15 May 2014, Volume 45 Issue 09

    

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研究 开发
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  Study on thermal neutron shielding ability of new carborane-containing polyester

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  . 2014, 45(09): 2-0.

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  A new carborane-containing polyester (abbreviated as CBR-PET) was prepared by the polycondensation reaction of 1,2-bis(p-carboxyphenyl)-o-carborane with ethylene glycol. The structures and molecular weight were confirmed by FTIR, 1H-NMR and gel permeation chromatography(GPC). The results of neutron shielding experiments showed that the CBR-PET performed good slow neutron shielding ability, which was enhanced with the boron contents increasing, and the tested largest attenuation coefficient(∑) among samples was 0.67cm-1. The thermal characterizations of the CBR-PET in argon were investigated by using thermogravimetry analysis（TG）from room temperature to 800℃, its initial decomposition temperature was 380℃ and its char yields at 800℃ was 72.9%.
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  Failure mode of Aluminum foam sandwich panels

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  . 2014, 45(09): 3-0.

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  The sandwich structure with metallurgy bonding interface and glu-bonding interface were carried out by the static three-point bending test. The effect of material deformation behavior and interface bonding strength on the failure mode are investigated. The results showed that the limit load of sandwich structure during pack rolling process higher than those with stickiness technology, The failure characteristic of sandwich structure with metallurgy bonding interface is the combination of core shear failure and indentation. We correct the related model through applying the superimposition effect of indentation and core shear failure to provide a theoretical basis for the limited load of sandwich structure.
工艺 技术
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  Effect of biological template modification on pore structure and gas sensitivity properties of SnO2 morph-genetic ceramic

  he xinhai ;WANG MENG ;;;Xiao-Lei SULe-hua QI

  . 2014, 45(09): 4-0.

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  　　 SnO2 morph-genetic ceramic with special ramie form has been prepared by taking modified ramie fibers as templates. The phase composition and microstructure of the prepared materials are discussed, and their specific surface area, pore size distribution and gas sensitive property of multiple gas (liquid) are tested. The results show that the structure and properties of morph-genetic materials can be controlled effectively by modifying textile fibers. The modification of templates has great influence on specific surface area and pore structure parameters of SnO2 morph-genetic ceramic, but less for grain size. Especially the SnO2 fabricated by ramie fibers template treated with alkali liquor shows high specific surface area and superior absorption characteristic for HCHO、C2H5OH and Petrol gas (liquid).
综述 进展
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  Progress in research on preparation method of α-Fe2O3 nanotubes

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  . 2014, 45(09): 5-0.

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  The research on preparation method of α-Fe2O3 nanotubes is a hotspot in photoelectric material. Based on the review that describes in detail the typical synthesis strategy of the α-Fe2O3 nanotubes, the AAO template method combined with and different deposition techniques their impact on α-Fe2O3 nanotubes’ morphology are compared, and the influence of the different technological parameters on the structure of the α-Fe2O3 nanotubes during preparation process with anodic oxidation method are also discussed. Finally, the application prospects and the aspects for the future research of α-Fe2O3 nanotubes were proposed.
研究 开发
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  Effect of Wheel Cladding on Wear and Damage Property of Wheel/Rail under heavy-haul condition

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  . 2014, 45(09): 7-0.

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  Abstract: Laser cladding Co-based alloy coating on surface of wheel/rail specimens by CO2 multimode laser. The wear property and damage mechanism of wheel/rail were investigated using a MMS-2A rolling wear testing apparatus. The results indicate that the organizations of coating layers are obviously thinner than substrate. The surface hardness of wheel/rail increased significantly and was about 1.5 times than that of substrate. With an increasing axle load, the friction coefficients and wear rate of wheel/rail specimens increased and the wear rate of wheel specimens was only 1/5~1/8 of rail specimens’. The wear volume of wheel/rail specimens linearly increased with the time increasing. The damage of wheel/rail specimens was more severe with the increase of axle load and the damage of wheel specimen was slighter than that of rail under the same condition. For coating layers of wheel, the adhesive and oxidative wears were dominating and the fatigue and oxidative wear for rail at low axle load. With an increase of axle load, serious fatigue damage was dominating for wheel/rail specimens and slight oxidative wear exists.
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  Preparation and application of the functional far-infrared rubber composites

  Yang LIU;

  . 2014, 45(09): 8-0.

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  For the problems of the shortage of petroleum resources and environmental pollutions which was caused by the development of automobile industry, a kind of functional far-infrared rubber composite material which can improve the physicochemical properties of fuel, increase the fuel combustion efficiency, and reduce the emissions of harmful gases was excogitated. The oil resistance, heat-resisting performance, infrared radiation performance and the composite materials on the properties of fuel were investigated. It shows that the tensile strength retention upon 90% after aging for 72h at 100℃, the breaking elongation retention above 50%,quality and volume change rate under 2% after soaking in IRM903 for 72h at home temperature，the highest 92% of the rate of far-infrared radiation has been reached when the far infrared powder15 parts. Owing to the effect of far-infrared composite materials, the evaporation of fuel increased, the surface tension of fuel decreased and then the available effect mechanisms of the composite materials on the properties of fuel oil were investigated by testing the activity changes of dutrex.
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  Studies on Modification of Clay with Cyclodextrin (CD)

  ; ;chen ming qing

  . 2014, 45(09): 9-0.

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  Cyclodextrin (CD) modified clays were synthesized by polycondensation of carboxylated CD (CMCD) and two kinds of calys such as sodium montmorillonite (MMT) and laponite, which were firstly modified by silane coupling agents with different chain lengths and functional groups. Effect of types of the clays and silane coupling agents on the amounts of CD into clays were investigated. The structures of the clays before and after modifications were characterized by Fourier transform infrared (FTIR) and nuclear magnetic resonance (1H-NMR). X-ray diffraction (XRD) and thermo gravimetric analyzer (TGA) were used to detect the modification forms and amounts of CD. The results show that silane coupling agents and CD could modified both on the surface and intercalation of the clays. The amounts of CD into laponite are higher than that into MMT. Moreover, when the functional groups of silane coupling agents is less, the distance of the modified clays is larger and the amounts of CD is higher.
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  Study of Growth Factor Loading Method in Scaffold Using Silk Fibroin as Carrier

  Ji-Xiang ZHU;;Yang Fan-Wen ;

  . 2014, 45(09): 10-0.

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  Silk fibroin (SF) is a biocompatible and slowly biodegradable biomaterial. β-sheet transformation made the water soluble silk fibroin change to an insoluble form. This physical transformation endowed the silk fibroin as a promising biomaterial to immobilize the bioactive molecule in a mild condition. Using SF as a co-absorbed and protective carrier, a novel bioactive molecule loading method in tissue engineering scaffold was developed. The influence of the growth factor loading technology to the property of gelatin porous scaffold was studied. The porosities of the scaffold before and after EGF loading were over 90% and the scaffold’s water uptake were 18 times more than its original mass. Compressive tests showed an increase of compressive modulus at 26.1kPa after SF/EGF modification. Elisa test displayed that active EGF could be detected in 4 weeks in vitro. The dose of released EGF from a milligram scaffold was in the range of 0.3ng-0.5ng in every time intervals and the cumulative release was 3.473ng during 28d. MTT test and SEM observation indicated that EGF loading scaffold improved the growth of epithelial cells. This growth factor loading method may be particularly useful in modification of tissue engineering scaffold.
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  Structure regulation and catalytic performances of surface modified carbon fiber supported iridium catalyst

  Jun DU

  . 2014, 45(09): 11-0.

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  Carbon fiber (CF) modified by anodizing (CF-Ox) and silanization (CF-Si) were applied for supported iridium catalyst. The effects of CF modification condition on the performances of the supported iridium catalysts were investigated by studying its catalytic activities in the methanol carbonylation reaction. The loading amount of Ir on CF-Ox is 2.17% and 4.88% for anodizing time of 2 min and 5 min respectively, The X-ray photoelectron spectroscopy results indicated that oxygen and nitrogen were introduced to CF surface after anodizing (CF-ox). The oxygen/nitrogen atomic ratio enhanced as the anodizing time from 2 min to 5 min, subsequently, the loading amount of Ir increased from 2.17% to 4.88% in the supported iridium catalyst. Comparing to the monodentate ligand iridium, the proportion of bidentate ligand iridium is increased, and resulted in the increase of acetic acid selectivity from 20% to 30%. For the 2 min and 5 min anodized CF, after introducing N-(β-aminoethyl)- γ-ammonia propyl methyl dimethoxy silane(CF-Si) which have coordinating groups by the surface hydroxyl condensation respectively, the loading amount of Ir increased to 4.49% and 6.43% respectively, while the ratio of monodentated iridium/bidentate iridium increased. The grafted silane molecular provids CF surface with a soluble soft chain of coordination sites, which contributed to the increase of Ir loading amount and improving the chemical environment for coordinated iridium. Consequently, acetic acid selectivity increased to 72.5% and 77.8%.
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  The influence of Polyaniline mass fraction in composite electrodes on electrochemical properties

  Hai-Yan WANG ;

  . 2014, 45(09): 12-0.

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  Polyaniline / carbon black fibrous composites and fibrous Polyaniline were respectively prepared via in-suit chemical oxidization polymerization and interfacial polymerization. The influence of Polyaniline mass fraction in composite electrodes was discussed on the electrochemical performance of the electrodes. The results show that the mass fraction of Polyaniline in the composite electrode materials is not the decisive factor for the electrochemical performance. The specific capacitance of the composites fibre（It’s diameter is about 200nm）with primary nano-particles is up to 432 F/g at 5mA/cm2 in 1mol/L H2SO4 electrolyte, which is higher than that (354 F/g and 416 F/g) of the composites in which the mass fraction of Polyaniline is higher than the former and Polyaniline fibre.
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  Surface morphologies transition processes on GaAs (001) surface

  Luo Zijiang

  . 2014, 45(09): 13-0.

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  Surface morphology transition processes (ordered flat →disordered flat →rough) on GaAs(001) surface are studied using scanning tunneling microscope and reflection high energy electron diffraction. We found that changes of Arsenic beam equivalent pressure and temperature were the main reason of the evolution of surface morphology transition. Atoms recombination were caused by high temperature which resulting in surface reconstruction change, which was the main internal mechanism and should play key role during the process of surface morphology transition on GaAs(001) surface. The surface morphology which consists of uniform surface reconstruction or one reconstruction hold absolute majority is in the state of ordered flat; and the surface morphology which mixed by multiple reconstructions is in disordered flat; when the surface reconstruction is difficult to distinguish, which surface morphology is in rough state. During our experiments we have an interesting discovery that the state of disordered flat should disappear at the processes of surface morphology transition on GaAs(001) surface while temperature and Arsenic beam equivalent pressure are high enough.
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  Evaluation of a chitosan-based in situ forming hydrogel

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  . 2014, 45(09): 14-0.

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  In situ forming hydrogels are important biomaterials in medical applications. Here, we report a new class of in situ forming hydrogel derived from water-soluble chitosan and sodium alginate derivatives. The hydrogel was characterized by FTIR spectroscopy. The surface morphology, gelation time, gel strength, swelling ratio and the pH of the hydrogel are examined. As a potential hemostasis material, Chitosan-based in situ forming hydrogel has splendid blood-control appearances in the hemostasis experiment. The following studies indicate that this hydrogel has no cytotoxicity and good histocompatibility. All the evidences provide a potential opportunity to use Chitosan-based in situ forming hydrogel as a biodegradable and biocompatible hemostasis material.
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  Friction and wear behavior of Ceramic Film on Drill Pipe Joint

  ;Liuge

  . 2014, 45(09): 15-0.

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  Abstract：In order to improve the wear resistance property of drilling pipe joint, Cermet consisting of nitrides, carbides and oxides of Ti, Cr, and Al is chosen to prepare multilayer metallic ceramic coating on the surface of drilling pipe joint. Rotating friction test is tested by MS–T3000 friction wear tester. Combined with friction surface morphology observation and wear debris composition analysis. The wear resistance and dynamic friction -wear mechanisms of ceramic coating is analysed. The results show that: In the initial stage of friction process, friction coefficients increased sharply, then stabilized at a certain value, and fluctuate in the range of values, and the fluctuation range gradually increase. Along with grinding ball gradually became ground flush, the wear behavior converted to surface-to-surface contact wear from the point surface contact wear and the grinding spot area is gradually increasing. Ceramic film samples were first mainly worn by abrasive wear. With the constant pressure of steel ball friction process and the rise of the friction regional temperature, grindings occurred plastic deformation and formed the increasing thicken transfer layer, covering on ground surface,which resulted in hindering the direct contact between ceramic sample and grinding, thus reducing the friction and wear of ceramic coating
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  Optimization and Operation Mechanism Analysis of Cz-Si Wafer Passivation by α-SiOx:H Film

  Hai-bin ZHANG ;;;;;

  . 2014, 45(09): 16-0.

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  Amorphous hydrogenated silicon sub-oxide (α-SiOx:H) is an excellent passivation material for silicon wafer. In this paper, the α-SiOx:H films are deposited to passivate n-type Cz-Si wafer by PECVD method, SiH4, CO2 and H2 are used as precursors. The deposition pressure and the ratio of the CO2/SiH4 flow rate (RCO2/SiH4) are optimized and their operation mechanisms on the passivation effect are analyzed. Quasi-steady state photoconductance method and spectroscopic ellipsometry are used to test the effective lifetime and imaginary part of the dielectric function (ε2) of the passivated wafers. It is found that: a) In this study, the doped oxygen in the films makes them amorphized. The operation mechanisms on the passivation effect of the two parameters are different. Generally, the deposition pressure affects the void fraction in the films and RCO2/SiH4 affects the hydrogen fraction and structure. (b) The highest effective lifetime 975 μs and the lowest surface recombination 3.9 cm/s are gotten when RCO2/SiH4 is 3.0 sccm/3.0 sccm and the deposition pressure is 22 Pa.
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  CO2 and H2O vapor adsorption performance of modified Mg-MOF-74 via ammonia aqueous solution

  ;Jianfeng Lin

  . 2014, 45(09): 17-0.

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  In this work, Mg-MOF-74 crystals were synthesized by hydrothermal synthesis method, and then modified by ammonia aqueous solutions of different concentrations to obtain the modified materials NH4@Mg-MOF-74. The CO2 and water vapor isotherms on the NH4@Mg-MOF-74 were determined by means of gravity method. Results show that the specific surface area of the modified materials NH3@Mg-MOF-74 became smaller, but their CO2 adsorption capacities on per unit surface area of adsorbent became significantly higher compared to Mg-MOF-74. Especially at P/P0 below 0.0010(1000 ppm), the CO2 adsorption capacity of NH3@Mg-MOF-74-2# reached 0.66mmol/g, having an increase of 65% in comparison with the original material Mg-MOF-74. In addition, the amount adsorbed of water vapor on the modified materials for were greatly decreased. e.g., the adsorption capacity of the NH3@Mg-MOF-74-1# for water vapor was reduced by 50% at RH=10%, suggesting that its hydrophobic property was improved significantly.
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  Chemical Structure and Properties Analysis of Superhydrophobic Myristate Acid Copper Surface

  Da Heng LI

  . 2014, 45(09): 18-0.

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  We construct super hydrophobic films on the surface of metallic copper by simple one-step method. The technical analysis includes scanning of electron microscope, contact angle measurement and antifouling performance test. The result shows that dendritic myristic acid micro-clusters were formed on the surface of copper specimen. The contact angle reached 160o and the antifouling performance is nice. Three elements played a key role in constructing hydrophobicity on the surface of copper specimen. The three elements are the concentration of ethanol solution with myristic acid, soaking time and soaking temperature. These results aid ourunderstanding of the formation of superhydrophobic myristic acid copper composites, and the design of superhydrophobic of non-ferrous metals materials.
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  Preparation, Microstructureand Film-forming Mechanism of Waterborne conductive Sulfonate Polyurethane/polypyrrole Conductive Composites

  ; Jing Mou

  . 2014, 45(09): 19-0.

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  Waterborne sulfonate polyurethane dispersions (SWPU) was prepared through prepolymerization method with 2,4-Diamino-benzene sulfonic acid sodium salt (DASS) as hydrophilic chain extender. Then with the assistant of FeCl3 oxidant, SWPU/polypyrrole (SWPU/PPy) dispersions with different mass concentration of polypyrrole (PPy) were prepared by in situ chemical oxidative polymerization, and the corresponding conductive composite films were obtained by solution casting method. With the introduction of PPy, new urea bond was formed through the reaction between SWPU and PPy. The high-temperature thermal stability was also improved. With the increase of pyrrole content, the average particle size of SWPU/PPy dispersions increased. Significant aggregation was detected among SWPU colloidal particles, and the SWPU/PPy particles disperse with each other. With the addition of certain amount of PPy, PPy was able to distribute uniformly across SWPU colloidal particles, and homogeneous nanocomposites were therefore formed; In addition, the surface roughness decreased, and good compatibility between SWPU and PPy was detected. However, particular morphology appeared when the mass concentration of PPy was higher than 15%, and surface roughness increased with increasing the mass concentration of PPy. Particular morphology became apparent when the mass concentration of PPy was 30%, the surface of SWPU/PPy was mainly composed of PPy. The percolation threshold of SWPU/PPy films was in the range of 1.5%～2%, and the surface conductivity reached 1S/cm when PPy content was 30%.
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  Solidification behaviors of water-based nanofluids

  Lisi Jia ;;;

  . 2014, 45(09): 21-0.

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  Titanium dioxide (TiO2) nanoparticles, carbon nanotubes (CNT) and graphene nanoplates were chosen to prepare water-based nanofluids. The solidification processes of Graphene/water, CNT/water and TiO2/water nanofluids were measured by the cooling curve method. Effects of nanomaterial shape, size, contact angle and specific surface area on the supercooling degree, starting time and total time of solidification of water were investigated. It was found that graphene nanoplates and TiO2 nanoparticles had the strongest and weakest effects on decreasing the supercooling degree and solidification times of water, respectively. Graphene nanoplates of 0.034 wt% eliminated the supercooling phenomenon of water completely, and reduced the starting time and total time by 61.22% and 30.53%, respectively. Analysis of nucleation revealed that the supercooling degree of nanofluid was mainly dependent on the total surface area of nanomaterials exposed to water. Compared to the contact angle, shape and size of nanomaterials, the specific area of nanomaterials was more important to the supercooling degree of nanofluid.
工艺 技术
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  Durability research of magnesium chloride hexahvgrate as a promising PCM for solar energy storage under medium temperature through thermal cycles

  . 2014, 45(09): 22-0.

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  In order to study the feasibility of magnesium chloride hexahvgrate(MgCl2?6H2O) as a PCM under medium temperature, six hundred accelerated thermal cycle tests had been conducted under sealed and unsealed conditions. The melting temperature and the latent heat of fusion, crystalline structure and degree of supercooling were determined by differential scaning calorimetry(DSC), X-ray diffraction(XRD) and multiway temperature detector respectively. The results indicated that the decrease in latent heat of fusion of MgCl2?6H2O under unsealed conditon was 54.2% and accompanied with a new phase MgCl2?4H2O after 200 cycles. The change in melting temperature, peak temperature of MgCl2?6H2O under sealed condition was ±1% and ±4% respectively, and the change in latent heat of fusion was and -15.2%~+1.5% except for the 300th melt/freeze cycle. MgCl2?6H2O solidified with a slight degree of supercooling in the range 0~2.2℃. It is indicated that MgCl2?6H2O under sealed conditon is a promising phase change material for solar energy use under medium temperature.
研究 开发
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  Aptamer Immobilization and Thrombin Detection on Graphene/Au Nanoparticles Prepared by Self-assembling Approach

  Zhihong zhangShunli Liu;;;;;

  . 2014, 45(09): 23-0.

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  In the present work, the nanocomposite of graphene/Au nanoparticles (g/AuNPs ) was prepared by the method of self-assembling approach and used as the bioactive layer for aptamer immobilization and thrombin detection. Firstly, trimethoxyoctadecylsilane or octadecanethiol, graphene, octadecanethiol and Au nanoparticles were self-assembled with the former one successively by the self-assembling of intermolecules. Then, aptamer modified by thiol groups was immobilized onto the surface of the nanocomposite multilayers and used to detect thrombin. The chemical component of the multilayers of g/AuNPs was investigated by X-ray photon spectroscopy. And the surface morphology of the nanocomposite layer was characterized by Atom force microscopy. The variations of the electrochemical properties of g/AuNPs were determined by the electrochemical working-station. Moreover, the mass change in the period of the self-assembling was measured by quartz crystal microbalance in situ. It demonstrates that the nanocomposite of g/AuNPs could be used as the bioactive layer for aptamer immobilization and thrombin detection.
工艺 技术
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  Influence of voltage on anti-oxidation C-AlPO4 coating prepared by pulse arc discharge deposition

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  . 2014, 45(09): 24-0.

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  A C-AlPO4 anti-oxidation coating was prepared on SiC pre-coated C/C composites by novel pulse arc discharge. The phase compositions, microstructures and anti-oxidation properties of the as-prepared coatings were characterized by XRD, SEM and isothermal oxidation tests. The influence of pulse voltage on the microstructure was investigated. Results show that the dense and homogeneous of the C-AlPO4 coating was achieved when the pulse voltage reaches 390 V. The as-prepared coatings exhibit excellent anti-oxidation property, which could effectively protect C/C composites from oxidation at 1773 K in air for 156 h with a weight loss of 0.83%. The anti-oxidation capability decrease of the coating at 1773 K is due to the generation of cross-holes in the coating, which can not be self-cured by the metaphosphate glass layer after oxidation for a long time.
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  (Ba0.9Ca0.1)(Zr0.15Ti0.85)O3 lead-free piezoelectric ceramics prepared by low sintering temperature

  jie YANG;Jia LIU; Renbo Yang

  . 2014, 45(09): 25-0.

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  Abstract: The (Ba0.9Ca0.1)(Zr0.15Ti0.85)O3 powders have been successfully prepared by sol-gel method, and the BCT-BZT lead free piezoelectric ceramics were obtained by traditional two-step sintering method under lower temperature(1290℃). The reaction process was analyzed with the help of the thermo gravimetric and differential scanning calorimetry. X-ray diffraction results showed that the structure of the BCT-BZT powders and ceramics were typical perovskite structure and the particle size was approximately 32 nm by Scherrer calculation. Moreover, the dielectric constant of ceramic was 6134 at the room temperature by TF analyzer 2000; the Curie Temperature was about 95℃. Especially, the piezoelectric response loops revealed that the maximum piezoelectric coefficient d33 reached 263 pm/V. We successfully get BCT-BZT lead-free piezoelectric ceramics by the method, the sintering temperature was about 200℃ lower than the solid phase reaction method, maintaining the good piezoelectric properties and reducing the sintering costs. So, it is conducive to realizing the large-scale industrial production of ceramics.
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  PREPARATION OF DIFFERENT STRUCTURES POLYIMIDE MICROSPHERES IN NON-AQUEOUS INVERSE EMULSION

  Jian-Jun LU;

  . 2014, 45(09): 26-0.

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  Abstract: Non-aqueous emulsion is consist of N, N-dimethyl formamide/ Pluronic- F127-Span85/Liquid paraffin. Poly(amic acid) precursors were fabricated by reacting with dianhydride (3,3′,4,4′-benzophenonetetracarboxylic dianhydride) and diamines (diaminonaphthalene; 1,4-phenylenediamine; 4,4'-oxydianiline) in non-aqueous emulsion, and corresponding polyimide microspheres were prepared by chemical and thermal imidization. The chemical structures and morphologies of the PI(s) were characterized by means of Fourier transform infrared spectrum (FTIR) and scanning electron microscopy (SEM). The result showed that the polyimide microspheres with smooth surface and fine sphericity had been obtained by controlling the flexibility of the molecular chain which was synthesized by aromatic dianhydrides and aromatic diamines. The average diameters of particles was about 20μm. The complete imidization can obtain by “two-step imidization” i.e., chemical followed by thermal imidization. The relationship of the imidization degree and the temperature of heat treatment showed the S-type curve. Meanwhile, By three kinds of diamine ODA, PPD and NDA form of PI microspheres, the temperature of complete imidization was achieved respectively in 300℃, 330℃ and 370℃. Keywords: Non-aqueous emulsion, Polyimide microspheres, Imidization
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  Preparation of O/W chitosan-based tea tree essential oil emulsive film material

  Yan Ge;

  . 2014, 45(09): 27-0.

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  Tea tree essential oil was coated with Tween 80 as surfactant to form an emulsion. Chitosan was used for the substrate and O/W chitosan-based tea tree essential oil emulsive film was prepared with cast method. Scanning electron microscopy, infrared spectroscopy, etc. were used to characterize the film’s structural feature and performance. The results showed that tea tree essential oil in chitosan solution was coated by Tween 80 to form a stable O/W emulsion casting solution. The particles of tea tree essential oil were in spherical form with a diameter of about 1μm in the film. The results of performance test indicated that the the addition of tea tree essential oil greatly enhanced antibacterial effect of chitosan film. Film had good conformability, water absorption, permeability and antibacterial property so that it is expected to be a new type of medical material in the future.
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  The preparation and cell response of the porous polyamide membranes with tunable structure

  Di Huang;;; ;;

  . 2014, 45(09): 28-0.

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  The porous polyamide (PA) membranes with different structure were prepared using phase-inversion technique by controlling the temperature of solvent evaporation. The morphologies and mechanical properties of the porous membrane were characterized by SEM and Universal Mechanical Testing Machine. The cytological properties of the porous membranes were studied in vitro by co-cultured with osteoblast-like MG63 cells. The results show that the pore size of the PA membranes is increasing with the increasing of the treatment temperature. The uniform pores is obtained and the average pore size is 10~20 μm when heated at 40℃. The elastic modulus and tensile strength reach (20.2±0.9) MPa and (5.2±0.5) MPa, respectively. The cytological experiments demonstrate that the porous membranes display favorable cytocompatibility. After co-cultured with the PA membranes prepared at 40℃, porous membranes act as a good matrix for MG63 adhesion, crawl and proliferation. The cytocompatibility, tunable mechanical properties, hydrophilicity of the porous membranes can meet the requirement of guided bone regeneration.
研究 开发
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  Study on the Preparation and Characterization of the Surface Sizing Agent for Papers Based on Leather Wastes

  Xiao-Li HAO

  . 2014, 45(09): 29-0.

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  The collagen extracted form leather wastes was as raw material, butyl acrylate and styrene was as monomers, and potassium persulfate was as initiator, a collagen-modified surface sizing agent for papers was prepared by emulsion polymerization method. The grafting rate and the precipitation rate of the product were as indexes, the preparation conditions of modified collagen surface sizing agent were optimized by single factor experiments. The product was characterized by FT-IR, Particle Size Analyzer and TEM. The sizing performance of the sizing agent was also studied. The results showed that the grafting reaction between collagen and non-ionic monomers was carried out. The grafting rate was about 65%. The structure of product was the ball type with the neat shape and uniform size. And the average particle size was about 0.117μm. The sizing agent was used in paper sizing, the ring crush strength and the anti-tensile strength of the papers increased respectively for 1.5 and 1.8 times. The water-absorbing value of 60s was decreased for 2.8 times. Papers obtained the stronger water resistance. The collagen extracted from leather wastes was as raw material. It has not only accelerates the recycling use of solid leather wastes, but also provides likely a novel sizing agent for papermaking industry.
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  Model simulation analysis of pressure-sensitive characteristics based on graphene film

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  . 2014, 45(09): 30-0.

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  Considering the mechanical behavior analysis of graphene film for high-performance pressure sensor design, the pressure-sensitive characteristics models in graphene film are established based on the relationship between the stress and the strain at the center of graphene film. Then with regard to the above-mentioned different theoretical models, the deflection deformation characteristics of graphene film are respectively computed by numerical analysis and simulated by using nonlinear statics analysis unit with ANSYS software. The results show that the effect of the prestressing force on deflection characteristics tends to be negligible as uniformly distributed loads increase. Moreover, the analytical solutions of Beams equations are more coincident with the ANSYS simulation results with a relative error of approximate 1%. The Beams equation-based model can also be used to preferably explain the pressure-sensitive behaviors of graphene film when the effects of graphene film thickness are taken into account, which further provides a theoretical model basis for the graphene-based micro pressure sensor probe design.
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  Effects of Activator and Al on the Microstructures of Si-Al-Y Co–Deposition Coatings on TiAl Alloy

  Yong-Quan LI

  . 2014, 45(09): 31-0.

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  Si-Al-Y co–deposition coatings were prepared on an TiAl alloy by pack cementation processes at 1050℃ for 4h, Scanning electron microscope (SEM), energy dispersive X-ray spectrometer (EDS) and X-ray diffractmeter (XRD) were employed to investigate the effects of pack AlCl3?6H2O and Al content on the surface morphologies, microstructures and phase constitutions of the coatings. The results show that the Si-Al-Y co–deposition coating could not obtained with 1 wt.% activators(AlCl3?6H2O) in pack mixtures; All the coatings prepared respectively with (3、5、8 wt.%) activators have a multiple layer structure, which are composed of an TiAl2 and γ-TiAl inner layer, and a Al rich inter-diffusion zone; The phase constituents of outer layers and middle layers of the coatings changed with increasing co-deposition activators in pack mixtures. The outer layer of the coating prepared at 1050℃ for 4h with the pack mixtures containing 3 wt.% activator were main composed of (Ti,X)5Si4 (X represents Nb and Cr) and little (Ti,X)5Si3 phases. However, the constituent phases changed into (Ti,X)5Si3 and TiSi2 in the out layer of the coatings prepared with 5 and 8 wt.% activators in pack mixtures, and the middle layer of the two coatings were composed of (Ti, X)5Si4 and (Ti, X)5Si3?, and the TiSi2 out layer with the favourable performances of high temperature anti-oxidation, so the the pack mixtures containing 8 wt.% activator was seclected for Si-Al-Y Co–Deposition. Al content in the pack has less effect on the phase composition of the coating, but changed the thickness of each layer.
工艺 技术
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  Effect on osteoblast adhesion and bone implants behavior of the titanium treated with microarc oxidation and alkali

  WANG Xiao Hong

  . 2014, 45(09): 32-0.

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  The surface morphology, coating composition, hydrophilicity deposition, cell adhesion and cytotoxicity of the titanium treated by Microarc oxidation（MAO） and alkali were compared. The results showed the coating treated by MAO-NaOH process showed a lot of cracks and honeycomb porous structure, and the coating was the porous reticular nano-structure with –OH polar group. The microstructure and composition could increase the surface hydrophilicity of materials. This would induce the rapid growth of hydroxyapatite. In vitro MG63 cell culture and MTT assay the MAO-NaOH samples showed distinct proliferation levels compared the other samples. It has no toxicity to the growth of MG63 cell and had better biocompatibility. After the titanium were implanted in rabbit femur for four weeks and the twelve weeks the histological sections showed materials were non-toxic, non-irritating, good histocompatibility with the surrounding tissue. The materials implanted animal bone environment could stimulate bone implanted and had bone conduction. Implanted experimental results showed that all materials had good biological security and good tissue compatibility and samples treated by MAO-NaOH had the more excellent biocompatibility comparatively.