifier and transformer oil as dispersion medium, lecithin as dispersant, homodispersed suspension was prepared. Magnetic microcapsules containing the suspension as the core material and gelatin- Arabic gum as the wall were prepared by the complex coacervation. The experiment shows that lecithin promotes the muti-phase core material stable and easy emulsification, adding acid rate,stirring speed and the mass of SDS and lecithin influence the size and the wall of the microcapsule, and different mass ratio of TiO2 and Fe3O4 has impact on the display effect.
  • Xian Li
    . 2011, 42(04): 10-0.
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    Chitooligosaccharides (COS) has been reported to have a lower molecular weight and a higher water solubility, and has lots of properties including antitumor activity. In this study, we investigated the role of COS on the mitochondrial membrane potential, proliferation and apoptosis of A549 cells. MTT results showed that COS inhibited A549 cell proliferation with increase of COS concentration and inducing time. 1mg/ml COS significantly declined the mitochondrial membrane potential, which was examined by flow cytometry. dead-live cell staining results showed that after incubating with COS, the red dead cells increased compared with control group. The results suggested that COS regulated apoptosis of A549 cells through decline of mitochondrial membrane potential.
  • LIU Jing ZHANG Guang-Hua
    . 2011, 42(04): 11-0.
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    Abstract: Replacing one of amino compounds with chitosan, the chitosan -triazinyl aminostilbene macromolecule fluorescent brighteners (CS-FBs) were synthesized through three-step condensation reaction. The photophysical and photochemical characteristics and whitening properties in aqueous solutions and ethanol were studied by ultraviolet ray absorption spectra, fluorescence emission spectra, photoinduced isomerization phenomena and paper application test of CS-FBs. Fluorescence quantum yield are determined using quinine sulfate in 0.5mol/L H2SO4 ( F=0.55)as fluorescence standard. The effect of concentration and polarity of solvents on fluorescence properties, as well as the ralationship of the structures and fluorescence properties were studied. The results show that, comparing with the traditional FBs, such as VBL,the light stability and fluorescence quantum yield of CS-FBs were greater, and photoinduced isomerization was lower , the whitening effect of coated paper and physical strength was enhanced. At the same time a red shift of fluorescence emmission wavelength and fluorescence quantum yield increaseing with the increase of solvent polarity. When the concenteation was over 9 10-4 g/mL,the fluorescence was quenched. Meanwhile, the type of substituents in the triazine ring can affect mainly the concentration of trans- and cis-isomers,but not affect significantly absorption- fluorescence assignments.
  • . 2011, 42(04): 12-0.
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    The granular activated carbons (GACs)from lignite used to separate CH4/N2 were prepatated by differevt processes while tragantine was used as binder. The effects of processes, binder ratio, heating rate and activated water dose on CH4/N2 separation capabilities and pore structure of GACs were investigated. The resuolts showed that pre-treatment method of carbonization/washing and addition agent of Mg2CO3(OH)2 could improve the CH4/N2 separation capabilities of samples while caustic wash and pre-oxygenation of raw material and KOH added in lignites were reduced the CH4/N2 separation capabilities of samples. When the carbonization temperature and activation temperature were invariable, the optimal mass ratio of binder, heating rate and activated water dose were 0.15~0.2, 5℃/min and1.9~0.2ml/min.
  • ;
    . 2011, 42(04): 13-0.
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    Pure phase BiFeO3 films were successfully prepared on ITO/glass substrates by Liquid Phase Self-assembled Method using Bi(NO3)3?5H2O, Fe(NO3)3?9H2O as raw materials and citrate acid as chelating agent.The influence of Fe3+/Bi3+ molar ratio on the preparation of BiFeO3 films was studied.The BiFeO3 films were characterized by XRD,EDS,XPS,FE-SEM and FT-IR.The results indicated that:the covering effect of citrate acid to Fe3+ is responsible for the larger deposition rates of the chelates of Bi3+, which made the Bi2O3 and Bi2O2.33 phase could be observed,and the pure phase BiFeO3 films are obtained when the Fe3+/Bi3+ molar ratio was added to 2.6;the films are dense,smooth,grown well, the thickness of the pure phase BFO thin film is approximately 275 nm;the oxidation state of Fe atom is Fe3+ in the films;the chelates of Bi3+ and Fe3+ are induced and adsorbed onto the ITO/glass substrates with different rates through the -OH,which form strong chemical bonding,the crystalline BiFeO3 films are obtained after annealing process.
  • Jian-Guo YU ;;
    . 2011, 42(04): 14-0.
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    Solid oxide fuel cell (SOFC) can directly use a number of carbon hydrogen (such as natural gas, etc.) over Ni-YSZ anode through steam reforming reaction. However, endothermic steam reforming reaction could result in larger temperature gradient in the cell. Doping Ti to partially instead Ni in Ni-YSZ anode may reduce catalytic characteristics in order to obtain the proper temperature distribution. In this work, based on fully three-dimensional calculation models, the performance of Ni-YSZ anode partially doping Ti was investigated. From the results, under all calculating conditions, when Ni content is more than 40%, the difference between max- and min- temperature in anode is linear with the variation of Ni content. However, the decrement of temperature difference increases when Ni content is less than 40%. On the other hand, the location of the same molar fraction of methane is nearly linear with variation of Ni content. Nevertheless, the max molar fraction of hydrogen decreases with reducing of Ni content, but the decrement of max molar fraction enhances. With the decrement of Ni content, output voltage reduces, and the decrement of output voltage enhances with the reduction of Ni content.
  • Hong-Xia WANG
    . 2011, 42(04): 15-0.
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    The diffusion-limited aggregation model (DLA) for fractal growth is used to study the nano-graphite aggregation, through computer simulation, the possible structures of nano-graphite aggregates are got. Based on the discrete dipole approximation method (DDA), the effect of the number of particles, original radius, fractal structure and orientation on infrared extinction are discussed through calculations, and the infrared extinction properties of nano-graphite aggregates are compared with the spherical nano-graphite particle with same volume. The research results show that proper aggregation of nano-graphites is good for infrared extinction and the infrared extinction properties of nano-graphite aggregates are better than spherical one with same volume.
  • ;;;
    . 2011, 42(04): 16-0.
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    A series of the composites of carbon nanotubes (CNTs) and PA66 were fabricated by melt-compounding. The dispersions of CNTs in the PA66, the crystal properties and mechanical properties of the composites were observed using field emission environmental scanning electron microscope, X-ray diffraction, differential scanning calorimetry and nanoindentation, respectively. The results show that the CNTs were dispersed homogenously in PA66 matrix, the melting temperature of composites decreased slightly, their crystallizing temperature, the hardness and modulus increased with increasing CNTs content, and the addition of 5wt% CNTs into the PA66 matrix improved the hardness and elastic modulus by about 11.3% and 19.2%, respectively.
  • ;
    . 2011, 42(04): 18-0.
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    Abstract : Using oleic acid as surface modifying agents, the PbWO4 nanocrystals coated with oleic acid were synthesized by hydrothermal method. The effects of amounts of oleic acid on the modification of nano-PbWO4 particles were also discussed. The as-prepared PbWO4 particles were characterized systematically by means of Scanning Electron Microscope (SEM),Fourier Transform Infrared Spectroscopy (FT-IR) and contact angle analyzer. It was found that the optimum amount of oleic acid was 6%;The results revealed that the —COOH group of oleic acid had chemically reacted with the surface of PbWO4 nanocrystals via surface modification by FT-IR; The oleic acid modified PbWO4 nanocrystals had good dispersion and not reunited. Furthermore, the contact angle between the modified PbWO4 and water amounted to 153.08°,which showed that the modified PbWO4 owned super hydrophobic surfaces. And it was helped to significantly improve the compatibility with organic matter.
  • Zhang Yan-Hui chao yue sheng
    . 2011, 42(04): 19-0.
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    Amorphous Fe78Si9B13 alloys have been treated by low frequency pulsating magnetic field. Hyperfine structures of the original and crystallized samples were analyzed by transmission M?ssbauer spectroscopy. The results show that one electron in Fe atom 3d6 shell jump into Si atom 3p2 shell in the Fe-Si phase, forming a stability electron group. Charge distribution around the Fe atom tend to symmetry. Orbital hybridization, distortion of lattice and disperse distribution cause the lower hyperfine magnetic field of the crystallized phase. The atomic magnetic moment tends to parallel to surface of sample.
  • ;Zhao Gaoling
    . 2011, 42(04): 20-0.
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    Abstract:Vanadium (V) doped titanium nitride (TiN) films were prepared by the atmospheric pressure chemical vapor deposition process in glass substrates. The effect of the deposition temperature on the structure, morphology, electrical and optical properties of the films were investigated by X-ray diffraction (XRD) , optoelectronic spectrometer (XPS) , field emission scanning electron microscope (SEM) , four point probe and ultraviolet-visible spectrometer. The results showed that the films were typical of granular structure. With increasing deposition temperature, the crystallinity improved, the proportion of V increased and the sheet resistance decreased. When the temperature is 600℃, the reflectivity of V doped TiN film in the near -infrared and medium-far infrared region are 50% and 93.74% respectively. We obtained TiN coating glass with both sunlight control function and low radiation function.
  • Lu-Yuan CHEN
    . 2011, 42(04): 21-0.
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    Thinking of the disadvantages of all the present testing methods for carbonization depth of cement-based materials, the author combined with their invention of the detection devices, and then formed a new anti-carbonation property detection method––method of carbonate content. This is a much more accurater determination of carbonation. For it can not only distinguish the area of carbonation out of carbonation reaction zone,but also won’t be affected by other factors which lead to cement neutral. Based on our experiment,we concluded that this method is indeed much better than phenolphthalein spray method. It is simple in principle and easy for operation. What’s more,it can measure all of the carbons derived from carbonized parts of the sample.
  • Wei XU ;
    . 2011, 42(04): 22-0.
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    Firstly a fluorine-silicon polymer (PFAMS) with pendant perfluoroalkyl and reactive epoxy groups was synthesized by Si-H additional reaction of polymethyltrifluoropropylsiloxane (PFHMS), allylpolyoxyethylene ether (AGE) and perfluorooctyl ethylene (PFOE). Then silica sols (KH550-SiO2) containing amino groups were prepared via sol-gel methods by aminopropyltriethoxylsilane (KH550) and tetraethyl orthosilicate (TEOS). Finally a novel fluorine-silicon polymer/nano-silica hybrid (PFAMS-SiO2) was fabricated through graft copolymerization method by the above two chemicals, PFAMS and KH550-SiO2 and super-hydrophobic cotton fabric was also constructed with contact angle of water on its surface 160.91° through immersing-padding-baking processes. Chemical structure, micro-morphology, thermal stability and application performances of the hybrid were investigated by the Fourier Transform Infrared Spectrum (FT-IR), Scanning electron microscopy (SEM), Thermo-gravimetric analyzer (TGA), X-ray photoelectron spectroscopy (XPS), and Static contact angle analyzer, respectively. Results showed that thermal stability of the hybrid was improved compared to fluorine-silicon polymer, a hydrophobic silicon film and many lotus-leaf-like micro-nano scale tubercles were coated on the surface of cotton fabrics. In addition, with increase of the amount of PFAMS-SiO2, super-hydrophobicity of the cotton fabrics increased, otherwise, softness of the treated cotton fabrics increased first and decreased afterwards. Permeability and whiteness of those fabrics had little change.
  • ;;
    . 2011, 42(04): 23-0.
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    Abstract:The effects of addition Pd on the martensitic transformation and mechanical properties of Ni56.5Fe17Ga26.5 alloys were investigated by SEM, XRD, TEM, DSC, TG and universal testing machine. The results show that the addition of Pd promotes grain refinement, more γ phase and the toughness of the alloy. The martensitic transformation temperatures and the Curie temperature of (Ni56.5Fe17Ga26.5)100-xPdx (x=0, 0.5, 2) elevate slightly with the increase of x. By the measurement of XRD and TEM observation on the alloys, it is found that the martensitic phase has a 14M type structure.
  • . 2011, 42(04): 24-0.
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    Silica spheres were synthesized by a two-step method. It has been demonstrated that the addition ratio of ammonia catalyst influences the morphologies and the shape of the SiO2 spheres.. The sizes of the silica spheres are mainly depended on the ratio of the TEOS reagents for both the the initial beads and the final silica spheres. It has also been pointed out how to measurement the mass and volume percentages for the silica in the paper.
  • chen ming qing
    . 2011, 42(04): 25-0.
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    P(DHCA-co-LCA)-b-PEG polyesters were synthesized by polycondensation of 3,4-dihydroxycinnamic acid (DHCA, caffeic acid), lithocholic acid (LCA) and poly(ethylene glycol) (PEG). The structure and molecular weight of the P(DHCA-co-LCA)-b-PEG polyesters were characterized by fourier transform infrared (FTIR), nuclear magnetic resonance (1H-NMR) and gel permeation chromatography (GPC). The thermal and photosensitive properties of the polyesters were investigated by differential scanning calorimeter (DSC), UV spectroscopy and fluorescence spectroscopy. It is proved that glass transition temperature (Tg) and fluorescence emission intensity of the polyesters decreased when PEG increased in feed, but the fluorescence emission intensity of the polyesters obviously higher than DHCA monomer. P(DHCA-co-LCA)-b-PEG polyesters could be photo-crosslinked under λ>310nm UV light and its reversible photo-cleavage could take place under UV light of 254nm. The micelle nanoparticles were obtained by self-assembly at selective solvent. It was found that these nanoparticles have a nice spherical morphology with a smooth surface and possessed a certain photosensitivity based on the analysis of laser light scattering (LLS) and transmission electron microscopy (TEM). Their average diameter was about 378nm.
  • Xiao-Lei SU
    . 2011, 42(04): 26-0.
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    The Al doped SiC powders have been prepared by combustion synthesis in 0.1MPa nitrogen atmosphere under different body pressure, using silicon (Si) and carbon black (C) powders as raw materials, aluminum (Al) as doping source and polytetrafluoroethylene (PTFE) as additive. The prepared powders have been characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive spectra (EDS). The microwave dielectric property of prepared powders has been measured in the frequency range of 8.2-12.4GHz. Results show the lattice parameter and dielectric property of prepared powders decrease with body pressure increasing. The synthesized mechanism and effect of Al doping on dielectric property of SiC powder have been discussed.
  • Jin-Yang LIN;;;
    . 2011, 42(04): 27-0.
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    Bi2O3 nanowires were synthesized from NaOH和Bi(NO3)3?5H2O with surfactants Oleic acid, heptane, and acetone added at room-temperature. The nanowires have a diameter of about 50 nm and a length in the range of several to tens of micrometers. X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) were employed to characterize the structure and morphology of these structures. The cathode array was prepared by screen-printed. The field emission of the sample started at a turn-on field of 2.6 V/μm at a current density of 0.1 μA/cm2,。This type of Bi2O3 nanowires can be applied as field emitters in displays as well as vacuum electric devices.
  • ;dong fa qin
    . 2011, 42(04): 28-0.
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    Abstract:Using copper sulfate (CuSO4?5H2O), ferric chloride (FeCl3?6H2O) and sepiolite as main raw material, CuFe2O4 magnetic particles were prepared by chemical co-precipitation method and then combined with sepiolite to produce magnetic sepiolite with different loadings of CuFe2O4. The phase, morphology and magnetic properties of the production were characterized by X-ray diffraction (XRD), transmission electronic microscopy (TEM) and vibration sample magnetometer (VSM). The results show that the grain size of CuFe2O4 with high crystallinity is about 16nm, and the saturation magnetization is 24.114 A ? m2/kg. CuFe2O4 particles load on the surface of sepiolite fiber well. The saturation magnetization and saturated adsorption capacity to Cu2 + for magnetic sepiolite increase along with the amount of CuFe2O4. When the loading of CuFe2O4 is 50%, the saturation magnetization and remanence magnetization of magnetic sepiolite is 13.416, 0.0395 A?m2/kg, respectively, coercive force is 0.9008A/m; and saturated adsorption capacity to Cu2+ and magnetic recovery rate is 17.82mg/g, 96.4%, respectively.
  • . 2011, 42(04): 29-0.
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    In this paper, the aqueous solution including humic acid (HA) was electrochemically oxidized using an activated carbon ?ber (ACF) felt as an anode. The results showed that HA can be effectively removed from water. Under suitable condition, the removal ratios of HA and COD can be up to 93.81% and 92.60%, respectively after 120 min of electrolysis. The influence of initial pH, current density, Na2SO4 concentration, initial concentration of HA and anode structure on the removal ratio of HA was investigated. The results indicated that the removal ratio of HA increases firstly and then almost invariant with the increase of current density and Na2SO4 concentration, and decreases with the increase of initial pH and initial concentration of HA; the specific surface area and the mesopore percentage of anode material are not in direct proportion to the removal ratio of HA, and the anode with moderate specific surface area and good electrochemistry performance is beneficial to the electro-oxidation removal of HA.
  • . 2011, 42(04): 30-0.
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    Super absorbent resin (SAR) was prepared via aqueous solution polymerization with acrylic monomer. The influences of functional groups in resin chains, reaction temperature and reaction pH on water absorbency of super absorbent resin were investigated. Results show that methyl have negative effect on water absorbency. Hydroxyl is a group for the well-being of water absorbency. The contribution of ester on water absorbency is poorer than carboxylic. The water absorbency of resin is decrease along with the increase of chain length of ester. When reaction temperature and reaction pH are rising, the water absorbency of resin is increased and then decreased.
  • YANG Jun
    . 2011, 42(04): 31-0.
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    The influences of rapidly solidification on the structure and property of the Fe-Mn-Si base shape memory alloy were studied.The results show that the because rapidly solidification big refined structure, Thus causes the alloy yield strength enhancement,At the same time, produce many martensite in rapidly solidification sample, this kind saves in advance the martensite is also helpful in enhances the substrate the intensity, thus suppresses the irreversible plastic deformation the production,lets more distortions undertake by the stress-inducedεmartensite,compares with the rolling sample, the shape memory effect enhances about 13%~200%; Because the crystal grain of the rapidly solidification sample is tiny, the crystal boundary are many, may supply the magnus build nucleus the position to be also many, therefore theεmartensite is long quite tiny, also easy to have the overlapping traversing phenomenon.
  • Jian-Kang SONG ;;
    . 2011, 42(04): 33-0.
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    Abstract: A novel method for the fabrication of porous 3-D scaffolds composed of poly(ethylene terephthalate) fiber and thermal melt fiber (PE/PP) by combining wet-laid paper-making and melt-reinforcing is presented. Scaffolds with porosity as high as 97% were achieved and no organic solvent was used during the processing. The materials were characterized by scanning electron microscope (SEM), FT–IR spectroscopy, and tensile test. SEM images confirmed uniform well-interconnected big pores and melted joints present in the scaffolds while FT–IR spectroscopy verified no chemical changes during the processing, and tensile measurements showed Young’s modulus, stress at break, strain at break were 5.34±1.26 MPa, 0.24±0.05 MPa, 5.73±0.78%, respectively. Human mesenchymal stem cells were seeded in the scaffolds, no cytotoxicity was determined and the cells grew well. The results show that the prepared scaffolds have promising prospects for stem cells culture.
  • WANG Yan;;;
    . 2011, 42(04): 34-0.
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    LiFePO4 is considered the first choice for the next generation cathode materials of lithium-ion battery because of its advantages, such as abundant resources, high capacity, medium voltage, excellent cycling performance and electrochemical properties stability. In this paper, olivine-type crystal structure and the synthesis process of LiFePO4 is to be introduced, Modification of its shortcomings is discussed,and its developing trend is also prospected.
  • Xie-Bin ZhuWANG Hai-tao;;;JIANG Tao
    . 2011, 42(04): 35-0.
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    ZAO precursors were prepared by a co-precipitation process with additive of PEG-6000 from zinc chloride, AlCl3?6H2O and ammonia solution in a water bath. ZAO powders were obtained upon calcinations. The phase structure, morphology, size and conductivity of ZAO powders were characterized by X-ray diffraction, scanning electron microscopy and digital conductivity instrument. The effects of the concentrations, pH value, reaction temperature, calcinations temperature and time on the conductivity properties of ZAO powders were discussed and the optimal technological parameters were attained. The results show that the ZAO samples are polycrystalline, well dispersed, rodlike, and the ratio of length to diameter reaches about 10, and correspond to hexagonal structure. the conductivity of ZAO samples increases with ammonia concentration increases, while decreases with pH value increases, increases and then decreases with increasing the reaction temperature or calcinations temperature and time. The optimum conductivity conditions of ZAO samples is the ammonia concentration of 1:0, pH=6, reaction temperature of 50℃, calcinations at 450℃ for 4h.
  • sun jian chun
    . 2011, 42(04): 36-0.
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    The electric iron was surface nanocrystallinzated by high energy shot peening (HESP)method. Ni and Cr were well mixed to the shot tank to accomplish them diffusion into the electric iron and the surface self-nanocrystallization of the electric iron at the same time. The microstructure and the corrosion properties of the self-nanocrystallizated layer and alloying layer of the electric iron were investigated by microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD) and electrochemical measurement system. Experimental results showed that under a 0.6 Mpa shot pressure and 6 minutes shot time, a self-nanocrystallizated layer with an average grain size of 47.9nm and a 0.0431% microstrain is obtained on the electric iron by HESP. Because of large number of grain boundaries and imperfects in the self-nanocrystallizated layer, which lead to increase of activity and decrease of corrosion properties of the self-nanocrystallizated layer. The corrosion potential of the Ni alloying layer is -0.548V while the Cr alloying layer is Ecorr=-0.514V, which are all larger than that of the electric iron. That means the corrosion properties of the electric iron are enhanced after alloying treatment.
  • . 2011, 42(04): 37-0.
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    Activated carbon was prepared by microwave heating from spent activated carbon loaded zinc acetate. The adsorption isotherms, breakthrough curves of toluene in activated carbon were measured at temperatures of 20, 30 and 40℃. The experimental data were analyzed theoretically by Langmuir isotherm and Freundlich model, and the isotherms could be well fitted with Langmuir model. The adsorption capacity of 273.23mg/g, average adsorption heat (△H) of -1.92KJ/mol, free energy (△G) and entropy(△S) of toluene in the activated carbon were calculated, and the adsorption process was an exothermic and spontaneous process. At the same time compared with three kinds of activated carbon, and the microwave regeneration of activated carbon had higher adsorption capacity at same conditions than any other activated carbon.
  • ; ;
    . 2011, 42(04): 38-0.
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    A novel porous scaffold of hydroxyapatite/calcium sulfate/multi-(amino acid) copolymer composite for bone repair was prepared by extrusion foaming. The morphology/microstructure and composition of the composite were characterized by scanning electron microscope (SEM), Infrared spectroscopy (IR) and X-ray diffraction (XRD), and the in vitro degradability of the composite scaffolds was investigated by using simulated body liquid (SBF). The results showed that the porous composite scaffolds had suitable pore size, porosity and higher compressive strength and some chemical interactions was present between the inorganic (HA and CS) and organic (PAA6) phases in the composite. The composite exhibited good degradability in SBF and its degradability enhanced with the increase of calcium sulfate amount, and the composite displayed a kind of surface degradation. NO obvious change of pH value was found during the composite soaking into SBF. The composite had good bioactivity that the apatite was easily deposited on its surface because a great deal of Ca ions could release from the composite into SBF solution.
  • Ling Liu ;;Zhou YANG
    . 2011, 42(04): 39-0.
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    Ag colloids solution was synthesized by reduction of AgNO3 from sodium citrate. Monodisperse Ag nanoparticles films were self-assembled by electrostatic deposition technique. We investigated the optical properties of Ag nanoparticles. The size of Ag nanoparticles and its surface plasmon resonance absorption properties were controlled by changing the concentration of the reactants and the following annealing temperature. Ag nanoparticles mediated emission of CdSe quantum dots (QDs) was also studied. By coupled Ag nanoparticles film to CdSe QDs, a significant enhancement in photoluminescence (PL) intensity of CdSe QDs was observed, which was due to the enhancement effect of surface plasmon resonance from metal nanoparticles.
  • ;cao wei wei
    . 2011, 42(04): 40-0.
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    The mathematical models of radiative heat flux density distribution for single carbon composite heating element was established, the numerical calculation and visual analysis of which were carried out by software of MATLAB, the results show that the radiative heat flux density of single element increased with the increase of emissivity of carbon composite, the non-uniformity of heat flux density also increased. The radiative heat flux density of single element increased with the increase of emissivity of quartz, also the non-uniformity of heat flux density also increased. With the increase of outside radius of quartz, the radiative heat flux density of single element firstly increased, under the setting initial condition, the heat flux density decreased rapidly when the outside radius of quartz tube was equal to 0.45cm, the non-uniformity of heat flux density slowly increased with the increase of outside radius of quartz firstly, and then had little change. The experiment results show that model test data is approximately accordance with simulating result, which supplies a reference to the improvement of carbon matrix composites electric heaters’ structure and the optimization designs of infrared radiative field in the future.
  • Nan XU;;
    . 2011, 42(04): 41-0.
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    The effects of solution and aging treatments on a 2 mm tungsten inert gas (TIG) butt welded joint was investigated.. The results show that with the increases of the aging time and the Al content ofalloys, the microhardnesses of the fusion zone (FZ) of the TIG welded Mg-Al-Zn alloys increased. In the initialstage of the aging treatment, the microhardness of FZ increased sharply and then changed slightly with the increase of the aging time.
  • Xin Xu;
    . 2011, 42(04): 42-0.
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    Abstract: In this paper, we present a new procedure for the rapid synthesis of luminescent CdTe/CdSe core-shell quantum dots (QDs) in water phase by microwave irradiation method. The influences of microwave irradiation and a series of experimental variables, including heating temperature, molar ratios and concentration of precursors on the synthesis of QDs were investigated systematically. The results of high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) showed that the as-prepared nanocrystals had high crystallinity. In comparison with the plain CdTe QDs, both the photoluminescence quantum yield (PLQY) and photostability against UV irradiation of the CdTe/CdSe core-shell QDs have been greatly improved.
  • . 2011, 42(04): 43-0.
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    Using FeCl3 as iron source, dimethylamine borane (DMAB) as surfactant, alpha Fe2O3 flower-like nanosheets were synthesized via a solution-phase method at a low temperature. The effects of reaction time and molar ratio of DMAB to FeCl3 on the morphology of product were studied. At 80 ℃, molar ratio of 1:1, uniform alpha Fe2O3 nanosheets could be synthesized. The morphology, composition and crystal structure of the nanosheets were characterized using scanning electron microscopy(SEM), X-ray diffraction(XRD), transmission electron microscopy(TEM).The growth mechanism of nanosheets was also discussed.
  • Lu Xu Dong ;
    . 2011, 42(04): 44-0.
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    Pure TiO2 and Eu3+ and Sm3+ co-doped TiO2 composite nano-particle were prepared by sol-gel method and characterized by the techniques such as XRD, DRS and SEM. The photocatalytic degradation of methylene blue (MB) in aqueous solution was used as a probe reaction to evaluate their photocatalytic activity. The mechanisms of effects of Eu3+ and Sm3+ co-doped on the photocatalytic activity of the TiO2 composite nano-particles were also discussed. The results show that Eu3+ and Sm3+ co-doped can significantly enhance the photocatalytic activity of TiO2 nano-particles. The co-doped of Eu3+ and Sm3+ shows a synergistic effect for photocatalytic activity of TiO2 nano-particles, can inhibt the phase transformation from anatase to rutile and decrease the diameter of TiO2 nano-particles. The matrix distortion of TiO2 nano-particles increases when the Eu3+ and Sm3+ have co-doped and the blue-shift of the absorption profile are clearly observed. When the co-doped amounts for Eu3+ and Sm3+ are 0.05% and 0.1% ,the photocatalytic activity of TiO2 can be improved sffectively, and its degradation rate reaches 96%.
  • ;He Guotian
    . 2011, 42(04): 45-0.
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    Abstract: Magnetorheological fluid is an excellent fluid material with intelligence. Its fluid properties, damping characteristic and magnetism characteristic have been widely studied, but its electrical properties’ research is relatively slow. This paper used MRF - J01T type MRF and inductance coil to constitute magnetorheological inductance and deduced the formula of calculating magnetorheological inductance. Besides, the article designed experiments to test the magnetorheological inductance’s properties with the change of the external magnetic field and analyzed the experimental phenomena in theory. So the paper provides an adjustment for magnetorheological inductance’s application in electronic measurement and sensing technology .
  • yan XIAO; Y.G. Chen ;
    . 2011, 42(04): 46-0.
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    Pure Mg or Al is one of the best candidates for hydrogen generation by hydrolysis, but it is hard for them to be pulverized and hydrogenated as well as their low yield of hydrogen. In comparison with pure Al or Mg, Mg17Al12 is a brittle intermetallic compound, which can be easily pulverized and hydrogenated, and the theoretical hydrogen yield by hydrolysis of the hydrogenated Mg17Al12 is as high as 13.6 wt%. The effect of pH value on hydrogen generation by hydrolysis of Mg17Al12 hydride was investigated in this paper. The result showed that the hydrolysis reaction of Mg17Al12 hydride can only be completed in strong acid. The ball-milling process of Mg17Al12 hydride together with MgCl2 can effectively improve the reactivity of Mg17Al12 hydride. For the mixture of the mole ratio 1:1 of MgCl2 to Mg17Al12 hydride which was milled for 1h before hydrolysis, the hydrogen yield reached 90%.
  • Fan HU
    . 2011, 42(04): 47-0.
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    In this paper, the effect of melting processes (vacuum induction and non-consumable vacuum arc melting) on the microstructure and hydrogen storage performance of kilogram-grade V-60% (TiCrFeMn) hydrogen storage alloys were investigated。The results show that the performance of alloy melted by medium frequency induction deteriorates because its oxygen content is too high,which results from the reaction of the liquid alloy and the crucible during melting process。The alloy made by non-consumable vacuum arc melting has a much better performance,where the initial hydrogen absorption and desorption capacity is 3.69 wt % and 2.25wt% respectively, and the hydrogen desorption plateau pressure is 0.45MPa
  • . 2011, 42(04): 48-0.
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    A series of Mo-N codoped TiO2 photocatalysts with different Mo doping level were prepared by a simple sol-gel method and investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible diffuse reflectance spectra (UV-Vis DRSs) and photoluminescence spectra (PL), respectively. The photocatalytic activities of the catalysts were evaluated by degrading methylene blue (MB). It is found that the visible-light absorption performance of TiO2 was obviously improved after the dopings. The photocatalytic activities of the codoped samples were enhanced as compared to the pure TiO2. However, due to the photo-generated charge carriers recombination induced by Mo doping, the photocatalytic activities of the samples were gradually depressed with the increase of Mo doping level.
  • LIU Sheng-Ming
    . 2011, 42(04): 49-0.
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    Al2O3-Ti(C,N)-Fe composite ceramic was produced by In-Situ synthesis from ilmenite and hot-pressing.The influences of metal bonding phase Fe on composition, microstructure and properties of products were researched.The results show that the adding of Fe element decreased the temperature of the carbothermic reduction; with the increase of Fe content, Fe phase began to reunion, the organizations of Al2O3-Ti(C,N)-Fe composite have become thick; at the same time, with Fe content increasing, the hardness of Al2O3-Ti(C,N)-Fe composite decreased slightly, bending strength decreased significantly.