bluuebunny/crossref_metadata_2025 huggingface dataset:
The Stability Study on Vanadium Dioxide
Authors: Li Dan Xia , Huang Wan Xia , Song Lin Wei , Shi Qi Wu
Published: August 2015

Vanadium dioxide (VO2) has attracted much interest in material field due to its unique semiconductor-metal phase transition properties. And now, the problem of stability has been highlighted and concerned for the practical application in VO2. In order to establish a relatively complete guide of stability study on VO2which would contribute to deeply and systematically researches, the article made a review of the stability study on VO2 from thermal excitation, photo-excitation and electro-excitation. Moreover, the key aspects for future research on the stability study of VO2was proposed.
Initial Growth Mechanism of Atomic Layer Deposited Hafnium Dioxide Using Cyclopentadienyl-Type Precursor: A Density Functional Theory Study
Authors: Zhou Guang Fen , Ren Jie
Published: August 2015

The initial growth mechanisms of atomic layer deposition of Hafnium dioxide thin films using Cp2Hf (CH3)2 precursor have been investigated. The calculations show that CH4 elimination reaction is energetically more favorable than CpH elimination reaction. As a result, the two ―CH3 ligands of Cp2Hf (CH3)2 may be dissociated prior to the two ―Cp rings. According to the activation barrier analysis, one CpH elimination may occurs sequentially following the first CH4 elimination reaction. During the pulse of Cp2Hf (CH3)2 precursor, the byproduct CH4 and a small amount of CpH are released.
Crater Structure and Photoluminescence of Porous Silicon
Authors: Chang Qing Li , Yan Yan Liu , Kun Wan
Published: August 2015

Porous silicon (p-Si) was fabricated by single-groove electrochemical anodic etching method; the influence of large etching current density on the surface morphology was observed. And the surface microstructure and photoluminescence (PL) of p-Si were shown by scanning electron microscope (SEM) and PL spectra, respectively. The SEM image showed that a new microstructure was formed at the large current density etching area, which resembled a crater structure; and the area away from the crater appeared the porous structure. The comparison results of the PL spectra for the different areas indicated that PL of the crater area has a shorter wavelength.
Improvement of Light Fastness of Liyuan Blue FL-RN Reactive Dye
Authors: Latif Zahid , Liu Fan , He Lin Wei , Cai Ying Jie
Published: August 2015

Cotton fabric was dyed with Liyuan Blue FL-RN reactive dye. The dye exhaustion and fixation percentages were calculated for all light, medium and dark shades. The dye shows very good exhaustion and fixation properties. Dyed samples were tested for light fastness property as per international standards. The results indicates the dye has a good light fastness property. The effect of UV absorber was studied in order to improve light fastness property. Cationic UV absorber CANFIX SUN was applied on the dyed cotton fabric by exhaust method. The results show that the color depth was similar after UV absorber treatment. In all the cases the use of UV absorber improved the light fastness of dyed fabrics as compared to untreated dyed samples.
Pilot-Scale Study on Masking Agents for Titanium Tanning
Authors: Puccini Monica , Seggiani Maurizia , Pomelli Christian , Vitolo Sandra
Published: August 2015

The many advantages offered by chrome tanning justify its widespread use for production of almost all types of leather. However, the traditional chromium (III) tanning process is constantly under threat from the pressure of legislation, and ever-tightening restrictions require to minimize chromium-containing effluents discharge and chromium-containing wastes production. Recently, the manufacture and use of chromium (III) free tanning agents compounds have been studied intensively. Among these, Titanium (IV)-based salts is one of the most promising substitutes.In this study, the use of titanyl sulfate as tanning agent for the production of high-quality bovine upper leather was investigated. In order to optimize the titanium tanning performances, a comparative evaluation, on pilot-scale, of citrate and lactate ions as masking agents was performed.The developed process has been validated through various analyses of the obtained crust leathers such as shrinkage temperature, scanning electron microscopy, and physical testing. The final leather obtained with the innovative method shows similar properties to those of the conventional tanned leather in terms of technical and mechanical properties.
Controllable Synthesis of Functional Polyaniline Nanotubes via a Complex Template
Authors: Wang Ying , Sun Dong Hao , Guo Yan Feng
Published: August 2015

Functional Polyaniline (PANI) nanotubes are easily synthesized in high yield by an in situ polymerization using a fibrillar complex of acid orange II (AO II) and FeCl3as a template. During the process, the complex templates help direct the growth of fibrillar PANI on their surfaces, resulting in the formation of composite micro/nanofibers of PANI. After polymerization, by the post-treatment of removing templates in 1.0 M hydrochloric acid solution, PANI nanotubes with azo function and high electric conductivity of PANI are readily fabricated. The PANI nanotubes have about 150nm-300nm in diameter and several microns in length. At room temperature, the electric conductivity of PANI nanotubes is up to 10-1S/cm order of magnitude. The characterizations, including FTIR, UV-visible, XRD and TG, are presented.
Preparation and Characterization of Silica/Polymer Hybrid Submicron Particles via a Semi-Continuous Soap-Free Emulsion Polymerization
Authors: Li Joshua Qing Song , Wang Yan Qiu , Wang Hai
Published: August 2015

Submicron hybrid particles were prepared by direct polymerization of three monomers of styrene, methyl methacrylate (MMA), and vinyl acetate (VAC) onto the hydrophilic surface of 230 nm silica submicron particles without any coupling agent in a semi-continuous emulsifier-free emulsion polymerization at a monomer starved condition. The polymerization was initiated by potassium persulfate with constant monomer feed at 0.01, 0.02, or 0.04 mL/min, after adding 230 nm silica seed particles. The particle growth was investigated with a laser particle size analyzer and SEM, and the particle surfaces by Fourier transform infrared spectroscopy (FT-IR). It was founded that the growth of the hybrid particles depended on the hydrophobic characteristics of the polymers. When monomer was the most hydrophobic styrene, polystyrene (PS) shells split off from the hydrophilic surface of the unmodified silica particle whenever the shells reached a limit of ~20 nm. However, both polymethyl methacrylate (PMMA) and polyvinyl acetate (PVAC) shells grew constantly on the hydrophilic surface of silica particles. In the process of the whole reaction, the SiO2/PMMA and SiO2/PVAC hybrid particles kept almost monodisperse.
Preparation of Silica/Polymer Hybrid Nanoparticles via a Semi-Continuous Soup-Free Emulsion Polymerization
Authors: Li Joshua Qing Song , Wang Hai , Wang Yan Qiu
Published: August 2015

Hybrid nanoparticles were prepared by direct polymerization of methyl methacrylate, vinyl acetate, and styrene monomers onto the unmodified hydrophilic surfaces of 33 nm silica nanoparticles in a semi-continuous soap-free emulsion polymerization at a monomer starved condition. The polymerization was initiated by potassium persulfate with constant monomer feed at 0.01, 0.02, or 0.04 mL/min. The growth of the core-shell nanoparticles were measured by a laser particle size analyzer. FT-IR spectra analysis confirmed the hybrid structures of the synthesized nanoparticles. SEM images and size exclusion chromatography (SEC) results indicated regular core-shell microsphere structures. The hybrid nanoparticles increased in monodispersity and size over 100 nm with the reaction. However, SiO2/polystyrene (PS) nanoparticles grew much faster compared with SiO2/polymethyl methacrylate (PMMA) and SiO2/polyvinyl acetate (PVAC). There was particle coagulation, about 12 SiO2/PS particles aggregating to one, in the early stage of the seeded process. In addition, PS secondary particles were formed before the particle coagulation, and then merged with the SiO2/PS nanoparticles in the particle coagulation. The formation of SiO2/polymer hybrid nanoparticles depended on the hydrophilic characteristics of the polymer, and the size of silica seeds.
Effect of n-LaB4O7 Additive on Tribological Behaviors of Ion Nitrocarburized Layer at Higher Temperature
Authors: Hu Chun Hua , Xue Jun , Wang Yun Kai , Li Ya Zhi , Deng Zhi Chang
Published: August 2015

The paper studied the effect of n-LaB4O7additives of different contents on tribological behaviors of the ion nitrocarburized layer at higher temperature. It is found that 7% n-LaB4O7additives can improve obviously the tribological performances of the ion nitrocarburized layer. This because that synergetic effect of friction reduction and wear resistance is produced between the n-LaB4O7additives and ion nitrocarburized layer under higher temperature, load and frequence, and the solid lubrication films including oxide, nitride and sulphate and so on are formed on the friction surface to separate the contact between the metal sufaces, and furthermore the n-LaB4O7particles on the friction surface play the "Micron nanobearing" function, which make the ion nitrocarburized layer have the more excellent tribological performances.
Effect of n-Na2B4O7 Additive on Tribological Performances of Ion Nitrocarburized Layer
Authors: Hu Chun Hua , Jiang Hai , Du Yun Feng , Wang Hai Peng , Deng Zhi Chang
Published: August 2015

The paper studied the effect of n-Na2B4O7additives of different content on tribological performances of the ion nitrocarburized layer. It is found that 7% n-Na2B4O7additive can improve greatly the friction reduction and wear resistance of the ion nitrocarburized layer under different conditions. This because that synergetic effect of friction reduction and wear resistance is produced between n-Na2B4O7additive and ion nitrocarburized layer under higher temperature, frequence and load, and the chemical reaction films including oxide, nitride, BN, and sulphide and so on formed on the friction surface play the solid lubrication function, and the n-Na2B4O7particles on the friction surface play the "Micron nanobearing" function, translating the sliding friction into the rolling friction, which can make the ion nitrocarburized layer possess the excellent tribological performances.
Preparation and Characterization of W@SiO2 Shielding Composite Microsphere
Authors: li Zuo Sheng , Zhang Yan , Liu Yu Jian , Fang Jun , Luan Wei Ling
Published: August 2015

W@SiO2 shielding composite microspheres were prepared by Sol-gel method for the first time. The component and morphology were investigated by Fourier transform infrared (FT-IR) spectra, Transmission electron microscopy (TEM) and Energy dispersive X-ray spectroscopy (EDX). The results reveal that polyvinylpyrrolidone (PVP) was introduced to the surface of tungsten nanoparticle successfully, and tungsten nanoparticle had been coated with silica. The appropriate hydrolysis reaction time is 3h, core-shell structure W@SiO2 shielding composite microsphere can be synthesized and free silica decrease sharply. Core element and shell element of W@SiO2 shielding composite microspheres were proved to be tungsten and silica respectively.
Kinetics and Thermodynamics of Adsorption of Cr(VI) on Nano Magnetic NiFe Particles in an Aqueous Solution
Authors: Zhang Lin , liu Kai Ge , Zhang Zhao Wen , Liu Yan
Published: August 2015

Magnetic nano materials were known as high adsorption properties Nano-structural Ni2.33Fe alloy was successfully prepared by hydrothermal method and was used to remove CrO42- ions from aqueous solution. The results show that the equilibrium adsorption quantity increased with the increase of initial CrO42- concentration and pseudo-second-order kinetic models were successfully used for fitting the kinetic data. Webb Maurice diffusion model shows adsorption was controlled by external mass transfer followed by internal particle diffusion mass transfer. And the fitting degree of the Langmuir isotherm and the experimental data was quite high. And the Freundlich isotherm also fitted well.
Synthesis and Characterisation of WS2 IF Nanoparticles via Solid-Gas Reaction between WO3 and S
Authors: Wen Yan , Yeprem H. Aygul , Zhang Shao Wei
Published: August 2015

WS2 inorganic fullerene like (IF) nanoparticles were synthesised via a modified solid-gas reaction route. Based on the reaction between WO3 and S at a relatively low temperature (between 450 and 950°C) in H2/Ar, nanosized WS2 (<100 nm) with IF structure were readily produced.
Influences of Pre-Sintered Ceramic Compacts Processing Parameters on Tool Wear
Authors: Li Xue , Li Jian Zhong , Yu Zu Yuan , Wang Mei Li , Xu Shuang Hu
Published: August 2015

As the requirements of MEMS continuously increase, the micro ceramic structures are widely used due to their favorable material properties such as high strength, hardness and resistance to high temperature, wear and erosion. However, the sintered ceramic compact is hard to be machined as its high strength. On the other hand, the low strength of green ceramic body makes it difficult to guarantee the machining accuracy. In this paper, ceramic compacts are pre-sintered below the sintering temperature. Pre-sintered ceramic compacts have suitable strength and are easy to be machined. Simple ceramic micro structures are easily generated with micro tools fabricated on line by wire electrical discharge grinding method (WEDG). Extensive experiments are carried out to investigate the influence of the strength of pre-sintered ceramic compact on the tool wear. It was found that the best machining results are achieved under the conditions of using the tool with a semi-circle cross section, the tool rotation speed of 1500 rpm and the pre-sintered ceramic compact formed under the pressure of 150MPa within the range of experimental conditions in this study.
Preparation and Characterization of Carbon/CNTs Hybrid Nanofibers via a Simple Electrospinning Route
Authors: Zhang Tao , Xia Long , Wen Guang Wu , Huang Xiao Xiao
Published: August 2015

Carbon/CNTs hybrid nanofibers (200-300 nm in diameter) were prepared by electrospinning a precursor of polyacrylonitrile (PAN) and surface modified CNTs. CNTs modified by strong acid are well dispersed in the PAN precursor which is critical for homogenous carbon/CNTs hybrid nanofibers. The prepared nanofibers are promising reinforcements for carbon or resin based composites.
Synthesis and UC Luminescence Properties of NaYF4:Yb,Er Microsheets
Authors: Lu Zi Biao , Tao Feng , Wang Zhi Jun , Liu Li , Ruan Dong Cheng , Liu Qi , Sun Yu Feng
Published: August 2015

Hexagonal NaYF4:Yb3+/Er3+ microsheets were successfully synthesized via a hydrothermal method assisted by sodium oxalate as a shape modifier. XRD, FE-SEM, TEM and SAED have been used to study the morphologies and crystal structure of the products. The effects of the pH values on the crystal structure, morphology and size were discussed. The hexagonal NaYF4:Yb3+/Er3+ microsheets show characteristic upconversion fluorescence at green (521-540 nm) and red (630-680 nm) corresponding to the 4f-4f transition of Er3+. The green and red emission intensity for microsheets has a great increase compared to that for hexagonal microspheres, and the intensity of the green emission is greater than that of the red one.
Preparation and Properties of CNTs Reinforced BMI/DBA Nanocomposites
Authors: Li Shuang , Zhao Xiong Yan , Wang Xin
Published: August 2015

This paper mainly describes the preparation of carbon nanotubes (CNTs) reinforced BMI/DBA composites, as well as the effects of CNTs contents on mechanical properties of BMI/DBA/CNTs nanocomposites. The results indicated that with the level of hydroxy-modified carbon nanotubes increased, the mechanical properties of the BMI/DBA/CNTs nanocomposites first increase then decrease. When the content of hydroxyl-modified carbon nanotubes was added to 0.75wt%, the mechanical properties of obtained nanocomposites reached the maximum. In addition, the hydroxyl-modified carbon nanotubes were found to be compatible with the polymer matrix effectively.
The Application of Nanoparticles in Enhancing Oil Recovery by Wettability Alteration
Authors: Jin Jia Feng , Wang Yan Ling , Liu Fei
Published: August 2015

Wettability is one of most important characteristics for governing the flow and distribution of reservoir fluids in the porous media,the wetting and spreading behavior of liquids on the solid surfaces changes if the wettability of solid surface is altered. Recent studies show the spreading behavior of liquids on solid surface can be significantly improved after nanofluid treatment. In order to investigate the influence of wettability alternation on enhancing oil recovery after nanofluid treatment,flushing oil experiment and contact angle measurement were conducted in the laboratory. The first experiment involved flushing crude oil with the nanofluid and conventional surfactants, respectively. In the second case, the contact angles of oil phase in nanofluid (conventional surfactant solutions)-crude oil-slide systems were measured after treating 36 hours. The results indicated that nanofluid can produce a better flushing efficiency compared with that of conventional surfactant, and the contact angles of oil phase increased from 33° to 118° after nanofluid treatment in nanofluid/crude-oil/slide system. The mechanism of enhanced oil recovery of nanofluid is mainly wettability alternation.
Measuring Microscopic Properties of a Single-Crystalline Diamond by Nano-Indentation Technology
Authors: Wei Qi Long , Yue Xiao Bin , Li Xiao Yuan , Liu Bo , Zhang Xiao Feng , Lei Da Jiang
Published: August 2015

Nano-indentation technology was brought to study microscopic mechanical properties of a single-crystalline diamond (SCD). Nano-indentation measurement was conducted on the {100} plane of SCD, and influences of various factors on measured results were analyzed, from which methods were confirmed to improve veracity of measurement. Properties of the indenter were checked with a fused silica sample both before and after indentation on diamond, which provided guarantee to veracity of results on diamond. It was found that tilt of diamond surface had so great influence that it could damage the indenter, and make the indentation curves anomalous. While damage of indenter could be avoided and valid measurement results could be obtained when tilt of diamondsurface was decreased below 0.10º and the maximal indentation force was less than 10 mN. Deformation of the diamond was almost full-elastic during indentation process. Indentation hardness of {100} plane of the SCD was about 70 GPa with standard deviation less than 3 GPa. And there had good reproducibility between two groups of measurements.
Effect of Titanium Dioxide Manufacturing Waste in Mechanical Properties of Red Ceramics
Authors: Ribeiro Daniel Véras , Figueiredo S.C. , Machado Alexandre T. , Valenzuela Diaz F.R. , Souza C.A.C.
Published: August 2015

Rotary-vacuum-filter mud (RVFM) is waste generated during the manufacturing process of titanium dioxide. In this work, RVFM and ceramic bricks containing different ratios of this waste are investigated. The mud samples were characterized using thermal analysis (TG/DTG). The aim of the present work was to determine the effect of adding RVFM on the ceramic properties of clay, such as apparent porosity, water absorption, linear shrinkage and flexural strength, used to produce blocks and tiles. Samples were dried out at 110°C and fired at 800°C, 950°C and 1100°C. The addition of RVFM tends to increase the apparent porosity and water absorption and to decrease the flexural strength of the ceramic specimens. Based on the results, ceramic specimens with 20% RVFM content burned at 800°C can not be used as bricks, and ceramic specimens with 20% RVFM content fired at 800°C and 950°C can not be used as tiles, according to Brazilian standards.
Impact of Doping of Bi3+ on Luminescent Properties of Red Phosphors Sr3-xGaO4F:xEu3+
Authors: Liu Rong Ying , Feng Yuan Zhang , Peng Zi Fei
Published: August 2015

It has been studied that the impact of doping of Bi3+on the luminescent properties of red phosphors Sr3-xGaO4F:xEu3+prepared with high temperature solid-state reaction method followed by doping into certain amounts of Bi2O3. The resulting samples are characterized by XRD, Emission Spectrum and Excitation Spectrum. As a result, it is shown that the strongest emission peak caused by the forced electronic dipole transition of5D0-7F2is at 618 nm with solely doping of Eu3+. In addition, the luminescent intensity of the as-formed phosphor increases and the most intensive emission peak red-shifts with doping amount of Bi3+while co-doping Eu3+and Bi3+. Meanwhile, the relationship of energy transition of Eu3+and Bi3+is also discussed herein.
Observation of Substrate Silicon Incorporation into Thin Lanthanum Oxide Film during Rapid Thermal Annealing
Authors: Zhang Jie Qiong , Yu Dan Qun , Wong Hei , Kakushima Kuniyuki , Iwai Hiroshi
Published: August 2015

Lanthanum oxide (La2O3) has been proposed as the promising gate dielectric material for future complementary metal-oxide-semiconductor (CMOS) technology. However, unlike the conventional homopolar materials such as silicon oxide or silicon nitride, La2O3 is more ionic and in particular at the La2O3/Si interface is less thermally stable. This work investigates the chemical and compositional variations of La2O3 thin film on the silicon substrate during rapid thermal annealing by using angle-resolved x-ray photoelectron spectroscopy (ARXPS) measurements. Results show that thermal annealing at temperatures above 500 °C would result in the incorporation of substrate Si atoms deep into the bulk of the La2O3 film and forming silicate phases both at the interface and in the bulk. These effects would result in the characteristic degradation of CMOS devices.
Photoelectrochemical Properties of Anatase TiO2 Films Prepared by Improved Liquid Phase Deposition
Authors: Lei Cai Xia , Jiang X.L. , Liu Y. , Liu X. , Ma Y.T. , Yang S. , Qin S.Z. , Zhang G.S. , Feng Z.D.
Published: August 2015

In this paper, the hydrothermal-assisted liquid phase deposition (HT-LPD) method has been developed to prepare TiO2 films. The crystalline structures and morphologies of as-prepared TiO2 films were analyzed using an X-ray diffractometer (XRD) and scanning electron microscope (SEM). It was found that the HT-LPD TiO2 film showed good crystallinity with preferrred orientation along c-axis. Moreover, the as-prepared TiO2 films consisted of two layers, with the tiny nanoparticles as the underlying layer and the flower-like clusters as the upper layer. The photoelectrochemical measurements revealed that, when illuminated by the white light, the HT-LPD TiO2 films exhibited a more negative photopotential value and an increased photocurrent value with elevated reaction temperature, excepting for the sample prerared at 150 °C. In summary, the TiO2 films prepared by the improved LPD method could be served as the promising photoanode for the photoelectrochemical applications.
Temperature Dependent Current-Voltage Characteristics of n-Type β-FeSi2/Intrinsic Si/p-Type Si Heterojunctions
Authors: Promros Nathaporn , Prajakkan Dalin , Hongsa Nantharat , Suthayanan Nattanee , Sittimart Phongsaphak , Takahara Motoki , Baba Ryuji , Mostafa Tarek M. , Shaban Mahmoud , Yoshitake Tomohiro
Published: August 2015

In this work, n-type β-FeSi2/intrinsic Si/p-type Si heterojunctions were prepared by facing-targets direct-current sputtering. We measured their current-voltage characteristics at low temperatures ranging from 300 K down to 50 K and investigated their ideality factor, saturation current and series resistance using thermionic emission theory and Cheung’s method. From thermionic emission theory, the ideality factor and saturation current density were calculated from the slope of the linear part from the forward lnJ-V and the straight line intercept of lnJ-V at zero voltage, respectively. When the temperature decreased from 300 K down to 50 K, the ideality factor increased from 1.12 to 11.13, whereas the saturation current density decreased from 2.09 × 10-6 A/cm2 to 1.06 × 10-9 A/cm2. Using Cheung’s method, we plotted the relations of dV/d(lnJ)-J and H(J)-J in order to estimate the series resistance from the slope of both plots. In addition, we estimated the ideality factor from a y-axis intercept of the dV/d(lnJ)-J plot. The series resistances from both plots were consistent with each other and increased with the decreasing temperature. The ideality factor estimated by Cheung’s method was in agreement with that obtained from estimation by thermionic emission theory.
Effect of Neodymium on the Glass-Forming Ability and Magnetic Properties of Fe-Based Bulk Amorphous Alloys
Authors: Man Hua
Published: August 2015

The glass forming ability and magnetic properties were investigated for adding neodymium to the Fe71-xNb4B25Ndx (x=0, 3, 5, 7,10) alloys prepared by copper suction casting. It was found that proper neodymium (x=5~10 at.%) could improve glass forming ability of Fe-Nb-B alloys effectively. Bulk amorphous Fe66Nd5B25Nb4 and Fe64Nd7B25Nb4 samples were obtained and presented high thermal stability and good soft magnetic properties. The value of activation energy of the first crystallization peak for the bulk amorphous alloy Fe64Nd7B25Nb4 is 683 kJ/mol.
Novel Ordered Layered Double Hydroxides Ultra Thin Films Functionalized with Dawson-Type Polyoxometalates: Synthesis, Characterization and Photocatalytic Behavior under Visible Light
Authors: Wang Jin Ping , Li Dan Feng
Published: August 2015

Novel ordered Ultra thin Films (UTFs) based on the hybrid assembly of exfoliated Zn-Cr Layered double hydroxide (LDH) monolayers and typical dawson-type polyoxometalate (POM) anions α-P2W18O626- (P2W18) were prepared by utilizing a layer by layer (LBL) technique. The structural integrity of the UTFs were characterized by ICP-AES, XRD, IR, UV/DRS, indicating that the Dawson structures remained intact in the hybrid compositions. The morphology and the thickness of the UTFs were evaluated via SEM. The visible light photocatalytic performances of the UTFs were tested in the degradation of aqueous azo dye Congo red (CR). The UTFs showed much higher photocatalytic activity than pure Zn-Cr-NO3- LDH, mainly attributed to the improved absorbance and response ability to the visible light.
Evaluation of Different Flame Retardant Combinations for Core/Shell Structured Wood-Plastic Composites by Using a Cone Calorimeter
Authors: Nikolaeva Marina , Kärki Timo
Published: August 2015

The fire retardancy of coextruded wood-plastic composites (WPCs) containing melamine, ammonium polyphosphate (APP), natural graphite, expandable graphite and carbon nanotubes (CNTs) in the shell layer was characterized with a cone calorimeter test. A coextruded composite manufactured without any fire retardant (FR) in the shell layer was used as a reference. The incorporation of different combinations of FRs in the shell layers of WPCs reduced the peak heat release rate by 3-43%, depending on the FR combination. Other studied parameters, such as ignition time, total heat release and mass loss rate were improved after FR systems loading. The best improvement of flammability characteristics was observed with melamine/natural graphite combinations, whereas the melamine/expandable graphite system resulted only in slight improvement of the studied parameters. However, it should be noted that the amount of expandable graphite loading was 2-4 times lower than the amount of natural graphite loadings. Incorporation of 2 wt.% CNTs in the shell layer did not show any significant improvement in the studied parameters. The total smoke release and carbon monoxide production were increased with melamine/APP loading in the shell layer.
Synthesis and Electrochemical Properties of Spherical LiFePO4/C Composite via Spray Drying
Authors: Wang Juan Mei , Ren Bing , Yan Ying Lin , Zhang Qing , Wang Yan
Published: August 2015

In this work, spherical LiFePO4/C composite had been synthesized by co-precipitation and spray drying method. The structure, morphology and electrochemical properties of the samples were characterized by X-ray diffraction (XRD), scanning electron micrograph (SEM), transmission electron microscope (TEM), constant current charge-discharge tests and electrochemical impedance spectroscopy (EIS) tests. The spherical LiFePO4/C particles consisted of a number of smaller grains. The results showed that the morphology of LiFePO4/C particles seriously affected the Li-ion diffusion coefficient and electrochemical properties of lithium ion batteries. Electrochemical tests revealed the spherical LiFePO4/C composite had excellent Li-ion diffusion coefficient which was calculated to be 1.065×10-11 cm2/s and discharge capacity of 149 (0.1 C), 139 (0.2 C), 133 (0.5 C), 129 (1 C) and 124 mAhg-1(2 C). After 50 cycles, the capacity retention rate was still 93.5%.
Research on Microstructure and Wear Resistance of (Fe,Cr)7C3/Fe Surface Gradient Composite
Authors: Wang Chong , Ye Fang Xia , Zhong Li Sheng , Yan Ying Lin , Lai Yu Jun , Wang Xin
Published: August 2015

In this study, the (Fe,Cr)7C3 particles strengthened gradient composite was produced by in situ synthesis process with subsequent heat treatment from gray cast iron (HT300) and high purity chrome plate. The microstructure, phase composition and wear resistance of the composite were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD) and scratch tester. The results showed that the thickness of the gradient layer was about 758 μm after heat treatment at 900 °Cfor 4 h. And it can be divided into three areas depending on microstructure. The outermost layer which was ~60 μm of thickness, was the dense ceramic layer with high volume fraction of (Fe,Cr)7C3 ~90%. No obvious grain boundaries were observed. The subsurface layer was the particles dispersed layer, which was ~525 μm of thickness, with the volume fraction of (Fe,Cr)7C3 decreased to 70%. The lowermost layer was ferrite, with about 173 μm thickness. A good metallurgical bond generated between the composite layer and matrix. The depth and the width of surface scratch increased with the raising loads from 0 to 100 N, and the cracks mainly included micro-crack, tiny dens crack, mixture crack and through-wall crack. The (Fe,Cr)7C3 particles were broken and scraped when the load exceeded 80 N.
Nonisothermal Crystallization Behavior of Poly(vinylidenefluoride)/Polysulfone/Diethylene Glycol Dibenzoate/Dibutyl Phthalate System via Thermally Induced Phase Separation
Authors: Zhang Jing , Qi Lu , Cui Zhen Yu
Published: August 2015

Differential scanning calorimetry (DSC) measurement is used to investigate the nonisothermal crystallization behavior of poly (vinylidene fluoride) (PVDF)/polysulfone (PSF)/diethylene glycol dibenzoate (DEDB)/dibutyl phthalate (DBP) system via solid-liquid (S-L) phase separation during a thermally induced phase separation process. The effect of benzene ring in PSF on PVDF crystallization for PVDF/PSF/DEDB/DBP system is investigated. It is found that the Ozawa model can describe nonisothermal crystallization behavior of PVDF/PSF/DEDB/DBP system in a certain crystallization temperature range. Jeziorny method indicates that the secondary crystallization of PVDF exists in the process of nonisothermal crystallization and is enhanced by the increase of cooling rate.
Microwave Assisted Synthesis of Quercetin-Selective MIPs Grafted on Silica Gel Surface
Authors: Xie Yi Hui , Ding Yan Hua , Liu Wen Qin , Bai Wen Ting , Huang Li Ping
Published: August 2015

The silica gel surface was alkylated by silane coupling agent KH-570 under the microwave assisted and orthogonal experiment was adopted to optimize the silica gel surface silanized experimental conditions with synthetic yield as index. With quercetin as the template molecule, 4 - vinyl pyridine as the functional monomer, ethylene glycol dimethyl acrylate as the cross linking agent, azodiisobutyronitrile as initiator, under the microwave assisted in silane silicone surface quercetin molecularly imprinted polymer was successfully synthesized. Take selected quercetin as index, another orthogonal experiment was implemented to optimize the quercetin-selective MIPs synthesis experiment on silica gel surface. What is more, the adsorptive property of quercetin-selective MIPs which was grafted on silica gel surface has been inspected. We have extracted of quercetin in the ethyl acetate from raspberry with quercetin-selective MIPs grafted on silica gel surface. Synthetic time have been shortened more than a dozen times, the efficiency of preparation of MIPs have been greatly improved.
Synthesis of Ultra-High Molecular Weight Polyacrylonitrile (UHMWPAN) by Aqueous Suspension Polymerization
Authors: Jiang Hui Yu , Zhou Mei Hua , Pan Ding
Published: August 2015

Acrylonitrile (AN) and itaconic acid (IA) were used to synthesize UHMWPAN by aqueous suspension method with 2,2’-azobisisobutyronitrile (AIBN) as the initiator and polyvinylalcohol (PVA) as the disperser at different temperatures (55°C~75°C) for different timings (1.0h~3.0h). The usage amounts of AN, IA, AIBN and PVA were also technical polymerization parameters used to obtain the optimal polymerization process. We found that the conversion and the viscosity average molecular weight both achieved the optimum levels when the conditions were as follows: the total monomer concentration (21wt%), the monomer ratio (AN: IA=98:2), the usage amount of the initiator (AIBN, 0.01wt%), the usage amount of the disperser (PVA, 0.1wt%), the polymerization temperature (70°C) and the polymerization time (2h).
The Formation and Characterization of Poly (p-phenylene benzobisoxazole) Pulps via Stirred Solutions
Authors: Liu Rong Biao , Li Xin Xin , Qian Jun , Han Zhe Wen
Published: August 2015

PBO (p-phenylene benzobisoxazole) short fibers, attached fine fibrils that are called PBO pulp, may precipitate directly from stirred PBO/methanesulfonic acid (MSA) solution by the use of water coagulant in fibrous pulp form. Scanning electron micrographs show that the precipitated PBO pulps have a ribbon-like structure similar to Kevlar pulps. The thermalgravimetric analysis (TGA) show there were no appreciable mass changes until 550 °C in the air. The process yields PBO pulps with different specific surface areas (SSA) depending on the stirring speed, stirring time and the concentration of the PBO/MSA solution. High SSA PBO pulps can be produced by increasing the stirring speed, prolonging the stirring time and reducing the concentration of the PBO/MSA solution.
Effect of Organoclay Platelets on Crystallization of PTT/EVA-g-MA Blends: Non-Isothermal Melt Crystallization Kinetics
Authors: Wang Kun Yan
Published: August 2015

PTT/EVA-g-MA (80/20 w/w) nanocomposites were prepared by the melt mixing with different organoclay (OMMT) loading. The effect of OMMT on the non-isothermal crystallization kinetics of composites was investigated by DSC. The Avrami and Ozawa methods were used to describe the non-isothermal crystallization process of pure PTT and composites with various loading of OMMT. The Avrami analysis results show that the crystallization rate of 80/20 (w/w) PTT/EVA-g-MA blends with the OMMT is faster than that of pure PTT. The Ozawa analysis can describe the non-isothermal crystallization of pure PTT very well, but it was rather inapplicable for the 80/20 (w/w) PTT/EVA-g-MA blends with various amounts of the clay.
The Preparation of CMC-PVA-AM Dust Suppression Agent and its Application Appraisement
Authors: Xiao Yu Chen , Zheng Chi , Gan Meng Ke , Lai Shui Li
Published: August 2015

In this article, a kind of synthetic polymer dust suppressants agent was prepared with poly (vinyl- alcohol) (PVA), carboxymethylcellulose (CMC) and acrylamide (AM). The chemical and physical properties of this dust suppressant was characterized by means of grafting rate, FT-IR analysis, TG test, viscosity analysis and SEM survey. The result showed that grafting rate was reached 95.6%; IR spectrum proved that monomers have been completely reacted basically; thermal gravimetric analysis was characterized that the dust suppressant has good thermal stability between 0°C-250°C; the amount of AM and SDBS were 50% and 1.0% (based on mass of the total materials), the polymer has a suitable viscosity; SEM was used to observe the shape characteristic of the coal dust which formed a link between the dust suppressant and coal dust. The water resistance of the dust suppressant was well in 24h.
Study on the Mechanical Properties of Carbon Fiber Composite Material of Wood
Authors: Shen De Jun , Lin Zi Sheng , Zhang Yan Fei
Published: August 2015

through the use of domestic carbon fiber cloth and combining domestic fast-growing wood of Larch and poplar wood, the CFRP- wood composite key interface from the composite process, stripping bearing performance, Hygrothermal effect, fracture characteristics and shear creep properties to conducted the system research .
Fiber reinforced composite (Fiber Reinforced Plastic/Polymer, abbreviation FRP) material by continuous fibers and resin matrix composite and its types, including carbon fiber reinforced composite (Carbon Fiber Reinforce Plastic/Polymer, abbreviation CFRP), glass fiber reinforced composite (Glass Fiber Reinforced Plastic/Polymer, abbreviation GFRP) and aramid fiber reinforced composite (Aramid Fiber Reinforced Plastic/Polymer, abbreviation AFRP).
PAN based carbon fiber sheet by former PAN wires, PAN raw silk production high technical requirements, its technical difficulty is mainly manifested in the acrylonitrile spinning technique, PAN precursor, acrylonitrile polymerization process with solvent and initiator ratio. Based on this consideration, the subject chosen by domestic PAN precursor as the basic unit of the CFRP as the object of study.
Ablation Property of the Plasma Sprayed NiCrAlY-ZrO2 Compound Coating on Stainless Steel Material
Authors: Deng Zhi Ping , Liu Zhao Hui , Zhang Hang , Li Yuan
Published: August 2015

The NiCrAlY-ZrO2 anti-ablation compound coating was prepared on one surface of a 201stainless steel by plasma spraying, and the ablation property was studied by the cyclic ablation experiment. The morphology and XRD pattern of the NiCrAlY-ZrO2 coating were characterized by SEM and XRD methods before and after ablation on the high-temperature oxyacetylene flame. The results show a good adhesion between the coating and substrate. After the ablation at high temperature flame, the smoothness of the coating surface declined. The coating, under the oxyacetylene flame of 2800°C, can effectively improve the anti-ablation property of the substrate material, the mass loss for the coated sample is 1/4 of the uncoated specimen under the same number of ablation cycles.
Research of Microstructure and Hardness of Co55 and W Coating Made by Laser Cladding
Authors: Zhang Wei
Published: August 2015

The experiment of laser cladding on the surface of 20 steel was made. The mixed powder of cobalt-based alloy powder (Co55) and tungsten powder was used as cladding material. There were three kinds of weight percent of tungsten powder, 5%, 10% and 15%. The microstructure and hardness of three kinds of laser cladding layer were studied. The microstructure of cladding zone was greatly refined after adding tungsten powder to Co55 powder. When the proportion of tungsten powder was 5%, the cladding zone was made up of dendritic crystal. The average hardness of cladding zone was 590 HV0.2. When the proportion of tungsten powder rose to 10%, there was reticular secondary carbide precipitating along the grain boundary. The average hardness of cladding zone was 648 HV0.2. When the proportion of tungsten powder rose to 15%, much granular carbide would diffusely distribute in Ni-based solid solution. The average hardness of cladding zone was 831 HV0.2.
A Effects of Nano-Particles Additives on Wear Performance of Micro-Arc Oxidation Coating Prepared on 2A12 Aluminum Alloy
Authors: Qiu Ji , Suo Xiang Bo , Ma Shi Ning , Shuai Gang , Wang Hong Mei
Published: August 2015

Nano-particle reinforced composite coatings were prepared on 2A12 aluminum alloy by micro-arc oxidation and the effect of nano particles on wear performance of coating was studied. By means of SEM, CETR micro-nano-indenter friction and wear tester and white-light interferometer, the surface morphology and the friction and wear property were tested. Results showed that compared with the coating without nano-particle addition, the size and amount of pores on coatings were decreased substantially after additon with 20nm nano-SiO2 particles, 80nm nano-SiO2 particles and 80nm nano-TiO2 particles, and the wear resistance of the micro-arc oxidation coating was improved.
Microstructure and Hardness of NbC Coating Produced In Situ
Authors: Cai Xiao Long , Zhong Li Sheng , Wang Jie Fang , Shao Tian Tian , Zhao Na Na , Xu Yun Hua
Published: August 2015

The niobium carbide (NbC) coating on gray cast iron has been produced by in situ which combined infiltration casting and heat treatment. The microstructural observations of the coating have been obtained by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). And the growth mechanism of NbC grain was studied. The results show that the mechanism is orientation connection which means two particles of the same lattice orientation will be directly connected together and oriented attachment growth. Fine NbC grain can improve the nanohardness value of the coating with 23 GPa, meanwhile, it increase the elastic modulus with the value of 493.7 GPa.
Early Corrosion Behavior of Pipeline Steel Containing 1% Cr in Sea Water Environment
Authors: Liu Zhen Guang , Gao Xiu Hua , Du Lin Xiu , Li Jian Ping , Hao Ping Ju
Published: August 2015

The corrosion behavior of pipeline steel containing 1%Cr is studied by using immersion experiment. The corrosion rust is characteried with macroscopic/microscopic surface morphology, corrosion kinetics and corrosion phases. The results demonstrate that the main corrosion products are lepidocrocite and goethite, Cr-rich compound consists of the inner layer. The corrosion process could be divided into three stages. At stage 1, the corrosion rate decreases fast, and the distributed corrosion products are formed. At stage 2, the granular corrosion products appear on coupons surface gradually, and a plain corrosion rate is obtained. At stage 3, a compact and dense corrosion layer attaches to coupons surface, and corrosion rate decreases mildly.
Mechanisms of Plant Polyphenol Genistein on Regulation of EMT in Ovarian Carcinoma
Authors: Lin Xiao , Li Yu
Published: August 2015

More and more studies have reported that epithelial-mesenchymal translation (EMT) plays key roles not only on genesis, development and metastasis, but also on drug-resistance of chemotherapy of tumor. Meanwhile, the fact that beta-catenin transfer from membrance and cytoplasm to nucleus is major steps in process of EMT [1]. Research found that Genistein would suppress Wnt/beta-catenin signal pathway though inhibiting beta-catenin translation [2]. Furthermore, our research showed that Genistein could decrease the expression of GSK-3beta in ovarian carcinoma cell SKOV3. Beta-catenin and GSK-3beta are important factors of EMT, which indicated that Genistein would regulate EMT signal pathway through beta-catenin and GSK-3beta, but the mechanism is not clear. So, there has been great interest in understanding the molecular mechanisms on the effect of Genistein.
Fabrication of Eprinomectin-Loaded PLGA Microspheres and their In Vitro Veterinary Release Profiles
Authors: Zhao Ying Ge , Tian Rui Qiong , Zhang Jing , Liang Xiao Yang , Shang Qing
Published: August 2015

To prolong the bioactivity of eprinomectin (EPM), a batch of EPM-loaded PLGA microspheres were fabricated by a solvent evaporation method. The morphology of resultant microspheres was observed with an S-4800-I scanning electron microscope (SEM). The EPM release behaviors were investigated with a dialysis method and fitted with Zero-order, First-order, and Higuchi dynamical models. The optimum formula, CPVA 2.0 w/v%, stirring rate 1, 200 r/min, CPLGA 4.0 wt%, and oil/water ratio 1/250, was obtained from single-factor experiments. SEM images suggested that the resultant microspheres were monodispersed spheres with a few micropores on their surfaces. Furthermore, more pores and hollows were observed in the degraded PLGA matrix. EPM-loaded PLGA microspheres showed the maximum release amount in the mixture of alcohol/PBS (4/6, v/v). The release process lasted for 30 d, which increased the bioactivity and insecticidal efficacy of EPM. Besides, microspheres with the diameter of 50 μm showed a better release behavior than those from 100 μm and 150 μm ones. Therefore, such method had a promising application on sustained release of veterinary medicine.
Influence of Rotation Rate of Collecting Roller on the Mechanical Property of PCL/SF Tubular Scaffolds
Authors: Luo Jing Wan , Xia Zhen Ran , Qu Jing , Yu Yan Ni , Li Jing , Li Ming Zhong
Published: August 2015

The composite tubular scaffolds with highly oriented nanofibers used for vascular repair could improve the biomechanical properties of tubular scaffolds, satisfying the biomechanical requirement for the change of blood pressure and conducing to cell adhesion, migration and proliferation. The tubular scaffolds from poly(ε-caprolactone)(PCL) and silk fibroin (SF) composite nanofibers were successfully fabricated through electrospinning using cylindrical roller with an outer diameter (OD) of 3.0 mm. The influences of the collecting rotatation speeds on electrospun PCL/SF nanofibers orientation and radial/axial mechanical properties of the scaffolds were investigated. The results revealed that the electrospun PCL/SF tubular scaffolds fabricated at 1500 and 2000 r/min (linear velocity of 2.1, 2.8 m/s, respectively) possessed good arrangement around the circumferential direction of roller and sufficient radial strength and suture strength. The electrospun PCL/SF tubular scaffolds with circumferential-direction structure as a new vascular graft may be useful in vessel tissue engineering.
Application Research of Lipid Microsphere Biological Carrier Material on Prescription of Tanshinone II a Lipid Microsphere by Central Composite Design-Response Surface Method
Authors: Liang Xin Li , Lv Dan , Luo Juan , Guan Xue Jing , Liao Zheng Gen
Published: August 2015

To optimize the prescription of tanshinone IIA lipid microspheres by central composite design method, and evaluate the quality. Through evaluating average particle size, stability constant and the encapsulation efficiency of the lipid microsphere to investigate the concentration of the egg yolk lecithin and the poloxamer and the percentage of Soybean oil in the total oil phase which may impact the properties of tanshinone IIA lipid microsphere. Building the mathematic relation between the index and factor by the binomial expression, according to the best mathematical model of the evaluation indicators to describe response surface and then to use response surface method to predict the best prescription which will be analysed. According to the prescription optimization to prepare tanshinone IIA lipid microsphere and evaluate its quality. The results showed that each index of the binomial equation fitting is good, the correlation coefficient of the average particle size, stability constant and the encapsulation efficiency are 0.97, 0.92 and 0.84 respectively. The optimized prescription is as follows: egg yolk lecithin1.38 g, F68 0.19 g, LCT 2 g, MCT 18 g, all the indexes of the optimized prescription are similar to the target values.