30 August 2013, Volume 44 Issue 16
    

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    研究 开发
  • The synthesis of 3D Bi2WO6/TiO2 heterojunction photocatalysts and enhanced photocatalytic activity
    Zhen-Feng ZHUYU WANG;
    . 2013, 44(16): 1-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    3D multicomponent Bi2WO6/TiO2 composite heterojunction photocatalysts were prepared by the dipping method and followed by TiO2 particles layer-by-layer deposited on the surface of flower-like Bi2WO6 superstructures. The prepared TiO2，Bi2WO6 and Bi2WO6/TiO2 heterojunction photocatalysts were characterized by X-ray diffraction(XRD)，scanning electron microscope(SEM)， UV-Vis diffuse reflectance spectra， and photoluminescence(PL)， respectively. Meanwhine， the photocatalysts activity of the prepared catalysts was evaluated by photocatalytic degradation of RhB solution under 500W Xe lamp light irradiation. The results show that the photocatalytic activity of Bi2WO6/TiO2 heterojunction photocatalytic is superior to that of pure TiO2 and Bi2WO6. When the content is 15wt%TiO2， the composite photocatalyst most effectively promote the separation of electrons and holes and result in an increase with photocatalytic activity. The special interface of the formation of heterojunction can significantly reduce the recombination of photogenerated electron and hole pairs and show the higher light-harvesting ability.
  • Properties and preparation of cyanate ester resin /graphite oxide composites
    Chun-Bao ZHAO ;;
    . 2013, 44(16): 2-0.
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    Graphite oxide(GO) was modified with dodecylamine and characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and nuclear magnetic resonance spectroscopy(NMR). The modified graphite oxide (GO-DDA) was incorporated into cyanate ester(CE) systems to prepare CE/GO-DDA composites. The effects of GO-DDA amounts on the curing reaction of cyanate ester, thermal conductivity and insulation performance of the composites were investigated emphatically. Results of DSC showed that the addition of modified graphite oxide could facilitate the curing reaction of cyanate ester and decrease the curing temperature of cyanate ester. The experimental results of thermal conductivity and insulation performance indicated that GO-DDA provided significant enhancement of thermal conductivity of cyanate ester composites, adding 1.0wt% GO-DDA achieving a 48% increase in thermal conductivity. The composite (1.0wt% of GO-DDA) also had a good insulation performance. Moreover, the addition of small amount of GO-DDA could facilitate to improve fracture toughness of the CE composites.
  • Study of the effect of environmental and friendly corrosion inhibitors on magnesium alloy
    ;li qing;
    . 2013, 44(16): 3-0.
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    Magnesium alloy is one of the most commonly used light metal material, and adding corrosion inhibitors to corrosion medium is an effective method to improve the corrosion resistance of magnesium alloy. In the view of environment protection, we study the corrosion inhibition of four inhibitors for AZ91D magnesium alloy in 3.5 wt.% NaCl by electrochemical polarization, impedance technology and SEM. According to the properties of the four inhibitors, strengthen the adsorption of the four inhibitors is achieved through adding pefloxacin mesylate. Finally, These environmental friendly corrosion inhibitors have a certain degree inhibition effect, and joining pefloxacin mesylate can further enhance the inhibition effect to AZ91D magnesium alloy in 3.5 wt.% NaCl.
  • A new type of carbon fiber of the electromagnetic shielding effectiveness research
    ZHU pei
    . 2013, 44(16): 4-0.
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    Abstract: Bacterial cellulose for carbonization in different temperature will get a series of carbon fiber which is reticular structure. Using X-ray diffraction (XRD) and transmission electron microscope (TEM) to characterization the prepdprepared carbon fiber crystal structure and microstructure. Through the vector network analyzer in frequency 600 MHz - 14 GHz range for electromagnetic parameter tests on it. Application of electromagnetic shielding theory can calculates and gets the electromagnetic shielding effectiveness of the carbon fiber. The results show that the carbon fiber in frequency for 6 GHz - 14 GHz which get in the carbonization of 1200 ℃, the shielding effectiveness are greater than 30 dB, while it in14 GHz , the highest can achieve 41 dB. The carbon fiber which is low density and the shielding effect is good has a good application prospect in the electromagnetic shielding area.
  • Research on the effect of phenol amine catalyst HP-30 to the structure and properties of PU rigid foams
    Qiting Lu; ;
    . 2013, 44(16): 5-0.
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    In this work, The 60 Kg?m-3 PU rigid foam with high compression performance has been successfully prepared with polyether polyol GR-835G and polymethylene polyphenylisocyanate PM-200 as main raw materials, phenol amine catalyst HP-30 as the trimerization catalyst，and H2O as the blowing agent. The results show that, HP-30 can play important roles as not only the trimerization catalyst, but also the blowing agent. The cream time, rise time and gel time of the foaming systems, become shorter with more HP-30, while the apparent densities of the foams have a trend with bigger then smaller, and bigger finally. The H2O dosages need be changed for maintaining the same apparent density with the increase of the HP-30 dosages. However, there is almost no effect to the foaming time and the voscosity of the foaming system with H2O dosage changed under 1 wt%. The compression properties of 60 Kg?m-3 foams can be improved witn the HP-30 dosages increased. When the HP-30 dosage is 13 pphp, the compressive strength and compressive modulus of the PU rigid foam are 0.772 MPa, 30.0 MPa, respectively. In addition, the possible mechanism of HP-30 has also been disscussed.
  • Preparation and Characterization of Bi0.9Ho0.1Fe0.95Cr0.05O3 Ceramics
    ;;;;
    . 2013, 44(16): 6-0.
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    Abstract: Bi0.9Ho0.1Fe0.95Cr0.05O3(BHFCO) ceramic was synthesized by the solid-state reaction method. BHFCO ceramic has a perovskite rhombohedral R3c structure proved by XRD measurements, and the lattice parameter is smaller than BiFeO3. The dielectric properties test and the differential scanning calorimetry show BHFCO ceramic exhibits a strong relax ferroelectric feature and the Neel temperature is 315 ℃. Well room temperature saturated ferroelectric hysteresis loops has been observed., and the remanent polarization is around 20.25 μC/cm2 . X-ray photoelectron spectroscopy proves the valence states of Fe ions of BHFCO ceramics is 3+. Well room temperature saturated ferromagnetic hysteresis loops also has been observed, and the remnant magnetization and saturation magnetization are 0.476 emu/g and 2.290 emu/g respectively.
  • The influence of polycarboxylate superplasticizer on the dispersion of carbon fiber
    ;Cong-bo xie
    . 2013, 44(16): 8-0.
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    Improving the dispersion of carbon fiber with simple technical methods is helpful to enhance its application effect. In this paper, the dispersion of carbon fiber in solutions of an esters polycarboxylate superplasticizer(PC) and methyl cellulose(MC) was investigated by measuring turbidity; the influence of the dispersing agents on the electrical resistivity of carbon fiber reinforced mortar (CFRM) was tested and uniformity of the distribution of carbon fiber was observed using a scanning electron microscope. It is shown that the carbon fibers with different length-diameter ratio were dispersed uniformly in the PC solution, but only carbon fibers with small length-diameter ratio did in the MC solution. The electricity of CFRM prepared from carbon fiber dispersed in PC solution increased significantly, while that of CFRM with high water-cement ratio increased to some extent when the carbon fiber was dispersed in MC solution. Although the water reducer FDN improved the fluidity of fresh CFRM, the electricity of the harden CFRM didn’t increase. It is suggested that the water reducer PC had a amount of polar groups adsorbed on the surface of the carbon fiber and increased the repulsion between carbon fibers, therefore improved the dispersion of the carbon fiber in CFRM along with improved the mechanical properties of CFRM. The observation by SEM images confirmed the positive effect of PC on the dispersion of carbon fiber in CFRM.
  • Anionic polyurethane-acrylate dispersion prepared by in-situ surfactant-free emulsion polymerization and its strengthening mechanism for paper fiber
    . 2013, 44(16): 9-0.
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    A facile route to prepare polyacrlate/polyurethane microemulsion (APUA) by in-situ surfactant-free emulsion polymerization was proposed. Polyurethane prepolymers (PU) were functionalized by hydroxyethyl acrylate (HEA) to obtain PU end-capped with vinyl groups, and copolymerization among vinyl-containing PU and vinyl monomers was initiated subsequently. The products were thereby utilized for the surface modification of paper. FT-IR demonstrated the copolymerization between vinyl-containing PU and polyacrylate (PA)；TGA demonstrated the introduction of PA into the PU, which can delay the degradation of APUA films. The average particle size decreased from 63.33 nm to 22.54 nm with the increase of HEA content. Transmission electron microscope showed that APUA particles unmodified with HEA displayed as spherical morphology with heterogeneous particle size, while core-shell morphology and mono-modal distribution of particle size was detected for APUA particles modified with 4 wt% HEA. However, the average particle size increased with increasing PA content, and several PA particles were simultaneously encased in PU colloidal particles. It can be also found that the folding strength of paper modified with 7 wt% APUA increased from 58 times to 134 times when w (DMBA)=10%, w (HEA)=4%, n(NCO)/n(OH)=1.6 and w (PA)=35%. Scanning transmission electron photographs further certified that the cracks and defects on the fibers were apparently reduced, resulting in the effective improvement of the strength.
  • Effect of Nano-Fe3O4 on The Properties of Brushite Cements
    Guang-Da LI
    . 2013, 44(16): 10-0.
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    In present research, magnetic brushite cements containing nano-Fe3O4 were synthesized and characterized. The weight ration of nano-Fe3O4 versus cement matrix was 1/20, 1/10 and 1/5. The results show that nano-Fe3O4 changes cement properties by changing of the physical and chemical structure. The cement setting time is prolonged to 9-27 min and the setting heat is reduced with more nano-Fe3O4 content. Moreover, the syringeability and compressive strength of cements firstly increases and then decreases with more nano-Fe3O4 addition. Cement nano-Fe3O4 ration of 1/10 presents the best syringeability（injection coefficient about 89%）and the highest compressive strength (～45MPa), and is significantly superior to the cement without nano-Fe3O4. Meanwhile, under a magnetic ?eld of 1.59 × 106Am?1, the saturation magnetization of cement increase from 0.49 to 5.51 A?m2?kg-1 and the coercive force rises from 233.23 to 707.64 A?m -1 with more nano-Fe3O4 addition. Furthermore, the cement biodegrability is inhibited by nano-Fe3O4. When nano-Fe3O4 addition ration reaching 1/5, the cement mass loss rate is decreased from 14.9% (without nano-Fe3O4) to 7.5% after soaking for 28 days.
  • Intense pulsed emission characteristics of CNTs grown on the surface of micro-cube array
    hua-li MA; ;Fan-Guang Zeng
    . 2013, 44(16): 11-0.
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    Carbon nanotube films were synthesized on the surface of micro-cube array Si with electroless plated Ni layer（Si/Ni-CNTs） by pyrolysis of iron phthalocyanine (FePc). Intense pulsed field emission of CNTs was researched with diode structure on 20GW pulse power system. For single pulse emission，emission current peak of Ni/Si-CNTs linearly increases with pulse field peak; at the applied peak electric field of~31.4 V/μm, peak current and current density can achieve ~14.74KA and ~1.23KA/cm2,emission current ability of CNTs is obviously better than that of report. For many continuous and same peak pulses emission, Si/Ni-CNTs are provided with good repeatability of pulsed emission，and present better emission stability.
  • The Studies on Structure and Optical Properties of TeO2-Nb2O5-AlF3-BaCl2 Glass
    . 2013, 44(16): 12-0.
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    Abstract：Oxyhalide tellurite glasses:(80-x)TeO2-10Nb2O5-10BaCl2-x AlF3（x=10，20）were prepared using conventional melting method.The impacts of component changes on the the physical properties, structure and optical properties of the glasses had been studied using density specific gravity balance，glass dilatometer, Prism coupling instrument, Raman spectroscopy and infrared - visible - UV spectrophotometer.The results show that the glass density and refractive index decrease with the increase of the AlF3 content in the glasses.On the other hand, their average coefficient of linear expansion decreases and their thermal stability enhances in front of the Tg temperature. Furthermore, [TeO4] trigonal bipyramid and [TeO3] trigonal pyramid are reduced in the glass structure. Finally, they have obvious blue shifts in UV spectral absorption edge and their direct and indirect optical Bands gap decrease.
  • Preparation and the third-order optical nonlinearities of the sodium borosilicate glasses
    XIANG Weidong ;;;;
    . 2013, 44(16): 13-0.
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    The transparent bulk sodium borosilicate glasses were prepared by using tetraethyl orthosilicate, boric acid, ethanol sodium as precursor, and anhydrous alcohol, glycolic methyl ether and anhydrous alcohol as precursor solvent by both sol-gel and atmosphere control methods. The mechanism thermal decomposition, the formation process of the glasses and the phase structure of the glass were investigated by means of thermogravimetry-differential thermal analysis (TG-DTA), fourier transform infrared (FT-IR) and X-ray powder diffraction (XRD), the result revealed that the transparent and density sodium borosilicate glasses were obtained. Furthermore, Ultraviolet visible absorption instrument and Z-scan technique were employed to measure the optical properties of the glass. The results indicated that the glass has the excellent optical transmittance, and the third-order nonlinear optical refractive index γ susceptibility χ(3) of the glass are determined to be -1.95×10-17m2/W and 1.49×10-19m2/V2, respectively.
  • the Effects of Core/Shell Ratio on Rheological Properties and Gelation of Polyacrylate Plastisol
    . 2013, 44(16): 14-0.
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    Abstract:Different polyacrylate latexes with core-shell structure were prepared by semi-continuous seed emulsion copolymerization using various core/shell ratios (the ratio to monomer is 10/0, 8/2, 7/3, 6/4, 5/5 respectively). The effects of core/shell ratio on the rheological behavior and gelation conversion of polyacrylate plastisol were investigated by rotary rheometer. The size and morphology of latex particle And plastisol surface membrane were characterized by dynamic light scattering (DLS) and scanning electron microscopy (SEM). The results of the rheological test demonstrated that plasticized system presented a bigger viscosity and lower gel temperature as well as shorter storage period with the core/shell ratio increasing; plasticized system viscosity decreased with shear rate increased, which shows the non Newton fluid behavior; Frequency scan result displayed the gel system for viscoelastic modulus linearly increased slowly as the scanning frequency increased, suggesting that the present system has a better stability.
  • Effect of electrodeposition methods on corrosion resistance of Ni-SiC nanocomposite coatings
    xia fa feng
    . 2013, 44(16): 15-0.
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    Abstract: Ni-SiC nanocomposite coatings were prepared on 45 steel by direct current (DC), pulse current (PC) and ultrasonic pulse electrodeposition (UPC) methods, respectively. The effect of processing methods on microstructures, components and corrosion resistances was investigated. The results illuminate that the Ni-SiC coating synthesized by UPC deposition method possess a compact and exiguous morphology. The average grain size of Ni and SiC in Ni-SiC coatings prepared by DC method is 175.4 and 81.5 nm, while that synthesized by UPC method is 74.8 and 36.3 nm, respectively. SEM and EDS show that electrodeposition method has great influence on the corrosion resistance of coatings, and the coating prepared by UPC deposition has better corrosion resistance than that by DC and PC deposition.
    • 工艺 技术
  • The investigation about the effect of the flow on the kinetics of step growth on (100) face of ZTS crystal
    Song-Sen SONG;min cheng ;chuan zhou
    . 2013, 44(16): 16-0.
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    Abstract： In-situ observation of displacement process of steps on the (100) face of ZTS crystals was observed by using optical microscopy, and the steps growth kinetics were investigated under different supply speed of solution and different supersaturations. The experimental results show that with the supply speed of solution increases, the mean displacement velocity of steps increases firstly and then decreases, which reaches a maximum when the supply speed of solution is S≈1.2ml/min; In the static growth solution, the mean displacement velocity of steps increases nonlinearly with the increase of supersaturation, the values of dead zone and the critical supersaturation were determined, meanwhile the kinetic coefficients and activation energy of steps were calculated at different supersaturation stages.
    • 研究 开发
  • Defect study of MgO-CaO material doped with CeO2
    . 2013, 44(16): 17-0.
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    MgO-CaO material was generated by using analytically pure Ca(OH)2 and Mg(OH)2 as the raw materials, CeO2 as the dopant and sintered at 1650℃ for 3h with the mixing and pressing of planetary ball mill. Furthermore, XRD and SEM analysis of the sample characterization was performed. According to the results, with the additions of CeO2, the lattice constants of CaO increase and then decrease; bulk density of the samples increases and apparent porosity decreases, strengthening the densification of MgO-CaO materials. In the sintering densification process, MgO grains grow more than CaO; pores in MgO-CaO grains gradually decrease while pores in MgO grains gradually increase and no pores in CaO grains. The nature of CeO2 promoting densification is to substitute and solutionize with CaO, Ce4+ approaching into CaO lattices, enlarging the vacancy concentration of Ca2+ and accelerating the diffusion of Ca2+.
  • Investigation on preparation and properties of the dual-phase proton conductor BaCe0.9Y0.1O3-δ/La1.95Ca0.05Ce2O7-δ
    ;Ling Wang
    . 2013, 44(16): 18-0.
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    The dual-phase proton conductors BaCe0.9Y0.1O3-δ-La1.95Ca0.05Ce2O7-δ(7:3, 6:4, 5:5, 4:6, 3:7) were successfully synthesized by the solid state reaction method. The phase composition and microstructure of the samples were investigated by XRD and SEM. Chemical stability against CO2 and boiling water was tested. The total conductivities of the samples in air, Ar and wet 4%H2/Ar from 450℃ to 850℃ were measured by IM6e electrochemical workstation. The results indicate that the samples sintered at 1500℃ with different ratio consist of the BaCe0.9Y0.1O3-δ and La1.95Ca0.05Ce2O7-δ dual-phase composition and the samples are very dense after sintered. With La1.95Ca0.05Ce2O7-δ content increase in BaCe0.9Y0.1O3-δ-La1.95Ca0.05Ce2O7-δ dual phase samples, the samples show an increased chemical stability against CO2 and boiling water. The sample with BaCe0.9Y0.1O3-δ-La1.95Ca0.05Ce2O7-δ(3:7) has the highest conductivity among the samples and its conductivity is 2.49×10-2S?cm-1at 850℃ in wet 4%H2/Ar. Its conducting activity energy is 1.13eV.
    • 综述 进展
  • Review on Hysteretic Modeling Methods of Giant Magnetostrictive Materials
    Bin WANG
    . 2013, 44(16): 19-0.
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    Establishing effective hysteresis nonlinear model is the key in the using process of giant magnetostrictive material. The hysteresis phenomenon and features are introduced and the status of the domestic and overseas scholars’ study on the hysteresis modeling is reviewed. The methods are divided into two categories: mathematic models and mechanism model. Different models are compared from its history, limitation and the difficulty of realization. Two typical models are discussed emphatically, such as Preisach model and J-A model. Through analysis, the future research direction of the hysteresis modeling is forecasted.
    • 研究 开发
  • Investigation on Pyrolitic Carbon-coated Microcrystalline Graphite as Anode Material for Li-ion batteries
    ;
    . 2013, 44(16): 20-0.
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    The phenolic resin carbon-coated microcrystalline graphite, as anode materials for lithium-ion battery, was prepared by being coated with phenolic resin carbon by immersion method, following with carbonization. The influences of the content of phenolic resin carbon on the structure and electrochemical performances of microcrystalline graphite were investigated. The results show that the process improved the surface morphology of microcrystalline graphite without destructing its crystal structure. With the proper coating content (4%), the initial coulombic efficiency increased to 81.4%, and the deintercalation capacity remained 257.9 mAh?g-1 at the current density of 0.5C after 50 cycles.The high rate charge/discharge performance is improved dramatically.
  • Thermal conductivity anisotropy of expanded graphite / LiCl-NaCl phase change material
    Yuefeng LI;zhang dong
    . 2013, 44(16): 21-0.
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  • Effects of Templates on the Growth and Optical Performances of Sm2O3 Microcrystal
    . 2013, 44(16): 22-0.
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    Sm2O3 microcrystal was controllably synthesized with the aid of different templates using SmCl3?6H2O and NaOH as the main raw materials and isopropanol as the solvent. The precursor was obtained in the reaction for 48h at the solvothermal condition of 200℃. After 800℃ thermal treatment for 1h, Sm2O3 microcrystal with different structures and morphologies was obtained. The phase, morphology and optical performances of the product were characterized by XRD (X-ray diffractometer), SEM (scanning electron microscope) and Lambda 950 spectrophotometer and the effects of different templates on the phase, morphology and optical performances of the product were studies. The results show that the different templates have the different effects on the structure, size and properties of the product. Using CTAB as the template, Sm2O3 microcrystal with cubic and monoclinic phases, and hexagonal flake structure is prepared and its energy gap is 4.828 eV.
  • Preparing the functional materials of PF - CaCO3 prepolymer by the Sol-gel method
    jia zhen;wei zhi wang;guo-liang li
    . 2013, 44(16): 23-0.
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    In this paper, the polymer materials of phenolic resin and nano-CaCO3 of excellent performances were prepared phenolic resin nanocomposites. We aim to get a functional material which can replace some expensive fillings and chemical agents and reduce the resin amount, saving energy. We first prepared nano-CaCO3 powder by adding the modified agents of Dodecyl betaine, then taking them into self-made phenolic resin adhesives. Through the scanning electron microscope (SEM), infrared spectrum analysis (FTIR), differential scanning calorimeter/thermo-gravimetric analysis (DSC and TG), PF-CaCO3 prepolymer prepared was uniform and good thermal stability and adding dodecyl betaine content of 2.5 ml was better.
  • A novel pH and electric responsive superabsorbent composite
    Ying Liu; ;;
    . 2013, 44(16): 24-0.
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    Poly(acrylamide-co-methacrylatoethyl trimethyl ammonium chloride)/ montmorillonite was synthesized by aqueous solution polymerization method using acrylamide (AM) and methacrylatoethyl trimethyl ammonium chloride (DMC) as monomers, ammonium persulfate (APS) as the initiator, N,N’-methylene bisacrylamide (NMBA) as the cross-linker and montmorillonite (MMT) as the filler. The swelling behavior of superabsorbent composite was studied by immersion of the composite in deionized water and pHs. The superabsorbent composite deswelling behavior induced by a direct current electric field was investigated. this superabsorbent composite can absorb 819 times water and exhibits a volume constriction of 86.5% under an applied voltage of 30 V.
  • Experimental Investigation on Curing Performance of Neoprene Rubber Modified by BBr3
    Feng-Juan ZENG;Jun DU ;;
    . 2013, 44(16): 25-0.
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    Polar chlorine atom is connected to carbon atom of double bond on neoprene rubber molecular main chain, which inhibits the double bond activity and reaction performance. This leads to poor CR vulcanization activity and difficult vulcanization. Brominated neoprene rubber was prepared by in aqueous BBr3 solution and its molecular structure of the main chain was converted by chemical method to improve the curing performance. Results showed that CR molecular chain of the α-H was replaced by bromine atom. Mooney viscosity was improved by 3.06%. Scorch time and vulcanization time was shortened by 57% and 8.8%, respectively. The vulcanization rate was improved.
    • 工艺 技术
  • Experimental and numerical stamping of carbon woven fabrics
    Tong Liang DU
    . 2013, 44(16): 26-0.
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    Abstract：Forming composite parts with double curvature could lead to complex fabric redistribution and reorientation. The mechanical properties of the final parts are deeply dependent on this fabric redistribution and reorientation. Based on fiber reinforced continuum mechanics theory, a simple hyperelastic constitutive model was previously developed by the authors to characterize the anisotropic nonlinear material behavior of woven composite fabrics during forming. This study investigated the complex fabric redistribution and reorientation of carbon woven fabrics during stamping over a double-curvature mould. Carbon woven fabrics were cut into samples with different yarn angles relative to the edges of the rectangular mould, namely 0° and 45°. The hyperelastic model was used to simulate the forming process. Simulation results such as fabric boundary draw-in and local shear angles were compared with experimental results. A very good agreement was obtained. The proposal of this experiment and its numerical simulation are critical to the numerical simulation and process optimization of woven composites forming.
  • Preparation of nanosized spinel lithium manganate by high-gravity reactive co-precipitation
    ; ;;
    . 2013, 44(16): 27-0.
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    Abstract： Spinel lithium manganate precursor were prepared by co-precipitation method in a rotating bed with helix channels (RBHC) using lithium nitrate and manganous nitrateas as lithium source and manganese source, ammonium carbonate as precipitant. Nanosized spinel lithium manganate powders were obtained upon microwave calcination at temperature of 750℃ over 2h. The phase structures and morphologies were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transform electron microscopy（TEM）. The results showe that nano spinel LiMn2O4 powders with high crystallinity, uniform particle size, the average size of about 60 nm can be synthesized by high gravity reactive co-precipitation method.
  • Study on the Rapid Thermal Annealing Process of Fe-based Amorphous and Nanocrystalline Strip
    Lin ZHANG;Zhenghou Zhu
    . 2013, 44(16): 28-0.
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    In this paper,The influences of fast heating rate and different tapping temperature for the soft-magnetic properties of the Fe-based amorphous and nanocrystalline Strip are studied. The study of this paper is using the strips with the width of （10±0.2）mm and the thickness of （33±2）μm are taken as samples, then they are coiled to the magnetic cores whose standards are φ20×φ30×10(mm). The initial temperature is 480 ℃,and with 1℃/min rate to annealing temperature.When the heat treatment process of amorphous strips is 540℃×60min and the tapping temperature is 200℃，the soft magnetic properties of which are the best，such asμi=135800、Bs=1.157T、Hr=0.6781A/m、Hc=0.6434A/m (f=1kHz). they don't appear to be much different from the common vacuum heat treatment ,the best soft magnetic properties of that areμi=159700、Bs=1.122T、Hr=0.5964A/m、Hc=0.6828A/m (f=1kHz).Meanwhile,when the tapping temperature exceeding 300℃,the soft magnetic properties would violently decline.
    • 研究 开发
  • Effects of Relative Humidity on Morphology and Performance of PVDF Porous Membrane
    Zhi-Ying WANG
    . 2013, 44(16): 29-0.
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    Abstract: Hydrophobic polyvinylidene fluoride (PVDF) membrane were tailored by non-solvent induced phase inversion assisted with coarse substrate. N,N-dimethylacetamide(DMAc) and octanol were used as solvent and non-solvent addition, respectively. In this method, the polymer dope solution was cast on coarse substrate and the film was put on the balance placed in a chamber for a fixed time interval, where temperature and humidity were controlled. Then, it was immersed into water coagulation bath. The effects of relative humidity on the morphology, permeability and hydrophobic of PVDF membrane were investigated. As the humidity in the gas phase increased, the number of top surface pores and pore size increased and the crystalline particles of the bottom surface grew better. In addition, it was found that the thickness of skin layer near top surface decreased with increasing humidity. At higher humidity condition, the dense skin layer disappeared and exhibited symmetric spongy structure. There was little nitrogen flux in the case of lower humidity of under 50%, whereas the nitrogen flux increased obviously with increasing humidity in the case of humidity higher than 50%. With the increase of the humidity, the hydrophobic of the bottom surface had no obvious change, and the water contact angles of the membranes were all higher than 130°.
  • Effect of chitin-based tissue engineering carriers on corneal epithelial wound healing
    Xian-xian SUI;
    . 2013, 44(16): 30-0.
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    Abstract：Objective：To study the feasibility of culturing corneal epithelial cells on chitin-based carrier and to investigate its promotion effect on corneal epithelial wound healing of New Zealand rabbits. Methods: The chitin was dissolved by sodium hydroxide and urea and the chitin-based membranes were obtained after the formic acid volatilized. The thickness, water content, transparency, mechanical strength, biocompatibility and degradation were measured. To evaluate the cytocompatibility of the membranes with corneal epithelial cells cultured on the surface of the carrier membranes. Constructed the tissue engineering corneal epithelial, and then transplanted them to damaged corneal epithelia of New Zealand rabbits, the repair effect was observed. Results: The thickness of CH was 0.2mm.The water content of chitin-based membranes was 81.59%. The transparencies on different wavelength were greater than 80%, the load intensity on dry state and wet state were 6.56N and 29.85N. Animal tissue compatibility experiments showed that no remarkable inflammation appeared. They were benefit to the cell-adhesion and promoted the corneal epithelial wound healing .There are significant differences between tested group and contrasted group. Conclusion: The material is basically in line with the requirements of cornea tissue engineering scaffold. It pointed out a direction for the research of cornea tissue engineering.
    • 综述 进展
  • A research review on the encapsulants with high transmittance character
    ;Li Wang;Lan-Ying ZhangHuai Yang
    . 2013, 44(16): 31-0.
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    The efficiency of photovoltaic (PV) of modules are significantly affected by the transparency of encapsulants. From the viewpoint of decreasing of optical loss and increasing of utilization rate of sunlight, the present paper reviewed and evaluated the reported methods of modifying the ethylene-vinyl acetate (EVA) copolymer encapsulant with high transparency character, as well as the risk assessment on modified methods. This review would provide the solution to increase transition efficiency and decrease costs of PV.
    • 研究 开发
  • Biocompatibility study of a new type of medical high nitrogen nickel-free stainless
    ;Xing-zheng ZOU ;;No ;
    . 2013, 44(16): 32-0.
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    The adhesion of osteoblasts and blood platelets on the surfaces of high nitrogen nickel-free stainless steels were investigated. Blood platelet adhesion testing was performed to evaluate the blood compatibility of high nitrogen nickel-free stainless steels, and MTT cytotoxicity testing and cell adhesion testing were carried out to evaluate the cell compatibility of high nitrogen nickel-free stainless steels. Results showed that the effect of nitrogen content on the platelet adhesion was not obvious. Nickel-free stainless steel materials with different nitrogen contents are not harmful for the osteoblast growth, morphology and proliferation, and there is not significant effect of nitrogen content on the cell adhesion in a certain content range. Cell toxicity test showed that both the high nitrogen nickel-free stainless steel and titanium alloy had no obvious toxic side effect on the osteoblast growth.
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