bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Blending Modification on Tensile Performance of CPE/PVC
Authors: Xie Xiao Ling , Li Wen Hai , Wei Ying Hui
Published: July 2011

The samples were modified by using chlorinated polyethylene (CPE) to increase the toughness and using dioctyl phthalate (DOP) to increase the plasticity. The tensile strength and breaking elongation of the samples were studied by changing the chlorinated polyethylene (CPE) and dioctyl phthalate (DOP) contents and the hot-pressing temperature. It was shown by the test results that, with the increase of chlorinated polyethylene (CPE) and dioctyl phthalate (DOP) contents, the tensile strength of the samples was decreased while the breaking elongation was increased. By increasing the hot-pressing temperature, the blending effect between polyvinyl chloride (PVC) and chlorinated polyethylene (CPE) as well as the mechanical performance of the samples were increased, however, over-high hot-pressing temperature would result in plasticizer precipitation.
Preparation and Characterization of Polylactic Acid/Acetate Starch Blends with Tetrabutyl Titanate
Authors: Chen Jin Zhou , Gao Zhen , Xie Peng Ping , Guo Kai , Niu Ming Jun , Li Xin Fa
Published: July 2011

In order to reduce the cost of the polylactic acid (PLLA) material and to improve its flexibility to expand the application of PLA-based plastic, a series of PLLA/SA blends with tetrabutyl titanate (Ti(OBu)4) used as compatibilizer were prepared in the presence of 10% triethyl citrate (TEC) as plasticizer. It was investigated the effect of the compatibilizer and its content on the mechanical properties, structure and morphologies, heat-resistant performance, melt flow rate, and water-resistant performance and other implications of blends. The results showed that: adding the compatibilizer Ti(OBu)4 could significantly improve the compatibility of PLLA and SA, the mechanical properties and thermal stability of the blends were increased, while melt flow rate and water absorption were decreased. When the content of compatibilizer Ti(OBu)4 was 8 wt%, PLA/SA blends(75/25 wt%) had the best overall performance.
Preparation of Chitosan - Hydroxyapatite Nanocomposites
Authors: Zhang Jing Xian , Jiang Dong Liang , Lin Qing Ling , Chen Zhong Ming , Huang Zheng Ren
Published: July 2011

Chitosan/Hydroxyapatite composites with a homogeneous nanostructure have been prepared by a co-precipitation method. Initially, a chitosan solution was prepared and mixed with the (NH4)2HPO4 solution. After homogenizing, the obtained chitosan/ (NH4)2HPO4 solution was gradually dropped into the Ca (NO3)2.4H2O solution under stirring. The solution pH was adjusted to 9 using NH3.H2O. The precipitate was compressed into a cylindrical form followed by post treatment. The microstructure, phase composition and mechanical properties of the resulting chitosan-HAp composites were characterized. In the presence of chitosan, HAp crystallites were found to be well aligned along the c-axes in the respective aggregates. Fourier transform infrared spectrometer results indicated that an intermolecular bridging complexes might have been developed between the chitosan and HAp. The compact composites obtained were mechanically flexible, the highest strength was found to be 38.4 MPa for chitosan/HAp samples with a 20 wt% of chitosan.
Preparation and Characterization of A Metal-Based Al/Al2O3 Gradient Coating
Authors: Li Su Ping , Feng Jian Qiu , Jia Xiao Lin , Liu Bao Lan
Published: July 2011

An Al/Al2O3 gradient coating applied on a heat-resistant stainless steel was prepared through a slurry process by using aluminum and γ-Al2O3 powders as the transition filler material, alpha alumina as the surface coating material, aluminum dihydrogen phosphate as the binder, and sodium molybdate as the corrosion inhibitor. The effects of heat treatment temperature, adhesive/filler ratio and γ-Al2O3 content on the bonding strength, microhardness and thermal shock resistance were investigated. The crystal phase and microstructure were characterized by XRD and SEM. The results indicated that the composition of the coating changed continuously from surface to coating-substrate interface. The coating could offer high bonding strength and good thermal shock resistance when heat treated at 700°C.
Mechanical Properties and Ordered Structure of Bacterial Poly(3-Hydroxybutyrate-Co-3-Hydroxyhexanoate) Fibers Stretched after Isothermal Crystallization near Tg
Authors: Ding Chang Kun , Cheng Bo Wen , Wu Qiong
Published: July 2011

Biodegradable fibers of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) were prepared by melt spinning, followed by one-step-drawing with small crystal nuclei grown after isothermal crystallization near the glass transition temperature (Tg) and annealing at room temperature under tension. This new drawing technique is a very attractive method for obtaining flexible fibers from low-molecular-weight biopolyesters produced by recombinant bacteria. The ordered structure of PHBHHx fibers was investigated by tensile measurement, scanning electron microscopy, and wide-angle X-ray diffraction (WAXD). The tensile strength of 10 times one-step-drawn fiber after isothermal crystallization increased to 100 MPa. The WAXD profiles of PHBHHx fibers showed sharp reflections corresponding to highly oriented α-form (21 helix conformation) crystal.
Effects of Microcrystalline Cellulose on the Thermal Properties of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)
Authors: Zhou Zhe , Yu Hou Yong , Zhu Mei Fang , Qin Zong Yi
Published: July 2011

The composites of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with different microcrystalline cellulose (MCC) contents were prepared by a solvent casting method. The effects of MCC on the thermal properties of PHBV were studied by TGA and DSC. The DSC results showed that the melt crystallization temperature of the PHBV/MCC increased from 41.9 °C for PHBV to 59.8 °C for the composites containing 20 wt. % MCC, which indicated that the crystallization of PHBV became easier with the addition of MCC. It also illustrated that the MCC could be used as an effective nucleation agent for the crystallization of PHBV. Moreover, it was found that the thermal stability of the PHBV/MCC composites increased compared with the neat PHBV.
Synthesis of a Glycodendrimer with Five Repeating Mannoside Units
Authors: Wang Chao
Published: July 2011

The synthesis of a glycodendrimer by incorporating repetitive mannoside units onto a glucoside core was completed in order to prepare a multivalent probe to study fundamental carbohydrate-protein interactions.
Flame Retardance and Thermal Decomposition of EVA Composites Containing Melamine Phosphate and Dipentaerythritol
Authors: Wang Zheng Zhou , Liu Lin , Jie Gan Xin , Jiang Ping Kai
Published: July 2011

Flame retarded ethylene-vinyl acetate copolymer (EVA) was prepared in a melt process containing melamine phosphate (MP), or MP in combination with dipentaerythritol (DPER) as flame retardants. The influence of MP and MP/DPER on flame retardant properties of EVA was investigated by limiting oxygen index (LOI) and UL 94 test. Thermal decomposition of the flame retardants and flame retarded EVA composites was studied by the thermogravimetric analysis. The results show that MP used alone in EVA does not exerts good flame retardancy, even at a loading of 50wt%. It is found that the flame retardant properties of the EVA/MP/DPER composites is greatly improved when a suitable amount of MP substituted by DPER. Moreover, mechanical properties of the EVA composites were studied.
The Synthesis and Characterization of Thiophene Derivative Polymers
Authors: Chen Wei Xing , Zhang Su Yan , Ma Ai Jie , Wang Qi Guan
Published: July 2011

Thiophene derivative polymer is an important kind of conductive polymers. They often have good electrochemical activity, environment stability and ease of processing. Here, 3-bromothiophene and 3-thiophenezoic acid as monomers, using chemical oxidation approach, the poly (3-thiophenezoic acid) (PTPA), the copolymer of 3-bromine thiophene (BTP) and 3-thiophenezoic acid (TPA) are synthesized in the media of chloroform or methanol. The structures of both polymers are characterized with FT IR, NMR and UV-vis. The results showed that the reactivity of TPA can be improved after alkalizing. The copolymer has strong absorption in the UV region. Its absorption band and intensity are higher than that of PTPA.
Static and Dynamic Mechanical Properties of Chlorobutyl Rubber Composites with Variable Sulfur/Accelerator Ratio
Authors: Wang Yan Bing , Yan Hao , Huang Zhi Xiong
Published: July 2011

The Composite based on CIIR and variable sulfur/accelerator ratio were prepared by compounding and vulcanizing process. Tensile properties and dynamic mechanical properties of CIIR were studied. The results indicate that tensile strength and loss factor are influenced by sulfur/ accelerator ratio. Tensile strength and modulus are improved with increasing sulfur/accelerator ratio while loss factor decrease with increasing sulfur/ accelerator ratio.
Induced Amorphization in Pyrographite by Radiation Using High Voltage Transmission Electron Microscope
Authors: Tamayo Meza Pedro Alejandro , Schabes Retchkiman Pablo , Flores Herrera Luis Armando , Yermishkin Viacheslav A. , Ordáz Yañez Carlos F. , Sierra Hammurabi
Published: July 2011

A high dose of electron irradiation generates amorphous zones with critical vacancy concentrations in the pyrographite. The degree of disorder “” of amorphization of Graphite, natural graphite, pyrographite and polycrystal pyrographite are analyzed as a function of time “t”, and the amorphization kinetics under different voltages inside the HVTEM.
Factors Influencing Dye Colors
Authors: Fang Hua , Li Lu Hai , Li Wen Bo , Leng Xian , Hu Xu Wei , Li Wei Wei
Published: July 2011

In order to anticipate the color of dye ink more accurately, WENZHOU Mernuo Red-10 as an example, who was dissolved in different polarity solvent by magnetic stirring and ultrasonic agitation, the influence for properties of solvent on color of dye was researched with the coating method through contrasting sample papers. The influence for pH values of the solution and adding water to Red-10 solution on color of dye were also researched. It's shown that with the increased polarity of the solution,the absorption wavelength of Red-10 reduced gradually,light shade effect was caused. For the same solvent,with the pH values of the solvent increased,the absorption wavelength of Red-10 reduced gradually,light shade effect was caused.And all the factors affect the L,a,b values of the Red-10 dye's samples.
Study on the Chemical Constituents of Apocynum venetum Bark
Authors: Li Ming Hua , Han Guang Ting , Chen Hao , Yu Jian Yong , Zhang Yuan Ming
Published: July 2011

The alcoholic extract of the Apocynum venentum (AV)bark were purified by silica gel column chromatography. The isolated chemical constituents were identified by MS, NMR, IR spectra. The main chemicals isolated from AV bark were quercetin (1), kaempferol (2), isoquercitrin (3), luteolin (4), hyperoside(5), 7-hydroxy-6-methoxy-2H-1-benzopyran-2-one (6), b-sitosterol (7), stigmasterol (8), 3, 4-dihydroxy-benzoic acid methyl ester (9), 3, 5-dihydroxybenzaldehyde (10) and 3, 4-dihydroxy-benzoic acid (11). The compounds (1)～(6) and (8)～(11) were obtained from AV bark for the first time.
Characteristics of Calcium Carbonate Crystal Structure and Size Distribution in Solution under the Electromagnetic Field
Authors: Xing Xiao Kai , Sun Rui Yan , Wang Shi Gang
Published: July 2011

Various non-chemical water treatment methods have been utilized to solve fouling problems. All of these methods have never been scientifically proven to be a valid tool for controlling scales, and one of reasons could be the lack of understanding of the operational principle and treatment mechanisms. The present study focuses on characteristics of calcium carbonate crystal size distribution in solution and crystal structure on the surface under the electromagnetic field in order to comprehend the mechanisms of the Electromagnetic treatment device (ETD). An electromagnetic treatment setup was built for treating scaling water, and a series of fouling tests were carried out with and without ETD, analyzing the particles size distribution in solution by Dynamics Light Scattering (DLS) technology and making Scanning Electron Microscope (SEM) photos. The main results were as follows：The number of precipitate nucleation in solution was few and the particle growth was slow without ETD. In opposition to the case untreated, a rapid particle growth was observed and the number of nucleation was expected to be more, due to the ETD effectively increasing the ions and crystals collision frequency and effectiveness by utilizing the induced electric field. It was implied that the particle growth was promoted mainly by coagulation process but not nucleation growth in all the experimental temperature range. In the high temperature, the crystal phase of calcium carbonate could be changed from aragonite type without ETD to calcite with ETD. In the lower temperature, all the precipitated crystals in solution were calcite and there were little differences between with ETD and without ETD.
Synthesis and Photoluminescence Properties of Hierarchical Bis(8-Hydroxyquinoline) Nickel Flower-Like Structure
Authors: Zhang Jun Hao , Wang Jiao Long , Wang Hong Liang , Jia Liang , Qu Zhao Kun , Kong Qing Hong
Published: July 2011

Hierarchical bis(8-hydroxyquinoline) nickel(NiQ2) complex has been synthesized with a facile method in a mixed solvent system at 120 °C for 12 h. The molecular formula of the products is speculated by the C, H and N element analysis and thermal gravimetric analysis, and Fourier-transformation infrared spectroscopy was also utilized to measure its structure, which further confirm the molecular formula of the products. The observation of field emission scanning electron microscopy shows that the morphology of bis(8-hydroxyquinoline) nickel complex is flower-like structure. According to the result, it is found that the photoluminescence of bis(8-hydroxyquinoline) nickel complex is stronger than that of 8-hydroxyquinoline, which indicate that inorganic elements played key roles in their luminescence properties.
Analysis of Recovery Current Related to Core Material and Structure of DC Power Supply in High Voltage Active Electronic Current Transformer
Authors: Wang Hai Ming , Reed Gregory , Jones Alex K.
Published: July 2011

The recovery current is an important parameter that influences the performance of the DC power supply based on the power CT in a high voltage active electronic current transformer. It is closely related to the saturation state of the core of the transformer, which harvests energy from the magnetic field generated by the current through the high voltage power line. The recovery current of three types of core material are systematically discussed in terms of their characteristics, which are the Silicon Steel, the Nanocrystalline Alloy, and the Fe-based Amorphous. The closed core of the Nanocrystalline Alloy and Fe-based Amorphous has the feature of low recovery current. Both of them can carry out a lower recovery current within 0.5A in the DC power supply; The gapped core of the Silicon Steel is able to work at the highest recovery current among the three types of cores in the same dimension, which benefits the higher input current of the DC power supply, beyond 2000A. Resultant data of analysis provides a prospective reference for design of the DC power supply with a wide range of input current by application of the combined cores.
Preparation and Corrosion Resistance of Electroless Plating of Ni-Cr-P/Ni-P Composite Coating on Sintered Nd-Fe-B Permanent Magnet
Authors: Wu Ming Ming , Lou Bai Yang
Published: July 2011

This paper introduces electroless plating Ni-Cr-P/Ni-P composite coating technologies and techniques on the Nd-Fe-B permanent magnet surface. It has got a Ni-Cr-P/Ni-P composite coating successfully on the Nd-Fe-B substrate surface through rational processing plan. The coating surfaces are bright and have low Porosity, good binding between the electroless plating and Nd-Fe-B matrix. The experimental results show that the composite coating prepared by Ni-Cr-P electroless plating (15min) and Ni-P acidic electroless plating (45min) has amorphous structure, simple process and better anticorrosion property in both alkaline and acidic medium.
Microstructure, Magnetic and Optical Properties of Metal/ Semiconductor Magnetic Granular Film
Authors: Huang Bao Xin
Published: July 2011

Fe/In2O3 magnetic granular films have been prepared by rf sputtering method. The results reveal that the nanometersized Fe particles uniformly dispersed in the amorphous matrix In2O3 for the as-deposited samples. At room temperature, the Fe0.35/(In2O3)0.65 film shows a superparamagnetic behavior. The average diameter of particles (d = 5 nm) estimated from the fitting values of the saturation magnetization of Fe particles MFe and magnetic moment mis fitted well with that observed by TEM. The spectra analyses indicate that the indirect photon transitions of granular Fex/ (In2O3)1-x films substitute for the direct photon transition of In2O3 film in the absorption process. The band gaps of magnetic granular films decrease monotonously with the increase of volume fraction of Fe particles in the magnetic granular films, and the tail width of localized states becomes wider in concentration range of Fe studied.
Effect of Alkali Hydrogen Peroxide Pre-Extraction on APMP Pulping Process of Pink Sheets Bamboo
Authors: Song Xue Ping , Meng Xue Mei , Ou You Xi , He Hui , Lin Ji Zhen , Wang Shuang Fei
Published: July 2011

In this paper, the technique of alkali hydrogen peroxide extracting hemi-cellulose and the effects of pre-extraction on APMP pulping process of the Pink Sheets bamboo are investigated. The results show that the yields of pentosan and bamboo chip are optimal under the conditions of the dosage of hydrogen peroxide 1.5%, the reaction temperature 90°C, liquid ratio 1:8, holding time 4h. After pre-extracting the tensile index and folding strength decline, and the burst index is kept and the tear index increases slightly. But there is little loss to the brightness of APMP, and the refining energy is reduced largely after pre-extracted.
Bifunctional Fe3O4@SiO2@Eu-Polyoxometalates Nanoparticles and Study on their Magnetism and Luminescence
Authors: Zhang Hong Yan , Wang Jun , Fan Shao Hua
Published: July 2011

In this paper, we report the synthesis of the bifunctional Fe3O4@SiO2@Eu-polyoxometalates particles. The magnetite nanoparticles (Fe3O4) homogeneously coated with silica spheres prepared with the Stöber method. The so-obtained Fe3O4@SiO2 core/shell particles were modified by 3-aminopropyltriethoxysilane and finally grafted with the luminescent Europium -polyoxometalates. The core-shell particles were characterized by scanning electron microscopy, transmission electron microscopy, FT-IR, UV, magnetism and luminescence spectroscopy. The results indicated that the core-shell particles show both interesting luminescence and magnetic properties.
Study on the Electro-Optcial Properties of GH LCD
Authors: Zhang Rui Li , Li Guo Ying , Huang Zi Qiang
Published: July 2011

It’s the first time to have a research on the electro-optical properties of GH-LCD more systemic. At the beginning of the paper, the electro-optical characteristic curves have been analyzed for the different cell thickness, such as 6μm, 9μm and 11μm. The result shows that GH-LCD and TN-LCD have the similar electro-optical property, and the dichroic dye contained in the GH-LCD is the key to control the color switch. Viewing angle property in the range of ±30° was tested in the horizontal direction. The visibility of the left angle is wider than the right angel, and the contrast of the left angle is better. Then, the case that the orthogonal orientation of liquid crystal cell thickness is 11μm will be discussed in the paper. When the cell thickness is 11μm and there’s no polarizer, the electro-optical characteristic curves was measured and compared. Research shows that the polarizer can filter out polarized light to enhance contrast. The electro-optical curve with polarizer has been measured when a certain percentage of the chiral agent was added into guest-host liquid crystal (negative). When the voltage gets to 15V, there is a state of phase change that the display color immediately turns from black to milky white. Compared with liquid crystal without being added chiral material, the contrast reduces obviously, but response time becomes lower than before. The research on electro-optical properties maybe makes the GH-LCD to be applied to the naked eye 3D display.
Microstructure of In Situ Al3Ti0.4Zr0.6p/Al Fabricated with Electromagnetic Field
Authors: Li Gui Rong , Zhang Xun Yin , Zhao Yi Nan , Yuan Fei , Zhang Ting Wang , Wang Hong Ming , Zhao Yu Tao
Published: July 2011

The K2TiF6 ,K2ZrF6 powder and aluminum were selected as the raw materials to in situ synthesize the particulates reinforced aluminum matrix composites. During the fabrication process the electromagnetic field was imposed. The atomic ratio of Al/Ti/Zr in the particulates is determined as 3/0.4/0.6. The Al3Ti0.4Zr0.6 is a new kind of intermetallic compound, some properties of which fall in between those of Al3Ti and Al3Zr. Electromagnetic field plays an important part in fining particles and promoting their uniform distribution. When the electromagnetic induced intensity is 0.05T the particles have 0.5-2μm average size and uniform distribution in matrix. The crystal grains of matrix resemble equiaxed ones. The average size of grains are nearly 100μm, 50μm and 25μm when the electromagnetic induced intensities are 0, 0.025T and 0.05T seperately.
Preparation of Polymethyl Methacrylate-NaYF4:Yb:Er Composite Material Used for Holographic Display
Authors: Liu Li , Gao Ting , Zhou Jie , Huang Xing
Published: July 2011

In this study, we successfully prepared polymethyl methacrylate (PMMA) /NaYF4:Yb:Er up-conversion composite luminescence material by solution cast method. PMMA was used for polymer matrix, and NaYF4:Yb:Er for rare earth up-conversion luminescence component, and this composite material was prepared for holographic display. Fourier transform infrared spectroscopy (FTIR) and luminescent spectroscopy were measured to analyze structure and luminous performance of the composite material respectively.
Improvement of Giant Magneto-Impedance Effect in Fe-Based Nanocrystalline Wires
Authors: Feng Su Qin , Li Yin Feng , Wang Jian Yong , Feng Chun Hui , Zhao Shuang Yi , Zhao Xi Mei
Published: July 2011

In order to obtain materials with more ideal GMI effect, (DZ/Z）max, the substitution effects of R (R = Co, Ni and Cr) for Fe in Fe63.5R10Cu1Nb3Si13.5B9 soft magnetic wires have been studied. We found that although the Finemet composition shown excellent GMI effect, the substitution of Co can raise notably the field sensitivity, Q, Ni makes a little improvements of (DZ/Z）max, and Q, and Cr diminishes the undesirable hysteretic effect. In additions, the influence of annealing conditions upon the GMI effect of the best composition Fe63.5Cr10Cu1Nb3Si13.5B9 was also investigated. It indicated that the sample obtained by the ways of Joule heating under the application of suitable tensile stress exhibits 200% and 30%¤Oe for (DZ/Z）max and Q, respectively. This sample can serve as a proper choice for magnetic sensors.
Synthesis and Characterization of Tri-N-Octylamine-Intercalated α-Zirconium Phosphate
Authors: Chen Ruo Yu , Yao Wei , Wang Hong Ning , Wang Jian Wu , Zhong Jing
Published: July 2011

Tri-n-octylamine-intercalated α-zirconium phosphate (TOA-ZrP) was prepared in the presence of (C4H9)4NOH for the first time. The interlayer distance of (C4H9)4NOH-intercalatedα-zirconium phosphate (B-ZrP) is 14.7 Å, larger than that ofα-ZrP (7.6 Å). The TOA-ZrP sample is highly crystallized with the interlayer distance of 22.3 Å. The molar ratio of TOA toα-ZrP in the intercalation composite was found to be 1/1.21. The composite can find application in solid extraction.
Catalytic Application of H4SiW12O40/SiO2 in Synthesis of Acetals and Ketals
Authors: Yang Shui Jin , Huang Yong Kui , Yu Li
Published: July 2011

A novel catalyst, H4SiW12O40/SiO2 was synthesized by a sol-gel technique, and characterized by FT-IR and XRD. Catalytic application of H4SiW12O40/SiO2 for synthesis of acetals and ketals were tested. The variation of different reaction parameters, such as mole ratio of aldehyde/ketone to alcohols, catalyst dosage and reaction time on the yield of acetals and ketals were also studied. The results reveal that the H4SiW12O40/SiO2 catalysis generally results in good yields of acetals and ketals under mild reaction conditions and the high activity and stability of the catalyst is well retained on recycling.
Heat Treatment of Heavy Forgings with diameter 1700mm
Authors: Su Juan Hua , Liu Xiao Fei , Chen Yun Yun , Shi Yu Lin
Published: July 2011

In order to establish a suitable heat treatment process after forging for the heavy forgings to prevent “grain inheritance”, a heat treatment process including pretreatments, pre-heating, normalization, super-cooling and dehydrogenation is proposed. The heavy forgings with the ratio 1.3 of largest diameter 1700mm to its length 1260mm are manufactured by two times upsetting and elongating process. The results show that the heavy forgings treated according to the forging process and the heat treatment process are all qualified and up to the standards of supersonic inspection.
Catalytic Activity of SWNTs/Pd Catalyst in Suzuki Reaction
Authors: Cao You Ming
Published: July 2011

Pd catalyst is very active in Suzuki reaction. As a heterogeneous catalyst, SWNTs/Pd shows highly catalytic ability with Suzuki reaction. We will demonstrate the effect of catalyst’s amount, the reaction time and temperature on Suzuki reaction in this work. In comparison, a control experiment used commercial Pd/C as catalyst in Suzuki reaction has been done. An optimum reaction condition of about reacting 60 min at 50°C with 5% (mass%) catalyst is confirmed finally, and a better catalytic ability of SWNTs/Pd than commercial Pd/C is also observed.
Force Calculation of Cycloid Gear at Three Supporting Points Of Gear Pin for Speed Reducer with Three Cycloid Gears
Authors: Sun Ying Shi , Guan Tian Min , Zhang Xu
Published: July 2011

FA high-precision drive, namely cycloid driving speed reducer with three cycloid gears, adopts the new driving structure of three cycloid gears at eccentric angle of 120 between each other. The paper analyzes the force of cycloid gear and pin gear at three supporting points of gear pin mainly by analysis, and compares the force of cycloid gear of the speed reducers with two cycloid gears.
Research on Test about Stress Corrosion Cracking of SPV50Q Spherical Tank
Authors: Kong Fan Yu
Published: July 2011

SPV50Q steel belongs to high-alloyed steel that is widely used to fabricate storage tank for liquefied petroleum gas. However, it has a great tendency to the problem of environmental cracking under the service condition of LPG containing wet sulfide hydrogen surpassing the lowest allowance for steels. In order to quantitatively evaluate the cracking susceptibility on this steel in the wet H2S environment, the pre-fatigue crack M-WOL specimen stress corrosion cracking tests in three H2S concentrations were performed under the different welding conditions, and in safety performance analysis of equipment, and preventing countermeasure had been proposed. The method could be extended forecasting accident in LPG SCC.
Preparation and Isothermal Crystallization Behavior of Poly(lactic acid)/Graphene Nanocomposites
Authors: Chen Yan Hua , Yao Xia Yin , Pan Zhi Juan , Gu Qun
Published: July 2011

Poly(lactic acid) (PLA)/graphene nanocomposites were prepared by solution blending using chloroform as a mutual solvent. Transmission electron microscopy (TEM) was used to examine the quality of the dispersion of graphene in the PLA matrix. The isothermal crystallization behaviors of PLA and PLA/graphene nanocomposites were investigated by differential scanning calorimetry (DSC). The isothermal crystallization kinetics were analyzed by Avrami model based on the DSC data. The results showed that the well dispersed graphene nanosheets could act as a heterogeneous nucleating agent and lead to an acceleration of crystallization during the PLA isothermal crystallization process. According to the Arrhenius equation, the activation energies were found to be -106.9 and -46.6 kJ/mol for pure PLA and PLA/0.1 wt % graphene nanocomposite, respectively. The crystal morphology were characterized with polarizing optical microscope (POM).
Prediction of Heat Distribution Shape and Nozzle Diameter of Plasma Arc Cutter
Authors: Ghosh Aniruddha , Bhatia Shailendra , Chattopadhyaya Somnath
Published: July 2011

Theoretical three-dimensional Gaussian heat distribution model of the complex heat flow and plasma properties of cutting plasma torches have been developed. For cutting metallic plates, plasma torches must produce a narrow supersonic plasma jet with enough energy and momentum densities to melt, vaporize, and remove the metal from the impingement region. Our model allows us to study the details of the heat distribution and to make predictions on pick temperature development on metal surface, heat transfer to the work piece, force i.e. the forces acting on the melt (aerodynamic drag, gravity, viscosity and surface tension) during plasma arc cutting, the main forces acting on the melt is believed to be the aerodynamic drag force and the gravity is significant only for thick metal plates. With the help of these assumptions and diameter of Gaussian heat source’s volume, diameter of nozzle has been calculated for thin work piece. A good agreement is found between the model results and the available experimental data.
Residual Stresses in Locally Long Fiber Reinforced Aluminum Parts
Authors: Sun Shao Chun , Chen Zhi Yuan , Wu Qiang , Ma De Xin , Zhao Yu Tao
Published: July 2011

In locally long fiber reinforced aluminum parts two types residual stresses exist. They are the microscopic residual stress between fiber and matrix and the macroscopic residual stress between reinforced and unreinforced zones. The residual stresses between fiber and matrix in γ-Al2O3 long fiber reinforced aluminum alloy Al-6-1-1 were measured with X-ray Diffraction process as well as simulated with FEM method. The results indicated that the residual stresses in both fiber and matrix were distributed very unequally. The maximum tensile residual stress occurred at the boundary in the matrix and the maximum compressive residual stresses occurred near the boundary in the fiber. The macroscopic residual stresses between the reinforced and unreinforced zones were also measured with borehole method as well as simulated with FEM. It was found that the macroscopic residual stresses at most locations in both the reinforced and unreinforced zones were not harmfully high. However in both reinforced and unreinforced zones there were small sub-zones of very large tensile residual stresses.
Effect of Mo2C Content on Microstructure and Composition of Ti(C,N)-Based Cermets Mixing in Water
Authors: Feng Ping , Zhang Xiao Ming , Jin Song , Zheng Teng Biao
Published: July 2011

Element Mo plays a significant role in Ti(C,N)-based cermets. In this work, mixing was carried out in water and cermets with high mechanical properties were fabricated. The effect of Mo2C content on microstructure and composition was investigated by field emission scanning electron microscope (FSEM) and energy dispersive spectrometer (EDS). Results showed that microstructure becomes uniformly distributed, binder distribution becomes symmetrical and the particle size becomes small with increase of Mo2C content. The volume fraction of (outer + inner) rim structure increases, the volume fractions of core structure and binder phase decrease instead. It was found that Mo2C content in raw material affects compositions in phases. With the level of Mo2C content rising, the concentration of element Mo in rim structure increases, the concentration of element Ti in binder decreases.
Research on Ceramic Matrix Composites (CMC) for Aerospace Aplications
Authors: Zhang Quan Ming
Published: July 2011

The research on ceramic matrix composites and their applications in aerospace field were discussed in terms of their advantages and features, fabrication methods, domestic and foreign research progress, difficulties and key technologies to be solved, and future development trends and directions.
Fabrication of Pressureless Sintered β-Sialon-ZrO2 Composites
Authors: Zhang Jian , Bu Jing Long , Wang Rong Lin , Wang Zhi Fa
Published: July 2011

β-sialon-ZrO2composites with Si5AlON7 or Si4Al2O2N6 bonding phase were prapared in N2 atmosphere at 1550°C with Si, Al2O3, AlN and ZrO2 (Ca) as raw materials by reaction in situ pressureless sintering. Effect of Z value and content of β-sialon batch on its sintering performance, phase composition, microstructure, and thermal expansion character were investigated. Results showed that the phase of Si5AlON7 was formed in samples with β-sialon designing Z=1, and phases of Si5AlON7 and Si4Al2O2N6 were formed in samples with β-sialon designed Z=2 and β-sialon designed Z=3, respectively and Bending strength of samples increase with content of β-sialon batch. When content of β-sialon batch equals 10wt%, 15wt% and 15% respectively, the samples with β-sialon designed Z=1, Z=2, and Z=3 have lower apparent porosity, microstructure of homogeneous and compact and lower thermal expansion coefficient, respectively.
Effects of Nanoparticles TiN on the Crystallization Behavior of PET Nanocomposites
Authors: Gu Xiao Hua , Zhou Jia Liang , Liu Jian Hong
Published: July 2011

In this paper, crystallization kinetics behavior of a high heat-absorbing PET / TiN nanocomposite ,the effect of the crystallization behavior of adding nanoendothermic agent,and their crystallization rate and crystallization were studied by differential scanning calorimeter (DSC) ,researching the effect of crystallization behavior of PET with modified TiN and using Avrami equation to study non-isothermal crystallization kinetics. The results show that the kinetic rate constant Zc increasing with the increase of cooling rate, the crystallization half time t1 / 2 subsequently reduced, the crystal growth become fast; TiN is a good nucleating agent in PET, improve PET’s crystallization rate, adding TiN reduce the crystallization activation energy. This has important significance to guide nanocomposite processing.
Thermodynamical Analysis of the Reaction between AlN and ZrO2 and Experimental Substantiation
Authors: Wang Yan , Wang Rong Lin , Yu Li Xue , Bu Jing Long
Published: July 2011

Two equations with discrepancies of solid-state displacement reactions between AlN and ZrO2 were analysed by thermodynamic calculation, and its results were substantiated by experiment. Results of thermodynamic calculation showed that the reaction equation of Bayer and Mocellin proposing could occured at 1411.26K, and it accord with TG-DTA and SEM analysis results, i.e. the reaction equation of Bayer and Mocellin proposing was true.
Certification for Effect of Environment on Composite Properties
Authors: Zhang Jia Rui , Feng Zhen Yu , Zou Tian Chun
Published: July 2011

The environment which can have a great effect on the composite aircraft structure performances must be considered during the design and certification process. In this paper, the extreme temperature and humidity span of the worst environment conditions in aircraft structure design and certification are investigated, and some test methods involving environment influences are also discussed. The studying results can be used in design and certification for environment influences of composite aircraft structures.
Theory Calculation of Diffussion Coefficient Based on Molten Slag Structure
Authors: Min Yi , Wang De Yong , Jiang Mao Fa
Published: July 2011

The diffusion coefficients of slag constituents were calculated using Eyring equation. The Urbain slag viscosity calculation method was modified by improving the constiuents dividing method based on slag depolymerisation degree NBO/T calculation. the amphoteric oxides such as TiO2, Cr2O3, Fe2O3, B2O3 and Al2O3 were specifically dividied into glass former part and modifier part, and the diffusion dimension was calculated according to the value of NBO/T. The results of diffusion coefficients showed that, the modified method is more accurate than the Urbain method within the calculation conditions. Based on the modified diffusion coefficient calculation method, ladle slag composition was optimized to enhance the deoxidization rate.
Improving Staircase Effect in the Process of Ceramic Laser Gelling
Authors: Yen Hsiao Chuan , Tang Hwa Hsing , Wu Chun Hung
Published: July 2011

Based on ceramic laser gelling process, the purpose of this research is to obtain a proper slurry, which can be employed to cast layer with a thickness smaller than 100 μm to improve the staircase effect occurred in layer manufacturing, by optimization of the water content to fabricate ceramic part with better surface. The slurry was composed of alumina particles with average size of 0.5 μm as the structure element, silica sol as an inorganic binder and ammonium polymethacrylate as a dispersant. The slurry was dispersed uniformly by a ball mill. The results revealed the variation of water content will significantly influence the viscosity of the slurry and the formability of the ceramic green part. High water content led to poor binding of the particles and induced the delamination of the consolidated layers. On the contrary, low water content led to high shear force between scraper and slurry surface; such force damaged the previous layer during the casting process. As a result, the water content of 34 wt% was the most favorable to casting thin layers. The capability of casting 40 μm layer, which is smaller than that obtained by previous studies, was achieved. Because of the thinner layer, the staircase effect was improved.
Analysis of Stresses for Cross-Ply Laminates with a Matrix Crack under Bending
Authors: Zeng Qing Dun , Ouyang Mao Hua
Published: July 2011

On the basis of the shear-lag theory, an analysis was presented for stress redistributions of cross-ply laminates with a transverse matrix crack in the 90º ply under bending by establishing a layered shear-lag model. The present results show that approximate solutions of displacement and stress distributions for cross-ply laminates with a transverse crack under bending can be obtained by using a shear-lag method. The present paper therefore affords a new approach for studying the stress redistributions and failure mechanism for cross-ply laminates with flaw under bending.
Effects of Gd on Microstructure and Mechanical Properties of AZ61 Magnesium Alloy
Authors: Zhang Dai Dong , Zhang Hu , Yu Xue Hua , Zhang Xiao Ru , Fang Da Qing
Published: July 2011

The effects of different amounts of rare earth Gd added into AZ61 on the microstructure and mechanical properties of magnesium alloys were studied in this paper. And it adopts T6 heat treatment. When 2% Gd has been added, the microstructure of the alloy becomes uniform. The grains are refining. Gd is prior to reacting with Al for forming Al2Gd phase with high melting point. It is in the form of dot-like and globosity along the grain boundary. And β-Mg17A112 phase is reduced and its shape is thinner. The Al2Gd phase hinders dislocation movement. It markedly improves the mechanical properties of the alloy at room temperature and high temperature.
Program for the Analysis of Wind-Induced Vibration of Steel Roof Structures
Authors: Yang Wei Guo , Wang Yao Feng
Published: July 2011

Wind loads are key considerations in the structural design of steel roof structures, especially for large span ones. The analysis of wind loads on large span steel roof structure (LSSRS) requires large amounts of calculations. Due to combined effects of horizontal and vertical winds, the wind induced vibrations of LSSRS are analyzed with the frequency domain method as the first application of the method for the analysis of wind responses of LSSRS. A program is developed to analyze the wind-induced vibrations due to a combination of wind vibration modes. The program, which predicts the wind vibration coefficient and wind pressure acting on the LSSRS, is designed with input and output interfaces to other finite element software, resulting in preferably solving the wind load analytical problem in the design of LSSRS. The effectiveness and accuracy of the proposed method and the program are verified by numerical analyses of practical projects.
The Effect of Injection Molding Process Parameters on the Buckling Properties of PBT/Short Glass Fiber Composites
Authors: Ho Ming Hsiung , Wang Pin Ning , Fung Chin Ping
Published: July 2011

This study investigates the effect of various injection molding process parameters and fiber amount on buckling properties of Polybutylene Terephthalate (PBT)/short glass fiber composite. The buckling specimens were prepared under injection molding process. These forming parameters about filling time, melt temperature and mold temperature that govern injection molding process are discussed. The buckling properties of neat PBT, 15 wt%, and 30 wt% are obtained using two ends fixed fixture and computerized closed-loop server-hydraulic material testing system. The fracture surfaces are observed by scanning electron microscopy (SEM). The global buckling forces are raised when increased the fiber weight percentage of PBT. Also, the fracture mechanisms in PBT and short glass fiber matrix are fiber pullout in skin area and fiber broken at core area. It is found that the addition of short glass fiber can significantly strengthen neat PBT.
Electrochemical Properties of Zinc-LaCoO3 Electrode for Alkaline Zinc-Based Battery
Authors: Wongchaisuwat Atchana , Boonpong Rapat , Worayingyong Attera , Arunchaiya Marisa
Published: July 2011

The electrochemical behaviors of zinc anode in the presence of the additives added to the electrodes are presented. LaCoO3 was used as an additive to improve the electrochemical properties of the zinc anode. LaCoO3 synthesized by sol gel method (Schiff base complex) was added to Zn and ZnO powder with the weight ratios of 1:0.05 and 1:0.002 respectively. The electrochemical properties of the zinc and zinc/LaCoO3 electrodes in 6M KOH solution were investigated by voltammetric technique and electrochemical impedance spectroscopy (EIS). The cyclic voltammograms showed that zinc electrodes with LaCoO3 additive gave higher anodic currents and ZnO passivation delayed. The cathodic Tafel plot indicated that the hydrogen overpotential shifted toward more negative value. The EIS revealed that the charge transfer resistances of the zinc/LaCoO3 electrodes were higher than that of zinc electrodes.
Isotropic Pyrolytic Carbon Fabricated by Developing Self-Heating Plates Chemical Vapor Deposition
Authors: Xie Zhi Yong , Tan Rui Xuan , Li Jian Qin , Huang Qi Zhong
Published: July 2011

Isotropic pyrocarbon was deposited on self-heating plate at 1100°C and atmospheric pressure via a novel deposition reactor. Two graphite papers were mounted horizontally in chemical vapor deposition furnace, which were used as self- heating plates with alternating current flowing through them. And the upper surface of the lower self-heating plate also was used as substrate of pyrocarbon deposition. The microstructure of the deposit was investigated by polarized light microscopy, scanning electron microscope, transmission electron microscopy and laser Raman spectra, respectively. The results showed that there were some irregular clusters of globular structure and onion-like structure in the deposits. The thickness and density of deposit were13-15 mm and 1.88 g/cm3 in 30h. A novel deposition model of electromagnetic effect on intermediate product has been developed in order to establish a better description of the deposition process.
Friction Properties of Carbon Nanotubes Reinforced Nitrile Composites under Water Lubricated Condition
Authors: Li Fang , Yang Xue , He Lin , Shuai Chang Geng
Published: July 2011

The friction coefficient of carbon nanotube reinforced the nitrile composites under water lubricated condition was investigated using a ship propeller bearing friction tester at different condition. The mechanical properties of the composites were also tested. The results showed that CNTs could improve the mechanical properties and reduce the friction coefficient of nitrile rubber considerably under water lubricated conditions, due to the effective reinforcing and self-lubricating effects of CNTs on the nitrile matrix. With the increasing pressure, the friction coefficient of the nitrile/CNT nanocomposites decreased under the water lubricated condition, which is because that the surface deformation of the nanocomposites was in favor of the water films forming. However, with the increasing temperature of water, the friction coefficient of the nitrile/CNT nanocomposites increased under water lubricated condition, owing to the thinner operating film and the increasing real contact area.
Effects of Amino Acids in the Defined Medium on Cellulose Production by Acetobacter xylinum
Authors: Wang Zhi Guo , Li Cong Fa , Liu Si Xin
Published: July 2011

17 amino acids were used to examine their effects on production of bacterial cellulose (BC) by Acetobacter xylinum. It found that these amino acids can be classified into three groups based on BC production: the efficient group (His/Glu/Asp/Thr/Leu/Ala/Cys), the less efficient one (Met/Ser/ Arg/Phe/Val/Pro/Try/Cystine/Tyr) and the non-efficient one (Lys). Among the efficient group, effects of amino acids on BC were insignificant except His through a L8 (27) factorial design, so it concluded that His was the best amino acid for BC produced by A. xylinum in defined medium. Even so, His was not the best nitrogen source, compared to ammonium sulphate. When His and ammonium sulphate co-existed in the medium, they were both comsumed by A. xylinum independently, but their synergic effect on BC production was not significant.
Fabrication, Microstructure and Properties of Nitrides Bonded Alumina Castables by In Situ Nitridation Reaction
Authors: Jia Quan Li , Ye Fang Bao , Zhang Yu Cui
Published: July 2011

Nitrides(Si3N4/Sialon) bonded alumina castables were fabricated by in situ nitridation reaction. Effects of the formation of nitrides on the physical properties, hot strength and thermal shock resistance were investigated. The results show that the phase composition of castables is alumina, a-Si3N4, b-Si3N4 and Si2N2O after fired at 1400ºC and 1450ºC, and is alumina, b-Sialon and O’-Sialon after fired at 1500ºC. Hot modulus of rupture and thermal shock resistance of specimens are noticeably improved due to the formation of nitrides.
Hierarchical Structures of Silicon Oxynitride Nanowires Formed by a Gallium-Catalyzed In Situ Reactive Technique
Authors: Xiang Shi Biao , Xiang Xu
Published: July 2011

Novel doughnut-like loop structures of silicon oxynitride were grown over a Si substrate via self-assembly of ordered nanowires. These hierarchical structures were formed by metallic gallium-catalyzed vapor-liquid-solid growth at high temperature under a flow of NH3 gas. The product was characterized by XRD, SEM, EDS mapping and XPS techniques. XRD characterization confirms the formation of Si3N4 and silicon oxynitride phases. The silicon oxynitride loop structures assembled by ordered nanowires have outer diameters of 10-14 mm and wall thickness of 2-3 mm. The nanowire bundles in a single loop exhibit a petal-like growth mode. EDS mapping verifies the elemental distribution over the structure. XPS analyses disclose the binding contribution from Si3N4, silicon oxynitride and silicon oxide. The formation mechanism of the self-assembled structures was analyzed based on the growth process.