30 October 2012, Volume 43 Issue 20
    

  • Select all
    |
    研究与开发
  • Preparation and properties of conductive silver-plated aramid fibers
    ;Xin-Guo ZOU;;;
    . 2012, 43(20): 1-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    Conductive aramid fibers were prepared by electroless silver plating on the fibers. The aramid fibers underwent NaH-DMSO treatment,sensitization, activation and electroless silver deposition on their surface respectively. Influence of different silvering bath compositions and process conditions on weight gain percentage, resistance and surface morphology was investigated and the optimized process of electroless silver plating on Kevlar fibers was obtained. In addition, the breaking strength of silver deposited aramid fibers remained at values up to 44 N.The resistance of silver deposited Kevlar was 0.25Ω/cm.
  • Research on time-resolved imaging of fingerprint developed by SrAl2O4:Eu2+, Dy3+
    Xiao-Bo XIONG; Guoxiang Yin;Jian Zhang;
    . 2012, 43(20): 2-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    Conventional development of latent fingerprints is compromised when the prints are on the difficult and patterned substrates. In consideration of this problem, Eu2+, Dy3+ co-doped SrAl2O4 (SED) was synthesized by sol-gel method. It was characterized by X-ray diffraction (XRD), and photoluminescence (PL) spectrometer respectively. Owing to super long afterglow properties of SED, it was introduced to development of fingerprints on non-porous and semi-porous substrates, and image of fingerprint. Compared with common fluorescent powders, SED powders was more applicable for latent fingerprint detections on various substrates, including glass, ceramic tile, plastic, smooth hard paper, print paper, and leather. It was quite significant that background disturbance of difficult and patterned substrates was effectively eliminated or diminished, and time-resolved imaging was achieved using SED powder for fingerprint detection.
  • Growth Rules and Capacitor Effect of Pure Titanium TA2 Ceramic Coating in Microarc Oxidation
    Hong-Yuan WANG
    . 2012, 43(20): 3-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    Experiments on the rules of ceramic coating growth were conducted in the process of pure titanium TA2 microarc oxidation (MAO). The surface morphology, thickness and phase component in different stages were also analysed. Based on oxidation process and dielectric theories, theoretical model and equivalent circuit were established. The analysis results show that the ceramic coating distributes in fragmentation firstly and then in connection, and the completed TiO2 ceramic coating has alternating current (AC) coupling capacitor effect. All the analysis agrees with the experimental results, and it can provide a theoretical and experimental base for improving the performance of coatings as well as MAO technologies.
  • Synthesis and growth mechanism of CNTs/FeNP hybrid structures
    Hao LI
    . 2012, 43(20): 4-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    Through in situ depositing of iron nano particles (FeNP) coating with carbon on the surface of carbon nanotubes (CNTs), different morphologies of CNTs/FeNP hybrid structures were prepared by catalytic chemical vapor deposition method. The micro morphology and structure of hybrid structures were characterized using scanning electronic microscope and transmission electronic microscope. Results show that iron nano particles were connected with CNTs through graphite sheet structures, with good interconnections. At low thiophene proportion, the diameter of CNTs decreased, and the amount of CNTs increased. When the thiophene proportion was higher than 0.5%, CNTs/FeNP hybrid structures were achieved. The components and relative proportions of hybrid structures were analyzed by X-ray energy dispersive spectroscopy and X-ray diffraction, it turns out that iron existed mainly on the form of α-Fe, γ-Fe and Fe3C in the system; iron proportion increased with the increasing thiophene proportion. By studying the formation of iron nano particles and its deposition on the CNT surface, the formation mechanism of CNTs/FeNP hybrid structures was illustrated.
  • Influence of synthesis parameters on photocatalytic properties of titanium dioxide nanotube arrays
    Lu Jin;Jie MA
    . 2012, 43(20): 5-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    Abstract: TiO2 nanotube arrays were fabricated by electrochemical anodization of Ti foil in glycerin(or glycol), H2O and NH4F electrolyte. To study the influence of voltage, reaction time and electrolyte to TiO2 nanostructure and photocatalytic performance , SEM and XRD were used to analysis the morphology and composition of TiO2 nanotube arrays. The crystal phase transition were also investigated here under anneal temperature. The result shows that higher voltage and longer reaction time lead to better degradation ratio of methyl orange, using electrolyte composed of glycerin surpass that of glycol.
  • The Simplified Method of Analyse Macro Pore Feature of Aerated Concrete and Its Validation
    ;
    . 2012, 43(20): 6-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    The paper use MATLAB technology to designs an application software to analyze the macro pore feature of aerated concrete. The macro pore structure characteristics of aerated concrete such as pore area distribution, average pore size, porosity were obtained using this method. The method accuracy was validated by analyze a known pore feature picture correctly, and feasibility was validated by the result is close to which get from image analysis system. Tests showed that the simplified method of analyse the macro pore feature of aerated concrete is accurate and credible.
  • Effects of Si and RE on the microstructure and properties of AZ31 magnesium alloy
    Ji-qiang LI
    . 2012, 43(20): 7-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    The effects of Si-RE on the microstructure and mechanical properties of AZ31magnesium alloy were investigated. The phase present in the alloys have been identified by optical metallography(OM), scanning electron microscopy(SEM) /energy dispersive X-ray spectroscopy(EDS) and X-ray diffractometer (XRD). And the mechanical properties have also been measured by material test machine at room temperature. The results show that he microstructure is obviously refined and the tensile strength of AZ31 based alloy at room temperature is significantly improved. Compared to AZ31, the tensile of AZ31-0.4%Si-0.5%RE alloy has higher ultimate tensile strength and elongation. Its ultimate tensile strength and elongation are enhanced by 42MPa and 3.9%, respectively. Although addition alloy elements can’t change the fracture mode of AZ31, SEM fractographs of tensile fracture surface have obvious plastic deformation. It indicates that has had the bigger plastic deformation before failure.
  • Steady flow and thixotropic behaviors of collagen/ 2-propanol blends
    Jiheng Li;;
    . 2012, 43(20): 8-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    The effects of steady flow, yield stress and thixotropic behaviors of collagen on the concentration of 2-propanol were studied by the rheometer. The results showed 2-propanol changed the viscosity of blends with the low shear rate, while, the viscosity of blends was insusceptible to the 2-propanol with the high shear rate. The Power low model and the Carreau model were used to fit the steady flow of the blends, and the parameters obtained from models, such as viscosity coefficient K and non-Newton index n, described the rheological behaviors of blends well. The values of the yield stress of blends decreased with adding 2-propanol, suggesting that 2-propanol improved the flow of the collagen solution and the stability of blends decreased. In addition, the thixotropic area of the blend with 1mol/L 2-propanol was smaller than that of the pure collagen solution, indicating that entangled chain could reverse soon. However, the thixotropic area of the blends with 2 and 3mol/L 2-propanol was larger than that of the pure collagen solution, suggesting that reversion ability of the blends decreased and it was not good for the stability of the blends.
  • The Preparation and Luminescence of Eu Activated SrMoO4: 3+ Red Phosphor
    xian-feng Meng
    . 2012, 43(20): 9-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    A red phosphor Sr0.6MoO4:Eu0.43+ was synthesized by hydrothermal method with the starting materials: Eu2O3，Sr(NO3)2 and (NH4)6Mo7O24?4H2O. The crystal structure, morphology and luminescent properties of the phosphors were investigated by XRD、FE-SEM and PL. The results showed that non-agglomeration phosphor with a like tetragonal-dipyramid morphology and particle sizes about 0.5 to 2.0μm were produced. The main emission peak of the samples was at 614nm（5D0→7F2 transition of Eu3+）. The excitation spectrum showed that this phosphor can be effectively excited by ultraviolet (396nm) and blue (466nm) light, nicely fitting in with the output wavelengths of ultraviolet or blue LED chips. The Sr0.6MoO4:Eu0.43+ phosphor may be a good candidate phosphor for white LED.
  • Study on the Performance of Photocatalytic Degradation of Methylene Blue Using ZnAlTi Layered Double Hydroxides
    Wu Pingxiao
    . 2012, 43(20): 10-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    ZnAlTi layered double hydroxides (LDHs) with different Zn:Al:Ti ratio were synthesized by dynamic urea hydrolysis method. Part of these samples were calcined at 500, 600, 700 and 900 ℃, respectively for 4 h, obtaining calcined photocatalysts ZnAlTi-LDHs. The effects of experimental parameters such as the different molar ratio of catalyst, catalyst dose, and calcination temperature on the photocatalytic degradation of methylene blue (MB) process were evaluated in detail. The results showed that under the conditions of reaction temperature at 30℃, Ti:Al molar ratio of 2:1, 1.0 g/L catalyst loading, 10 mg/L initial MB concentration within 12 h UV-light irradiation, 94.4% degradation rate of MB was obtained.
  • Microstructures and hydriding/dehydriding characteristics of La2Mg17-Ni composites by mechanical milling
    Zhuo-Cheng LIU ;
    . 2012, 43(20): 11-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    Abstract: In order to improve the hydriding/dehydriding property of the La2Mg17 alloys, La2Mg17+Ni+NbF5 mechanical milling were performed in an argon protective atmospheres. The structures of mechanical milling composites were characterized by XRD and SEM, respectively. The hydrogen storage properties were measured by automatically controlled Sieverts apparatus. The research showed that absorbed/desorbed hydrogen capability significantly enhanced due to ball-milling technology. Further indicated that Ni powder and NbF5 prompted the nanocrystalline/amorphous structures formation, which is the main reason of hydrogenation/dehydrogenation were modified.
  • Preparation and Characterization of Organophilic Long-chain Alkyl Silane Functionalized Graphene
    ;
    . 2012, 43(20): 12-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    Functionalized graphene (FG) was prepared in one-step by treating graphene oxide (GO) with hexadecyltrimethoxysilane and triethylamine. Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD)，Atomic force microscopy (AFM) and Ultraviolet-visible (Uv-vis) spectroscopy were performed to characterize the structure and properties of FG. Investigation results confirmed that the silane molecules were attached on the surface of GO by Si-O-C, meanwhile the residual oxygen-containing functional groups of GO were removed and the sp2-hybridized structure of graphene was restored. FG has an excellent lipophilicity and can be stably dispersed in various solvents such as N, N-dimethylformamide (DMF), tetrahydrofurane, acetone and toluene. The maximum dispersibility of FG in DMF is 1.90 mg/ml. AFM showed that FG was exfoliated into single sheets in DMF with a thickness of about 1.7 nm.
  • Investigation on the removal rate and planarization properties of an alkaline slurry for Cu CMP
    Xin-Liang TANG
    . 2012, 43(20): 13-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    The dual damascene cooperate with chemical mechanical planarization (CMP) is an effectively way to fabrication copper interconnects. Slurry plays an important role in the Cu CMP process. In this paper, we have developed an alkaline slurry for copper pattern wafer CMP. Firstly, we have studied the characteristics of removal rate of copper under different pressure, rotation speed (RS) and flow rate (FR) by using the alkaline slurry, the results indicate that the influence of pressure on removal rate is larger than RS and FR, the removal rate was increased with the pressure, RS and FR increased. The results obtained from copper pattern wafer CMP indicate that the slurry has a considerable planarization capability.
  • Preparation and properties of grafted and non-grafted polyurethane/epoxy resin interpenetrating polymer networks
    Ying-Xian ZHOU ;
    . 2012, 43(20): 14-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    Grafted and non-grafted polyurethane/epoxy resin interpenetrating polymer networks (PU/EP IPNs) were prepared by a sequential method, and effect of different PU/EP mass ratio on mechanical and thermal properties of these two types of IPNs was investigated. FTIR analysis confirms the formation of carbamate grafted structure within grafted PU/EP IPNs via a reaction between -NCO of polyurethane and -OH of epoxy resin. Results of mechanical properties test indicate that incorporation of polyurethane pre-polymer into epoxy resin could significantly improve the materials’ mechanical performances: when the mass ratio of PU/EP is 15/85, grafted PU/EP IPNs’ tensile and impact strengths reached their maximums, which are 36.7 MPa and 22.39 kJ/m-2 respectively; while PU/EP’s mass ratio is 10/90, non-grafted PU/EP IPNs achieved its optimal tensile and impact strengths, which are 27.8 MPa and 19.34 kJ/m-2 separately. TG analysis shows that grafted PU/EP IPNs obviously exhibits a better thermal stability than non-grafted IPNs.
  • Synthesis and Self-assembly Behaviors of N,N-Dialkyl-3,6-O-Sulfopropyl Chitosan derivatives
    ;
    . 2012, 43(20): 15-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    N,N-dialkyl-3,6-O-sulfopropyl chitosan(SPDACS) was synthesized by the reaction of 1,3-propane sultone and N,N-dialkyl chitosan(DACS) whose hydroxyl groups were activated by NaH using THF as solvent. The product were characterized by FTIR, 1H NMR, EA and Solubility test. The self-assembly behaviors of SPDACS in aqueous solution were studied. The results show that SPDACS were soluble in acidic, neutral and alkaline aqueous solution. SPDACS self-assembled nanomicelles with the spherical shape was successfully prepared in the water. The CMC and the average particle size of SPDACS with heparin structure verified by toluidine blue discoloration test decreased from 0.014 mg/mL to 0.006 mg/mL and from 169.4 nm to 117nm with the increase of the carbon chain length from 8 to 12. The results show that the SPDACS was expected to become a drug carrier with good blood compatibility.
  • Review of the researches of compositionally graded ferroelectric thin films
    ;
    . 2012, 43(20): 16-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    Compared with the homogeneous ferroelectric thin films, the compositionally graded ferroelectric thin films have many excellent performances. The dielectric properties of the compositionally graded ferroelectric thin films are significantly enhanced. Therefore, the performance of the tunable microwave device applications is effectively improved. The properties of up and down graded ferroelectric thin films are also different. However, the cause of these differences has not been experimentally proved. In addition, the polarization offset of the hysteresis loop is still a controversial problem. Thus, researches of compositionally graded ferroelectric thin films are of great significance both in the practical applications and the improvements of the theories. The article reviews the researches of compositionally graded ferroelectric thin films, and also proposes some problems needed to be solved.
  • PLGA Captopril-loaded nanofibers and their in vitro release profiles
    Li-Min ZHU
    . 2012, 43(20): 17-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    Ultrafine Captopril(CPL)-loaded poly(lactic-co-glycolic acid) (PLGA) fibers were successfully prepared by electrospinning method from co-dissolving solutions of PLGA and Captopril in dichloromethane (DMC) ：acetone（ACT）(2:1(v/v))that was made as the spinning solutions. The the optimal spinning parameters were obtained that was PLGA 20 wt%, CPL:PLGA = 2:10(w/w), voltage: 12.5 kv, the rate :1 mL/h，the ratio of solvent : DCM: ACT= 2:1(v/v). The samples thereby obtained were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), Differential Scanning Caborimetry) (DSC) and X-ray diffraction (XRD) measurements. In vitro release study showed that a sustained release was achieved after a burst release at the early stage. The burst release and overall drug was reduced as the pH of buffer solution increased.
  • Strength analysis and hydrostatic test for fibre filament-wound tube with lining
    Guang-Lei XU
    . 2012, 43(20): 18-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    Strength analysis model for fibre filament-wound tubes with lining under inside pressure was studied. The whole model was divided into elastic stage and plastic stage if lining was assumed to be ideal elastic-plastic material，working strength and burst strength for fibre filament-wound tubes can be obtained by two stages, respectively. Two kinds of fibre filament-wound tubes with lining were calculated by theoretical analysis model，one was carbon fibre tube and the other was glass fibre tube, and failure mode of them were also forecasted. Hydrostatic test show that strength analysis model is consistent with test results.
  • Tribological characteristic of electronic copper foil rolling oil and study of their lubricating property
    ;
    . 2012, 43(20): 19-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    Tribological characteristic of copper foil rolling oil with single system oiliness and extreme pressure additives were investigated using a four ball test machine. The additive types of copper foil rolling oil were determined. By using orthogonal experimental design, tribology properties of copper foil rolling oil, which contains different amount of compounded system additives, were studied. The best compounded system was selected and its effect of process lubrication was studied through rolling experiments. The results show that load-bearing capacity of oil film and extreme pressure anti-wear property of copper foil rolling oil can be effectively improved, when oiliness agents are alcohol and ester compound, and extreme pressure agent are BANT and EAK compound. The best compound proportion of ester, alcohol, BANT and EAK is 3:2:1:3, which can effectively reduce the rolling friction and rolling energy consumption. The average rolling pressure is reduced by about 15% and rolling power is reduced by about 17% compared with no additive rolling oil. At the same time, the rolled surface of copper foil is very smooth. Therefore, the compounded system has a good application prospect in copper foil rolling lubrication.
  • Research progress on preparation technology and property of organic liquid-absorptive functional fiber based on polymethacrylate
    Nai-Ku XU ;;
    . 2012, 43(20): 20-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    There is a special absorption capability to polar and non-polar oleo-organic liquid for polymethacrylate fiber, so it can be used in the field of organic liquid pollution treatment, and has been arrested attention of researchers. The recent progress of new thought and methods for the preparation of organic liquid-absorptive functional fiber based on polymethacrylate in our team was reviewed from preparation technology and absorption property. The development research on fiber products was summarized. In addition, aiming at the existing problems during the preparation process of polymethacrylate fiber，the research direction of follow-up was also discussed in this paper.
  • Research on Behaviour of Bending Deformation for A NiTi Alloy Aortic Stent
    Hai-Quan FENG;
    . 2012, 43(20): 21-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    The models of chest aorta stent for axial flexibility analysis were established by software of Pro/E and Ansys. The flexibility of twenty-seven niti alloy stent was simulated and verified. On this basis, the effect to performance of cross section in central part was analyzed systematically when stent structure was changed. The results show that flexibility of stent can been improved by decreasing linkers of circumferential direction as well as increasing length or number of cell, but the former is more significant than the latter. Cross section deformation in central part is affected obviously by the number of linkers when stent structure is changed.
  • Preparation of N-Doped TiO2 Ceramic Membrane and Its Photocatalytic Properties Research
    Zi-Bo WANG;; Shu-Li BAI
    . 2012, 43(20): 22-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    Doped TiO2 sol was prepared by sol-gel method, the sol was coated on an inorganic ceramic membrane by the way of dipping-raise method to make a photocatalytic ceramic membrane with antifouling. Dye wastewater containing salt (direct fast scarlet dye 4BS) was treated by the combination of photocatalytic technology and membrane separation. Initial concentration, pH, trans-membrane pressure and cross-flow velocity on treatment effect of the dye wastewater was investigated. The results showed that the dye rejection of this composite ceramic membrane was 99% and the retention of inorganic salt was less than 1%, the permeate flux of the composite membrane under irradiation was increased by 90%, compared with the processes of membrane separation without irradiation.
  • Surface Modification of PVA fiber with Epoxy Chloropropane and its Mechanism of Curing Reinforcement
    . 2012, 43(20): 23-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    Suspension multi-grafting copolymerization was adopted to surface modify the water-soluble polyvinyl alcohol fiber (PVA) by use of epoxy chloropropane. In addition, influences of the unmodified and modified PVA fiber content, epoxy chloropropane addition, drying temperature and time on paper wet strength were discussed. It was found that PVA fibers modified with epoxy chloropropane were more effective to increase the paper strength, and significantly improve the problem of staining the trough or aggregation, as well as the dispersibility of PVA fibers in water. Composite paper of enhanced strength was obtained when PVA fibers were prepared under the following conditions: drying temperature was 100-110℃，drying time was 10 min, solubility temperature was 80℃. What’s more, the structure of the fiber was characterized by Fourier transform infrared spectroscopy (FT-IR), indicating that the epoxy groups were successfully introduced into the fiber surface. And the results from scanning electron microscopy (SEM) and atomic force microscope (AFM) further demonstrated that the hydrophilic groups on the PVA surface were taken place by hydrophobic epoxy.
  • Effects of Structure and Surface Property on Adsorptive Separation of Carbon Molecular Sieve for CH4/N2 and CO2/N2
    ;Min GU
    . 2012, 43(20): 24-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    In this paper, with the Takeda(CMS-1) and Kuraray(CMS-2) Carbon Molecular Sieve (CMS) from Japan together with the BF CMS(CMS-3) from Germany as adsorbents, we measured the adsorption isotherms by use of hi-precision intelligent gravimetric analyzer, studied the CMS’s adsorption equilibrium separating property and adsorption kinetics on N2，CH4 and CO2, characterized the pore size distribution and surface functional group of CMS. The effects of structure and surface property on adsorptive separation of CMS for CH4/N2 and CO2/N2 were researched. The experimental results show that the dynamics separation for CH4/N2 and the equilibrium separation for CO2/N2 are realizable on CMS-1 and CMS-2. The effect of equilibrium separation for CH4/N2 and CO2/N2 is better than dynamics separation. The pore size is the key factor which affecting CMS’s adsorptive separation performance. The difference of pore diameter distribution causes even more obvious steric hindrance-dynamics separation effect for CH4/N2 on CMS-1 and CMS-2, as well as the equilibrium separation effect on CMS-3. The oxygen functional group is in favor of improving the adsorptive separation property of CMS.
  • Effect of microwave power on the composition, structure and performance of n-type doped nano diamond thin films
    Bing Wang
    . 2012, 43(20): 26-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    Nanocrystalline diamond thin films doped with N had been prepared on Si substrate by microwave plasma chemical vapor deposition(MPCVD) technology using CO2, CH4 as actiong gas source and the methanol saturated solution of melamine as doping source carried into deposition chamber with Ar gas. Then the composition, structure and electrical conductivity of obtained films were characterized through laser Raman spectroscopy, atomic force microscope, and hall effect testing means in which the emphasis was focused on the influence of microwave power on the gained film feature. The results showed that Nano diamond thin films with good nitrogen doping effect could be prepared using the designed process, and with microwave power increasing, the grain size, grain boundary width, surface roughness, as well as the electrical conductivity of grown diamond films also increased obviously. Finally the good electronic conductivity of the film material likewise proved that the selected reaction system in our process is a effective technical approach type to gain N-type diamond film, and at the same time the input microwave power has important influence on the doping effect of deposited film in which only under appropriate microwave power the big electronic conductivity and good quality of the film can be prepared.
    • 综述
  • Research Progress of Non-Equilibrium Effects of Solidification in Thermodynamic High Undercooled Melt
    ;;PAN Jing ;Xin-cai LIU
    . 2012, 43(20): 27-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    The solidification of thermodynamic high undercooled melt is a kind of non-equilibrium rapid solidification, which exhibits unique solidification mechanism and microstructure characteristics compared with the conventional solidification. The non-equilibrium effects of solidification in thermodynamic high undercooled melt involve refinement of grain size, precipitation of metastable phases, spinodal decomposition and formation of bulk amorphous, etc. Researches on these aspects possess important theoretical significance and practical value for the development of new kind of high-performance materials. Related researches have progressed rapidly in recent years. In this paper, the research progresses on the refinement mechanism of microstructure, the precipitation mechanism of metastable phases, the phenomena of spinodal decomposition and the formation of big bulk amorphous were summarized and analyzed.
    • 研究与开发
  • Research on Response Mechanism of Contact Resistance under Tension
    Xi Fang
    . 2012, 43(20): 28-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    This paper discussed the contact resistance between the carbon fiber monofilament before and after loading under micro-meter scale. With taking the experiments of mechanical resistance and tunnel effect, contact resistance with two adjacent fibers has different corresponding style to the loading within different loading procedure. In the first procedure the contact resistance decreases linearly with larger tension strain. In the second procedure the contact resistance which is caused by tuuuel effect becomes higher with larger tension.
  • Effect of volume fraction of nickel on optical properties of Ni-Al2O3 solar selective absorbing films
    Zhen-Xiang LI;;;Jian-Xi ZHAO
    . 2012, 43(20): 29-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    The effect of the volume fraction of nickel on the optical properties of Ni-Al2O3 solar selective absorbing films was investigated by computer simulation. The knowledge obtained was used to guide the optimization of Ni-Al2O3 coatings fabricated by aqueous sol-gel method. The results of theoretical simulation showed that the double absorbing coatings, of which consists of a base layer with metal-like character and a middle layer with volume fraction less than 0.50 times of the base layer, together with an anti-reflection top layer could produce excellent optical absorption. Based on the principles, the optimized Ni-Al2O3 coatings were fabricated by aqueous sol-gel method, which attained a high solar absorptance of 0.94 and a low thermal emittance of 0.04.
  • Study on modified polypropylene membrane induced by UV-irradiation grafting
    ; Shao-Ning LIYa-nan Fan
    . 2012, 43(20): 30-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    A new kind of hydrophilic membrane was prepared through grafting polymerization of acrylic acid (AA) and methacrylic acid (MAA) onto the surface of polypropylene (PP) membrane initiated by ultraviolet (UV), using benzophenone as photosensitizer. The factors influenced the grafting degree were discussed, such as the concentration of photosensitizer, irradiation time and solvent type. Attenuated total re?ection-Fourier transform infrared spectroscopy (ATR-FTIR) and scanning electron microscopy (SEM) were used to characterize the chemical and morphological changes of the original and grafted PP membrane, the results indicated that acrylic acid was grafted onto the surface of PP membrane. Static contact angle measurements and water absorption ratio were used to characterize the hydrophilic changes of the polypropylene membrane surface. In addition, the grafting degree of AA in water was obviously higher than that in organic solvent, furthermore, the grafting degree of AA was commonly higher than MAA under a same grafting conditons. The contact angle of grafted PP membrane decreased from 95° to 35°over a critical grafting degree of 11.8%, the hydrophilic of PP membranes improved dramatically.
  • Dielectric properties of SnO2—Zn2SnO4 composite ceramics
    ;Liben Li
    . 2012, 43(20): 31-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    Zn2SnO4 powder was prepared by solid state reaction and densified SnO2—Zn2SnO4 composite ceramics were obtained using traditional ceramic technology. The effect of Zn2SnO4 content on the dielectric properties of the composite ceramics was investigated, as well as the mechanism of high dielectric properties. Relative dielectric permittivity of 85mol%SnO2+15mol%Zn2SnO4 ceramics reached 104 at 40Hz, which was much higher than that of SnO2 and Zn2SnO4 ceramics. The dielectric properties and admittance varied with Zn2SnO4 content simultaneously and further investigations show that the high dielectric dielectric permittivity of SnO2—Zn2SnO4 composite ceramics are originated from the double Schottky barrier at grain boundary.
  • Effects of Annealing Treatment on Microstructure and Electrochemical Properties of La0.68Gd0.2Mg0.12Ni3.3Co0.3Al0.1 Hydrogen Storage Alloys
    ;
    . 2012, 43(20): 32-0.
    Abstract ( ) Download PDF ( ) Knowledge map Save
    La0.68Gd0.2Mg0.12Ni3.3Co0.3Al0.1 hydrogen storage alloys were prepared by induction melting and then annealed at different temperature(1173 K~1273 K) in the closed container for 16h.The effect of annealing temperature on the microstructure and electrochemical properties of La0.68Gd0.2Mg0.12Ni3.3Co0.3Al0.1 were investigated by means of inductively coupled plasma(ICP), X-ray diffraction (XRD), electron probe micro-analysis (EPMA) and electrochemical measurements. The results showed that the A5B19 alloys mainly consisted of Ce5Co19-type（Pr5Co19-type）﹑PuNi3-type和CaCu5-type phase. Meanwhile, with increasing annealing temperature, Pr5Co19-type phase abundance in annealed alloys increased, and Ce5Co19-type phase abundance decreased. The Pr5Co19-type phase abundance was 87.75 wt%, and Ce5Co19-type phase abundance was only 0.78 wt%when annealing temperature was 1273K.The electrochemical measurements showed that these alloys had little effects on activation performance under different annealing temperature, but it was great impact on electrode capacity and cycle stability. The discharge capacity of the alloys reached 373.01 mAh/g when annealing temperature was 1273K. After 100 charge–discharge cycles, the discharge capacity retention rate( S100 )of the alloy electrode(T=1273K) reached 90.2%.
Author Center
Review Center
Journal Online
Copyright © Jorunal of Functional Materials
Tel: 023－68264739　 　
E-mail: gnclbjb@126.com　
Total visitors:
Visitors of today:
Now online:
渝公网安备50010902000552号　渝ICP备2022001025号-1