31 October 2015, Volume 46 Issue 20

    

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综述 进展
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  Progress of the single phase magnetic multiferroic material CaMn7O12

  . 2015, 46(20): 1-0.

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  Abstract: CaMn7O12 as a new single-phase multiferroic material has attracted considerable attention due to the special physical mechanism of the ferroelectric. The ferroelectricity is induced by a long-period helicoidal(proper-screw) spin spiral. Because of the particular magnetic orders, magnetic multiferroic material CaMn7O12 exhibits high magnetoelectric effect, large polarization (Pc=2870uC/m2) that along the c-axis direction and higher Néel temperature (TN1 = 90K). This paper reviews the crystal structure of CaMn7O12, the origin of the special magnetic orders, the magnetoelectric coupling effect and the physical mechanism of the induced multiferroic properties.
工艺 技术
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  Synthesizing and Analysing Electrochemical Features on Mesoporous Carbons Materials

  Chun-Xia HAN;Wen-zhong Yang

  . 2015, 46(20): 2-0.

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  Abstract: In this paper, mesoporous carbons were successfully sythesized by direct pyrolysis of ferric citrate salts in a nitrogen atmosphere. The morphology, pore structure and porosity of the samples were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and N2 adsorption–desorption techniques. The pyrolysis process of Ferric citrate was studied by TG technology in nitrogen atmosphere. Cyclic voltammetry (CV) is applied to evaluate the electrochemical potential of MCs. Based on the results, we can find out that the MCs prepared by directly pyrolysising ferric citrate has excellent electrochemical performance.
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  Improvement of recrystallization texture in high silicon steel shin sheets by two-stage cold rolling method

  Jin-Long LIU;

  . 2015, 46(20): 3-0.

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  High silicon steel thin sheets with thickness of 0.20mm were produced by conventional rolling and annealing methods. Recrystallization texture under different cold rolling process was investigated by means of X-ray diffraction. Compared with the one-stage cold rolling method, the two-stage cold rolling method is beneficial to weaken the adverse γ recrystallization texture. Furthermore, by properly assigning the reduction of first and second cold rolling, γ recrystallization texture can be completely eliminated and strong η recrystallization texture develops. It is an effective way to improve the recrystallization texture of high silicon steel thin sheet that priority of nucleation at shear bands dominates the recrystallization by modifying the deformation microstructure using two-stage cold rolling method.
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  Contrast studies of the Process optimization and Characterization of Shielding Fabric by Amorphous Ni-Fe-P and Ni-P Alloy

  Xue-Yan WU ;

  . 2015, 46(20): 4-0.

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  A flexible shielding fabric with dense uniform coating was prepared after electrical deposition of amorphous Ni-Fe-P and Ni-P alloy on copper-coated polyethylene terephthalate (PET) fabric. The effects of coating composition and the deposition rate were discussed by the current density, temperature and pH value. The morphology, composition, and structure of coating were analyzed by SEM, EDS, and XRD characterizations. The EMI shielding effectiveness and corrosion resistance were also tested. The results fabric possesses dense, smooth, and uniform coating, when the processing conditions are 60℃, pH=1.5, and current density =8.7A/dm2. The coating fabric consists of amorphous Ni-Fe-P alloy with 16.62% P (weight percent), which has excellent of corrosion resistance. By contrast the EMI shielding effectiveness of amorphous Ni-Fe-P was better than amorphous Ni-P. The EMI shielding effectiveness of this coated fabric achieves 69.20dB-80.30dB in a broad frequency range between 300kHz~1.5GHz.
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  Numerical Analysis on Ablation Process of Thermal Protective Coating under Laser Irradiation

  Ke JIN

  . 2015, 46(20): 5-0.

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  The erosion experiments of the thermal protective coating were carried out and the interface temperature between coating and substrate was compared. According to the ablation process of protective coating, a transient mathematical model was developed to describe the surface ablation, interface migration, heat and mass transfer with ablation process in the protective coating. The model was numerical solved and validated by comparing the numerical results with the measured data. The temperature distribution along the thickness direction of the protect coating was pursued and the migration rate of coating surface was investigated. It is shown that the proposed model is suitable for describing the thermal process in protective coating, the migration rate of coating surface increases at the beginning and then reaches a steady state, meanwhile, the interface temperature increases at the beginning and then decreases. Some measures may be used to be good for protecting of substrate such as increasing the thickness, decreasing the thermal conductivity of the protective coating. The work in this paper is theoretically valuable for the further research and application of thermal protective coating.
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  Sodium acetate orientated hollow magnetite nanoparticles fabrication and characterization

  Quan-Guo HEJing LIANG;Jun LIU

  . 2015, 46(20): 7-0.

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  Monodispersed magnetite (Fe3O4) nanospheres with hollow or porous interior structures were prepared via a facile one-pot solvothermal route. The simple fabrication process was characterized by using Iron (III) chloride hexahydrate (FeCl3?6H2O) as only ferric ion resource and anhydrous sodium acetate (NaAc) as structure-directing agent in an ethylene glycol solution without templates or surfactants involved. The hollow Fe3O4 nanoparticles were carefully investigated in morphology, crystal structure and magnetism by various characterization methods. A plausible mechanism based on sodium acetate orientation and subsequent local Ostwald ripening is proposed.
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  Fatigue Strength Analysis of Co-Cr Alloys Targeted Drug Eluting Stent by Finite Element Method

  Zhen Jing GUO;

  . 2015, 46(20): 8-0.

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  After the implantation, the fatigue performance of the drug eluting stent has significant influnce on the success of coronary stent implantation. The finite element method was used to analyse the stress distribution of the stent during the process of using, and the fatigue strengh was analysed according to the Goodman curve. The security of the stent was described by the safety factor. It could be found from the analysis that the high-stress area always located in the arc parts during the deformation process. However, all the feature points of the two kinds of stents located under the fatigue limit line. So the failure by fatigue of the stents will not happen during the using process. Moreover, there is a negative correlation between the safety factor of the stent and the length, width, and thickness, respectively. The results prove that the fatigue strength of the stent can be analysed successfully through the finite element method, which provides the reference for the stent design.
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  Research on construction workability of asphalt-rubber mixture with warm mix additives

  . 2015, 46(20): 9-0.

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  In order to research the construction workability of warm mix asphalt-rubber mixture, three kinds of representative warm mix additives were selected to make warm mix asphalt-rubber based on the mechanism of difference warm mix technology, and the dosages of warm mix additives to the asphalt-rubber were determined by technique index results, then the construction workability of warm mix asphalt-rubber mixture was researched both by viscosity-temperature dependency test on warm mix asphalt-rubber mastic and superpave gyratory compaction(SGC) test on the mixture from different discharging temperature. Results indicate that, the surfactant warm mix additives has no significant effect on technique index of asphalt rubber, but it’s opposite to organic viscosity reducer, and it is recommend that the dosage of Sasobit is 2%、Evotherm M1 is 0.6% and Evotherm DAT is 11.1%; viscosity-temperature dependency test on warm mix asphalt-rubber mastic can be a method to judge the warm mix effect of surfactant warm mix additives; the three kinds of warm mix additives can not only improve the volume parameters of the specimens by SGC from lower discharging temperature, but also enhance the asphalt-rubber coating ratio, and all of them can reduce the construction temperature of rubber asphalt mixture at least 20℃.
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  Microstructure and property of Ni/Co/Al2O3 laser cladding layer on the surface of mold copper plate

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  . 2015, 46(20): 10-0.

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  Ni/Co/Al2O3 composite coatings are prepared on the surface of mold copper plate with Laser cladding of Co42 powders as cladding layer and Ni/Al2O3 nanocomposte as interlayer, the microstructure, hardness and corrosion resistance of layers are analyzed by OM, SEM, microhardness tester and electrochemical system. The results indicate that Ni/Al2O3 nanocomposte is compact and uniform with fine grain. Laser cladding layer. Under the condition of 4.5kW laser power and 240mm/min scanning speed, the laser cladding layer is metallurgical bonded to the substrate excellently，the grain of the laser cladding layer is refined, the laser cladding has a average microhardness value of 1000HV and excellent corrosion resistance.
研究 开发
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  Experimental study on the preparation ofUHPC with cascade-grinding iron ore tailings

  ;Zhi-Gang ZHU;

  . 2015, 46(20): 11-0.

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  A research about the influence of cascade-grinding process grinding iron ore tailings, gypsum, slag and cement clinker on producing a high performance gel material based iron ore tailing-slag was began, influence of different cascade-grinding technology on powder particle size characteristics and gel’s properties was discussed, the strength and durability of ultra-high performance concrete based TSBC or PO52.5 cement were compared. Research results show that the particle size of powder material of three-stage grinding is smaller than twin-stage grinding, three-stage grinding better plays "micro-grinding ball" of particles to improve grinding efficiency. The tougher iron railings sand ought to be the first grinding stage , the first grinding time is can not too long or lead to too much powder of secondary grinding covering particle materials and reducing grinding efficiency. UHPC of TSBC not only has the strength of the conventional UHPC made by normal materials even more excellent durability performance.
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  The study of the attenuation performance of modified expanded graphite by plating copper to IR/MMW wave

  . 2015, 46(20): 12-0.

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  The expansible graphite was modified by plating copper to improve the attenuation performance to IR/MMW wave.The study optimize the plating condition by the influence of weight increasing ratio, such as temperature,time and loading quantity.The attenuation performance of modified expanded graphite to IR/MMW wave was tested. The results show that the modified expanded graphite meanly adhere to a little copper grain,t he phase structure of nickel plate is microcrystalline by XRD, The modified expanded graphite in certain loading quantity have the better attenuation performance to IR/MMW wave. When the loading quantity is 15g/L, the attenuation rate is 88.96%、62.85%、82.25%、92.24%. Compared with the un-coated expanded graphite, the attenuation rate respectively added 10.34%、9.41%、6.56%、4.86%.
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  The influence of ultrasonic wave on the corrosion resistance of Mg,Al-hydrotalcite conversion film on magnesium alloy

  Zhi-Xin BA

  . 2015, 46(20): 13-0.

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  The hydrotalcite (Mg6Al2(OH)16CO3?4H2O) film was prepared on magnesium alloy by ultrasonic wave, and the effect of power and frequency of ultrasonic wave on its microstructure and corrosion resistance was also investigated. The surface morphology and phase composition were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), respectively. The polarization curve and electrochemical impedance spectroscopy (EIS) were applied to evaluate the anti-corrosion performance. The results show that the film formation can be significantly accelerated by ultrasonic-assisted treatment. The film forming rate increases with the ultrasonic power and frequency, while the quality of film will be deteriorated through overwork. When the ultrasonic power and frequency is 100W and 80 kHz, respectively, a thicker and integrated layer is formed on the magnesium alloy. Its corrosion resistance is superior to that of the bare magnesium alloy, and the corrosion current density is approximately 1/20 that of the substrate.
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  Preparation of water-soluble chitosan and application in microencapsulated cell culture

  . 2015, 46(20): 14-0.

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  To improve the water-solubility of chitosan, a simple N-acetylation in homogeneous medium was developed to prepare soluble chitosan. The degree of deacetylation (DD), structure of functional groups and crystalline state of soluble chitosan were characterized by FTIR, NMR and XRD, which helped to analyze the water-solubility mechanism. Moreover, microcapsules were prepared with soluble chitosan and tested for immobilized cell culture. The results showed that DD of soluble chitosan was 56%, and the formation of amorphous structure due to decrease of degree of crystallinity was the main reason to get soluble chitosan. Finally, it was observed that cells in microcapsules with soluble chitosan kept high activity and grew gradually to form cell aggregation during culture process. These results demonstrated that the water-soluble chitosan was feasible for preparing microcapsules and applying in cell culture.
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  Preparation and research of growth of carbon nanotube on carbon fiber and its composite materials

  . 2015, 46(20): 15-0.

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  It was reported that the catalyst precursor was uniformly loaded on carbon fiber modified by electrochemical anodic oxidation via dipping method, on which CNTs with a good alignment was uniformly deposited by catalytic decomposition of acetylene using chemical vapor deposition (CVD). The effect of current strength on the morphology of catalyst particles and CNTs on carbon fiber surface was investigated by field emission scanning electron microscope (FESEM). The different process parameters such as growth temperature, different catalysts and the position of deposition in relation to morphology and quality of the products have been investigated. It was found that the proper current strength was 0.4A by this study. In contrast to the untreated carbon fiber and desized carbon fiber, the interlaminar shear strength of composite with CNTs grown on carbon fiber with Co used as catalyst as reinforcement increased 11% and 26.5%, respectively.
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  Ultrasound assisted enhancement in Vanadium and Tungsten Leaching from Waste SCR Catalyst

  Zhang-Chen ZHANG;;;;xia qi bin

  . 2015, 46(20): 16-0.

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  Recovery of valuable metals such as vanadium and tungsten from waste SCR catalyst provides significant important social, environmental and economic benefits. A process was developed for V and W recovery from SCR catalyst by using soda roasting and water leaching intensified by ultrasonic wave. The effects of ultrasonic time, ultrasonic power, liquid-solid ratio on the leaching rate were investigated. Results showed that ultrasound-assisted leaching method was more efficient for V and W recovery than conventional stirring leaching method. The leaching rates of V and W enhanced with ultrasound energy were reached at 76.92% and 69.87% respectively for 3 min. The leaching rates increased by 23.08% and 2.59% compared with the conventional stirring leaching for 3 min. The maximum leaching rates of V and W reached at 89.01% and 96.05% respectively. The optimum conditions for the process are 2 h ultrasonic leaching time, liquid-solid ratio of 12:1, and ultrasonic power of 500 W. The dissolution kinetics curves of V and W from SCR catalysts could be well fitted by the Stumm model. The dissolve of V is a first-order reaction, while the dissolve of W is a second order reaction.
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  Study on procine acellular dermal matrix crosslinked by ethylene glycol diglycidyl ether in the ethanol

  ;Nian-hua DAN

  . 2015, 46(20): 17-0.

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  Preparation of graphite-like carbon nitrideand Its catalytic performance for thermal decomposition of ammonium perchlorate

  Ling-Hua TAN ;;;

  . 2015, 46(20): 18-0.

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  The g-C3N4 was synthesized melamine used as precursor via semi-closed method. The structure and morphology of g-C3N4 were characterized by means of X ray diffraction(XRD), transmission electron microscopy(SEM) and fourier transform infrared spectroscopy(FT-IR). The catalysis of g-C3N4 on thermal decomposition of ammonium perchlorate(AP) was investigated by thermal gravimetric analysis (TG) and differential thermal analysis (DTA). The results show that the g-C3N4 has layered structure. The g-C3N4 make the two decomposition peaks of AP combine and the high-temperature decomposition peak value of AP decrease by 73.8℃, which exhibits good catalytic performance. The g-C3N4 has excellent conductive properties and can accelerate the electron transfer in the process of oxidation-reduction cycle to make the decomposition of AP at a much lower temperature.
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  Effect of polyethylene glycol modification on the morphology and optical property of P3HT/ZnO composite film

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  . 2015, 46(20): 19-0.

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  ZnO nanoparticels with average size about 200 nm synthesized by one-step hydrothermal method were firstly modified by surfactant polyethylene glycol (PEG). The effects of PEG molecular weight and dosage on the surface morphology and optical properties of ZnO film were discussed. The energy level structure of PEG was researched. Then poly(3-hexylthiophene) (P3HT) was adopted to prepare the composite films with pure ZnO and ZnO modified by PEG, respectively. The effects of PEG passivation on the morphology and optical property of the composite films were characterized by atomic force microscope, ultraviolet-visible spectrophotometer and photoluminescence spectra. The results showed that ZnO film modified by PEG with molecular weight 6000 and dosage of 5 wt% had regular morphology; The energy level of P3HT matched well with that of ZnO modified by PEG; Compared with P3HT/ZnO composite film, P3HT/PEG/ZnO composite film would have more regular surface, less surface defects, better absorptivity and higher fluorescence quenching, which indicated that PEG modification increased the contact area between ZnO and P3HT as well as promoted the charge transfer between their interface.
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  Research on microstructure and mechanical properties of high strength steels BR1500HS during hot stamping

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  . 2015, 46(20): 20-0.

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  In this paper, comparative analysis for microstructure and mechanical properties of high strength steel BR1500HS between before hot stamping and after hot stamping were investigated through optical microscopy, micro hardness tester and universal tensile tester. Meanwhile, relationship between time and temperature at different cooling rates was obtained, as well as martensitic transformation curve. The analysis results show: the original microstructure of high strength steel BR1500HS at room temperature is 90F + 10B, yield strength and tensile strength are 462Mpa and 627Mpa respectively; while the best microstructure of forming part is 98M + 1B + 1F, and the maximum hardness and maximum tensile strength are 501.2 HRV and1633.69MPa respectively, both hardness and tensile strength are basically matched with the martensite content obtained by experimental observations. Martensitic transformation curve shows: temperature range for martensitic transition of BR1500HS is 375 ~ 325 ℃, and time range for martensitic transition is 15 ~ 25s; when cooling rate is greater than 40 ℃ / s, martensitic transformation more fully.
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  Effects of Magnetic Viscosity on Measurement Results of Magnetic Properties for Permanent Magnetic Material

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  . 2015, 46(20): 21-0.

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  The effects of magnetic viscosity on measurement results of magnetic properties for permanent magnetic material are investigated, and the variation of magnetic viscosity coefficient with time and temperature is discussed at detail. It is turned out that the value of intrinsic coercivity increases with the magnetic field change rate. The relation curve between the magnetic viscosity coefficient and the applied magnetic field presents the parabola shape, and the peak is located in the magnetic field corresponding to intrinsic coercivity. The magnetic viscosity coefficient increases with temperature, enhanced magnetic viscosity effect is observed.
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  Research on a polarization-insensitive metamaterial absorber based on planar spiral structures

  . 2015, 46(20): 22-0.

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  We present the design of a polarization-insensitive metamaterial absorber based on spiral structures. The measured results indicate that the metamaterial absorber demonstrates a reflectance of -4.5dB at 2.2GHz. The thickness of the metamaterial absorber is 2.2mm, about 1/62 of the working wavelength. The areal density is 0.88kg/m2. When the angle between the bottom side of the metal substrate and the field polarization direction are respectively 0o, 30o, 45o, 60o and 90o, the MA shows similar low reflectivity. This metamaterial absorber is lightweight, ultrathin and polarization-insensitive to the incident electromagnetic wave compared with traditional microwave absorbers.
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  Study of Surface Relief-Gratings Lithography of Epoxy-Based Bisazobenzene Polymer BP-2A-35-CN

  Xiang-Xian WANG Hua Yang ;

  . 2015, 46(20): 23-0.

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  Epoxy-based bisazobenzene polymer BP-2A-35-CN with favorable photoinduced mass transport phenomena and wide spectral response range is synthesized, and the UV–VIS absorption spectrum of the polymer film is measured. One-dimensional surface relief-gratings (SRGS) of azobenzene polymer is inscribed by two 532nm laser beams interference. The lithography method of two-dimensional SRGS of azobenzene polymer is proposed by rotating the sample with 90 degree，and the two dimensional SRGS is successfully inscribed. The suggested lithography method can realize simple technics and low cost lithography technology by visible light waveband laser interference, which uses azobenzene polymer BP-2A-35-CN as the photolithography medium and bases on two laser beams interference combing sample rotation.