bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Anion on the Morphologies of ZnO Synthesized by an Aqueous Solution Method
Authors: Cui Shi Cai , Zhang Da Feng , Pu Xi Peng , Qian Xian Hua , Ge Tian Tian , Yan Dong
Published: July 2011

ZnO were rapidly synthesized using different zinc salts (Zn(NO3)2, Zn(CH3CO2)2, ZnCl2 and ZnSO4) by an aqueous solution method at 90°C. The products were characterized by X-ray diffractometry and scanning electron microscopy. The results show that the anions have remarkable effects on the morphologies of ZnO. When Zn(NO3)2, Zn(CH3CO2)2 or ZnCl2 was used, ZnO was obtained with ellipsoidal, under-developed ellipsoidal and nano-particles morphologies, respectively. In the case of ZnSO4, layered basic zinc sulfate was obtained. The remarkable effects of anions on ZnO can be ascribed to the adsorption of the anions on the surface of ZnO, which hinders the further growth of ZnO nuclei. The effect of SO42- was further investigated by changing the mole ratio of SO42- to NO3-.
Effects of Synthesis Parameters on Controllable Growth of Highly-Ordered TiO2 Nanotube Arrays
Authors: Li Shi Pu , Lin Shi Wei , Liao Jian Jun , Li Dan Hong , Cao Yang , Li Jian Bao
Published: July 2011

Titania nanotube arrays were fabricated in deionize water and glycerol mixed electrolyte containing a certain amount of NH4F. Three different polishing methods were used for pretreatment of Ti substrates: polished by hand with abrasive paper, by polishing machine, or by chemical polishing fluid (HF:HNO3=1:4, in volumetric ratio). The morphology of three different samples were imaged by scanning electron microscopy, and their photoelectrical properties were studied as well. Experimental results showed that Titania nanotube arrays grown on the Ti substrate and polished by polishing fluid has highly-ordered and well-defined nanotube structure. The effects of anodization potential and duration on synthesis of highly-ordered TiO2 nanotubes were also studied in this paper. Both the layer thickness and nanotube diameter linearly increase with the increasing potential. The layer thickness also increases with prolongation of anodization time. By optimizing the preparation conditions, we can successfully control the geometrical structure of TiO2 nanotube arrays with diameters in the range between 50 and 200 nm and the layer thickness between 800 and 2000 nm.
Dispersibility of Nano TiN Powder in Ethanol Liquid
Authors: Jin Song , Feng Ping , Zheng Teng Biao
Published: July 2011

Effect of pH value and dispersant of polyethylene imine (PEI) on dispersion of nano TiN in ethanol liquid was investigated by sedimentation volume and viscosity, surface electric characteristic of particles was measured by Zeta potential. Results showed that pH value and PEI concentration had an important effect on dispersion of nano TiN. Excellent dispersibility was obtained through adjusting PEI amount and pH value. It was found that PEI was an efficient dispersant for nano TiN to disperse in ethanol liquid. The dispersibility follows by electrostatic and space steric stability mechanism.
Electronic Transport Properties of the Azobenzene-Based Optical Molecular Switch with Different Substituents
Authors: Xia Cai Juan , Liu Han Chen , Wang Jing
Published: July 2011

By applying nonequilibrium Green’s function formalism combined first-principles density functional theory, we investigate the electronic transport properties of the azobenzene -based optical molecular switch with different substituents. Theoretical results show that the donor/acceptor substituent plays an important role in the electronic transport of molecular devices. The switching performance can be improved to some extent through suitable donor and acceptor substituents.
Β-Cyclodextrin-Cross-Linked Polymer Microcolumn Dynamic Preconcentration/analysis for Trace Cadium
Authors: Zhu Xia Shi , Gu Ying , Hou Ting Ting
Published: July 2011

The adsorptive capability of β-Cyclodextrin-cross-linked polymer(β-CDCP) for cadmium was assessed in this work using column method. It was found that the complex (Cd(II)-5-Br-PADAP) could be quantitatively retained on the β-CDCP in the pH 8.5, eluted completely with 1.5 mol×L-1 HCl. Under the optimum conditions, the linear range, detection limit (DL) and the relative standard deviation (R.S.D.) was 2.0-60.0 μg×L-1, 7.8 ng×L-1 and 2.20% (n=3, c=20.0 μg×L-1) respectively. The separation of Cd(II) was achieved from water samples with an enhancement factor of 20. Moreover, the β-CDCP could be used repeatedly and offered better recovery. The method was validated using a certified reference material, and applied for the determination of trace cadmium in water samples.
Sonochemical Synthesis of Nanocrystalline MgSeO3 and its Photocatalysis Behavior
Authors: Gu Xue Jun , Fang Da Wei , Liu Yu , Wang Qiang , Zang Shu Liang
Published: July 2011

Nanocrystalline MgSeO3 was synthesized by method of ultrasonic precipitation, and was determined by X-ray powder diffraction patterns and transmission electron microscope. Photocatalyst behavior of MgSeO3 has been studied by decomposing organic acid black dye.
Microwave-Assisted Synthesis and Photocatalytic Activity of Quantum-Sized ZnO
Authors: Xu Wen Guo , Ma Cheng Xiang , Lu Shi Xiang , Dai Lian , Zhang Hai Feng
Published: July 2011

ZnO was prepared using zinc acetate dehydrate (Zn(CH3COO)2·2H2O) and lithium hydroxide monohydrate (LiOH·H2O) as raw material through a microwave-assisted sol-gel method. The prepared ZnO presents the wurtzite structure. The influence of different reaction temperature and heating time to the size of ZnO was researched. The photocatalytic activity of ZnO was evaluated by the degradation rate of C.I. Reactive Blue 4 in aqueous solution. The particle size of ZnO is about 4.33 nm at the reaction condition of 50°C for 10 min and the photocatalytic performance is the best. The degradation rate of C.I. Reactive Blue 4 could exceed 75% in 30 min at room temperature when the initial concentration of C.I. Reactive Blue 4 was 40 mg/L and the concentration of the quantum-sized ZnO was 0.1 g/L.
Controlled Synthesis of Hollow TiO2 Nanospheres Templated by Polymeric Micelle with Core-Shell-Corona Architecture
Authors: Liu Jing Jing , Li Cai , Mu Yi Qiang , Li Dong Sheng
Published: July 2011

Hollow TiO2 nanospheres have been successfully prepared by templating the polymericmicelles of poly (styrene-b-[3-(methacryloylamino)propyl] trimethylammonium chloride- b-ethylene oxide) (PS-b-PMAPTAC-b-PEO), which shows a core-shell-corona structure in aqueous solutions. It was found that, in such system, the wall thickness of the hollow TiO2 is fine tuned by varying the concentration of the TiO2 precursor.
Effect of Nano-Graphite on Friction Performance of Cu-Based Friction Material
Authors: Du Jian Hua , Li Yuan Yuan , Zheng Xiao Hui
Published: July 2011

The Cu-based friction materials with nano-graphite were prepared through powder metallurgy technology. The microstructure and friction performance were studied through scan electronic microscope (SEM) and friction tester, respectively. The results indicate that coefficient of the Cu-based friction materials with 2 wt% nano-graphite is high and stable. Comparing with the friction materials without n-C, the wear resistance and heat resistance of the friction materials with nano-graphite has been improved by 11 % and 25 %, respectively. The nano-graphite particles will reduce the abrasive wear and enhance the wear resistance of the Cu-based friction materials.
Effect of La on Solute Segregation during Solidification of Al2O3•SiO2f/A356 Alloy Composite
Authors: Liu Zheng , Liu Xiao Mei
Published: July 2011

Al2O3·SiO2f/A356 composites contained La were fabricated by squeeze casting, and effect of La on the solute segregation and microstructure were researched. The results indicate that the microstructure in the composite can be refined by La, which enriches near the interface to be favorable to improve the wettability between the fiber and Al alloy. The phases RE-richening do not formed at the interface. There is no special influence of La on the Mg segregation in the matrix alloy. The distribution of Mg and La in the composite are near the interface.
Effects of Fly Ash Particle Sizes on the Compressive Strength and Fracture Toughness of High Performance Concrete
Authors: Cheng An Shun , Huang Yue Lin , Huang Chung Ho , Yen Tsong
Published: July 2011

The study aims to research the effect of the particle size of fly ash on the compressive strength and fracture toughness of high performance concrete (HPC). In all HPC mixtures, the water-to-binder ratio selected is 0.35; the cement replacement ratios includes 0%, 10% and 20%; the particle sizes of fly ash have three types of passing through sieves No. 175, No. 250 and No. 325. Three-point-bending test was adopted to measure the load-deflection relations and the maximum loads to determine the fracture energy (GF) and the critical stress intensity factor (KSIC). Test results show that adding fly ash in HPC apparently enhances the late age strengths of HPC either for replacement ratio of 10% or 20%, in which the concrete with 10% fly ash shows the higher effect. In addition, the smaller the particle size is the better the late age concrete strength will be. The HPC with the finer fly ash can have higher strength development and the values of GF and KSIC due to the facts of better filling effect and pozzolanic reaction. At late age, the GF and KSIC values of concrete with 10% fly ash are all higher than those with 20% fly ash.
PVDF-HFP/PVC Blend Based Lithium Ion Conducting Polymer Electrolytes
Authors: Basri N.H , Ibrahim S , Mohamed Nor Sabirin
Published: July 2011

Flexible free standing polymer electrolyte films have been successfully prepared using a blend of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and poly(vinyl chloride) (PVC) doped with lithium perchlorate (LiClO4). The conductivity of the film was influenced by salt concentration and the degree of crystallinity. An optimum room temperature conductivity obtained was 2.10 x 10-4 S cm-1 for PVDF-HFP/PVC containing 35 wt.% LiClO4. The temperature-dependent conductivity of the polymer films exhibited VTF-type behaviour.
Experimental Study on Impermeability and Frost Resistance of High Strength Concrete Used in Shaft of Coal Mine
Authors: Hou Jing Feng , Guo Dong Ming , Xu Hui Dong , Yang Zeng Kun
Published: July 2011

This paper presents results of impermeability and frost resistance tests of a series of high strength concrete which will be used in Yuncheng coal mine shaft lining. And the shaft is one of the most difficult to construct using freezing method because of the extreme thick overburden soil. The results show the impermeability and frost resistance of the selected concrete mix proportion options can meet the special requirements of the shaft construction. It’s due to the low water-cement ratio, admixture and water-reducing agent decreases void caused by excess water. And the composite mineral admixture forms bubbles to cut off the tiny water permeable channels in cement stone. Also the filling effect and pozzolanic effect caused by fly ash contribute a lot. The research on high strength concrete used in shaft of coal mine with thick overburden soil is still rare worldwide.
Experimental Research and Finite Element Analysis of Concrete-Filled Steel Box Columns with Longitudinal Stiffeners
Authors: Zhang Jun Guang , Liu Yong Jian , Yang Jian , Xu Kai Lei
Published: July 2011

For further study of mechanical properties of concrete-filled steel box columns (CFSBCs) with longitudinal stiffeners, axially loading tests of CFSBCs with longitudinal stiffeners was conducted to obtain their ultimate bearing capacity and failure modes. The test results were compared with those of hollow steel box columns with longitudinal stiffeners. Cross section of the test specimen was scaled from a chord member of Dongjiang Bridge. The experimental results show that failure mode of CFSBCs with longitudinal stiffeners is local buckling of steel plates, which is different from that of concrete-filled thin wall steel tube columns with longitudinal stiffeners. Although longitudinal stiffeners can prevent global buckling of steel plates, the effect is less obvious than that of concrete-filled thin wall steel tube columns. Meanwhile, three-dimensional finite element models (FEM) of the specimens were modeled using computer program ANSYS to obtain bearing capacities and load-strain curves. The FEM results coincide quite well with the test results. Further, influence of width to thickness ratio on mechanical behavior of CFSBCs was analyzed using FEM.
Industrial Production and Application in LCCs of Bauxite-Based Homogenized Grogs
Authors: An Jian Cheng , Wang Lin Jun , Feng Yun Sheng
Published: July 2011

The Bauxite-based Homogenized Grog (BHG) was industrial producted using bauxite with about 70 wt.% Al2O3 as starting materials and its properties were tested. Through comparing with high-grade bauxite clinker, the applications in LCCs of BHG and bauxite clinker were discussed. The results showed that the BHG with mullite as chief phase, with consistent components and structure and properties using middle or low grade bauxite as starting materials can been prepared industrially by homogenization process, vacuum-extrusion moulding and high-temperature sintering method. It also resulted that the BHG can replace competently high-grade bauxite clinker to apply in LCCs as coarses and the LCCs with BHG as coarses have more outstanding properties.
Behavior of Concrete Permeability Considering ITZ
Authors: Yu Ai Ping , Lu Hai Bo , Zhao Yan Lin , Wei Ke Yu
Published: July 2011

In this paper, concrete was analyzed as a composite consisting of coarse aggregate, mortar matrix and interfacial transition zone (ITZ). Because permeability of each phase are not the same, ITZ will affect the concrete permeability. Effect of ITZ on the concrete permeability was studied by laboratory test and numerical analysis.The diffusion coefficient of ITZ, mortar,and concrete can be caculated by laboratory test. The results indicate that the diffusion coefficient of ITZ is far greater than mortar，which is about 40 times of mortar. The chloride ions diffusion ignoring ITZ and considering ITZ were simulated, the results show that the diffusion coefficient of concrete was bigger when the ITZ was considered, which was closer to the experimental results.
The Effect of Nb2O5 Addition on the Dielectric Properties of BaTiO3-Based Ceramics
Authors: Zhang Yun Xia , Hao Jun Jie , Qi Jun Ting
Published: July 2011

In this paper, the effect of Nb2O5 on the microstructure and dielectric properties of BaTiO3-based ceramics has been investigated. In the study，Nb2O5 is added to the BaTiO3-based ferroelectric material by conventional solid state synthesis. The structure is identified by X-ray diffraction method and SEM is also employed to observe the surface morphologies of the sample. The specimens of the ferroelectric doped with 2wt% Nb2O5 sintered at 1260°C for 1h exhibit attractive properties, its dielectric temperature coefﬁcient is lower than 15% over a wide temperature range from －55 to +180°C.
Investigation of Sulphate Attack on C-S-H Gel
Authors: Feng Xiao Xin , Li Xiu Juan , Wei Qing Min
Published: July 2011

C-S-H gel was prepared by extracting from the hardened cement paste, and was immersed in Na2SO4 solution and MgSO4 solution respectively. The microstructure of the C-S-H gel attacked by sulphate was observed by means of scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction. It is found that C-S-H gel is attacked by both Na2SO4 and MgSO4, and gypsum forms whether in low or high concentration solution of Na2SO4 and MgSO4.
Research on the Failure Feature of AAC Load Bearig Block Wall Based on the Quasi-Static Test
Authors: Yu Jing Hai , Sun Qiong
Published: July 2011

Based on the experimental investigation of quasi-static test of 6 pieces of the AAC block walls, the failure features of the AAC block wall are studied and analyzed, failure features and shear strength of the walls due to different height to width ratio and vertical pressing stress are also studied. The results indicate :1) the failure process and characteristics of the walls were basically the same,firstly produced the Shear inclined cracks in the central of the wall,then formed the main cross inclined crack and some secondary cracks.2)The failure feature belonged to the shear failure, the height to width ratio and vertical pressing stress have great influence on the failure feature of AAC load bearing block wall.
Study on Toughening Cement-Based Composites with CaCO3 Whisker and Fiber
Authors: Cao Ming Li , Yao Hang
Published: July 2011

Low tensile strength and high brittleness are the inherent defects of cement-based composites. So improving the toughness effectively is an urgent need for developing high-performance cement materials. The aim of this study is to study the toughening effect by mixing CaCO3 whiskers and polypropylene fibers in cement mortar. The results showed that CaCO3 whiskers could increase the split tensile strength of cement mortar of 28d age by 26.2% at maximum with the whisker content of 10wt.%; when CaCO3 whiskers content was 10wt.% and polypropylene fibers content was 0.20vol.%, the split tensile strength of cement mortar was increased by 21.1% at 28d age; when the fiber length was 19mm, the composite toughening effect of whiskers and fibers was more effective. The toughening mechanisms of CaCO3 whiskers and polypropylene fibers in cement mortar were also discussed.
Study on the Difference of Amorphous Substances of Coal Ashes
Authors: Wang Bo , Song Yuan Ming
Published: July 2011

There is much difference among the amorphous substances of different coal ashes, the important basis for their utilization. The micromorphology and content of the amorphous substances were measured by scanning electron microscopy (SEM) and chemical method respectively, and the 28d compressive strength ratio was also used to characterize their contribution to the cement-coal ashes system. The results show that the amorphous substances of BFBC/CFBC ashes are irregular and loose textured, which are significantly different from those of PC fly ashes that are spherical and compact. The content and the pozzolanic activity of the amorphous substance of BFBC ashes are greater than that of PC fly ashes.
Morphology and Structure of Aluminum Substituted C-S-H Synthesized by Reaction of Alkali Silicate and Calcium Nitrate Aqueous Solution
Authors: He Yong Jia , Lu Lin Nu , Zhang Jian Ming , Hu Shu Guang
Published: July 2011

Synthetic C–S–H and C-A-S-H samples with different Ca/Si molar ratios (1.0 and 1.5) were prepared by precipitation from solution. The effects of incorporations of aluminum ion into C-S-H gels on their microstructure were studied by applying Fourier Transform Infrared Spectroscopy (FTIR), BET nitrogen adsorption and scanning electron microscopy (SEM). Results show that in FTIR spectra, peaks nearing 970 cm-1 and 450 cm-1 wave number change obviously with the substitution of Al3+into C/S1.0 C-S-H. In BET diagram, it also can be found that the substitution of Al3+into C/S1.0 C-S-H lower the specific surface area. Furthermore, SEM graphs also show that the morphology change in C/S=1.0 C-S-H after the substitution of aluminum ion. However, little difference can be found in FTIR spectra and BET diagrams after Al3+ doped into C/S1.5 C-S-H. So, it can be concluded that the effects of the substitution of aluminum ion on the structure and morphology of C-S-H are affected by Ca/Si molar ratio
Study on Reaction Process of Synthesis of Indole from Aniline and Ethylene Glycol
Authors: Xing Jun De , Liu Zhi
Published: July 2011

The reaction process of synthesis of indole from aniline and ethylene glycol was studied by GC-MS. Based on experimental results, a new reaction process proposed. It was found to be quite complicated with involvement of a few of main phases: condensation, cyclization, elimination and so on, which provides a theoretical guild for the development of used catalysts. It could be presupposed that the yield of synthesis of indole was related to dehydrogenation activity of catalysts.
3D Finite Element Analysis on a 270m Rockfill Dam Based on Duncan-Chang E-B Model
Authors: Sun Da Wei , Zhang Guo Dong , Wang Kang Ping , Yao Hui Qin
Published: July 2011

Since no super high CFRD with dam height more than 233m been ever built in the world, more problems of 270m high CFRD are still to be explored and solved. The 270m extra high Maji CFRD is to be constructed. In order to get stress and deformation characteristic of this dam, 3D finite element analysis was carried out. To make comparison on stress and deformation of Shuibuya dam which has been built, the Duncan-Chang E-B model parameters of Shuibuya dam, which was obtained by large scale tri-axial experiment, was used here to prediction this 270m high dam behavior. According to the calculation results, some beneficial conclusions were obtained and the design scheme of the 270m dam will be optimized.
Strength Test and Forecast of CFRP-Confined Concrete Preloaded under Uniaxial Compressive Force
Authors: Li Su Juan
Published: July 2011

In this paper, preloaded specimen is used and confined by CFRP to act as structural concrete member in service. And the test to examine the behavior of the test piece has been carried on. After this, the strength and its influence factor has been analyzed. Referring the former strength model, the particular factor axial ratio B of the specimen this test has been taken into account.Then refering the existing model, the improvement has been made. And the new strength model for forecast to CFRP confined preloaded concrete is put forward, also it can be used as reference for reinforcing design of engineering.
Correcting Prediction Model of Printing’s Dot Area by the Spectral Reflectance
Authors: Zhao Chen Fei , Han Qing , Wen Xiao Li
Published: July 2011

Yule-Nielsen spectral neugebauer (YNSN) model is widely used in printing for predicting dot area. The model’s accuracy is effected by the paper’s performance, ink kinds, wavelengths, and printing conditions. In the paper, the relation between the solid color patch’s spectral reflectance and the printing’s dark dot area is discussed. By experiments, the solid color patch’s spectral reflectance is adopted as fixed index of YNSN model, which can reduce the deviation of the dark color patch. The research has a certain significance for controlling printing quality and reducing the producing cost.
Applying Research on Microwave Promoting Curdle Technique of High Performance Concrete
Authors: Wang Zheng Jun , Jin Xiao Ou , Sun Dian Min , Zhao Felix
Published: July 2011

In order to estimate late strength of high performance concrete on based of early strength, so which can realize shorting time cycle of proportion design and proportion verification of high performance concrete, and can realize controlling node of key working procedure for the structure of high performance concrete in the course of construction. The paper obtained early strength and established relationship between early compressive strength and late compressive strength of high performance concrete on based of method of microwave promoting curdle. Getting early strength can realize to predict compressive strength through applying in the method of microwave promoting curdle.
Experimental Study on Compound Binding Material of Alkali Activated Metakaolin and Ground Granulated Blast Furnace Slag
Authors: He Yong Jia , Lu Lin Nu , Hu Shu Guang
Published: July 2011

Compound binding material was prepared by the alkali activation of metakaolin and ground granulated blast furnace slag. Hydration product components, microstructure and mechanical properties of the hardened paste were investigated by IR, XRD, SEM, MIP, and compressive strength measurement. Results indicated that hydration products included C-S-H and geopolymer, and both of them were amorphous although there were differences in their structure and morphology. When the dosage of slag was less than 50%, the compressive strength of hardened paste increased as the dosage increased, which was mainly because C-S-H produced by the reaction of GGBFS and alkali filled void in geopolymer phase, and part of unreacted slag particles acting as microaggregate to prevent from extension of microcrack in the hardened paste, so the porosity of hardened paste decreased and compressive strength increased.
Novel Low-Temperature Electrolyte for Li-Ion Battery
Authors: Ren Yong Huan , Yang Chun Wei , Wu Bo Rong , Zhang Cun Zhong , Chen Shi , Wu Feng
Published: July 2011

In order to overcome the limitation of Li-ion batteries at low temperature, series of electrolytes are prepared. Specially，FEC is chose to work as electrolyte solvent to enhance its poor performance. Electrolytes are composed of EC, PC, EMC and FEC, while VC is added as additive. Electrolytes with different ratio are examined, then the electrolyte with the best conductivity is studied in detail. Its characters are evaluated by CV, EIS and charge/discharge tests et al. The discharge curves of LiCo1/3Ni1/3Mn1/3O2/Li show that battery with this FEC-based electrolyte at 233K could yield 51% of room temperature capacity. Most obviously, MCMB/Li half cell with this electrolyte could fill 91% of its normal capacity at 233K while batteries barely charge any with traditional electrolyte（LiPF6/EC+DMC(1:1 in volume)）. This nice charge behavior won’t emerge unless the conductivity could basically meet the demand at 233K. The property of FEC-based electrolyte outweighs commercialized electrolyte as this article confirms.
The Electrochemical Characterization of Electrochemically Synthesized MnO2-Based Mixed Oxides for Supercapacitor Applications
Authors: Ye Zhi Guo , Zhou Xian Liang , Meng Hui Min , Hua Xiao Zhen , Dong Ying Hu , Zou Ai Hua
Published: July 2011

Nanostructured elements, including: manganese-molybdenum (Mn-Mo) oxide, manganese-molybdenum-tungsten (Mn-Mo-W) oxide, manganese-molybdenum-iron (Mn-Mo-Fe) oxide, manganese-molybdenum-cobalt (Mn-Mo-Co) oxide, manganese-vanadium-tungsten (Mn-V-W) oxide, manganese-vanadium-iron (Mn-V-Fe) oxide and manganese-iron (Mn-Fe) oxide, have been anodically deposited onto titanium substrates by employing an iridium dioxide interlayer (Ti/IrO2 anode). The electrochemical characteristics of the resultant oxide deposits have been investigated by cyclic voltammetry (CV) in an aqueous 0.1 M Na2SO4 solution. The voltammetric behaviors of the oxide deposits observed are significantly influenced by the doped elements. Molybdenum doping is found to be advantageous at improving the capacitance characteristics of anodically deposited manganese oxide. Comparatively, iron and vanadium doping are found to be unfavorable. The structure and crystallinity of these deposits have been identified by X-ray diffraction (XRD). The surface morphologies of these oxides were acquired from field emission scanning electron microscopes (FESEM). The high values of electrical parameters for the doped deposits are attributed to the net-like and sponge-like nanostructure, and low crystallinity of the doped manganese oxides. The deposit of Mn-Mo oxides exhibits an excellent capacitive-like behavior, possessing the maximum specific capacitance of 810 F g-1 at a CV scan rate of 5 mV s-1 in aqueous 0.1 M Na2SO4 solution.
Study on Synthesis and Electrochemical Property of LiMnPO4 by Microwave Method
Authors: Wang Li Zhen , Wang Kun , Zhang Yong , Zhang Lin Sen , Zhang Kai Qing , Han Yan Juan
Published: July 2011

The LiMnPO4 cathode materials for lithium-ion batteries were synthesized by microwave processing combined with precursor synthesized by sol-gel method. The structure, surface morphology and charge-discharge performance of LiMnPO4 were characterized by X-ray diffractometry, scanning electron microscopy and electrochemical measurement respectively, and the effect of pH, microwave power and heating time on the electrochemistry properties were explored. The results show that when the pH value of the solution was kept at 9, pure phase LiMnPO4 cathode material could be synthesized by microwave heating for 20 min under 480W, with a initial discharge capacity of 57.3mAh/g at 0.1C and a stable cycle ability.
Improving the Rate Capability of Unburned Carbon from Oil-Fired Fly Ash as an Anode Material in High-Power Lithium Ion Batteries
Authors: Wu Yu Shiang , Yeh Tzuo Shing , Lee Yuan Haun
Published: July 2011

Unburned carbon is an industrial waste product of oil-fired fly ash. Recycled ground unburned carbon with an average particle size of 5 μm after heat treatment at 2500°C displayed an first coulombic efficiency of approximately 89.8% at a charge and discharge rate of 0.1 C. The discharging capacity of this type of carbon was 293.7 mAhg-1, and its capacity retention was approximately 94.7% after 50 cycles. However, the first coulombic efficiency of ground unburned carbon receiving nitric acid treatment after heat treatment increased to 91.1%, its discharging capacity increased to 318.6 mAhg-1, and its capacity retention increased to 98.5% after 50 cycles. Rate capability tests show that the unburned carbon after heat treatment exhibited a higher capacity in the lower C-rate region (0.2~3 C) at a 0.2 C rate charge and variable C-rates discharge. However, unburned carbon with nitric acid treatment is a suitable material for the higher C-rate region (5~10 C). Unburned carbon after heat treatment exhibited a higher capacity in the lower C-rate region (0.2~0.5 C) at the same C-rate charge and discharge.
Influence of Sintering Atmosphere on the Physical and Electrochemical of LiFePO4/C
Authors: Lin Yan , Wu Jian Bo , Xu Ai Jiao , Xu Jin Yong
Published: July 2011

LiFePO4/C was synthesized from a gel precursor with ferric iron and an organic chelating agent as carbon source. Reductive atmosphere of N2 + H2 with H2 content of 0-20 vol % was used in the sintering process of LiFePO4/C composites. The microstructures of the obtained LiFePO4/C particles were characterized by X-ray diffraction, field emission scanning electron microscopy, element analysis and particle size analysis. The results showed that suitable reductive sintering atmosphere was needed to get pure LiFePO4/C phase, but too strong reducibility led to the formation of iron phosphides, most of which was Fe2P. The amount of Fe2P increased with the increase of H2 content in the sintering atmosphere. The rate capability of LiFePO4/C was improved when the sintering atmosphere became more reductive, while the discharge capacity of 0.1C decreased, which was probably due to the appearance of Fe2P phase.
Solvothermal Synthesis of Pyrite (FeS2)
Authors: Ma Hao , Zou Zheng Guang , Wu Yi , Long Fei , Yu Hui Jiang , Xie Chun Yan
Published: July 2011

Pyrite nano-powder was synthetized in a high-pressure solvothermal process in the ethanediol solvent, with Fe(NO3)3·9H2O and NH2CSNH2 as the raw materials. The sample was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) and the results show that the product has a pure phase in a typical cubic crystal. The effects of temperature, aging time and surfactant on the shape of the crystallites were investigated systematically. The nano-powder synthetized shows itself in various micro-shapes such as granule, globular and flake, with its diameter ranging from hundreds of nanometers to one micrometer.
Properties and Synthesis of Kaolin / Potassium Polyacrylate / Acrylamide Composite Superabsorbent Resin
Authors: Ren Hao , Li Jie , Zhang Yu Fen , Huang Tai Zhong
Published: July 2011

The aqueous solution polymerization methods were used for the synthesis of superabsorbent resin. The effects of different experimental factors on synthetic resin water absorbency were investigated in this paper. The variables examined in this study included monomer concentration, neutralization degree, initiator and crosslinker concentration, reaction temperature and time, etc. The maximum absorbencies of distilled and 0.9% saline water are 919 times and 92 times respectively under optimum condition. Analysis from FTIR and SEM shown the polymer molecules can be firmly fixed with kaolin, the bonding of kaolin and polymer is good in CSR.
Preparation and Biocompatibility of Nano-Hydroxyapatite/β-Sheet Silk Protein Composite
Authors: Yang Hui , Zhang Lu Lu , Wang Chuang
Published: July 2011

To enhance the mechanical strength of hydroxyapatite (HAP), a nano-HAP/β-sheet fibroin (nano-HAP/SF) composite was synthesized by mixing nano-HAP sols with SF sols. A β-sheet structural SF was prepared by a salt-resolving method. The nano-HAP sols was prepared by a co-precipitation method. The phase composition of HAP and nano-HAP/SF composites were investigated by X-ray diffraction and Fourier transform infrared spectroscopy (FTIR). Their morphologies were observed by scanning electron microscopy. The mechanical strength of the nano-HAP/SF composite was measured by a universal material detector. The bioactivity and biocompatibility of the obtained composites were confirmed by tests in simulated body fluid (SBF) and by a culture of rat osteoblasts cell. Results showed that the obtained SF is a typical silk II with β-sheet conformation. The FTIR spectra analysis indicated that the chemical bonds were formed between SF and HAP in the nano-HAP/SF. The result of SBF test demonstrated that the needle-like crystals of HAP were formed on the surface of the sample and the result of cell culture showed that the rat osteoblasts grown and reproduced well on the surface of the composite. The compression strength of SP/HAP reached 63 MPa.
Theoretical Study on Crystal Structure and Hydrogen Storage Properties of Sodium Hydride
Authors: Lei Jie Hong , Yan Zheng Zhou , Duan Hao , Zhang Yun Juan
Published: July 2011

In this paper, the crystal structure and hydrogen storage properties of the sodium hydride at different x value (NaHxD1-x, NaHxT1-x, NaDxT1-x; x=0, 0.25, 0.5, 0.75, 1.0) are investigated by using density functional theory within the generalized gradient approximation (GGA). The calculated results of NaH (D, T) are in good agreement with the other theoretical results. It has been found that, densities decreased with the increase of x value, while lattice parameters stay constant. The hydrogen storage properties of sodium hydride were predicted. The density-value x (ρ-x) relationship, the variations of the hydrogen storage properties with different crystal structure were obtained systematically.
Effect of Foaming Agent AC on the Properties of A12O3-SiC-C Trough Castables
Authors: Huang Jian Kun , Tu Jun Bo , Wei Jun Cong , Gao Chun Hui , Wang Yi Long
Published: July 2011

The effects of foaming agent AC on anti-explosion performance and physical properties of castables for trough of blast furnace were investigated by using brown corundom, silicon carbide, Secar 71 cement and microsilica as the main starting materials. The results showed that the incorporation of foaming agent AC decreased the temperature and the maximum rate at which water escaped from the castables, and hence improved the anti-explosion properties of the castables. The reason was that foaming agent AC would decompose and release gases during heating and generate superfine open pores at lower temperature favoring the expulsion of water. With increasing the content of foaming agent AC, the apparent porosity increased while the bulk density and modulus of rupture as well as crushing strength decreased. The developed castables were successfully applied to factory experiment, indicating excellent anti-explosion performance.
Hydrothermal Synthesis of GdVO4:Eu 3+ Phosphors by Optimizing its Preparation Conditions
Authors: Yan Ying Lin , Xu Yun Hua , Wang Juan , Luan Zhen Xing
Published: July 2011

Eu3+ -doped GdVO4 powders have been synthesized via a novel hydrothermal method using commercially available Gd2O3, NH4VO3 and Eu2O3 as the reacting precursors. The influences of several important parameters, such as hydrothermal temperature, reaction time and pH value, of the experiment were investigated. The obtained samples were characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), and photo-luminescence spectroscopy (PL). The experimental results showed that the optimal reaction condition was processed at 180°C for 12 h and adjusted pH value to 4. The morphology of products was uniform pseudo-octahedron with a little conglomeration. All the phosphors exhibit the characteristic dominant red emission of Eu3+ ion (5D0 → 7F2) at 618nm.
Characterization of Aminoalky Cellulose Adsorbent
Authors: Zhu Heng , Lin Xiao Yan , Luo Xue Gang , Li Ying
Published: July 2011

Aminoalky cellulose is a white, solid cellulose derivative, which could be used adsorbent in order to remove TNT, heavy metal and dyes due to the large of amino. In this paper, the preparation of aminoalky cellulose was reported, and the aminoalky cellulose was characterized by FT-IR, XRD, SEM and TG. The results showed that aminoalky cellulose was successfully prepared, an amorphous phase and a crystalline phase are included in the AmAC, and the decomposition temperature of AmAC was 288.23°C. Some surface properties of AmAC was measured, and the mean pore diameter and total pore volume of the AmAC is about 260.409 Å and 0.363827 cm3 g-1, respectively.
PtRu-SiO2-TiO2/C Anode Electrocatalyst for Direct Methanol Fuel Cell
Authors: Ju Jian Feng , Wu Dong Hui , Shi Yu Jun
Published: July 2011

The PtRu-SiO2-TiO2/C anode electrocatalyst ( loading 10wt% PtRu ) of direct methanol fuel cell is prepared by the surface reductive deposition method, using Vulcan XC-72 carbon black coated with nanometer SiO2-TiO2 (SiO2-TiO2/C) as the isotopic carrier. The surface characteristics of nanometer SiO2-TiO2 is studied through nitrogen adsorption, which shows that it is of porous structure together with large surface area, that is benefit to enhance the activity of SiO2-TiO2 and the dispersion of PtRu nanoparticle on the carrier of SiO2-TiO2/C. X-ray diffraction( XRD ) and transmission electron microscopy( TEM ) are used to characterize the catalyst. The PtRu nanoparticle homodisperse in SiO2-TiO2/C carrier with diameter around 2.4 nm. Cyclic voltammograms and chronoamperograms are conducted to compare the electrochemical methanol oxidation activity of the PtRu-SiO2-TiO2/C catalyst with the commercial PuRu/C catalyst ( 20 wt% of PtRu ). The results show that PtRu-SiO2-TiO2/C has higher catalytic activity and anti-poisoning ability for methanol oxidation, the addition of porous SiO2-TiO2 can replace the PtRu to some extent, comparing with the commercial PuRu/C catalyst, not only the loading of PtRu has been cut down 50%, but also the electro-oxidizing activity of methanol improved. The electro-oxidizing mechanism is basically analyzed.
High Transparency and Thermal Stability of Alicyclic Polyimide with Crosslinking Structure by Triallylamine
Authors: Chen Juo Chen , Tseng Wen Yen , Tseng I Hsiang , Tsai Mei Hui
Published: July 2011

Colorless alicyclic polyimides (ALPIs) were synthesized from an alicyclic dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (BCDA) and an aromatic diamine, 3,4'-oxydianiline (3,4'-ODA). For comparison, a series of crosslinkable ALPI membranes with different content of crosslinkable reagents were prepared. The crosslinkable PI reacts with the crosslinkers and forms covalent bond to create the crosslink structure between PI backbones by free radical reaction. Almost of the crosslinkable PIs exhibit excellent dimensional stability and higher transparency because of the crosslink structure and non-conjugate alicyclic chain. All of the crosslink ALPIs could be coated into flexible and tough films. They had a UV-Vis cut-off at 297 nm and a transmittance of higher than 80% in near ultraviolet region. These PIs show low coefficient of thermal expansion ranging from 57.36 to 47.53 ppm/°C, the glass transition temperature in the range of 336.2-333.0 °C, the decomposition temperature in the range of 433.7-440.0 °C. The crosslinkable ALPIs show excellent optical properties with the excited wavelength ranging from 340 to 328 nm and stronger emission intensity than linear PI, the haze lower than 0.7, the refractive index about 1.6 and the abbe numbers over 165.
Carbon Nanotubes on the Performance of Al3+ Doped α-Nickel Hydroxide
Authors: Liu Chang Jiu , Li Pei Pei , Huang Liang Hua
Published: July 2011

The effect of carbon nanotubes (CNTs) addition on the electrochemical performance of Al doped α-nickel hydroxide is studied. The microstructure and electrochemical performance of the prepared samples are characterized by XRD,SEM, electrochemical impedance spectroscopy, charge-discharge at different rate, and Charge-discharge cycling stability tests. The results show that the addition of CNTs could decrease the electrochemical reaction impedance dramatically, increase the specific discharge capacity at higher rate, and improve the Charge-discharge cycling stability reversibility.
Synthesis of Cathode Materials Fe-Doped NiS2 by Mechanical Alloying for Li/NiS2 Cells
Authors: Liu Xiao Jing , Park Dong Wook , Xu Zhe Zhu , Kang Sang Dae , Ahn In Shup , Ahn Hyo Jun
Published: July 2011

In order to synthesize the fine compound iron-doped nickel disulfide (NiS2) with environmentally friendly nickel, sulfur and iron powders, mechanical alloying (MA) was conducted for 8 hrs with SPEX Mill at a speed of 1000 rpm. In this process, stearic acid was added as a kind of process control agents (PCAs) to prevent the excessive cold welding. Meanwhile, for the purpose of getting nanocrystalline of Fe-doped NiS2 powder particles to improve the contact areas between the active materials, the wet milling process was also done for 30 hrs with normal hexane (C6H14) as a solvent PCA. The prepared powders were characterized by FE-SEM, XRD, EPMA, EDS and TEM. Finally, the charge/discharge properties of Li/Fe-doped NiS2 cells were investigated at room temperature by employing 1 M LiCF3SO3 (lithium trifluoromethanesulfonate) dissolved in TEGDME (tetraethylene glycol dimethylether) as the electrolyte. The initial discharge capacity of Li/Fe-doped NiS2 cell using wet milled powders as the cathode material is 792 mAh/g, which may indicate its high energy density and good future as cathode materials for lithium-ion batteries.
Effects of Titania and Silica Nanoparticle on Paint Film
Authors: Teng Tun Chien , Teng Tun Ping , Pan Shu I
Published: July 2011

In this paper, a two-step method is adopted to add titania (TiO2) nanoparticle and silica (SiO2) nanoparticle in commercial water-based paint to form the nano-paint with various concentrations of the added nanoparticle. The paint is sprayed onto the steel plate to form a coated film as the test samples. The experiments are implemented in order to investigate the effects of the nanoparticle on reflection spectra, surface hydrophobic and heat transfer performance of the coated film. The experimental results show that adding the nanoparticle indeed has positive effects on the above properties. This research contributes to the development of the functional paint for various applications.
Spin Precession from Hyperfine Interaction on Magnetoresistance in Nonmagnetic Organic Semiconductors
Authors: Zhao Jun Qing , Zhang Tian You , Jia Zhen Feng , Ding Meng , Zhang Ning Yu , Wang Feng Xiang , Ji Yan Ju , Pang Yan Tao , Chen Ying , Fu Gang
Published: July 2011

We investigate the effect of hyperfine interaction on magnetoresistance in nonmagenetic organic semiconductors. A Lorentz-type magnetoresistance is obtained from hyperfine interaction-dependent spin precession picture. The magnetoresistance depends on initial spin orientation of electron to hole in electron-hole pairs. Increasing hyperfine interaction slows down change of the magnetoresistance with magnetic field. The field dependence, the sign and saturation value of the magnetoresistances are composite effects of recombination and dissociation rate constants of singlet and triplet electron-hole pairs.
Liquid-Phase Synthesis of NiO-Loaded Ag Nanoparticles and Enhanced Photo-Degradation Performance
Authors: Tian Zong Min , Xiang Xu , Li Zhi Wei , Li Feng
Published: July 2011

We have synthesized layered Ni(OH)2 via a facile liquid-phase precipitation method. NiO with a micro/nano-structure was obtained via calcining Ni(OH)2 precursor at 350°C. The as-prepared NiO was utilized as a support to load Ag nanocrystals. SEM and TEM observations showed that Ag nanoparticles were homogeneously distributed onto NiO support and the Ag nanoparticles have sizes of 4-5 nm. The photocatalytic activity of NiO-loaded Ag was investigated by the photodegradation of methylene blue (MB) under the irradiation of visible light. The results suggest that the loading of Ag nanoparticles can enhance the photo-degradation performance of pristine NiO.
Effect of Growth Temperature on the Indium Incorporation in InGaN Epitaxial Films
Authors: Chang P. C , Yu C. L , Jahn Y. W , Chang S. J , Lee K. H
Published: July 2011

InxGa1-xN epilayers have been grown by metalorganic chemical vapor deposition (MOCVD) at different temperatures between 740°C to 830°C. The thickness of InGaN film is 50nm for all samples. The incorporation of indium is found to increase with decreasing grown temperature. The optical properties and film quality of the samples have been investigated by photoluminescence (PL) system and X-ray diffraction (XRD). The Full Width at Half Maximum (FWHM) of PL and XRD decreases with increasing the grown temperature. We also found that the peak emission of PL shifts with changing the grown temperature. The effect of temperature on the film properties was determined. This understanding will lead to better quality control of the optoelectronic devices.
A New Method for Preparation and Luminescence of YBO3 :Eu3+ Phosphor
Authors: Jia Lin Yan , Shao Zhong Bao , Tian Yan Wen
Published: July 2011

The pure phase red phosphor yttrium borate doped with Eu3+ was prepared by a new solid state reaction named high temperature ball milling method. The phosphor was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and luminescence spectra. The results show that the single phase YBO3:Eu3+ phosphor was obtained at 600°C, which is obviously decreased in contrast to conventional solid state reaction method. The particles are approximately nanometer size with narrow distribution range and spherical morphology. In emission spectra, the strongest peak at 597nm is due to the transition 5D0→7F1 of Eu3+ ions under 394nm monitoring wavelength. The luminescent properties of YBO3:Eu3+ phosphor with 25 mol% doping concentration of Eu3+ is optimal.
Structural Stability Analyses of Composite Laminate Wind Turbine
Authors: Cheng Tai Hong , Kim Ill Soo , Park Soon Young , Li Zhen Zhe , Shen Yun De
Published: July 2011

The paper describes a structural stability analysis of fiber reinforced 10kW composite laminate wind turbine blades by using finite element method. The E-glass/epoxy orthotropic materials DB300、DBL850、L900 were employed for construction of a composite laminate shell structure. The composite laminate sheel structures were constructed by two types of lamination method. The rotating effect of wind blade was considered using the linear and the nonlinear static analysis. The results of the nonlinear analysis of displacement and stress show much lower than the linear analysis, because of the geometry nonlinear effect. From the contours of stress and displacement, the maximum stress appeared at the root of the blade, and maximum deformation occurred at the tip of the blade. Finally, the modal properties of the wind blade was investigated, including the natural frequency, modeshaps, and the centrifugal effect.