30 September 2014, Volume 45 Issue 18

    

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研究 开发
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  Effect of TEMPO-mediated Oxidation on Adsorption Properties of Spherical Regenerated Cellulose Aerogels

  . 2014, 45(18): 1-0.

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  TEMPO-mediated oxidation system was used for the regenerated cellulose aerogel’s surface carboxyl modification, and carboxylated regenerated cellulose aerogel was prepared. Morphology, chemical structure and adsorption properties characterization of the cellulose aerogels with different oxidation processing time were analyzed by SEM, FTIR, UV spectroscopy, atomic absorption and so on.The results showed that carboxylate content of the spherical regenerated cellulose aerogels were increased with the increase of oxidation processing time,but their structural stability were decreased, and the product with higher carboxylate content(1.25mmol/g) and relative stable structure could be obtained within the modification time of 12h;TEMPO oxidation treatment could increase the permeability of the spherical aerogel surface, and avoid the internal network’s aggregation due to drying and hydrogen bonding;The spherical cellulose aerogels’ adsorption properties on cationic dyes and some metal ions were improved because of the introduction of carboxyl,in which the maximum adsorption capacity for auramine O and metal ions Cu2+ respectively were 1.24mmol/g and 0.55 mmol/g.
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  Factors Influencing the Surface Permeability of Concrete and Their Action Mechanisms

  . 2014, 45(18): 2-0.

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  In this study, the influences of different immersion conditions on the pore structure and surface layer sorptivity are investigated. After cured for 28 days under standard conditions, concrete specimens with different mix proportions are immersed in ultrapure water and 5% NaCl solution, and Autoclam (a surface sorptivity tester) is used to measure the evolution of surface sorptivity of the concrete specimens following time. In parallel, paste particles taken from the specimens are cured and immersed under the same conditions, and used for pore structure characterization. It is found that immersion in NaCl solution can significantly improve the surface water-absorption resistance of concrete as compared with the ultrapure water immersion. For example, for concrete PC1, at the immersion age of 90 days, the surface water-sorptivity of concrete immersed in NaCl solution is 0.91 of the specimen immersed in ultrapure water, while this factor decreases to 0.76 at the immersion age of 150 days. This influence can be attributed to the fact that the penetration of chloride ions into concrete makes the pore structure finer, and reduces the volume fraction of pores under 100 nm. It’s found in experiments that for PC1, the volume of pores under 100 nm in specimens under NaCl solution immersion is 32.42% lower than that under ultrapure water immersion, and this ratio is 57.24% for PC2. It is proved that chloride ions facilitate the hydration of cement, thus the immersion in NaCl solution helps cement paste in concrete achieving better hydration and denser microstructure.
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  Fabrication of through-hole PAA template with large interpore distance in oxalic acid solution

  ;;;;Ye SONG

  . 2014, 45(18): 3-0.

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  In order to fabricate well-ordered and through-hole porous anodic alumina (PAA) template with large interpore distance, ethanol and oxalic acid aqueous solution were mixed as an anodizing electrolyte. In addition, high voltage was not applied to the goal value directly but gradually. Thus, anodizing voltage in the oxalic acid solution was far beyond 40V commonly achieved, up to 150V in this work, PAA with large pore diameter (~200nm) and large interpore distance (~350nm) were fabricated. Besides, how to remove the thick barrier layer formed at high voltages was also investigated. The results show that PAA template with through hole could be achieved after being immersed in 5wt% phosphoric aqueous solution for 180min at 30℃, the thickness of barrier layer decreases at a rate of ~1.26nm/min under such condition.
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  Phase-field method simulation of faceted dendrite growth in Si-Ni alloy

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  . 2014, 45(18): 4-0.

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  As a useful numerical modeling method in predicting solidification process of supercooled melt, phase-field method was applied in simulating the dendrite growth extensively. In this paper, a phase-field model of faceted dendrite growth in binary alloy was built by adjusting interface energy, and the faceted dendritic growth of Si-Ni binary alloy was simulated. The simulation results showed that, when the anisotropic strength coefficient υ exceeded the critical value 1/15, the morphology of dendritic growth performed as a faceted dendrite, and the curvature effect disappeared, then a discontinuous angular contracture was presented; and a large number of side-branches generated in the spine of the primary dendrite. In order to verify the availability of the faceted dendritic phase-field model, the simulation results was analyzed and compared with the experimental observation.
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  Comparative Study on Coordination Kinetics of Alginate Fiber with Different Metal Ions

  ;Yongchun Dong

  . 2014, 45(18): 5-0.

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  Alginate fiber was used to coordinate with three metal ions including Fe3+、Cu2+ and Ce3+, respectively. Coordinating characteristics of alginate fibers with metal ions were mainly studied and the effect of temperature and initial concentration of metal ion on the coordination capacities of alginate fibers with metal ions was also examined．The kinetics coordination between them was examined and their kinetic parameters were also determined and compared. The results indicated that increasing the initial concentration of metal ions led to an enhanced metal ion coordinating capacities．The coordination of alginate fibers with metal ion were correlated with Langmuir and Freundlich adsorption model, and showed the better agreement with first order kinetic equation. Moreover, the coordinating capacity and reaction rate constants of three metal ions with alginate fiber were ranked in the order: Fe3+ > Cu2+ > Ce3+, while their activation energy shows a reverse trend, suggesting that Fe3+ and Cu2+ reacted with alginate fibers more easily than Ce3+ at the same conditions.
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  Azo-bridged porphyrin-based conjugated microporouspolymer: synthesis and gases storage properties

  ;Zhi Li ;;;

  . 2014, 45(18): 6-0.

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  A novel conjugated microporous polymer (Azo-1) based on porphyrin block and azo(-N=N-) bridge was successfully synthesized by potassium hydroxide assisted nitrogen-nitrogen coupling reaction. The new prepared materials Azo-1 was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA). Besides, the surface area of Azo-1 was measured by N2 sorption/desorption at 77K. CO2 (273 K and 298 K) and H2 (77 K and 87 K) physisorption properties at different temperatures were also studied to further look into the gases storage properties of Azo-1. FTIR spectroscopy is useful for probing the structure of such kind of insoluble networks. The peak at 1597 cm-1 in the FTIR spectrum indicates that there are plenty of azo bonds in this material. The SEM image of Azo-1exhibits a typical amorphous morphology. Simultaneously, the enlarged TEM image of Azo-1 shows obvious porous structure. The thermal stability of Azo-1 was analyzed by TGA under nitrogen flow. This material shows its onset weight loss (~5% weight loss) at 195℃, which suggests that this material possesses high thermal stability. The N2 sorption isotherms were measured at 77 K to characterize the porosity of this network. The specific BET surface area of Azo-1 is high up to 571 m2g-1.The calculated pore size distribution based on non-local density functional theory (NL-DFT) indicates that Azo-1has two very narrow pores at 1.6 and 4.0 nm. Besides, the CO2 uptake of Azo-1 under 273 K is up to 94.2 mg g-1, and the H2 uptake under 77 K is up to 8.6 mg g-1. Based on the CO2 and H2 sorption/desorption isotherms, the isosteric heat for adsorption of CO2 and H2was calculated as high as 37 and 7 kJ mol-1, respectively.
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  Preparation and property of form-stable phase change materials based on C/SiO2 nanofibrous mats

  ;;;Yi-Bing CAI

  . 2014, 45(18): 7-0.

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  In present work, binary fatty acid eutectics were firstly prepared; then the PAN/SiO2 nanofibrous mats with different SiO2 amounts were prepared by using electrospinning method. The C/SiO2 mats were taken as supporting materials, which were made from the PAN/SiO2 mats through stabilization in air followed by carbonization in nitrogen. The C/SiO2 nanofibrous mats-based form-stable phase change materials (CSNPCM) with binary fatty acid eutectics absorbed in and/or supported by the overlaid mats of electrospun C/SiO2 nanofibers were fabricated. The structural morphologies and thermal energy storage properties of form-stable PCMs were characterized by scanning electron microscope (SEM) and differential scanning calorimeter (DSC), respectively. The absorption capacity of C/SiO2 nanofibrous mats on binary fatty acid eutectics decreased with the increase of SiO2 amount. SEM results showed that binary fatty acid eutectics embedded and dispersed evenly in the three dimensional network structure of porous nanofibrous mats. DSC results indicated that the addition of SiO2 decreased the phase change latent heat of form-stable PCMs, whereas there were no appreciable changes on the phase transition temperatures.
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  Tribological Properties of Non-soap Base High Temperature Functional Grease

  . 2014, 45(18): 8-0.

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  The natural silicate mineral attapulgite powders were modified respectively by a silane coupling agent KH-550 and cationic surface active agent cetyltrimethyl ammonium bromide (CTAB), then the powder surface successfully connected branches organic group. With organic modified attapulgite powders as a thickening agent, the different labels high temperature greases were prepared, which had the dropping point above 280 ℃. The technical indicators of various grease samples were investigated with GB and industry standards. The German Optimal SRV-Ⅳ friction and wear machine was used to evaluate the tribological properties of grease samples under the given load variable speed and constant speed variable load conditions. And SEM, EDS and XPS were used to analyze the friction surface. The results showed that: each grease sample’s technical indicators are in line with national standards and industry standards for grease performance requirements, and greases have excellent extreme pressure; the load and speed affect the tribological properties of grease samples made of KH-550 modified attapulgite very much, tribological properties of which are lower than the overall samples which were prepared by CTAB modified attapulgite powders; the high-temperature grease, whose thickener is organic attapulgite powders, has a forming repairing layer on the friction surface function in lubrication process.
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  A Novel Sorbent Prepared by Two-Step Grafting of Acrylic Acid and Methyl Methacrylate Monomer onto a Polypropylene Matrix

  . 2014, 45(18): 9-0.

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  Abstract: In order to improve the hydrophilicity of polypropylene (PP) nonwovens, grafting of acrylic acid (AA) and methyl methacrylate (MMA) onto PP matrix through ultraviolet (UV) radiation was achieved in an isopropanol/water acidic aqueous solution. AA and MMA were grafted onto a pre irradiated PP matrix by a two-step grafting reaction for preparation of a novel composite sorbent PP-g-(AA+MMA). The grafting conditions were optimized and the effects of grafting parameters were investigated. The present study suggested that the grafting degree played a dominant role in the sorption implication of PP-g-(AA+MMA). Fourier transform infrared spectra (FT-IR) and X-ray photoelectron spectra (XPS) were used to characterize the chemical changes of the PP matrix surface. The morphological behaviors have been estimated using specific surface area, porosity and scanning electron microscopy (SEM). Static contact angle (CA) measurements showed that the hydrophilicity of PP nonwoven was enhanced after graft polymerization. The thermal stability of PP-g-(AA+MMA) was evaluated by different thermo analysis (DTG) and differential scanning calorimetry (DSC). The improvement of reusability are shown as the increased of tensile modulus as a function of physical properties.
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  A study of the influence of UHMWPE fiber on failure morphology and bending performance for lumber

  . 2014, 45(18): 11-0.

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  In order to research whether Ultra high molecular weight polyethylene (UHMWPE) fiber could be used in wood-based composite, three layer structure of wood composite materials from planed timber- UHMWPE fiber- veneer was designed and prepared, PUR was selected as adhesive for this structure. The influences of UHMWPE fiber and veneer thickness composited with lumber on bending performance and ILSS of lumber were examined. The chemical constituents of deboning fibers were characterized by infrared spectroscopy (FTIR).The mechanism of lumber heightened was discussed. The results showed that PUR could be used in UHMWPE/lumber composite; UHMWPE fiber obviously changed the wood failure process and failure morphology, and improved the bearing capacity of wood; the effect reinforced by UHMWPE fiber is closely related to the thickness of veneer. Reinforced effect of UHMWPE fiber much affects the shear performance of bonding interface.
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  The research of center deflection of magnetic PDMS membrane mixed with Fe3O4 nanoparticles under magnetic force

  wang chun shui;

  . 2014, 45(18): 12-0.

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  This paper adopt the PDMS as matrix , the Fe3O4 nanoparticles of 20nm modified with the silane coupling agent (KH-570) as fillers, the magnetic polydimethylsiloxane(PDMS) membrane obtain through two kinds of material which was mixed in different proportions, The stress of magnetic membrane is analyzed theoretically, then test the deflection of magnetic membrane under the supporting cavity of different radius, different height of the support cavity(the distance between magnetic membrane and permanent magnet),different magnetic field, different mass fraction of Fe3O4 nanoparticles with the help of micro X-ray three-dimensional imaging system, the same time Hysteresis curve of magnetic was tested to PDMS membrane by Vibrating Sample Magnetometer(VSM). The experiments show under the same excitation, the magnetic membrane center deflection is larger under the condition of supporting cavity of larger radius, shorter height, and bigger mass fraction, under the different excitation , the magnetic membrane center deflection increases with the increase of magnetic field intensity , which is consistent with the analysis of theory. At the same time, volume change caused by the center deflection indicates the ability of driving liquid ,which provides theoretical basis for the micropump in the application of microfluid.
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  Application of water-borne polyurethane/ polyvinyl alcohol composite surface sizing agent in the specialty paper

  WANG Yong Chao;

  . 2014, 45(18): 14-0.

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  The anionic waterborne polyurethane emulsion was successfully prepared by the reaction of polycaprolactone diols (PCL), toluene diisocyanate(TDI), dimethylolpropionic acid(DMPA). A series of waterborne polyurethane/polyvinyl alcohol compound latex were synthesized by polyurethane, polyvinyl alcohol and aziridine as crosslinker. The results show that the compound emulsion owns excellent sizing property when m(WPU)=75%. The papers’ folding endurance can reach 1025 times, paper stiffness reach 72.1mN, the dry and wet tensile strength respectively reach 162.3N, 57.4N, sizing value reach 97s. The polymer was characterized with FT-IR，DLS and TG.
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  Topology optimization of microstructures of cellular material based on the properties of macrostructures

  . 2014, 45(18): 15-0.

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  The elasticity tensor of the heterogeneous material is obtained from the microstructure through the homogenization theory, and this property is integrated into the analysis of the macrostructure. Then, the sensitivity analysis for the material unit cell is established from the macrostructure displacement field. The optimum of cellular material and composites with periodic microstructures is designed from given material so that the macrostructure has the maximum stiffness. Several numerical examples are presented to validate this optimization algorithm efficaciously, and it can be used for variety of anisotropic microstructures of cellular materials and composites design. The various effects on the topological design of the material microstructure are discussed. It is also shown that the topology of material microstructure is related to the load and shapes of the macrostructure. In addition, the sensitivity filter is effective on solving the numerical instability problems such as checkerboard and mesh dependence.
工艺 技术
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  Preparation and study of γ-ray protective properties of lead tungstate rubber composite

  . 2014, 45(18): 16-0.

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  In this paper, lead tungstate(PbWO4) crystals with two different morphologies have been synthesized via a direct precipitation method by using various surfactants. All of crystals will lead to good mechanical properties and γ-ray protective performance of PbWO4 rubber composite when they were added into natural rubber latex as functional units. By using XRD, SEM, fluorescence(PL), electronic universal testing machine and NaI(TI) detectors, the structure and property of microcrystals have been analyzed, the mechanical properties and γ-ray protective performance of composite rubber have been characterized. The results indicated that PbWO4 microcrystals were well dispersed in natural rubber latex. PbWO4 crystals with better photoluminescence properties will present higher γ-ray shielding rates which reaches the highest value of 20.79% (filler content 30%). And smaller size of PbWO4 crystals which dispersed well in natural rubber latex will contribute to improving γ-ray shielding rate. The mechanical strength is significantly higher than those pure natural latex without adding PbWO4 crystals.
研究 开发
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  EBSD and HRTEM observations on the twins in Hg3In2Te6 crystals with defect zinc-blende structure

  LUO Lin Yadong Xu

  . 2014, 45(18): 17-0.

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  Electron backscattered diffraction (EBSD) and High-resolution transmission electron microscopy (HRTEM) are used to study the twins in Hg3In2Te6 (MIT) crystals with defect zinc-blende structure. The results show that strain energy of the majority of matrices is smaller than that of their corresponding twins. All twin boundaries of some band-like twins are incoherent. In addition, the existence of high-density structural vacancies do not change the twinning plane and the twinning direction. The above results can be explained by deformation twins with the consideration on the influence of high-density structural vacancy clusters. HRTEM observation shows that steps and twinning dislocations exist at the twin boundaries, which are consistent with deformation twins.
工艺 技术
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  The preparation of mesoporous activated carbon by microwave radiation heating walnut shell

  ;;ZHANG Yong

  . 2014, 45(18): 18-0.

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  Abstract: The mesoporous activated carbon was prepared by microwave radiation process using walnut shell as carbon source. The as-prepared activated carbon was well characterized by XRD, SEM and Nitrogen adsorption-desorption. The influences of microwave power and radiation time on the capacitance characteristics of activated carbon for electrochemical capacitors was investigated by glavanostatic charge-discharge,cyclic voltammetry (CV)and AC impedance spectroscopy. Microwave power at 480 W and radiation time for 9 min were regarded as the optimum process.The activated carbon prepared under this process had the average pore size of 4.44 nm and the mesoporous rate of 78.51 %. The specific surface area was 1530 m2/g and its shape was irregular, porous and amorphous structure. The specific capacitance was 226.4 F/g at the charge-discharge current of 100 mA/g. It kept 192.2 F/g after 1000 cycles, and the capacity fade of activated carbon was only 0.015% when cycled at 100 mA/g.
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  A method to improve the microstructure and menchical porperties of carbon nanotube/cement matrix

  Geng-Ying Li

  . 2014, 45(18): 19-0.

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  Carbon nanotubes (CNTs) have long been recognized as the stiffest and strongest man-made material known to date. CNTs reinforced cement matrix, having high mechanical properties, an excellent piezoresistivity and electromagnetic shielding property, may be used for developing an intrinsically self-sensing structural material.However, CNTs are usually very difficult to disperse in an aqueous solution due to their low mass and strong van der Waal's attraction to each other, which often induce clumping. A new method was used to disperse CNTs on basis of mechano-chemistry effect in this paper by grinding carboxylated CNTs and fly ash. The mineralogy and microstructure were analyzed by using scanning electron microscope. It is shown that CNTs are wrapped by cementitious, and dispersed throughout cement matrix.Furthermore, the strength of composites was improved after modified by using this method.
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  Influence of Pretreatment on Electroless Nickel Platingon High Volume Fraction SiCp /Al Composite

  Jian-Yun zhang

  . 2014, 45(18): 20-0.

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  The high volume fraction SiCp/Al composite was processed by pretreatment, then it was proceeded by electroless nickel plating. The influence of deoiling, roughening, activating on electroless nickel plating on SiCp/Al composite was investigated. The microstructure of electroless nickel plating on composite was analyzed. The results show that organic solvent is better than alkaline solvent for deoiling. H2O2 system is more appropriate than HF system for roughening. Infiltrating in activation solution consisted nickel acetate, sodium hypophosphite and alcohol at room temperature, then thermo deoxidizing at 160 ℃ temperature for 30 minutes, the procedure makes electroless nickel plating rate higher. After pretreatment, electroless nickel plating deposited on SiCp/Al composite surface is dense, uniform, firmly combined.
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  Temperature rise and reflective performance of nickel films with microprism structure electrodeposited at indirect-ultrasonic electrochemical deposition

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  . 2014, 45(18): 21-0.

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  Working mould with microprism structure of reflecting material was fabricated by indirect-ultrasonic electrochemical deposition. Temperature rise reason at indirect-ultrasonic electrochemical deposition was investigated. Combined influence of temperature rise and cavitation on reflective performance of working mould was studied. X-ray diffraction, retroreflectometer and 3D laser scanning microscopy system were used to analysis the structure, surface retroreflective coefficient, surface morphology and surface roughness of the casting films. The results show that electrolyte temperature was increased when increasing the time by using indirect-ultrasonic. Surface retroreflective coefficient and roughness of working mould were increased first and then decreased when increasing the ultrasonic power. Ultrasonic cavitations account for a major role under low frequency, and ultrasonic temperature plays a main role under high frequency. Also, when the intensity of sound is 70kW?m-2 and the frequency is 40 kHz, the roughness of working mould is minimum and surface retroreflective coefficient is maximum.
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  Preparation of New-type Supported Particle Electrodes and Treatment Efficiency of Quinclorac Pesticide Wastewater

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  . 2014, 45(18): 22-0.

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  New-type Supported Particle Electrodes with Sb doped SnO2 as the activated components were prepared on high-impedance porous ceramic material substrates by the impregnation-calcination process. The surface micrograph and crystal structure of the particle electrodes were characterized by the means of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The research on particle electrode electro-catalytic activity efficiency was based on the performance about the degradation of quinclorac wastewater by the three-dimensional electro-catalytic oxidation method. The results indicated with the increase of the surface area and pores of the particle electrodes and Sb doped SnO2 crystals, the electro-catalytic activity efficiency was improved. With the cell voltage was 15 V, the electrode separation was 7 cm, the amount of electrolyte was 0.1 mol?L-1and the reaction time was 120 min, the COD removal rate could reach 64.3% and the corresponding energy consumption became 14.4 kWh?(kg COD)-1.Compared with the two-dimensional electrode system, the COD removal rate increased by 26.9% but the energy consumption decreased by 99.3%.
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  Hydrothermal synthesis of flower-like γ-AlOOH

  Zhen-Feng ZHU

  . 2014, 45(18): 23-0.

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  Abstract: The flower-like γ-AlOOH was successfully prepared via Hydrothermal method at 165℃ for 3h, by using Al2(SO4)3?18H2O and urea as raw materials，CTAB and sodium tartrate as surfactants. The as-prepared products were characterized by SEM, XRD and TGA. The experimental results show that the as-synthesized flower-like γ-AlOOH with a diameter of about 4 um was composed of uniform nanosheets.
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  Preparation and characterization of porous hydroxyapatite scaffolds lined with composite coatings

  . 2014, 45(18): 24-0.

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  Highly interconnected porous hydroxyapatite (HA) scaffolds with high porosity (≈78%) were prepared by particle leaching method in the present work, and subsequently the as-prepared HA scaffolds were lined with PCL/nano-HA (nHA) or PCL/micro-nano-bioglass (nBG) composite coatings, the contents of the powder were varied from 10wt% to 40wt%. The four types of scaffolds were signed as HA, PCL/HA, nHA-PCL/HA and nBG-PCL/HA. The mechanical testing results showed that compressive strengths of nHA-PCL/HA and nBG-PCL/HA were 1.41~1.98 MPa and 1.35~1.78 MPa, respectively. The biomineralization results indicated that much apatite was formed on the surface of nBG-PCL coated scaffolds after immersed in SBF for 21 days. Cell culture experimental results showed that osteoblasts grew well on all scaffolds, indicating that all scaffolds possessed positive biological compatibility. Histological section evaluation showed that there was a large amount of new bone forming in nHA-PCL/HA and nBG-PCL/HA scaffolds comparing to other two scaffolds after implanted for 2 months in the back muscle tissue of dogs, which exhibited that the two biological particles in composite coatings played a positive role in the induction of new bone formation at non-osseous sites.
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  Resistance Method to Measure the Aspect Ratio of Kaolinite

  Zhi-Liang ZHANG;;

  . 2014, 45(18): 25-0.

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  Aspect ratio of kaolinite is an important parameter in many areas of kaolin application, however, the appropriate instruments and techniques to measure it have not been put forward so far. The principle of resistance method for grain size measurement reflects the relationship of resistance changes with the particle size and morphology, based on that, the aspect ratio of kaolinite can be calculated. Through detailed analysis of the output data and graph of Coulter Counter instrument worked on resistance law, it is found that the output electrical pulse height reflects the volume of a particle, the electrical pulse width reflects particle length through the hole, and by comparing with standard spherical particle pulse data, the aspect ratio calculation formula of kaolinite is established: AR=3/2 ( (n+(W-W_n)/(W_(n+1)-W_n ))/L )^3. The accuracy of this method is verified by case study.
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  Self-propagating -heat treatment fabricate layered cathode material Lithium cobaltate

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  . 2014, 45(18): 26-0.

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  In this paper，layered cathode material LiCoO2 were synthesized by self-propagating high temperature synthesis and heat-treatment technology．X-ray diffractometer and scanning electron microscopy (SEM) were used to investigate the effects of annealing temperature，annealing time and the mole ratio of Li to Co on purity，crystal structure and microstructure of LiCoO2．The results show the optimum condition as follows：molar ratio of Li to Co is 1.03:1，molar ratio of NH4NO3 to Co is 4:3，molar ratio of C6H12N4 to Co is 4:3，annealing temperature is 800℃ and annealing time is 1.5h．Under the optimum condition，the percentage of LiCoO2 phase in the products is as high as 99.25%，and the crystal has good layer structure.
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  Thermo-sensitive N-isopropyl Acrylamide Grafted Polytetrafluorothylene Microporous Membrane for Skin Dressings

  ;;GUO Zhi Jun;

  . 2014, 45(18): 27-0.

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综述 进展
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  Research Progress in the Target Materials of Nuclear Fusion

  Ke JIAN ;;

  . 2014, 45(18): 28-0.

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  Ignition by laser driven inertial confinement fusion is one of the most effective way to achieve nuclear fusion. Design and preparation technology of the target have always been the core technology in the study of laser driven inertial confinement fusion. In this paper, the current status of the target material was reviewed. The simulation results show that using pure B4C hollow microspheres as the target is very conducive to the ignition experiment. At last, the fabrication of B4C microspheres was offered in order to meet the demands of target.
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  Research Progress of Mussel Inspired Biomimetic Adhesives

  . 2014, 45(18): 29-0.

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  The application of traditional fixed materials or tissue adhesives are usually required in tissue repairing. Although having numerous advantages compared to traditional approaches, tissue adhesives cannot meet the require-ment of clinical application completely. Due to proteins secreted by plaque, which contain abundant of DOPA, marine mussels are able to adhere to a variety of materials firmly in the wet condition. Up to date, amounts of studies have been carried out to reveal the mechanism of mussel. Furthermore, the biomimetic adhesives, which component and structure were similar to those of mussel adhesive proteins, have been developed inspired by the excellent adhesion properties of mussel plaque. In this review, the mechanisms of mussel and related studies of the biomimetic adhesives were introduced. The perspective studies of biomimetic adhesive materials in the future were also highlighted．
研究 开发
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  Study on the preparation and properties of glass fiber/PCBT composites by in-situ polymerization

  Hai-Jun ZHOU ;;;

  . 2014, 45(18): 30-0.

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  Abstract：Glass fiber(GF) reinforced poly(cyclic butylene terephthalate)(PCBT) composites were prepared by in-situ polymerization of cyclic butylene terephthalate(CBT). The effects of the polymerization temperature and the catalyst content on the viscosity average molecular weight, the crystallinity of PCBT and the mechanical properties of GF/PCBT composites were investigated. The experimental results indicated that the viscosity-average molecular weight and the crystallinity of PCBT were gradually increased and finally tended to stabilization with increasing of polymerization temperature. The mechanical properties of the GF/PCBT composites were constantly strengthened with increasing of polymerization temperature. When the polymerization temperature was 210℃, the viscosity-average molecular weight of PCBT was 7.16×104 g/mol, and its crystallinity reached 43.9%，the tensile strength and flexural strength of the GF/PCBT composites was 271.44±3.40MPa and 257.70±3.73MPa, respectively. With increasing of catalyst mass fraction, the viscosity-average molecular weight and the crystallinity of PCBT were gradually increased and finally tended to stabilization. The mechanical properties of the GF/PCBT composites were constantly strengthened with increasing of catalyst mass fraction. When the catalyst mass fraction reached 0.4%wt, the viscosity-average molecular weight of PCBT was 7.13×104 g/mol, and its crystallinity reached 44.4%, the tensile strength and flexural strength of the GF/PCBT composites was 265.10±3.31MPa and 260.30±2.03MPa, respectively.
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  Optimal design of borosilicate glass/alumina tape-casting slurries and study of sintering properties

  ;Hongqing Zhou ;;

  . 2014, 45(18): 31-0.

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  The influence of different solvent systems and the dispersant content on the rheological properties of glass/ alumina were investigated using efficient tape casting technology. Slurry formulations were optimized by the method of changing the ration of the inorganic to the total present in tape and the ration of plasticizer to binder. The effect of tape-casting slurry composition on bulk density of green tape and bulk density, microstructure and phase of the sintered samples was studied in detail. The results showed that the appropriate composition and content of slurries improved bulk density, dielectric properties and microstructure of sintered samples. The samples sintered at 850℃ had a dielectric constant of 7.7, a dielectric loss of 2.0×10-4 and a thermal expansion coefficient of (7.30-7.65)×10-6/℃ in the range of 25-500℃, which satisfied with the requirements of LTCC packaging materials.
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  Synthesis of Co3O4/meso-SiO2 composite and its mesoscopic structure adjusting

  . 2014, 45(18): 32-0.

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  Co3O4/Meso-SiO2 composites were synthesized in one-step by using the chelating surfactant N-lauroyl ethylenediamine triacetic acid (LED3A) as templated which coordinated with Co2+. The coordination effect between Co2+ and LED3A was verified by UV spectroscopy (UV). The suitable calcination temperature of samples were analyzed by thermo-gravimetric (TG). The compositions and structures of Co3O4/meso-SiO2 composites were characterized by fourier transform infrared spectroscopy (FTIR), thermo-gravimetric (TG), X-ray diffraction (XRD), N2-adsorption-deorption and high resolution transmission electron microscopy (HRTEM). The results showed that nano-Co3O4 was formed in the silica pores. Besides, the composites with different mesoscopic structures, such as the cubic Pm3n, the two-dimensional hexagonal p6mm, the cubic Ia3d and so on, were formed through adjusting the amounts of Co2+ which affected the polar head electronegativity of LED3A.