bluuebunny/crossref_metadata_2025 huggingface dataset:
X-Ray Photoelectron Spectroscopy of (La0.7Sr0.3)MnO3Thin Films Prepared by Pulsed Laser Deposition
Authors: Xiong Hui Fang , Cheng Tie Dong , Tang X.G. , Chen Jian , Liu Qiu Xiang
Published: July 2011

(La0.7Sr0.3)MnO3 (LSMO) thin films were grown on Si (100) substrate by using pulsed laser deposition (PLD) process. Both structure and surface morphology of the films were investigated by X-ray diffraction (XRD) and atomic force microscopy (AFM). Furthermore, the chemical states and chemical composition of the films were determined by X-ray photoelectron spectroscopy (XPS) near the surface. From XRD, the results indicate that the films grown on Si (100) substrates have a single pseudocubic perovskite phase structure with a high (100) orientation. The XPS results show that La, Sr and Mn exist mainly in the forms of perovskite structure and a SrO layer was found on outermost surface. The films resistivity emeasured under room temperature is 6.4´10-4 W×cm.
Electrical Behaviors of LEDs Prepared by Wide-Band GaN Material
Authors: Li Yang , Li Ding , Wang Cun Da , Feng Lie Feng
Published: July 2011

Electrical behaviors of light-emitting diodes (LEDs) prepared by wide-band GaN material were measured accurately using alternating-current (AC) small-signal together with an I-V plot. An abnormal negative capacitance (NC) was observed in all measurend LEDs, and at the same voltage the lower the frequency is, the more obvious NC is. Form the slopes of ln(I)-V plot and the relation between NC and voltage the ideality factor was approximately obtained.
A New Photochromic Diarylethene for Reversible Molecule Switching Properties Based on Pyrrole and Thiophene
Authors: He Shang Hua , Liu Gang , Wang Ren Jie
Published: July 2011

A new unsymmetrical photochromic diarylethene bearing a pyrrole and a thiophene aryl unit 1-(5-cyan-1,2-dimethylpyrrole)-2-(5-aldehyde-2-butylthiophene) perfluorocyclopentene(1a) has been synthesized. Its properties, including photochromism and kinetics were investigated in detail. It underwent reversible cyclization and cycloreversion reactions upon alternating with UV and visible light both in solution and in PMMA film. The results showed that this compound exhibited reversible photochromism, changing from colorless to blue upon irradiation with UV light, in which absorption maximum were observed at 649 nm and 583 nm in solution and PMMA amorphous film, respectively. This new photochromic system also exhibited remarkable reaction kinetics in hexane solution.
Three-Dimensional Optical Bit Memory in Sm(DBM)3Phen-Doped and Un-Doped Poly(methyl methacrylate)
Authors: Nie Zhao Gang , Li Xin Zhong , Tai Yu Ping , Lim Ki Soo , Lee Myeongkyu
Published: July 2011

The feasibility of three-dimensional optical bit memory is demonstrated by using the change of fluorescence and refractive index in Sm(DBM)3Phen-doped and un-doped Poly(methyl methacrylate). After a femtosecond pulsed laser irradiation, a refractive-index bit and a fluorescent bit can be formed at the same position inside the bulk sample. Multilayer patterns recorded by tightly focusing the pulsed laser beam were read out by a reflection-type fluorescent confocal microscope, which can detect the reflection signal and also the fluorescent signal of the stored bits. The signal-to-noise ratio via the two retrieval modes was compared as a function of recording depth. The stored bits were retrieved with a high signal-to-noise ratio in the absence of any crosstalk and the detection of the fluorescent signal enables retrieval of the stored bits with a higher S/N ratio.
Thermoelectric Properties of Cu-Substituted Bi2Ca2Co2Oy Misfit Oxides
Authors: Hao Hao Shan , He Qing Lin , Zhao Li Min
Published: July 2011

Co2-xCuxOy (x=0.0, 0.2, 0.4) Samples were prepared by solid-state reaction method and the effect of Cu substitution on the thermoelectric properties was investigated. The presence of Cu element improved the grain size and electrical conductivity, but Seebeck coefficients were reduced by Cu substitution. It was found Cu substitution is an effective way to improve the thermoelectric performance system at high temperature.
Electrochemical Deposition Mechanism of Polyaniline at High Potential in Organic Electrolyte
Authors: Li Feng Yi , Wang Wei , He Ben Lin , Sun Ming Liang , Song Ling Xia
Published: July 2011

Polyaniline (PANI) was deposited on the glassy carbon electrode in organic electrolyte. The deposition mechanism and properties of resulted PANI were characterized with Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Electrochemical Impedance Spectroscopy (EIS). The results show that: the polymerization of PANI can carry in a relatively high potential (2.4V), and the electrochemical deposition mechanism of PANI at high potential in organic electrolyte is different from that in inorganic system due to the low conductivity and diffusion coefficient of organic electrolyte. The electro-conductivity of PANI is good in the range of 0.2~0.8V which is wider than that reported in inorganic electrolyte.
Dielectric Properties Investigation of Mg-Doped Barium Titanate Ceramics
Authors: Chen Ri Ke , Zhang Hai Tao , Chen Di , Wu Xin Zheng , Zhang Guo Qing , Deng Xiang Yun
Published: July 2011

The dielectric characteristics of Barium titanate (BT) based ceramics are evaluated in a broad frequency range at room temperature and at elevated temperature; the measured frequency is 0.1Hz to 1GHz. The results showed that the dielectric constant increases sharply with the decreasing frequency and is higher than 3000 appeared in lower frequency for Mg 1% doped BT bulk ceramics, which may be resulted from space charge polarization becoming more dominant as compared to the dipolar polarization especially when the frequency is lower than 1 kHz. The dielectric relaxation peaks of Mg-doped BT bulk ceramics appeared both at low and radio frequency whereas pure BT ceramics showed relaxation peak only at radio frequency, what's more, the relaxation frequency of Mg-doped sample is rather low than pure barium titanate ceramics. The dielectric relaxation motion approximately obeys Debye relaxation model approved by Cole-Cole diagram. Thermal activation energy is 0.46eV obtained by Volgel-Fulcher law fitting, which demonstrated that dielectric relaxation due to oxygen vacancies in the Mg-doped BT ferroelectric ceramics.
Research and Application of Lost Foam Technology of Goods Train Low-Carbon Alloy Steel Casting
Authors: Wang Xin Jie
Published: July 2011

Apply an organic whole technological medium of computer aided three dimensions design 、computer aided solidification process numerical value simulation engineering ＆ computer aided numerical control programming manufacturing, by means of optimization product pattern structure、foundry processing parameters 、die auxiliary equipment and tool、riser gating system ＆ die cavity numerical control cutter location source file , the type of Z8A goods train low-carbon alloy adapter lost foam casting has been under development .Compare lost foam technology to ordinary sand mold casting ,the casting monomer weight lightened 3kg , grade of casting weight precision come to MT7 , grade of casting size precision come to CT8 ,foundry processing yield come to 65% ；Casting defects easily appeared in the course of large quantities production has been analysed ＆ offered solution methods in this article.
The Analysis of Toy Design Factor for Customer Loyalty in Taiwan
Authors: You Jang Shyong , Lee Hsiao Chiu
Published: July 2011

Based on product analysis, this paper identifies six toy design factors, including a set meal model, cartoon characters, mechanical functions, quality, price, and channels. Then, based on the results of previous research analysis, this paper considers the satisfaction level, word-of-mouth recommendation, priority level, and repeat purchase intention, as the four evaluative indicators of customer loyalty. Subsequently, this paper adopts questionnaire surveys to investigate the effects of customer loyalty, following which, a variance analysis reveals that a set meal model, cartoon characters, and mechanical functions are the three toy design factors that can significantly influence customer loyalty.
The Effect of PTFE on the Mechanical and Friction and Wear Properties of GF/PA6 Composites
Authors: Li Jian
Published: July 2011

The effects of PTFE on the tensile and tribological properties of glass fiber reinforced polyamide 6(PA6) composites were studied. Tribological tests were conducted on an M2000 friction and wear tester using a block-on-ring arrangement. It was observed that the PTFE played a main role in the tensile-resistant and wear-resistant properties of the PA6 composites. The tensile properties were ruled by the fiber–matrix adhesion. And the excellent tribological performance of the PTFE fillers improved the tribological properties of PA6 composites.
Study on the Interaction of Fluorescent Probe 2-(2'-Chloro Phenyl)-5-(2'-Hydroxyl Phenyl)1,3,4-Oxadiazole with DNA
Authors: Ding Mei , Lei Ying Jie , Xu Fang , Jie Ou Yang
Published: July 2011

The interaction between self-synthesized fluorescent probe 2-(2'- Chloro phenyl)- 5- (2'- hydroxyl phenyl)1,3,4-oxadiazole (HOXD) and Calf thymus DNA was studied using UV absorption spectra and fluorescence quenching spectra．The data of fluorescence quenching of HOXD by DNA were analyzed according to Stern-Volmer equation and Lineweaver-Burk double-reciprocal equation．The results indicated that the fluorescence quenching of HOXD might be static one attributed to the formation of adduct from HOXD and DNA, which was confirmed by the data of temperature effect experiment. Further results presented in the paper showed that intercalation binding might be the interaction mode between HOXD and DNA.
Preparation and Properties of PVA/PAAm IPN Hydrogels-Copper Nanoparticles Nanocomposites
Authors: Luo Yan Ling , Feng Qiang Suo , Xu Feng
Published: July 2011

Copper nanoparticles were fabricated in poly(vinyl alcohol)/polyacrylamide interpenetrating polymer networks (PVA/PAAm IPNs) by reduction of copper ions with sodium hypophosphite in aqueous solutions. The PVA/PAAm IPNs hydrogels were synthesized in terms of a simultaneous interpenetrating route in the presence of glutaraldehyde and N,N'-methylene-bis-acrylamide. The swelling and mechanical properties of the resulting PVA/PAAm/Cu nanocomposite hydrogels were investigated by a gravimetric method and compression stress-strain test. The results indicated that the copper nanoparticles were assembled in the PVA/PAAm IPN hydrogels in a spherical shape, and were well dispersed and stabilized by the polymer networks, with a size range from 10 to 20 nm. The complexation of PVA and PAAm with Cu2+ in PVA/PAAm IPNs played an important part in avoiding the aggregation of copper nanoparticles, and providing particle size and size distribution controllability and stability. The nanocomposite hydrogels exhibited slightly lower swelling, but better compression mechanical properties than that of the control PVA/PAAm IPNs. These properties can be easily tuned by changing the component ratios to meet the requirements of the specific applications such as drug controlled release or tissue engineering.
Thermo-Sensitive Materials for the Time-Temperature Indicator
Authors: Wang Bin , Ye Zhi Neng , Ji Liu Quan , Hu Nian Xi
Published: July 2011

[Purpose] To show storage-resistant food internal quality changes such as canned food. [Method] By measuring the time-temperature-gray relational model of thermo-sensitive paper, compare it with the time-temperature-quality movement model of storage-resistant food. [Results] The analysis of the example show that: through controlling the production process and prescription of thermo-sensitive paper, adjusting the dosage of color-producing reagent, enabling the variation rule of gray match with the quality change of storage-resistant food. [Conclusions] Based colorless dyestuff 2-phenyl-3-methyl-6, 6-2 D-amino fluoran and 2, 2-bis (4-hydroxyphenyl) propane color developer thermo-sensitive system, through controlling the production process and prescription of thermo-sensitive paper to show the quality change of storage-resistant food.
Research for CNC Machine Tool Servo System Fault Diagnosis Expert System
Authors: Wang Shu Qiang , Gao Jing Ge , Lu Wei
Published: July 2011

A new method of CNC machine tool servo system fault diagnosis expert system is proposed.We analyse and design the protype structure of CNC machine tool servo system fault diagnosis expert system base on the methods and theories of expert system. Feasible for the establishment of the expert system are described from knowledge base to reasoning model,and we also provide an important basis for the establishment and development of the expert system.
Microstructure and Abrasive Wear Characteristics of In Situ WC Bundles – Reinforced Iron Matrix Composites
Authors: Zhong Li Sheng , Xu Yun Hua , Yu Peng , Liu Xiao Jie , Ye Fang Xia , Yan Hong Hua
Published: July 2011

An in-situ synthesis process combining an infiltration casting with a subsequent heat treatment was applied to fabricate special tungsten carbide (WC) bundles-reinforced iron matrix composites in this work. The microstructure and wear-resistance of the tungsten carbide bundles reinforced iron matrix composites were studied by using scanning electron microscopy, X-ray diffraction and wear tester. Results showed that the tungsten carbide bundles distributed in the matrix with the center-to-center spacing 2.2 mm, and the diameter of each tungsten carbide bundle is about 1 mm. Most of the tungsten carbides agglomerated, but still there were tungsten carbide particles and the size of tungsten carbide particle was about 10—15 μm. The weight loss of the tungsten carbides bundle reinforced iron matrix composites increased with the increase of the loads and the weight loss of the composites is much less than those of the gray cast iron under the same condition. The wear mechanism of tungsten carbide bundles-reinforced iron matrix composites appears as: micro-cutting, micro-ploughing, broken tungsten carbide and broken particles re-embedded in the matrix.
The Mechanical Properties of Jute Fiber Mats Reinforced Vinyl Ester Resin Composites
Authors: Qi Ning , Zhao Lei
Published: July 2011

Surfaces of jute fiber needled mats were treated by alkali, potassium permanganate and A-151 silane coupling respectively, and those reinforced vinyl resin composites were made by VARTM method . The changes of the surface energy of the jute fiber mats were analyzed basing on the dynamic contact angle, and the surface of the jute fiber and the interface morphology of the composites were observed by SEM. The results showed that interface compatibility and the comprehensive properties of the composites were improved evidently, because the surface energy of the jute fiber was lowered and the surface micro-structures of the fiber were changed. Especially, the tensile strength and flexural strength of the composites treated by A-151 silane coupling increased by 63.08% and 94.79% respectively.
Research on Mercury Emissions Regularity and Adsorbing Mercury by Activated Carbon in Coal-fired Power Plants
Authors: Liu Zhang Xian , Sun Pei Pei , Chen Song Tao , Shi Li Juan
Published: July 2011

The coal-fired power plant is the main anthropogenic source of mercury pollution. The mercury in flue gas exists as elemental mercury(Hg0), oxidizing state mercury(Hg2+) and particulate mercury(Hgp). Mercury speciation distribution in flue gas was influenced and controled by the factors including conditions of ignition, desulphurization or denitration and Based on the investigation of coal-fired power plant technologies of removing Hg, this research uses the modified activated carbon (MAC) and studies its removal efficiency. Result indicates that the uptake of Hg by MAC was﹥90%.
Hydration Kinetics Of Carbonized Spinel Carbon Brick With Al
Authors: Yang Ding Ao , Yuan Shou Qian , Jiang Ming Xue , Li Yu Zhang , Zheng Jian Ying , Yu Zhi Ming , Xiao Qing Hai
Published: July 2011

The hydration kinetics of carbonized spinel carbon bricks with different proportions of Mg / A1 additive has been studied in water steam of super thermostatic bath between 25°C and 85°C.The kinetic equations for hydration of the brick have been derived according to the experimental data and the theory of kinetics. Methods of various protections against hydration have been discussed. It shows that chemical reaction control occurs in the carbonized spinel carbon brick with Al and Mg at 44.3°C-84°C. The cracking time reduces from 40h to 4h with the rising of temperature verifies from 44°C to 84°C, the hydration is controlled by diffusion between 24.7°C and 33°C. And cracking does not appear after 50-day-and-night hydration at 24.7°C.
The Study of Post-Fire Load Bearing Capacity of Steel Column under Axial Compression Exposure to one-Side Fire
Authors: Chen Jian Feng , Zhou Tian Hua , Lu Lin Feng , Wu Han Heng
Published: July 2011

The section of steel column under axial compression presents heterogeneous material and its load condition changes after experiencing fire damage of one side. Taking H-section steel column under axial compression commonly used in engineering for study object in this thesis in order to study post-fire residual load bearing capacity, the post-fire eccentric effect of steel column under axial compression exposure to one-side fire is analyzed using the method of equivalent section which considering the change of the material strength after high temperature, the influence of non-uniform temperature field on material properties and the stiffness degradation of member section. Calculation methods of the eccentricity and additional moment are proposed and further given a formula of residual load bearing capacity.
Secondary Energy Analysis of Typical Steel Manufacturing Process
Authors: Hu Chang Qing , Zhang Yu Zhu
Published: July 2011

Energy saving of iron-making system and secondary energy recovery are the main approaches for the Chinese steel industry’s sustainable development. The theoretical analysis of secondary energy generation of four typical BF-BOF steel manufacturing processes showed that improving the resource and energy efficiency, and strengthening recovery and rational utilization of by-product gases are the main way of energy saving for steel industry. According to the status of secondary energy recovery of Chinese steel industry, the technological development tendency energy saving, greenhouse gas emission reduction for Chinese steel industry are presented.
Research on Processing Technology of Polyester Fabric Reinforced Polypropylene Thermoplastic Laminated Composites
Authors: Lin Jia Horng , Lin Ching Wen , Chen Jin Mao , Li Ting Ting , Chang Ting Wei , Lou Ching Wen
Published: July 2011

Thermoplastic composites are eco-friendly to environment. In this study, PET/PP thermoplastic composite laminates were produced by interleaving polypropylene (PP) sheets with polyethylene terephthalate (PET) plain fabrics in the condition of varying thermocompression temperature, pressure and time. Afterwards, peel resistance, tensile and impact properties of PET/PP thermoplastic laminates were tested. And the tensile and impact performance of PET/PP laminates was respectively about 40 % and 320 % higher than PP laminates. It was shown that when thermal compressing under pressure of 40 Kg/cm2 at 230 °C for 0.5 minute, PET/PP thermoplastic laminates had optimum tensile and impact properties.
Monte Carlo Study on Thermal Transport in Si/Ge Superlattice Basing on Phonon Dispersion Discrepancies
Authors: Wang Zan , Zhu Hong Yu , Ruan Yi Wu
Published: July 2011

Based on the classical diffuse mismatch model (DMM), the dedicated Monte Carlo model for Si/Ge superlattice is proposed and the method to cope with the scattering at the interface is provided. In this model, phonons transport between two different materials can be taken as the movements between the different phonon dispersion relationships. If there is a corresponding position in the other material, the phonon with a given frequency will be able to pass through the interface, otherwise it will be reflected.
Processibility and Mechanical Properties of Mullite-Filled Styrene Butadiene Rubber Composites
Authors: Liu Qiong Qiong
Published: July 2011

Mullite (3A12O3·2SiO2) is an aluminosilicate ceramic of great technological importance. We investigated its potential as fillers in rubber. Mullites untreated or treated with 3% γ-mecapto-propyltrimethoxysilane (A-189) were added into styrene-butadiene rubber (SBR) materials on a laboratory-sized two-roll mill. For comparison, commercial precipitated silica was also used. The effect of these fillers on the cure characteristics, processibility and mechanical properties of SBR at various loadings, ranging from 0 to 50 phr was investigated. The results showed that mullite was a semi-reinforcing filler for SBR materials and exhibits better overall cure properties, lower Mooney viscosity, lower tensile set, better resilience as compared to precipitated silica, while it is inferior to precipitated silica especially with regard to tensile strength, tear strength and abrasion resistance. The presence of the silane coupling agent can enhance mechanical properties of filled SBR vulcanizates to some extent.
The Design for the Main Reaction System of a New Welding Material
Authors: Jiang Jin Yong , Chang Wen Ping , Du Shi Guo , Lu Gui E , Huang Jia Qi
Published: July 2011

Gunpowder composite welding rod is a new type of welding material, which can accomplish welding without electricity and gas. In this article, the effect regularities of two types of thermite on the energy densities of gunpowder composite welding rod have been obtained with thermodynamical equilibrium equations. These results are very useful for the design of the main reaction system of this welding material.
Optimal Design of Sisal Fibre Reinforced Resin Matrix Composite
Authors: Xu Xin , Song Sheng Yin , Liu Yong Gang , Feng Yao Rong
Published: July 2011

Using a friction-abrasion testing machine with a constant speed, the friction and wear properties of sisal fibre reinforced resin composites containing different sisal fibre contents at a series of friction temperatures were investigated, and its tribology mechanisms were discussed. The results shown that the friction and wear properties of sisal fibre reinforced composites reach the optimum value when the mass ratio of resin to sisal fibre is 3/4. To compare with asbestos fibre, mineral fibre and steel fibre, the optimized sisal fibre reinforced composite has the best stability of friction coefficient with a low wear rate at different friction temperatures. The sisal is an ideal substitute of asbestos for resin matrix frictional composite.
Analysis of Break Impact Load on Composite Insulators Used as Tension String
Authors: Liu Bin , Liu Cao Lan , Liu Sheng Chun , Liu Zhen , Zhu Kuan Jun
Published: July 2011

An analysis process for break impact loadings to tower, conductors and unfaulted insulators is proposed when one of the composite multi- insulators tension string comes to rupture. A finite element method is used to simulate the break impact process in order to consider the whole structural model of transmission lines and geometric nonlinearity. And a two-step calculation process, form-finding analysis and break impact analysis, is performed. The calculation results are verified by testing data. And an impact influence coefficient is defined to characterize the influence of maximum impact loading to tower, unfaulted insulators, conductors and fittings. A typical example with the structure of three-composite-insulators string and two/three suspension points is presented. The impact loading characteristics are obtained with different fracture locations. The obtained results are beneficial to design composite multi-insulators tension string structure.
Effect of PA6 Addition on the Mechanical Properties of PMMA Blends
Authors: Li Zhen Hua
Published: July 2011

This article studies the mechanical properties of PA6 reinforced polymer blends comprised of a soft PMMA matrix. These composites are designed as a model system to investigate the impact of the content of the two phases on the composite mechanical properties. The addition of the PA6 phase to the matrix PMMA increases the strength of the blend, but lowers its toughness as it decreases the elongation at break. When PA6 particles are added the blends become relatively brittle. The composites containing moderate content of PA6 particles show enhanced tensile modulus and strength. This enhancement is associated with the formation of a network within the polymeric matrix comprised of PA6 particles welded together by the minor component.
Research on Crack-Resistance Property of Asphalt Mixture as Road Stress-Absorbing Interlayer
Authors: Xu Wen Yuan , Yu Hong Gang
Published: July 2011

The stress-absorbing interlayer of modified asphalt mixture studied in this report is a special asphalt pavement mixture. Capable of delaying the occurrence of reflection cracks, the asphalt mixture is mainly composed of aggregate passing through a 9.5 mm sieve, machine-made or natural sand, and modified asphalt binder. Because the adopted modified asphalt binder can form the highly elastic network structure in the mixture with good fatigue resistance, the stress-absorbing interlayer of modified asphalt mixture can effectively delay reflection cracks of semi-rigid base pavement.
Experimental Study on Effects of Laminated Structure on Acoustic Insulation Property of Composites
Authors: Li Shan , Wang Rui , Liu Cheng Xia , Fu Ya Qin
Published: July 2011

In order to study the effects of laminated structure on acoustic insulation property of composites, the frequently-used flexible polyvinyl chloride (EPVC) sheets and non-woven fabric were selected as the substrate materials to prepare for ten types of nonwoven fabric/EPVC composites with different laminated structures in this study. Their acoustic insulation properties were tested and analyzed by the double channel acoustic instrument. The results showed that the different laminated order of composites has significant influence on its acoustic insulation property under the same conditions; and the acoustic insulation property of composites can be improved by the change of laminated order only.
The Distribution of Microstructure and Mechanical Properties of Carbon-Carbon Composites
Authors: Xie Zhi Yong , Tan Rui Xuan , Zhang Ming Yu , Su Zhe An , Chen Jian Xun , Huang Qi Zhong
Published: July 2011

The effect of microstructure and its distribution of pyrolytic carbon in different deposition stage in carbon-carbon composites infiltrated by multi-factor physical fields chemical vapor infiltration (CVI) on the mechanical has been studied by polarized -light microscopy, Raman spectra, scanning electron microscope and three-point bending tests. The temperature and the change of the [AS/VR]-ratio with progressive infiltration are key parameters for the formation of microstructure and its distribution of pyrolytic carbon around the same fiber. SL pyrolytic carbon corresponds to brittle failure mode and smooth two-step fracture surface due to its low and uniform texture，although the abnormal graphitization occurs in the carbon fiber near the fiber/matrix interface. In contrast, RL matrix can function for achievement of nonbrittle fracture behavior with a zig-zag-like fracture surface and a relatively high value of flexural strength due to high and nonuniform texture.
Deformation Behavior of a Multiphase Fine-Grained Mo-Si-B Alloy
Authors: Yu J.L. , Li Z.K. , Zheng Xin , Li H. , Wang D. H. , Zhang J. J. , Wang H.
Published: July 2011

Mo-9Si-8B-3Hf alloy consisting of a Mo solid solution and intermetallic phases Mo3Si and Mo5SiB2 was fabricated by hot pressing sintering to yield a fine microstructure with all three phases being in the size range of micrometer. The tensile properties of this alloy at elevated temperature were evaluated in vacuum at elevated temperatures. This alloy displayed extensive plasticity or superplasticity at temperatures ranging from 1400 °C to 1560 °C with strain rate of 3×10-4 s-1. The tensile elongation of 410% is measured at 1560 °C. Grain boundary sliding is the main mechanism of plastic deformation for this alloy.
Study on the Mechanical Properties and Creep Behaviour of Carbon Fiber Nano-Composites
Authors: Li Yi Luen , Chen Wei Jen , Shen Ming Yuan , Chiang Chin Lung , Yip Ming Chuen
Published: July 2011

The surface modification of carbon nanotubes（CNTs）has been recently observed to influence the distribution of CNTs in epoxy resin and the mechanical properties and electrical conductivities of these CNTs. Accordingly, the treatment of CNTs to with organic acids to oxidize them generates functional groups on the surface of CNTs. This investigation studies the consequent enhancement of the mechanical properties and electrical conductivities of CNTs. The influence of adding various proportions of CNTs to the epoxy resin on the mechanical properties and electrical conductivities of the composites thus formed is investigated, and the strength of the material is tested at different temperatures. Moreover, the creep behavior of carbon fiber（CF）/epoxy resin thermosetting composites was tested analyzed at different stresses, orientations of fiber, temperatures and humidities. The creep exhibits only two stages- primary creep and steady-state creep. The effects of creep stress, creep time, and humidity on the creep of composites that contain various proportion of CNTs were investigated at various temperatures. However, increasing the number of cycles in cyclic creep tests at room temperature resulted in a decrease in creep strain even at a high temperature of 55°C. Possible room temperature creep mechanisms have been proposed and discussed. Creep strain is believed to increase with applied stress, creep time, humidity, temperature and degree of the angle θ between the orientation of fiber and the direction of the applied stress. The test results also indicate that mechanical strength and electrical conductivity increase with the amount of CNTs added to the composites. Different coefficients of expansion of the matrix, fiber and CNTs, are such that overexpansion of the matrix at high temperature results in cracking in it. An SEM image of the fracture surface reveals debonding and the pulling out of longitudinal fibers because of poor interfacial bonding between fiber and matrix, which reduce overall strength.
Electrochemical Properties of Polyaniline/α-Zirconium Phosphate Nanocomposite and the Effect of pH Values
Authors: Wang Sheng , Liu Chao , Gong Jun Yan , Zhang Xiao Bo , Ma Juan Juan , Tong Zhi Wei
Published: July 2011

Nanocomposite based on polyaniline (PANI) and α-zirconium phosphate (α-ZrP) has been synthesized by in situ polymerization using aniline intercalation compound (ANI)/ZrP as intermediate. Aniline was successfully intercalated into the interlayer spacing of crystalline α-ZrP forming a double-phase intermediate by adsorption. The intercalated aniline was polymerized by adding appropriate amount of ammonium peroxodisulphate (APS) solution. The synthesized nanocomposites were characterized by XRD, SEM, and FT-IR. X-ray diffraction patterns showed that PANI was formed outside α-ZrP. TGA/DSC analysis showed improved thermal stability for the PANI/ZrP nanocomposite in comparison with pure PANI. The PANI/ZrP nanocomposite was studied by cyclic voltammetry (CV), which revealed good redox activity and electrochemical-cycling stability in acidic solution. The interaction between PANI and nanosheets greatly affected the electrochemical behavior of PANI/ZrP nanocomposite. The electrochemical behavior of PANI/ZrP nanocomposite in HCl solution with different pH values has been studied in detail.
TiC Particulates Prepared by Self-Propagating High Temperature Synthesis
Authors: Liang Yan Feng , Dong Sheng Quan , Xia Feng
Published: July 2011

TiC particulates were prepared by self-propagating high temperature synthesis (SHS). The effect of elemental aluminum on the formation of TiC particulates was particularly studied by differential thermal analysis (DTA) and sintering experiments of Ti-C-Al system. The sintered products were examined by XRD and TEM. The results showed that Ti did not react with C directly in the absence of elemental Al. The sintering process of Ti-C-Al system presented typical high-temperature self-propagating synthesis (SHS) features. TiC particulates could be maximally obtained through the appropriate control of the Al content in the system. The size of the resultant TiC particulates was about 0.15μm.
A Novel Approach to Disperse CuO onto the Zeolites Mordenite and Beta
Authors: Hao Xiang Ying , Zhang Cui , Liu Shuang Xi , Guo Hai Fu
Published: July 2011

Zeolites mordenite (MOR) and β decorated with high dispersion degree and loading content of CuO composite (symbolized as CuO/zeolite) were prepared via a novel method-the stepped hydrothermal synthesis. The resultant composite were characterized with details by powder XRD, ICP-AES, H2-TPR and TEM techniques. Shown by experiment, the stepped hydrothermal synthetic method adopted in the present research using urea as alkali source as well as benefiting from the ultrasonic wash treatment hardly damages the zeolitic framework structure. Compared with ammonia, high dispersion degree and loading level of CuO are yielded as a consequence of the employment of urea as alkali source. Besides, the ultrasonic wash treatment not only removes some CuO precursors that deposit on the external surface of the porous support but also produces a uniform distribution of CuO particles with smaller dimension on the surface of zeolites: CuO are dispersed in nanoscale of about 4-8 nm on mordenite and 2-5 nm on zeolite β. The present synthetic strategy could be therefore applied as a novel general method for the manufacture of functional materials in a wide spectrum.
The Properties of Coarse Grain Heat Affect Zone of Pipeline Steels with Excellent Deformability under Different Welding Heat Input
Authors: Yan Kai Juan , Gao Hui Lin , Zhang Xiao Yong , Tian Chen Chao , Yang Yan
Published: July 2011

The pipeline steels with excellent deformability becomes an important research direction of pipeline materials fields in recent years. In this study, the pipeline steels with excellent deformability was obtain by inter-critically accelerate cooling(ICAC) method, the influence of welding heat input on the microstructure and property of the coarse grain heat affect zone (CGHAZ) of X80 pipeline steels with excellent deformability is investigated using welding thermal simulation, mechanical testing and microstructure analysis. The result indicate that the strength and toughness of CGHAZ of X80 pipeline steels with excellent deformability decrease follow with welding heat input increase.
Microwave Modified Timber: Collaborative Research Integrating Product Design for New Materials Development
Authors: Thong Christine , Jackson Simon
Published: July 2011

The process of new materials development traditionally employs science and engineering based inquiry in the initial phases. This paper explores how product design can help determine the feasibility of new materials for commercial application earlier and provide benefits of reduced timeframes, cost and risk factors. It discusses a case study of new materials development based on Microwave Modified Timber Technology, set in the context of an Australian Collaborative Research Centre (CRC) for Wood Innovations. The study supports benefits in early integration of product design research into new materials development processes.
Microstructural Characterization and Properties of Silica Aerogels Doped with Nano-ITO Powder
Authors: Lin Ben Lan , Cui Sheng , Shen Xiao Dong , Leng Ying Li , Liu Xue Yong , Liu Yu
Published: July 2011

Silica-based aerogels doped with nano-ITO powder were synthesized using sol–gel process followed by supercritical drying. The main factors were studied including dosage of compling agent KH570 and ITO. The result shows that thermal radiation conductivity is 0.02659 W/(m•K) with ITO of 44.44% after 10 g ITO powder is modified with 1 mL KH570. The microstructure and physical characteristic of the SiO2–ITO aerogels were characterized by FTIR, SEM, TG-DSC and BET. Their specific surface was in the range of 513–775m2/g and their average pore size was mainly 20 nm. Nano-ITO powders are physically embedded by SiO2 aerogels.
Solvothermal Synthesis of Mn-Doped CdS Nanorods Using Single-Source Molecular Precursors
Authors: Du Zhen Ni , Xu Zhi You , Zhang Yong Cai , Zhang Ming
Published: July 2011

The synthesis of hexagonal phase Mn-doped CdS (Cd1-xMnxS) nanorods was achieved by solvothermal treatment of a class of easily obtained, air-stable single-source molecular precursors (cadmium manganese diethyldithiocarbamates, Cd1-xMnx-(DDTC)2) in ethylenediamine at 180 °C for 12 h. The structures and compositions of the as-synthesized products were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy and transmission electron microscopy.
Cracking Behavior of Oxide Films under Applied Stress
Authors: Rao Si Xian , Yang Su Ping , Tong Ji Bin , Wang Jing Ru
Published: July 2011

Cracking behaviors of oxide films on A3, 30CrMnSiA steel under applied stress were investigated in this paper. Theoretical deductions confirmed that critical cracking conditions for oxide films on A3 and 30CrMnSiA steel did exist. Electrochemical tensile experiments in 3%NaCl aqueous solution showed that the critical cracking stress for oxide film on A3 steel is about 220MPa,the critical cracking stress for oxide film on 30CrMnSiA steel is about 80MPa.In-situ dynamic tensile experiments verified the correctness of the experiments results in the electrochemical tensile experiments.
Spontaneous Oxidation Route to Se/Te Alloys Nanorods at Room Temperature
Authors: Zheng Rong Bo , Guo Xue Lian , Zheng Kang
Published: July 2011

The Se/Te alloys nanorods have been synthesized through spontaneous oxidation of NaHE (E = Se and Te) by dissolved oxygen at room temperature. Phase structures and morphologies of the Se/Te products are investigated by XRD, EDS, SEM, and TEM. The composition of Se/Te alloys could be tuned via simply changing the value of n (n denoted as molar ratio of the starting reagent Se to Te). In order to obtain pure Se/Tealloys nanorods, the value of n should be higher than 3. Otherwise, by-product t-Te would be formed. A possible nucleation and growth mechanism of the Se/Te nanorods was discussed.
Preparation of Chrysotile Nanotubes under Hydrothermal Condition
Authors: Huang Yang Feng , Cai Ye Bin , Liu Hao
Published: July 2011

In a neutral environment, Chrysotile nanotubes have been synthesized by hydrothermal method, with MgO and SiO2 powder as the starting materials. X-Ray Diffraction(XRD), Scanning Electron Microscopy(SEM), Transmission Electron Microscopy(TEM) are used to characterize the crystal structure and morphology of the as-prepared samples. We found that the diameter of Chrysotile is uniform. Their outer diameter is about 30~50 nm and the inner diameter is about 6~8 nm. The length of them is a few hundred nanometers. The XRD analysis indicates that the as-prepared Chrysotile is a Rhombohedral structures. The results of HRTEM and SAED showed that the {006} planes of serpentine roll up along the [600] direction to form the tubular structure. In addition, the curves of temperature and pressure with time showed that the water might participate in the reaction.
A Facile, Green Route - Electron Beam Irradiation to Nanocrystalline Cadmium Selenide at Room Temperature
Authors: Li Zhen , Peng Li Wei , Gao Fei , Pan Deng Yu , Wu Ming Hong
Published: July 2011

In this paper, a rapid, facile and green strategy — electron beam irradiation has been developed to prepare CdSe nanoparticles. 10 mA GJ-2-II electronic accelerator was applied as radiation resource. CdSe nanoparticles were synthesized using NH3 as complexing agent by electron beam method in a colloid system, which used Cd(Ac)2 and Na2SeO3 as raw materials. Nanocrystalline CdSe was prepared rapidly at room temperature under atmospheric pressure. The structure and morphology of prepared CdSe nanoparticles were analyzed by X-ray diffraction and transmission electron microscopy. UV–vis spectroscopy (U-3010, Japan Hitachi) and photoluminescence spectroscopy (PL, F-7000, Japan Hitachi) were used to investigate the optical properties of the CdSe nanoparticles. The effects of radiation dose on the formation of CdSe nanocrystallines were discussed. The possible mechanism of the CdSe grain growth by electron beam irradiation method was proposed.
Growth of Carbon Nanofibers with Ordered Macroscopic Structures by CVD Technique
Authors: Wu Qiang , Wu Jiang , Ueda Wataru
Published: July 2011

The growth of carbon nanofibers (CNFs) with ordered macroscopic structures could be achieved by CVD technique. Silica fiber, alumina fiber, and AAO membrane were selected as the typical ordered macroscopic substrates for CNFs growth. It turned out that silica fiber could act as the promising and effective substrate for CNFs growth on its surface. While alumina fiber and AAO membrane could also be expected to act as the potential substrates for CNFs growth on their surface.
The Research of Nanophotonic Grating Vertical Coupling
Authors: Cui Dan Feng , Xue Chen Yang , Tong Xiao Gang , Jin Yu Jian , Zhang Wen Dong
Published: July 2011

In this paper, we discuss the theory research and testing methods of a grating coupler. The grating coupling efficiency of parameters and the corresponding theoretical simulation was studied systematically. Meanwhile, the coupling efficiency in theory can be improved to 76% using an optimized grating design. The fabrication of the couplers in silicon-on-insulator is focusing on ion beam method (FIB). Using the tunable NewFocus laser with an adjustable extent of 1520~1570nm as the sources, Si waveguide grating is achieved vertical coupler through coupling a single-mode fiber with the diameter of 10.4. In the experiment, when the input wavelength is 1550nm, the maximum coupling efficiency is measured approximately 31% and 1 dB bandwidth is approximately 30 nm.
Synthesis of MnWO4 Nano-Particles by Low-Temperature Molten Salt Method
Authors: Song Zu Wei , Li Xu Yun , Shi Jin Sheng
Published: July 2011

Manganese tungstate nano-particles were successfully synthesized at low temperatures by molten salt method, and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and ultraviolet visible spectra techniques (UV-vis), respectively. The effects of calcining temperatures and salt quantity on the crystallization and development of MnWO4 crystallites were studied. Experimental results showed that the well-crystallized MnWO4 nano-particles with about 40 nm in diameter could be prepared at 270°C with 3:1 mass ratio of the salt to MnWO4 precursor for a holding time of 4 h. XRD analysis evidenced that the product was a pure monoclinic phase of MnWO4 with wolframite structure. UV-vis spectrum revealed that MnWO4 nano-particles had strong light absorption properties in both ultraviolet and visible light region.
Synthesis of Nanocrystalline InVO4 by Hydrothermal Process and its Visible-Light Photocatalytic Activity
Authors: Tang Pei Song , Chen Hai Feng , Cao Feng , Pan Guo Xiang , Wang Kun Yan
Published: July 2011

Monophasic orthorhombic InVO4 was synthesized using InCl3 and NH4VO3 as starting materials by a hydrothermal approach. The as-prepared InVO4 product was characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible diffuse reflectance spectroscopy (DRS). It was found that the as-prepared InVO4 shows strong visible-light absorption with absorption onset of 515 nm, indicating a narrow optical band gap of 2.4 eV. Furthermore, the as-prepared InVO4 shows high visible-light photocatalytic activity for decomposition of methyl orange, which is ascribed to the strong visible-light absorption.
Preparation of TiO2 Nanocrystalline Powder with High Specific Area Using Urea as the Template
Authors: Hu Yu Long , Zhang Xiao Dong , Liu Hong Fang , Shao Zhen Hai , Su Xiao Hong
Published: July 2011

TiO2 nanocrystalline powders with high specific area were prepared using urea as the template by the sol-gel method. The samples were characterized by X-ray diffraction, N2 adsorption isotherms, and transmission electron microscopy. Urea plays a key role in the preparation process of TiO2 nanocrystalline powders. Large amounts of small urea aggregates were formed in the sol-gel process and decomposed during the calcination process, which results in the formation of large amounts of mesopores. Urea also inhibits the agglomeration and growth of the TiO2 nanoparticle, which facilitates the preparation of a TiO2 powder with smaller nanocrystal size. The above effects of urea may be the main reason of the as-prepared sample with very high specific surface area.
Microwave-Assisted Preparation of Cu2O Octahedral Microcrystals
Authors: Deng Chong Hai , Hu Han Mei , Yang Ming Di
Published: July 2011

In this paper, we reported a facile microwave-assisted green chemical route to prepare pure, uniform, and monodispersed Cu2O octahedron wrapped by the {111} faces by using glucose as a reducing agent. X-ray diffraction (XRD), energy dispersive X-ray spectrometry(EDX) and field emission scanning electron microscopy (FESEM) were used to characterize the as-synthesized products. It was found that the morphology and structure of Cu2O crystals were greatly affected by the concentration of NaOH. A solid-solution-solid growth mechanism was possibly proposed on the basis of the comparative experimental results.
Organic Soft Template Method to Arrange Palladium Nanoparticles on Single-Walled Carbon Nanotubes
Authors: Tan Zhenquan , Abe Hiroya , Naito Mikio , Ohara Satoshi
Published: July 2011

A facile solution-chemical route was reported to deposit and arrange palladium (Pd) nanoparticles on single-walled carbon nanotubes (SWCNTs) using sodium dodecyl sulfate (SDS) as an organic soft template. SDS was previously formed supramolecular self-assembly on the walls of SWCNTs, which may act as adsorption sites of Pd (II) ions on SWCNTs. The Pd nanoparticles reduced by photo-reduction and formed one-dimensionally ordered arrangement on the surface of SWCNTs with a veriety of helices and tilted angles. Pd nanoparticles have an average size of 3 nm. The structure (distance, helix and tilted angle) of the ordered arrangements were determined by the supramolecular self-assembly of SDS wrapped on SWCNTs.
Novel Mechanochemical Synthesis of Carbon Nanomaterials by a High-Speed Ball-Milling
Authors: Ohara Satoshi , Tan Zhenquan , Abe Hiroya
Published: July 2011

A novel mechanochemical approach to produce sophisticated carbon nanomaterials is reported. It is demonstrated that carbon nanostructures such as carbon nanotubes and carbon onions are synthesized by high-speed ball-milling of steel balls. It is considered that the gas-phase reaction takes place around the surface of steel balls under local high temperatures induced by the collision energy in ball-milling process, which results in phase separated unique carbon nanomaterials.
Fabrication of Barrel-Type Pre-Formed Shape of Al2O3f+Cf/ZL109 Composite Material
Authors: Wang Xue Zheng , Song Xiao Rui
Published: July 2011

The fabrication of assorted fibers barrel-type pre-formed shape which contain of ZLl09 alloy with alumina fibers and short carbon fibers by vacuum coining and extrusion casting in this study. The examination results show that it can be produced Al2O3f+Cf/ZL109 assorted fibers composite material whose the structures are fine and close and the fibers distribute uniformly by squeeze casting technology. The interface between wild phase and matrix is good combination and no inclusions in the composite material. The fiber reinforcement is uniformly distributed in the matrix, and mainly in 2-dimension distribution.