bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurement and Estimation of Yarn Pore Size Distribution by Gravity Class
Authors: Du Wen Qin , liu Xiao Liang , Qi Hong Jin
Published: November 2010

To investigate the contribution of yarn pore size distribution to fabric pores structure, in this paper, based on the balance relationship between the capillary height and the hydrostatic pressure of the liquid in the yarn, we designed and assembled a device for measurement of μm scale pore size distribution of the cotton yarn. Through comparison and analysis of data and considering the very low water content in the yarn, we increased the number of yarn, designed a special cutting device and improved the measurement accuracy of weight. Finaly, we obtained histograms and curves with highly accurate (0.0001g) and good reproducibility. The results show that the yarn pore size is in tens-hundreds μm and displays a concave-like distribution, while the fabric pore size change is much more complex, suggesting that the pore in the fabric is not a simple summation of the pore in the yarn.
The Relevant Technology Research on Heat Balance Control of Aluminum Reduction Cell
Authors: Xia Xiang Yang , Li Jie
Published: November 2010

Due to the energy balance control of aluminum reduction cell has not solved so far, it analyzes the impact factors on electrolyzer’s heat balance (i.e., electrolyte temperature), and proposes a corresponding method of heat balance control ,which provides relevant measures for aluminium electrolysis industry ,s energy saving.
Property of Cu-Zr-Ti Ternary Alloys
Authors: Cai An Hui , An Wei Ke , Li Xiao Song , Luo Yun , Li Tie Lin
Published: November 2010

The influence of Zr on the property of Cu(50+x)Zr(40-x)Ti10 (0≤x≤30 at.%) alloys were investigated. The results show that the maximum size for the glass formation in this Cu-Zr-Ti system is less than 8 mm. The hardness increases with decreasing of the Zr content, then decreases when the Zr content exceeds 10~15 at.% due to the obvious alteration of the type of the crystalline phases and the microstructure. With decreasing of the Zr content, the transformation sequence of the main Cu-Zr phase is Cu10Zr7→Cu5Zr→Cu51Zr14; the transformation sequence of Cu-Ti phase is Cu4Ti3→CuTi→CuTi3. In addition, the atom ratio of Cu60Zr30Ti10 alloys is coherent with that of their corresponding crystalline phase, resulting in its better glass forming ability.
Fatigue Crack Growth Behavior of Friction Stir Welding of 6063-T5 Aluminum Alloys
Authors: Surapunt Supachai
Published: November 2010

The microstructure and fatigue crack growth behavior of friction stir welding of 6063-T5 aluminum alloys were investigated. For this propose, fatigue crack growth curves were determined in four different locations of notch, which are base metal, middle of welded zone (parallel to weld line), near interface and interface (shoulder limits). The crack initiation and crack propagation of the base metal specimens presented slower than those of stir welded specimens. The microstructure observations show that the grain sizes in stir welded zone are finer than that in the unaffected base material and in the heat affected zone.
Comparative Study on the Performance of New Highly Visible-Light Responsive Photocatalyst Bi20TiO32 with P-25
Authors: Sun Xu Hui , Bao Ta Na , Sun Lin , Ma Jun
Published: November 2010

Comparative research was done on the performance of new highly visible-light responsive photocatalyst Bi20TiO32 with P-25. Surface photovoltage spectrum of Bi20TiO32 indicates that its absorption wavelength starts from 550nm. Under Xe-lamp irradiation and the same catalyst dosage, the apparent rate constant of degrading methyl orange by P25 is 0.0465min-1, which is 2.7 times higher than that achieved by Bi20TiO32 (0.0172min-1). The apparent rate constant of degrading phenol by P-25 is 0.0543min-1, which is 1.8 times higher than that achieved by Bi20TiO32 (0.0296min-1). And the TOC removal of the solution by P-25 is also greater than by Bi20TiO32. But the performance of Bi20TiO32 under visible light irradiation is better than P-25. Under the visible light irradiation (>400nm), the apparent rate constant of degrading methyl orange by Bi20TiO32 is 0.0119min-1, which is 3.13 times higher than that achieved by P25 (0.0038min-1). The apparent rate constant of degrading phenol by Bi20TiO32 is 0.0133min-1, which is 33.25 times higher than that achieved by P-25 (0.0004min-1), and TOC removal by Bi20TiO32 is also much higher than by P-25.
Microstructure Evolution of Near Gamma TiAl Intermetallic under Tensile Impact Loadings at High Temperatures
Authors: Wang Yu , Zan Xiang , He Yue Hui , Wang Yang
Published: November 2010

The effect of temperature and strain rate on the mechanical behavior and microstructure evolution of Near Gamma Ti-46.5Al-2Nb-2Cr (NG TiAl) was investigated at temperatures ranging from room temperatures to 840 under strain rates of 0.001, 320, 800 and 1350s-1. The TEM analysis indicated that deformation twinning and stacking fault are the main deformation modes under dynamic loadings and dislocation slip is another important deformation mode under quasi-static loadings. The density of deformation twinning and/or stacking fault increases with the increased temperature and strain rate.
Study on Structure and Property of Broussonetia papyrifera (BP) Fiber
Authors: Zhang Xin , Qu Li Jun , Guo Xiao Qing
Published: November 2010

The morphology and structure of Broussonetia papyrifera(BP) bast and fiber were investigated by SEM, OM, FT-IR and X-ray analysis, and chemical composition of BP bast was analyzed. The results show that the cellulose content in the BP bast can be as high as 63.76%. BP fibers arrange parallel in the bast, which are linked by pection. The cross-section of PB fibers are irregular round with lumens that are almost invisible in the completely mature fibers. The crystallinity of the fiber could reach 83.26%. Most impurities such as hemi-cellulose, lignin, pectin could be effectively removed by degumming, while cellulosic structure is not changed. BP fiber has good mechanical properties, but the single fiber is too short to spin alone.
Tribological and Oxidation Properties Study of a Kind of Sodium Sulfonate-Modified Nano Carbonate Sodium
Authors: He Zhong Yi , Xiong Li Ping , Xu Huan , Li Tao , Qiu Jian Wei , Fu Xi Sheng
Published: November 2010

The tribological properties of a high base value sodium sulfonate-modified nano carbonate sodium as lubricating oil additive were introduced in this paper, and its antioxidant collaboration property with ashless antioxidant was evaluation by using pressure differential scanning calorimetry(PDSC). The results show that the product possesses good tribological properties, thermal stability, and a good synergistic antioxidation effect with ashless antioxidant, and mainly to increase oxidation free energy of base oil.
Effect of Pickling Process on Adhesion Strength of Ti Oxide Layer on Titanium Alloy Substrate
Authors: Izman Sudin , Kadir Mohammed Rafiq Abdul , Anwar Mahmood , Nazim Engku Mohammad , Kuan Low Yik , Khor Eng Kean
Published: November 2010

Titanium alloys are commonly used in biomedical application in hard tissues replacement especially for knee and hip implants. Surface modifications are required prior to diamond coating process for improving the tribological and wear properties of the titanium alloy. In this study, experiments were carried out to investigate the effects of different pickling times as well as temperature on the adhesion strength of oxide layer formed on the Titanium alloy after oxidation process. The aqueous acid solution of HF and HNO3 was used as a pickling solution. The chemical pretreatment was carried out at 4 levels by varying the pickling time as well as temperature. All treated samples were thermally oxidized in a fixed parameters at 900 °C for 25 hours. Surface morphology, oxide layer thickness and adhesion strength were measured after each step using FESEM and Blast Wear Tester (BWT). It was revealed that the thickness of oxide layer increases with pickling time but the adhesion strengths become weaker. It was also found that the adhesion strength of oxide layer formed on Ti substrate surface increases with the increase of temperature while the thickness of the oxide layer decreased within 40oC pickling temperature.
Investigation of Temperature and Deformation of Mold Copper Plate in Slab Continuous Casting
Authors: Zhang Xing Zhong , Jiang Zheng Yi , Dou Chun Xia , Zhang Qiang
Published: November 2010

Based on the cooling parameters of the mold copper plate for slab continuous casting in a steelmaking plant, the three-dimensional calculating model of the copper plate was established, and three-dimensional distributions of temperature, thermal stress and strain were simulated numerically by using finite element method (FEM). The maximum deformation of the mold copper plate, the highest temperature and thermal stress were obtained. This research is useful for the structure design of the mold.
Effect of Cryogenic Treatments on Mechanical Properties of 2A11 Aluminum Alloy
Authors: Wang Jun Jie , Xue Xiao Dai , Yang Zhen Qiang , Zhang Hong , Zhou Yuan
Published: November 2010

Effect of cryogenic treatments on mechanical properties of 2A11 aluminum alloy were studied. Cryogenic box with program control and electrical resistance furnace were employed to perform cryogenic treatment processes as well as heat treatment processes. Impact tester, tensile tester, three-coordinates measuring machine, high precision caliper and standard metallography were used to carry out tests. The influences of different process parameters on mechanical properties of 2A11 aluminum alloy were compared, and the results showed that cryogenic treatment could improve mechanical properties of 2A11 aluminum alloy. The dimensional stability increases after cryogenic treatment once, and increases further after cryogenic treatment again.
New Strength Criterion Based on Relationship between Elastic and Plastic Strains
Authors: Li You
Published: November 2010

Due to the limitations of the existing strength theories or criteria, the phenomenon of material failure cannot be not fully explained, which makes material strength criterion to always be an important direction to study. Reference [1] found that there was a certain relationship between elastic strain and plastic strain, and a preliminary summing-up of this relationship had been done.Based on the relationship, the dominant factor of material failure has been analyzed, and a new strength criterion has been established with plastic strain as the control value. The new criterion is of simple expression, and can be used to explain very well some experiment phenomena.
Analyzing Si Precipitation on Age Hardening of an Al-Si-Mg Cast Alloy
Authors: Wang Gui Qing , Liu Yan , Ren Guo Cheng , Zhao Zhong Kui
Published: November 2010

The correlation of age hardening behavior and Si precipitation in α(Al) of Al-8wt%Si-0.35wt%Mg alloy has been investigated by micro hardness measurement, electron probe microanalysis (EPMA) and transmission electron microscopy (TEM) analysis. The EPMA results show that Si concentration in the center of α (Al) dendrites is higher than that in the edge and the main concentration is about 1.5wt% for Al-8wt%Si-0.35wt%Mg alloy in as cast condition. After solution treatment at 530 °C for 8 h followed by water quenching (T4 treatment), hardness value decreases 9 HV, which is accompanied by the decrease of Si concentration in α (Al). Aging the as-cast sample and T4 treatment sample at 150 °C for 20 h, the main concentration of Mg and Si in α (Al) changes little. Hardness value after as-cast aging is only 3 HV lower than that after T6 treatment. Nanometer Si particles and β″ and/or β′ phases are found in aged samples. The higher hardness value for as-cast aging samples should contribute to the nanometer Si particles in α (Al).
Study of TiAl Alloy Surface Plasma Modified Corrosion Resistance
Authors: Wang Bing Ying , Yuan Xiao Mei , Liu Xiao Ping
Published: November 2010

Effects of Nb surface alloying and Nb-C duplex treatment alloying on corrosion behavior of TiAl in particular medium by constant potential of the three electrochemical corrosion properties, respectively, compared with the experimental base after alloying of corrosion resistance. Experimental results show that the corrosion resistance of the niobizing alloyed layer and the plasma carburized layer are increased in 3.5% NaCl,5.8% HCl,in 8.8% H2SO4 solution.
The Effect of Minimal Quantity Lubrication (MQL) on the Surface Roughness of Titanium Alloy Ti-6Al-4V ELI in Turning Process
Authors: Haron C.H. Che , Ghani J.A. , Sulaiman Mohd Ali , Intan L.R. , Kasim M.S.
Published: November 2010

This paper investigates the effect of minimum quantity lubricant (MQL) on the surface roughness of titanium alloy Ti-6Al-4V ELI when turning using uncoated tungsten carbide tool. The response surface method (RSM) design of experiment using Box-behnken was used to accomodate the turning experiment factors and levels. Turning parameters studied were cutting speed (100, 135, 170 m/min), feed rate (0.15, 0.2, 0.25 mm/rev) and depth of cut (0.6, 0.8, 1.0 mm). The results show that the feed rate was the most influence factor controlling the surface roughness produced. The feed rate (F) was found directly proportional with the surface roughness value (Ra) but inversely proportional to the cutting speed (Vc). MINITAB software was used to develop a surface roughness model, and the optimum condition was at 160 m/min of cutting speed, 0.18 mm/rev of feed rate and 1 mm of depth of cut. At the optimum condition low value of 1.54 μm surface roughness was obtained.
Low Frequency Mechanical Spectroscopy of High Damping Mg-3wt.%Ni Alloy
Authors: Wan Di Qing , Liu Ya Juan
Published: November 2010

The Dynamic Mechanical Analysis (DMA) was applied to investigate the low frequency mechanical spectroscopy response of as-cast high damping Mg-3wt.%Ni hypoeutectic alloys. There are two peaks appearing on the temperature dependent damping spectrum (-100 - 420 °C). The broad peak P1 is overlapped by some small peaks due to the thermally activated dislocation movement, while the P2 peak is a solute grain boundary relaxation peak.
Icosahedral Quasicrystal Grains Growth and Evolution in Mg-Zn-Y
Authors: Liu Ya Juan , Wan Di Qing
Published: November 2010

Unlike the growth of crystal, the growth of icosahedral quasicrystal seems to have its own characteristics. Petal-like icosahedral quasicrystal grains (i-phase grains) morphology usually has been observed in as-solidified quasicrystalline alloys. The distinguished morphology is belonged to a given i-phase grains growth evolution mechanism. We first introduced a novel model named “coherent” model to illustrate i-phase grains growth evolution.
Shrinkage Stress Analysis of the Restored-Tooth Structure by the Finite Element Method
Authors: Chen Guo Ping , Zhu Shui Wen , Tao Jun Lin
Published: November 2010

The purpose of this paper is to investigate the influence of interphase properties on restored-tooth structure due to polymerization shrinkage of resin-based composite. The stress within the restored tooth structure built up from the polymerization shrinkage of the restorative composite was computed accounting for the time-dependent and viscoelastic behavior of the composite. A sensitivity study was performed to examine the relative influence of geometric and material parameters of an interphase on the shrinkage stress development. It was found that a correlation exists between material and geometry properties at the restoration-tooth interface and higher shrinkage stresses were located at the interphase due to polymerization shrinkage. The varying material and geometry properties of restoration-tooth interface seemed to have a conclusive effect on the interfacial stress system, as well as on the longevity of the restoration.
Effect of Electropulsing on Grain Refinement of a Medium Carbon Low Alloy Steel
Authors: Yu Wen Peng , Qin Rong Shan , Wu Kai Ming
Published: November 2010

Electropulsing at room temperature was applied to a medium carbon low alloy steel 30CrMo with varying peak voltage and current. The results showed that the pearlite colony in the specimen treated with electropulsing was smaller than that without electropulsing treatment. It was found that the lamellar structure of pearlite was refined. The grain refinement of pearlite was more obvious when the applied electric current density was higher. This may be attributed to additional free energy for the nucleation of pearlite provided by electropulsing and/or the enhancement of dislocation movement caused by electropulsing.
The Influence and Research of the Metal-Coated FBG on Temperature Sensitivity
Authors: Wang Xiao Xia , Wang Win Lin
Published: November 2010

The Fiber Bragg Grating (FBG) sensor’s temperature sensitivity which is influenced by the metal-coated material and thickness was presented. The accurate equation was gotten according to the elasticity and fiber sensor theory. As indicated by the experiment, the changeable curve of the temperature sensitivity between theory equation and experiment is identical. And the FBGs sensitivities can be improved to 3~20 times.
Prediction of Fretting Fatigue Life of Aluminum Alloy LY12CZ
Authors: Yang Moo Sheng , Chen Yue Liang , Bi Yu Quan , Jiang Wen Hao
Published: November 2010

Stress in the interface of contacts was calculated applying finite element software/ABAQUS, with which the Ruiz fretting damage parameter was obtained and the location for crack formation was found. A new model for predicting fretting fatigue life has been presented based on friction work. The rationality and effectiveness of the model were validated according to the contrast of experiment life and predicting life. At last influence factor on fretting fatigue life of aerial aluminum alloy LY12CZ was investigated with the model. The results revealed that fretting fatigue life decreased monotonously with the increasing of normal load and then became constant at higher pressures. At low normal load, fretting fatigue life was found to increase with increase in the pad radius. At high normal load, however, the fretting fatigue life remained almost unchanged with changes in the fretting pad radius. The bulk stress amplitude had the dominant effect on fretting fatigue life. The fretting fatigue life diminished as the bulk stress amplitude increased.
Effects of Cerium on the Microstructures and Electrochemical Properties of Al-Zn-Sn Sacrificial Anodes
Authors: He Jun Guang , Wen Jiu Ba , Li Xu Dong
Published: November 2010

To improve the current efficient of Al-Zn-Sn alloy, the influence of different contents Ce on the microstructures and electrochemical properties of alloy was investigated. The results show that the appropriate amount of Ce was effective on improving the electrochemical properties of Al-Zn-Sn alloy. The corrosion potential shifted negatively and the current efficiency increased with the increasing of Ce contents. The optimal microstructure and electrochemical properties were obtained when the Ce content in the alloy was 0.5 wt.%. The good electrochemical properties of Al-7Zn-0.1Sn- 0.5Ce (wt.%) alloy is mainly attributed to the fine grains and the less segregation phases at grain boundary.
Process of Equiaxed Grains of RE-Al Alloy under Slope Vibration
Authors: Xie Shi Kun , Yi Rong Xi , Li Shu Qin , Pan Xiao Liang , Zheng Xiao Qiu
Published: November 2010

A new technique using slope vibration casting process during heating and isothermal holding period to prepare Al-7Si-2RE alloy has been studied. The small, near-spherical and non-dendritic microstructure with the semi-solid processing requirements has been obtained. Experiments show that the cooling method, pouring process and the convection of melt caused by slope vibration had significant effects on the formation of near-spherical primary gains. The water-cooled copper mold casting with slope vibration at the temperature near liquidus can obtain Al-7Si-2RE alloy with small homogeneous equiaxed grains, the average grain diameter is 48.3μm, and the average grain roundness is 1.92.
Effect of Ageing Process on Mechanical Properties of Martensite Precipitation-Hardening Stainless Steel
Authors: Xiang Song , Wang Jiang Ping , Sun Yu Ling , Yan Yong You , Huang Shi Gang
Published: November 2010

17-4PH precipitation-hardening martensite stainless steel is an important commercially available stainless steel. And the mechanical properties of this steel are very sensitive to quenching and aging process. In this paper, the effects of aging process on mechanical properties of this steel were investigated. The results show that the microstructure of this steel consists of quenched martensite, tempered martensite and precipitates. With the increase of the aging temperature, the strength decreases and the toughness increase. And the fracture mode of this steel transforms brittle fracture into toughness fracture.
Probabilistic Integrity Assessment of Pressure Piping Containing Defects
Authors: Li Ming , Wang Feng Hui , Chen Ping Wei , Lou Kang
Published: November 2010

In the present paper, integrity assessment is made to the defects in weld metal zone of pressure piping of X52 steel using the two basic routes, FAD and CDF, which are provided in the European flaw assessment procedure SINTAP. Based on the experimental data various analysis levels of SINTAP are discussed, including the uncommonly used J-integral level in particular. Furthermore, to meet the need of the reliability assessment of pressure piping containing defects in engineering applications, probabilistic procedures are employed to obtain several probability curves with given survivability on the J-integral level with respect to the great scatter of the tested fracture toughness which is required in the J-integral level analysis.
Prospect Analysis on New Ironmaking Technology of Oxygen Blast Furnace and Gas-Recycle
Authors: Han Yi Hua , Xue Qing Guo , Li Yan Zhen
Published: November 2010

Based on the global environmental deterioration, the greenhouse effect and a series of other problems, the necessity for the development on new ironmaking technology of oxygen blast furnace and gas-recycle in China was discussed. The new technology use coal and oxygen as the main raw materials. The development situation of new technology and its technical advantages over the conventional ones were introduced detailedly. The development situation of related technology abroad was described. The application prospect of this new technology was analyzed from the perspective of energy consumption and CO2 emission. Using the new ironmaking technology of oxygen blast furnace and gas-recycle, It bound to increase steel plant’s overall technological level in china, enhance industry competition and the effect of energy saving as well as emission reduction, promote low-carbon economy development.
Experimental Study on the Effect of Normal Stress on the Shear Banding in a Zr-Based Bulk Metallic Glasses
Authors: Liu Long Fei , Hu Jing , Li Hui Qiang , Zhang Guang Ye
Published: November 2010

A special fixture, which can control the ratio(λ) of normal stress/shear stress, was used to study the effect of normal stress on the shear banding behaviors in a Zr-based bulk metallic glasses in the present paper. The experimental results demonstrated that the plastic displacement increased with increasing of λ. Observations of shear bands pattern on the sample surfaces indicated that normal stress have significant impact on the inclined angle, numerical density and length of shear bands. In addition, normal stress is the major factor of inducing multiple shear bands with intersecting, branching and slipping. Based on the observations, the mechanism of plasticity enhancement due to the increasing of normal stress was explored.
Notch Fatigue Properties of TRIP-Aided Annealed Martensitic Steels
Authors: Yoshikawa Nobuo , Fuji Daiki , Sugimoto Kohichi
Published: November 2010

Fatigue properties of TRIP-aided annealed martensitic steels with chemical composition of 0.2%C, 1.5%Si, 1.5%Mn, 0-1.0%Cr, 0-0.2%Mo, 0-0.05%Nb, 0-18ppmB was examined for application of automotive diesel engine common rail. The steels achieved extremely higher notch fatigue limits and lower notch-sensitivity than the conventional structural steels, especially in steel with boron or without chromium and molybdenum. This was associated with (i) the TRIP effect of a large amount of stable retained austenite and (ii) strain-induced transformed hard martensite which suppressed the crack initiation and growth due to plastic relaxation.
Analysis Methods for the Tensile Behaviors of Woven Membrane Materials
Authors: Chen Shou Hui , Yu Hong Qin
Published: November 2010

The tensile performance of the woven membrane materials shows three characters: nonlinear, anisotropic and non-elastic. Besides, when suffering from the bi-axial loads, the tensile property of the woven membrane material is more complicated. These features make the analysis of the tensile performance of woven membrane materials more difficult. The analysis methods including the elastic matrix method, the mathematical function method, and the mechanical model method have been discussed in details.
Tearing Strength Calculation Model of the Synthetic Leather Base
Authors: Qian Cheng
Published: November 2010

The synthetic leather base is a composite, with the top and lower layers are nonwovens and the middle is woven fabrics. Firstly, the single rip tearing strength and drawing out resistances of the leather base were tested and tearing failure mechanics were analyzed. Then on the above basis, the single rip tearing strength calculation model of the synthetic leather base was built successfully. From theoretical model, main influencing factors are the weft and warp yarn breaking strength and the density of warp and weft yarns in the woven fabric, and also drawing out resistance of the leather base. Finally, experimental verification was made for the established model, which shows that theoretical values conform to the measured values well.
Electrochemical Performance of LiFePO4 Coated by Nano-Polyaniline Coater for Lithium-Ion Batteries
Authors: Gong Wen Qiang , Chen Yi Feng , Sun Bing , Chen Han
Published: November 2010

Aniline was polymerized on the surface of LiFePO4 particles by in-situ polymerization technique, forming LiFePO4/polyaniline composites. The composites were characterized by Thermo gravimetric analysis, specific surface area tests, high resolution transmission electron microscopy observation. The specific capacity, rate capability and cycling stability of composites were studied by charge-discharge tests. The experimental results show that the LiFePO4/polyaniline composite containing 6.75% polyaniline possesses the best electrochemical properties. Its initial capacity reaches 151.97 mAh.g-1 at C/10 rate, its cycling stability is excellent, its specific capacity is 124.89 mAh.g-1 at 1 C rate, its capacity loss is only 17.82% when rate increased from C/10 to 1 C.
Percolation Phenomenon in Thermal Conductivity of Carbon Black Filled Rubber and Morphology
Authors: Song Jun Ping
Published: November 2010

A kind of graphitized carbon black 40B2 was incorporated in natural rubber matrix and vulcanizates were prepared. The content of carbon black varied from 4 to 100phr for 100phr of natural rubber. Thermal conductivity of the CB/rubber composites was studied as a function of CB loadings and temperature. TEM and SEM were employed to explore the morphology of the carbon black and the composites. It was found that percolation phenomenon existed in thermal conductivity of CB/rubber composites at different filler loadings, which was much similar with percolation behavior in electrical conductivity properties of many composites, and the percolation threshold was about 13.63%. The influence of temperature on thermal conductivity was more obviously within the region from the percolation threshold to the volume fraction of 26.2%.However, no great effect could be found on the percolation behavior of the composites in thermal conductivity. The result of TEM indicated that the mean size of CB particles was about 25nm, the maximum size of CB aggregates was about 125nm, and the CB aggregates were multichain in shape. The results of SEM showed that the distribution of CB differed at different filler loadings. Before the percolation threshold, the CB aggregates existed isolatedly, nevertheless at the percolation threshold, some long chains made up of CB aggregates ran through the rubber matrix, which resulted in the rapid increase in thermal conductivity value, and then with the addition of CB loadings, the number of chains increased. When the volume fraction was up to 26.2%, some three dimensional networks formed.
Effect of Multi-Wall Carbon Nanotube on Fracture Mechanical Property of Cement-Based Composite
Authors: Luo Jian Lin , Duan Zhong Dong , Zhao Tie Jun , Li Qiu Yi
Published: November 2010

Cementitious composites reinforced with multi-wall carbon nanotube (MWNT) (MWFRC) were prepared with surfactant dispersion, ultrasonication, and subsequently high-speed mixing process. Fracture mechanical performance of the cured MWFRC was characterized according to three-point bending method (ASTM 399). It is found that the addition of nanotubes significantly improve the flexural strength, the stress-intensity factor of the nanocomosites with dispersed MWNT fiber, the maximal enhancement amplitude is near to 45%, 80% with respect to the baseline, respectively. The superior fiber bridging capability of the dispersed MWNTs upon the micro-cracks contributes to the reinforcement to cement matrix.
Evaluation of Galactomannan from Gleditsia Sinensis Lam. as Sustained Release Material in Colonic Drug Delivery
Authors: Jian Hong Lei , Zhu Li Wei , Zhang Wei Ming , Qi Xiang , Jiang Jian Xin
Published: November 2010

The galactomannan from endosperm of G. sinensis seeds was used as sustained release material in the matrix tablets prepared at different concentration of 5, 10 and 15 % corresponding to formulations of G5, G10 and G15, for the release of theophylline. The drug release behaviors of the systems were investigated, including the swelling and morphological studies and texture analysis. The dissolution tests were conducted in 0.1 M hydrochloric acid and pH 6.8 phosphate buffered saline. The results of release studies demonstrated that G10 with 10 % galactomannan concentration showed a better control of the drug release profiles. The percents of cumulative drug released in 24 h were 98.8, 90.2 and 83.4 % for G5, G10 and G15, respectively. All the systems exhibited the typical morphological behavior of a swellable matrix. Results of texture analysis on the swollen tablets confirmed that diffusion drug release mechanism played the major role in G10 and G15 systems while the drug delivery kinetic towards an erosion/relaxation mechanism for G5 matrix tablets.
A Critique on Evaluating Fatigue Crack Propagation Properties Using Miniature Specimens
Authors: Shin Chow Shing , Lin Shi Wei
Published: November 2010

There are situations where baseline fatigue crack propagation (FCP) data are needed but the available material for its evaluation is far from enough to fabricate full sized standard specimens. Miniature specimen testing techniques have been proposed but published data seems to be slightly but consistently slower under the same stress intensity than that from standard specimen results. In this work, an aluminum alloy and a steel, which have vastly different mechanical behaviors, are used to generate different stress states and premature crack closure to allow the validity of miniature specimen FCP data to be critically examined.
The Influence of HSO3- Activity on Electrochemical Characteristics of Copper
Authors: Liu Qian , Dong Chao Fang , Xiao Kui , Li Xiao Gang
Published: November 2010

The electrochemical behavior of copper in various concentrations of NaHSO3 solution was investigated with linear polarization and cyclic voltametry technique at room temperature. The results showed that the concentration of bisulfite ions has noticeable effects on the behavior of copper. With HSO3 -concentration increasing, the passivity region, ascribed to the formation of absorption layer Cu (HSO3) ads - or Cu (SO4) ads 2-, appearing at the lower potential range in the polarization curve inclined to transform into an active region; whereas another passivity region, due to the appearance of CuO or Cu2O layer on the surface, took place at a higher potential region. The formation and the reduction of CuO or Cu2O were irreversible.
Damage Localization and Severity Estimate for Lattice Material
Authors: Fang Hui
Published: November 2010

This paper presents a new method for the damage localization and severity estimate for lattice material based on substructure modal energy. The significant advantage associated with new method over traditional modal energy methods is that the spatially complete mode shape isn’t needed. Additionally, the new method does not require the analytical and measured modes to be consistent in scale, or to be normalized. Numerical studies in this paper are conducted for lattice material based on synthetic data generated from finite element models.
Acoustic Emission Study of Growth Process of Diamond Crystals under HPHT
Authors: Liu Lei , Su Qing Cai , Li Mu Sen
Published: November 2010

The growth process of synthetic diamond single crystals under high-pressure and high-temperature (HPHT) was investigated using acoustic emission (AE) technique. And AE parameters corresponding to growth process were analyzed. However, the AE features of diamond growth are relativelyweak and easily obscured by other AE sources. So the fast Fourier transformation (FFT) was used to calculate the frequency spectra of AE signals for identifying different AE sources. The results showed that the variation of AE counts and energy is in a good agreement with the formation process of synthetic diamond crystals. And the AE signals pronounced from diamond growth are concentrated in the frequency range from 100 to 250 kHz. Thus, AE technique is an effective way to monitor and study the diamond growth, and the frequency analysis can be a useful way to identify different AE sources.
A New Definition of Damage Variable for Rock Material Based on the Spatial Characteristics of Deformation Fields
Authors: Cao Yan Yan , Ma Shao Peng , Wang Xian , Hong Zhao Yong
Published: November 2010

Considering with the spatial characteristics of concentrated deformation field caused by the micro-cracks concentration and localization in rock, a new damage variable is defined based on the standard deviation of the strain fields of rock specimen surface during loading. When digital speckle correlation method (DSCM) is used to measure the deformation fields of rock specimen, the damage variable definition in this paper takes great advantages on damage measurement of rock methods. Using the new methods, the damage of rock would be measured for the whole loading process and the experiment is easy to be implemented. The validity of the proposed damage variable is verified by the experimental results on column-shaped marble specimen subject to uniaxial compression.
Effect of the Size of Powder on the Microstructures and Grain Refining Performance of AlTiC Alloys
Authors: Cao Jing , Wang Yong Feng , Wei Chun Xue
Published: November 2010

AlTiC master alloys have been prepared by Contact Reaction Method（CRM）.X-ray diffraction，SEM and EDS were used to analyses the AlTiC master alloys. It showed that morphology and distribution of TiC and Al3Ti particle have correspondingly changed with the change of the size of powder. As a result, the change in morphology and distribution of TiC and Al3Ti particle has considerably affected the gain refining performance of AlTiC master alloys. The result showed that: when the grain size of Ti is much smaller, the effect of refinement is much better.
Effect of Electromagnetic Field on Microstructure of 5052 Aluminum Alloy Sheet by Roll-Casting
Authors: Li Jin Tao , Xu Guang Ming , Cui Jian Zhong
Published: November 2010

The effect of electromagnetic field on microstructure of roll-casting 5052 aluminum alloy sheet has been investigated and analyzed. The results indicate that imposing static magnetic field can refine the grains of 5052 aluminum alloy during the roll-casting; accordingly, imposing static magnetic field and alternating current at the same time, the grains are remarkably refined and equiaxed due to electromagnetic oscillation effect.
Effects of Ge Doping on Electrochemical Migration, Corrosion Behavior and Oxidation Characteristics of Lead-Free Sn-3.0Ag-0.5Cu Solder for Electronic Packaging
Authors: Hua Li , Yang Gia Kuan , Zhang Hong Quan
Published: November 2010

Due to lead-free pressure, Sn-Ag-Cu solder is regarded as the potential candidate. However, higher melting point and faintish soldering restrict its wide application. Metal or rare earth metal doping can improve its soldering. In this thesis, Ge doping in Sn-3.0Ag-0.5Cu (SAC) solder were discussed. Effect of metal Ge doping on electrochemical corrosion behavior of lead-free SAC solder in 3wt.% NaCl solution were investigated by potentiodynamic polarization measurement. The electrochemical migration（ECM）attributed to dendrites growth were employed by the salt immersion experiment, and the oxidation characteristic was researched by thermo gravimetric analysis(TGA). The surface morphology and elemental composition of various elements in the doped solder were determined by analyzing the corrosion product or dendrites formed on the specimen by SEM, EDAX techniques. The results showed that the dendrite growth can be accelerated after Ge doping comparing to Sn-3.0Ag-0.5Cu solder. The shapes of dendrites were completely different before and after Ge doping, the fore looked like as tree leaves, the latter looked like little stem, all dendrites grown from different kind of material can be well differentiated by the help of their fractal dimension. EDAX result showed that the content on dendrites of Sn-3.0Ag-0.5Cu solder doping with Ge were mainly Sn, only little Cl- and Na+. Corrosive experiment showed that the corrosive current density (Icorr) increased with Ge content increasing when the percent content of Ge was less than or equal to 1%, the contrary effect suitable to that Ge doping larger than 1%. TGA result showed that Ge doping could improve the anti-oxidation capacity of SAC solder comparing to no doped solder. It provided a good technical support to develop a new lead-free solder substituting for Sn-37Pb.
Mid-IR and Raman Spectral Properties of Geometrically Frustrated Atacamite Hydroxyl Copper Chloride
Authors: Tao Wan Jun , Liu Xiao Dong , Zheng Xu Guang , Meng Dong Dong , Guo Qi Xin
Published: November 2010

The mid-IR and Raman spectra of geometrically frustrated atacamite hydroxyl copper chloride are measured by FTIR spectroscopy and HR800 Raman spectroscopy, respectively. The microscopic origins of bands within the functional group and the fingerprint regions are suggested by the known crystal structure parameters. Five distinct regions involved in hydroxyl stretching, overtones, hydroxyl deformation, Cu-O stretching, O–Cu–O symmetric stretching and O–Cu–O bending modes, pyramid-structure Cl≡Cu3 vibration modes, lattice modes, respectively.
Integrated Simulation of Castings Deformation during Casting and Heat Treatment Processes
Authors: Yu Hai Liang , Kang Jin Wu , Huang Shi Xiong , Huang Tian You
Published: November 2010

Deformation often appears in castings during casting and heat treatment processes, which determines the machining allowance setting and the machining size distribution of product. The paper presents a novel method for integrated simulation of the deformation behavior of castings during casting and heat treatment processes with a unified finite element model. Firstly, analyze the deformation of castings during casting process with the model containing mold and casting, and update the geometry of casting after casting process, then analyze the deformation of castings during heat treatment process and the final geometry shape of casting before machining could be obtained. By the method, investigation on the deformation behavior of a hydro turbine blade casting during casting and heat treatment processes was carried out, and the residual stress distribution and geometry shape of the casting were obtained.
Microencapsulation of Epoxy Resins for Self-Healing Material
Authors: Zhao Yang , Zhang Wei , Liao Le Ping , Li Wu Jun , Xin Yi
Published: November 2010

With the development of the embedded microcapsule concept for self-healing material, the preparation of microcapsule has been paid more attentions. A new series of microcapsules were prepared by in situ polymerization technology in an oil-in-water emulsion with polyoxymethylene urea (PMU) as shell material and a mixture of epoxy resins as core material. The PMU microcapsules were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electronic microscopy (SEM), particle size analyzer and thermo gravimetric analyzer (TGA) to investigate their chemical structure, surface morphology, size distribution and thermal stability, respectively. The results indicate that PMU microcapsules containing epoxy resins can be synthesized successfully. The optimized reaction parameters were obtained as follow: agitation rate 600 rpm, 60°C water bath, pH=3.5, core material 20ml and hot water dilution by in-situ polymerization. The size is around 116 μm. The rough outer surface of microcapsule is composed of agglomerated PMU nanoparticles. The microcapsules basically exhibit good storage stability at room temperature, and they are chemically stable before the heating temperature is up to approximately 200°C.
Preparation, Characterization and Tribological Evaluation of Calcium Borate Nanoparticles as Lubricant Additives
Authors: Li Jiu Sheng , Hao Li Feng , Xu Xiao Hong , Zhang Li , Ren Tian Hui
Published: November 2010

To develop a potential substitute for conventional lubricant additive, pure calcium borate nanoparticles (PCBN) and calcium borate nanoparticles modified with oleic acid (MCBN) were prepared. The microstructures of the as-obtained samples were characterized using X-ray power diffraction (XRD), transmission electron microscope (TEM) and infrared spectra (IR), and the dispersing stability of oil containing nanoparticles was also evaluated. Tribological properties of MCBN used as lubricating additive were evaluated using four-ball tribometer and compared with that of PCBN. The results indicate that MCBN show better antiwear and friction-reducing property than PCBN. The worn surface of the steel ball lubricated with MCBN was investigated by Polarized microscope (PM) and X-ray photoelectron spectroscopy (XPS), and the action mechanism of MCBN during friction process was preliminarily discussed.
Research on Internal Force and Deformation of Supporting Rock-Socketed Piles Based on Ultimate Resistance Mechanics Theory
Authors: Chen Fang , Qin Hao , Gao Chao
Published: November 2010

At present there have rarely studies on internal force and deformation for rock-socketed piles of deep excavation. The current approaches still exist and have many deficiencies and all of them didn't consider the effect of rock-socketed length. Based on the theoretical mechanics analysis of rock mass resistance, the computing methods of ultimate resistance Pult is applied to the analysis of force balance of rock-socketed part, the paper has put forward the detailed procedure for computing internal force and deformation of supporting rock-socketed piles in view of the rock-socketed length, moreover, the influence of the stability of rockmass is comprehensive considered in this method. Finally, an example is analyzed according to the procedure, the calculation results show that the method is much feasibility. The internal force and deformation of the retaining piles computed according to the procedure mentioned above satisfies the stability of rockmass.
Study and Application of Nano Antibacterial Technology on Nonwoven Materials
Authors: Qian Xiao Ming , Zhuang Xu Pin , Zhang Zhi Juan
Published: November 2010

The paper expatiates the nano material application on the nonwoven field and we carry on antibacterial test to the nonwoven fabric. All of these show that nano technology combine with nonwoven industry will have a great potential for widening product application field and promoting product overall performance, will create huge economical, social benefit on nonwoven industry in the future.
The Applications of Electrospun Nanofibers in the Medical Materials
Authors: Zhang Heng , Qian Xiao Ming
Published: November 2010

Electrospinning is a novel processing technique for the production of nanofiber non-woven materials and nanofiber non-woven materials have extremely high surface-to-mass (or volume) ratio and a porous structure .for the advantages of electrospun nanofiber non-woven materials, it can be used many filed. This review introduction the progress of electrospun nanofibers and summarize the application of electro spun nanofibers in the medical materials filed.
Structural, Magnetic and Microwave Absorbing Properties of Nanosized NiXZn1-xFe2O4 Powders Synthesized by Sol-Gel Technique
Authors: Zhu Xiang Rong , Lu Lin Feng , Shen Hong Lie
Published: November 2010

NixZn1-xFe2O4 (x=0.4, 0.6) powders are synthesized by sol-gel technique. The X-ray diffraction (XRD) measurements show their polycrystalline spinel structural characteristics. Both XRD and Atomic Force Microscopy demonstrate the samples are nanosized. At room temperature typical soft magnetism is exhibited by the samples. The reflection attenuation resulting from microwave absorption would reach to 1.9 dBm over the frequency range 6 GHz - 10 GHz when the samples are paved on a 10 cm  10 cm square aluminum plate with a thickness of about 0.35 mm.
Nanoindentation Test for the Strength Distrubution Analysis of Bonded Au Ball Bonds
Authors: Jalar Azman , Zulkifli Mohd Nubli , Abdullah Shahrum
Published: November 2010

The micromechanical properties at bonded Au ball bonds that have undergone three different time intervals of high temperature storage (HTS) have been characterised by using nanoindentation test. 12 indentations have been made at three different locations (Au, IMC and Si area) across the bonded ball bonds to evaluate the variation of hardness with the location of indentation. It was observed that each of the elements and compound that located at the bonded ball bonds exhibit different responses and micromechanical properties upon the nanoindentation tests. Au showed the highest creep behaviour compared to that of IMC and Si. It was observed that the plastic deformation response for Au and IMC were represented in load versus depth profile through the multiple pop-in events that exhibited in loading-unloading curve of Au and IMC. Finally, it was found that the hardness value and the tendency to brittle fracture of IMC were increased with the increment of the HTS time interval.
Characterization of Surface Strengthening Layer of 7A52 Aluminum Alloy by Supersonic Shot Peening and its Tribological Prop
Authors: He Jia Wu , Wang Xiao Ming , Ma Shi Ning , Li Chang Qing , Chen Chen
Published: November 2010

To improve its surface global performance, 7A52 aluminum alloy was treated by means of supersonic shot peening, then the structure of surface strengthening layer was characterized and its tribological properties were investigated, too. It was found that after having been peened, surface hardness of 7A52 aluminum alloy increased by 80%, surface crystalline grains were refined, a surface compression stress layer with thickness of 320μm was fabricated, which reached maximum 210MPa at the distance of 80~100μm from the top treated surface; The alloy performs superb tribological properties under both unlubrication friction and lubrication friction.