bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of Hydrophobic Silica/Fiber Composite Aerogels in Organic Absorption
Authors: Wei Wei , Li Chen Wei , Xie Ji Min , Zhu Jian Jun , Lü Xiao Meng , Yan Chang Hao
Published: February 2011

SiO2aerogels, the lightest solid material have attracted much attention recently. However, it is difficult to be used in practical applications due to its fragility. A facile one step polymerincorporation sol-gel process, together with a surface modification and a normal temperature drying process, was developed to prepare silica-fiber composite aerogels. Four fibers (polyester fiber, polypropylene fiber, lignin fiber, polycrylonitrile fiber) were selected to enhance the intensity of silica aerogels, respectively. The obtained samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) specific surface area. Results showed that samples have a plenty of hydrophobic methyl group attached to their surface. The continuous network structure composed of silica aerogels of high purity are non-crystallized, porous, surface areas from 800 to 980 m2/g and light weight nano-materials. Adsorption experiment of the above samples over organic solution (benzene, toluene) was tested. The composite aerogels absorbed the organic liquids by nearly 6-8 times its own mass, showing potential application in organic absorption.
Transition-Metal Impurities Removal from Metallurgical Grade Silicon by Electron Beam Injection
Authors: Zou Rui Xun , Jiang Da Chuan , Dong Wei , Gu Zheng , Tan Yi
Published: February 2011

The electron beam injection (EBI) process involves offering electrons around silicon powder, whose surface was oxidized, and subsequently the powder is washed by HF acid so as to remove the SiO2 film. The new electron beam injection process, in which micro electric filed formed between Si and SiO2 film will accelerate impurities diffusion from Si to SiO2 film, was developed and applied to eliminate the transition-metal impurities of MG-Si. It is proved to be effective to remove transition-metal impurities from metallurgical grade silicon (MG-Si). By applying the electron beam injection method, the removal rate of 10% to 59% was achieved during the refining process. The efficiency of impurity removal originates from two aspects: the impurity concentration gradient on both sides of Si/SiO2 interface; the micro electric field formed from Si to SiO2 film. A further increase in the removal rate can be realized by controlling the processing parameters.
Influence of Al2O3 Buffer Layers on the Properties of Indium–Tin Oxide Films on PET Substrate by RF-Magnetron Sputtering
Authors: Tang Wu , Chao Yi Peng , Fang Yong Si , Weng Xiao Long , Deng Long Jiang
Published: February 2011

Indium Tin Oxide (ITO) films on PET substrate sandwiching Al2O3 buffer layers with different thickness have been prepared by magnetron sputtering at low deposition temperature. The crystal structures, electrical and optical properties of ITO films have been investigated by XRD, four-point probe technology and UV-Vis spectrophotometer as a function of different Al2O3 buffer layers thickness, respectively. XRD reveals that there is an amorphous structure in ITO films with no buffer layer. However, ITO films became crystalline after sandwiching the buffer layer. It can be found that there are two major peaks, (222) and (400) of ITO film. A smallest resistivity of 3.53×10-4 Ω.cm was obtained for ITO film with Al2O3 buffer layers thickness 75nm. The average transmittance of ITO/Al2O3/PET films in the visible range of 400-760nm wavelength was around 80%. It can be conclude that the (222) orientation of ITO film is more in favor of low resistivity.
In Situ High Resolution Transmission Electron Microscopy Studies of High Temperature Behavior of Surface Al2O3 Thin Layer on an AlN Particle
Authors: Fukushima Hiroshi , Azuma Masanobu , Kanechika Yukihiro
Published: February 2011

A high temperature HRTEM holder equipped with a W-coil heater was used to make insitu observation of high temperature behavior of Al2O3 very thin (about 1 nm in thickness) protective film on AlN particles. The film was used to prevent AlN particles from damages by moisture. Rapid melting and rapid solidification of very small Al2O3 particles of about 2 nm in diameter were found within about 0.2 seconds. Therefore we concluded that the Al2O3 protective film worked as the sintering additives in the high temperature heating process. In the present study, very small Al2O3 particles were identified by the space between observed lattice fringe images. It was found that a tilt boundary was instantaneously formed and annihilated in an Al2O3 particle. There was also evidence that showed the formation and annihilation of edge dislocations within seven seconds during sintering.
Tribological Properties of Plasma Sprayed Self-Lubricating NiCr/Cr3C2-BN Composite Coatings
Authors: Huang Chuan Bing , Du Ling Zhong , Zhang Wei Gang
Published: February 2011

In this study, two kinds of NiCr/Cr3C2-BN composite powders were prepared with individual cladding (FKBN) and low pressure spray granulation (YLBN) methods, and the derived NiCr/Cr3C2-BN coatings were fabricated by plasma spraying technology. The microstructure, mechanical and tribological properties of the two coatings were systematically investigated. Both NiCr/Cr3C2-BN coatings have relatively high adhesive strength and microhardness, but the porosity of YLBN coating is much lower than that of FKBN coating. With comparison to FKBN coating, YLBN coating showed lower friction coefficient and better wear resistance, which was attributed to the more compact microstructure and uniform distribution of BN in the coating.
A Study of Yellow Solvent Dyes in Coated Paper Ink-Jet Ink System and Printing Test
Authors: Du Peng , Li Lu Hai , Ding Bing , Tang Xiao Jun , Xin Zhi Qing , Zhao Wen , Ni Ping Xiu
Published: February 2011

Because of clear image, bright color, high saturation of the color printing on coated paper, the ink-jet printing on coated paper catches more and more people’s eyes. In order to solve the problem of the ink-jet ink (cyan, magenta, yellow and black) on coated paper already developed out, whose yellow ink slants red and gloomy, different dyes are used to produce ink-jet ink. The inks were printed on the R-230 ink-jet printer on matt coated paper. The chromatic aberration is obtained on the basis of the colorimetric values in the ISO 12647-2:1996 eqv GB/T 17934.2-1999. It is found that the aberration of the Y79 is lower and its saturation is higher. The ink is filtered with 0.20 μm filter membrane and it can be used on ink-jet printing. The ink was used to print on the coated paper together with the previous cyan, magenta and black ink already developed out. The colorimetric values were measured and chromatic aberration and saturation is computed. The Color gamut graph of original inks and improved inks combination are made and compared to the standard of the ISO 12647-2:1996. It is found that the problems of hue unjust and gloomy color are improved compared to the previous four colors together. The cyan and magenta still stay away from perfect and it should be improved in future.
First Principle Study on Ti4AlN3 Properties under Pressure Effect
Authors: Chen Yang , Chu Mao You , Wang Li Jun
Published: February 2011

The structural, elastic and thermodynamic properties of the ternary layered nitrides Ti4AlN3 under the pressure effect have been calculated by using the full-potential linearized augmented plane-wave method within the generalized gradient approximation (GGA). The calculated properties such as cell parameters and bulk modulus, can found in good agreement with the experimental and other theoretical data. Using the quasi-harmonic Debye model in which the phonon vibration effects are considered, the thermodynamic properties such as thermal expansion coefficient, Debye temperature and specific heats in the whole pressure range from 0 to 50GPa and temperature range from 0 to 1600 K has been obtained.
Surface Treatment of Cubic Boron Nitride Grains Applied to Vitrified Bond Grinding Tools
Authors: Li Zi Cheng , Zhang Ai Ju , Li Zhi Hong , Zhu Yu Mei
Published: February 2011

Cubic boron nitride (cBN) grains treated with hydrochloric acid, nitric acid and sulphuric acid were investigated, respectively. The results indicated that the surface treatment technique with hydrochloric acid was an excellent method for improving the properties of cBN grains. After hydrochloric acid treating, cBN grains with clean surface and satisfied strength were obtained. Moreover, the bonding strength between cBN grains and vitrified bond was increased significantly for application in vitrified bond grinding tools.
Crystallization of Cu45Zr48Al7 Bulk Metallic Glass
Authors: Xu H.W. , Du Y.L. , Cheng J.L. , Chen Guang
Published: February 2011

The crystallization behavior of Cu45Zr48Al7 bulk metallic glass was studied by differential scanning calorimetry (DSC) and x-ray diffraction (XRD). Cu45Zr48Al7 bulk metallic glass exhibits two-stage crystallization in heating process. The crystallization peak temperature Tp1 and Tp2 shifted to higher temperature with increasing heating rate. It was found that the crystalline phases homogeneously nucleared at a constant rate and grew linearly at a constant rate in the supercooled liquid. Different bulk nanostructured alloys can be derived from Cu45Zr48Al7 bulk metallic glass by changing the heating rate and/or annealing temperature.
Morphologies of Quasicrystal Phase in Ternary Mg-Zn-Y Alloys
Authors: Wang Zhi Feng , Zhao Wei Min , Li Hai Peng , Qin Chun Ling , Wang Yue Mei , Liang Chun Yong , Chen Xue Guang
Published: February 2011

The paper studied various morphologies of the quasicrystal phase in Mg-Zn-Y alloys caused by different cooling rates. The cooling rates were reached through five kinds of cooling media. The cooling curves were monitored by multichannel data acquisition cards. A further heat treatment was made to study quasicrystal growth behavior. The results showed that, with the decrease of cooling rate, the quasicrystal morphology changed and its size became larger. Moreover, a planar quasicrystal morphology evolution schematic diagram during quasicrystal growth process was observed for the first time.
Preparation and Structural Phase Transitions of Silver Laurate
Authors: Li Ya Ling , Wang Shui , Zhang Xu , Chen Yuan Mei , Ning Jia Ning , Liu Guang Fei , Zhang Guo Qing
Published: February 2011

Thermal behaviors, compositions and structures of silver laurate prepared in wateralcohol system with double jet method has been investigated via DSC, FTIR, XRD and SEM, respectively. Silver nitrate, sodium hydroxide and lauric acid were used as reactants and PVP as protective agent. Results show that the highly ordered layer structures of as prepared samples were weakened at 173oC and 212oC and then decomposed at 238oC. The morphology changed from fiber-like to lamellar when the silver laurate was calcined at 212oC.
Construction of Biosensor Based on Glassy Carbon Electrode Modified by Composite Film of Multi-Walled Carbon Nanotubes and Poly(ethylenimine)
Authors: Sun Tao , Zheng Hai Tao , Li Wei Wei , Liu Pu , Ruan Yan Li , Suye Shinichiro
Published: February 2011

Multi-walled carbon nanotubes (MWCNTs) were dispersed in an aqueous solution containing water-soluble poly(ethylenimine), and used to prepare MWCNTs modified glassy carbon electrode (GC/MWCNTs). A scanning electron microscopy was employed for characterizing the surface morphology of the modified electrode. The electrochemical behaviors of coenzyme (reduced nicotinamide adenine dinucleotide, NADH) on GC/MWCNTs were studied by both cyclic voltammetry and amperometry, and it is found clearly that the high overpotential for the direct oxidation of NADH on bare GC electrode was largely decreased in the presence of MWCNTs. The GC/MWCNTs electrode exhibited excellent properties as a platform for the construction of electrochemical biosensors based on NAD-dependent dehydrogenases, and an alcohol biosensor was successfully developed by immobilizing alcohol dehydrogenase on GC/MWCNTs.
Preparation and Morphological Characteristics of Cellulose Micro/Nano Fibrils
Authors: Chen Wen Shuai , Yu Hai Peng , Chen Peng , Jiang Nai Xiang , Shen Jiang Hua , Liu Yi Xing , Li Qing
Published: February 2011

Cellulose micro/nano fibrils generated from biomass are relative new reinforcing materials for polymer composites, which have potential lightweight and high strength and are renewable. In the present study, the preparation method of extracting cellulose micro/nano fibrils from wood was introduced. After successful disintegration, the morphological characteristics of the wood fibers, purified cellulose fibers, cellulose fibers activated by ultrasonic-wave and cellulose micro/nano fibrils after homogenization treatment, were compared by visual examination and scanning electron microscopy. The results showed that cellulose micro/nano fibrils have been efficiently extracted from wood, which have great potential in the application areas of papermaking, bio-nanocomposites, food, cosmetics/skin cream, medical/pharmaceutical, and so on.
Synthesis and Characterization of Nanocrystalline SnO2 Powder
Authors: Liu Shi Min , Ding Wan Yu , Jiang Wei Wei , Chai Wei Ping
Published: February 2011

Nanocrystalline SnO2 powder has been synthesized via direct precipitation method starting from Sn, HNO3, HCl, and NH4OH. Thermal properties, crystal structural and morphological properties of the precursor and SnO2 powder were investigated using simultaneous thermogravimetry-differential thermal analysis, X-ray diffraction and transmission electron microscopy. The results indicated that the precursor was SnO2 rather than Sn(OH)2 or Sn(OH)4. On the basis of the precursor, well crystallized SnO2 powder with 4-5 nm in diameter was obtained, after calcined at 350 °C for 2 h.
Preparation of Chitosan/Poly(vinyl Alcohol) Blend Nanofibers Containing Ag-SiO2 Nanoparticles via Electrospinning
Authors: Zuo Fang Fang , Cheng Bo Wen , Kang Wei Min , Ma Yu Hao
Published: February 2011

Chitosan (CS) / poly(vinyl alcohol) (PVA) blend nanofibers containing Ag-SiO2 nanoparticles (CS/PVA/Ag-SiO2 nanofibers) were successfully prepared by electrospinning using formic acid (HCOOH) as solvent in this paper. The morphology, diameter and structure of the electrospun nanofibers were examined by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS). And the diameter distribution of the nanofibers was measured by Image-Pro Plus. The results showed that the ideal nanofibers with the diameter in 85-165 nm can be obtained with the proper technical parameters as follows: the spinning voltage at 40 kV, the extruding speed at 0.5 mL/h and the collecting distance at 200 mm. The CS/PVA/Ag-SiO2 nanofibers will present potential applications in wound dressing and bandage etc.
Reflective Liquid-Like Films of Silver Nanoparticles
Authors: Wu Long Jia , Wang Yu Guang , Zhang Lian Meng
Published: February 2011

Reflective liquid-like films of silver nanoparticles simultaneously have metallic luster and the macroscopic properties of a fluid. Owing to their special properties, the films can be potential materials for the component of a new kind of liquid mirrors. The influence of different sizes of nanoparticles on the films reflectivity has been considered in this study. A great improvement on the reflectivity of the films has been found with the increase in the silver nanoparticles’ size. Additionally, the volume of the liquid substrate also has an effect on the reflectivity of the films. Characterization of the films by X-ray diffraction indicates that the liquid-like films are mainly composed of fcc silver nanoparticles rather than silver compounds.
Hydrothermal Synthesis of Flower-Like Silver Nanoplate Micro-Assemblies in High Yields
Authors: He Xin , Yang Su Yu , Zhang Mei
Published: February 2011

We demonstrated the fabrication of the flower-like silver nanoplate micro-assemblies in high yields by a facile hydrothermal method. This novel nanostructure was synthesized in the presence of poly (vinyl pyrrolidone) (PVP) and ascorbic acid (AsA) at 150 °C for 10 h. The microassemblies with average size of 1~2 μm are consisted of several uniform nanoplates and show face centered cubic structure. The effects of the concentration of reactants, molar ratio of silver nitrate to ascorbic acid on the formation of the flower-like silver micro-assemblies were also presented.
Research on the Porous Structures and Properties of Composite Membranes of Polysulfone and Nanocrystalline Cellulose
Authors: Li Shuai , Gao Yuan , Bai Lu , Tian Wei Qian , Zhang Li Ping
Published: February 2011

Nanocrystalline cellulose (NCC) was used to improve hydrophilic property and permeability of polysulfone (PS) membrane. It was prepared from cellulose pulp by acid-catalyzed hydrolysis and high-pressure homogenization. The casting solution of a PS/NCC blend was obtained by adding NCC to a PS membrane solution and the composite membrane was prepared by phase-inversion method. In addition, the concentration of NCC was increased gradually from 0 wt% to 1.1 wt% during the preparation in order to examine the pure water flux and the retention of a bovine serum albumin (BSA). Simultaneously, the porosity and mean pore size of the membrane was detected and calculated. The result showed that the capacity for ultrafiltration was enhanced with appropriate NCC content. The membranes were also observed with atomic force microscopy (AFM) and scanning electron microscopy (SEM) to explore their porous structures.
Characterization of Asphalt Binders Modified with Hydrated Lime and Limestone Dust
Authors: Ma Li Xing , Li Zhi Da , Huang Jun Feng
Published: February 2011

The mixture of asphalt and filler called asphalt binder is an adhesive and packing material in asphalt mixture. In this paper, the influence of different filler sorts such as limestone dust and hydrated lime, and different rates of limestone dust and hydrated lime such as 2:1, 1:1 and 1:2 at the same mass ratio of filler/asphalt (1.0) on the asphalt binder’s properties has been studied. The paper gives a description of the most commonly used conventional tests, such as Penetration and Softening Point, and a more detailed description of the viscoelastic behavior and dynamic testing of bitumen by way of Brookfield viscometer and Dynamic Shear Rheometer (DSR). The contrasts among different test results were presented. It is found that there are a decrease in penetration and an increase in softening point with increasing hydrated lime content. The viscosity also increases obviously with the mass of hydrated lime increases. The DSR results show that hydrated lime can increase asphalt binders' anti-shear stress and G*/sinδ, and are helpful to its properties at high temperature. The four tests results were also incorporated to evaluate the temperature susceptibility and the rheological characteristics of asphalt binders.
Effect of Hot Extrusion on the Microstructure of In Situ TiB2 Particulate Reinforced Magnesium Matrix Composite
Authors: Wu N.N. , Fang C.F. , Bai Yun , Meng L.G. , Hao Hai , Zhang Xing Guo
Published: February 2011

The TiB2/AZ31 magnesium matrix composite was fabricated via self-propagating hightemperature synthesis (SHS) and then hot extruded. The influence of hot extrusion on the microstructure and property of TiB2/AZ31 composites was investigated. The results show that hot extrusion and synthesized TiB2 particles could refine the grain size obviously. The synthesized TiB2 particles are micro- and nano-sized, dispersing homogenously in the matrix. The interface between the matrix and the particles are good bonding. Meanwhile, slip and twinning are the main deformation modes during the hot extrusion. The fracture surface of hot-extruded TiB2/AZ31 magnesium matrix composite has more dimples than the as-cast AZ31 magnesium alloy. The improvement of microstructure seems to be beneficial for the fracture ductility of TiB2/AZ31 magnesium matrix composite.
Anticorrosive Properties of Epoxy/Polyurethane IPNs Coatings Modified by Organic Montmorillonite
Authors: Shan Shao Yun , Jia Qing Ming , Jiang Li Hong , Wang Ya Ming
Published: February 2011

Epoxy/polyurethane interpenetrating polymer network coatings(EP/PU IPNs) modified by organic montmorillonite(oMMT)were prepared by interpenetrating polymer technology and in situ intercalative polymerization methods. TEM analysis showed that there is interaction between the oMMT and EP, PU phase, and the oMMT plays a role of "cross-linking point", changing the EP/PU matrix microstructure. Electrochemical analysis showed that oMMT and IPNs of EP and PU exhibits synergistic effect on improving anticorrosive properties of pure EP. When PU content is 30%, oMMT content is 3%, the EP/PU IPNs coatings has the best corrosion resistance.
Solid Proton Conductor Based on Natural Diatomite
Authors: Wang Bo
Published: February 2011

Proton conductivity of the natural diatomite was studied by AC complex impedance technique. At room temperature, the highest proton conductivity was found to be 4.5　10-7 S·cm-1. By hydrating the diatomite, the proton conductivity was increased by two orders of magnitude. The room temperate proton conductivity of the hydrated diatomite (5.5　10-5 S·cm-1) was comparable to other hydrated solid proton conductors. Based on these results, the natural diatomite could be used as solid proton conductor for various electrochemical applications such as fuel cells, gas sensors, humidity sensors, and pH sensors.
Extensional Rheology of LDPE from Melt Spinning Technique
Authors: Zhong Lei , Liang Ji Zhao
Published: February 2011

The extensional rheology of low density polyethylene (LDPE) is studied bymelt spinning technique. Melt spinning mastercurves for LDPE are plotted for the measurement results of various temperatures and extrusion velocities. Linear relations between scaling factor b and T, Logb and Logv0 have been found. The analysis indicates that b can be regarded as a useful index of combination effects on the pre-orientation before extension, and on the unwrapping and orientation of macromolecular chains during extension. By using the values of b and the data from reference curve, extension viscosity curves of any setting temperature and extrusion velocity can be calculated, which will effectively enlarge the measurement range of melt spinning technique.
Microstructure and Properties of High Performance Concrete with Steel Slag Powder
Authors: Li Yun Feng
Published: February 2011

As an active admixture, super fine steel slag powder can be mixed into concrete to produce high performance concrete. The microstructures between cement paste mixed with steel slag powder and plain cement paste are experimentally studied. The SEM of the microstructures shows that microstructure of cement paste are changed by active mineral admixture, the internal structure of the cement paste are improved. Drying shrinkage of cement mortar with different steel slag kinds and different dosage of admixtures are measured. Experiments results show the effect of steel slag powder on drying shrinkage of cement mortar.
Temperature Field Simulation of Nitride Hard Film Irradiated by High-Intensity Pulsed Ion Beam
Authors: Chen Jun , Xing J. , Lin Li , Hao Sheng Zhi , Lei M.K.
Published: February 2011

Surface treatment of hard nitride film with high-intensity pulsed ion beam (HIPIB) was investigated in the present research. On considering the high energy density and short pulse duration of HIPIB source, a one-dimension physical model was built according to the structure feature of film-base sample. It was found that the irradiation of HIPIB lead to a very fast thermal recycle of heating rate 1011K/s and cooling rate up to 1010K/s. The highest temperature located at the surface of film irradiated. When using the HIPIB parameters of accelerating voltage 350kV, pulse duration 70ns and current density 60A/cm2, the surface layer of film would be melt with depth of about 0.35mm, that was verified by the experimental result along with the grain refinement effect due to the fast solidification process.
Microstructure and Properties of Thin-Wall Part by Laser Metal Deposition Shaping
Authors: Zhang Kai , Shang Xiao Feng
Published: February 2011

Laser additive direct deposition of metals is a new rapid manufacturing technology, which combines with computer aided design, laser cladding and rapid prototyping. The advanced technology can build fully-dense metal components directly from CAD files without a mould or tool. With this technology, a promising rapid manufacturing system called “Laser Metal Deposition Shaping (LMDS)” is being constructed and developed. Through the LMDS technology, fully-dense and near-net shaped metallic parts can be directly obtained through melting coaxially fed powder with a laser. Typically, the microstructure and mechanical properties of the as-formed thin-wall part were tested and analyzed synthetically. The results show that there are different grain categories distributing in certain position of thin-wall part, and the mechanical properties represent as anisotropy.
Synthesis of LiFePO4 Cathode Materials by a Chemical Method
Authors: Sun Yuan , Zhao Xiu Juan , Ren Rui Ming
Published: February 2011

The olivine-type LiFePO4 powder was prepared by a chemical method using the synthesized FePO4⋅2H2O, LiOH and glucose as raw materials. The synthesized FePO4⋅2H2O powder was obtained by co-precipitation method. FePO4⋅2H2O and LiFePO4 powders were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed the synthesized FePO4⋅2H2O powder at pH of 2.05 was in a single phase and nearly spherical in shape. Using the synthesized powders to prepared LiFePO4 at 600 °C in vacuum for 2 h was nearly spherical in shape and whose size was in the range of 0.1-0.5μm.
Features of Grain Boundary Character Distributions in a Austenitic Stainless Steel after Cold Rolling with Low Strain Followed by Single and Two-Step Annealing
Authors: Fang Xiao Ying , Guo Hong , Wang Wei Guo
Published: February 2011

The grain boundary character distributions (GBCDs) of two 304-type austenitic stainless steel samples, which are cold rolled with the same thickness reduction of 6% and then subjected to different annealing treatments are examined by Electron back-scatter diffraction (EBSD) techniques. The results indicate that, after 6% cold rolling, the two-step annealing (900°C/1 h+1050°C/5 min, Sample B) resulted in a quite different GBCDs compared with that obtained by single-step annealing (1050°C/5 min, Sample A) regardless of nearly the same fractions of S3 boundaries developed in the two samples. It was evidenced that large-sized cluster of grains interfaced by S3n boundaries (S3n CG) emerged in sample B, in which there are moderate preferential grain orientation distribution and {111} grain boundary plane distributions. Further discussions highlighted that, in the case of two-step annealing, the first annealing at relatively low temperature (900°C) for short time (1h) contributes a lot to the final optimization of GBCD and strain induced preferential boundary migration (SIBM) accompanied by multiple twinning via the migration and interactions between mobile S3n boundaries, especially incoherent S3 boundaries, might be the responsible mechanisms.
Study of Friction Coefficient and Friction Force on Magnetic Abrasive Finishing
Authors: Chen Yan , Shimamoto Akira , Gao X. , Zhang M.M.
Published: February 2011

In order to enhance grinding efficiency of the magnetic abrasive finishing (MAF) method, we usually use the sinter method or the cementation method to mix the magnetic particles and abrasive particles together. However, the cost is high, and the variety is incomplete. Therefore, with the ferromagnetism to iron particles, the alumina particles and the lipin three kind of material simple mixture participate in the magnetic abrasive finishing which directly polishes, already obtained the good effect through the experiment. This paper analyses and explains the characteristic of the friction coefficient and the friction force on magnetic abrasive finishing according as account and experiment data.
A Study of Wear Rate Estimation of Coatings by a Numerical Method
Authors: Yang Yu Sen , Huang Wesley
Published: February 2011

The paper reported using a mathematical model that simulated the wear volume in comparison to measurement by a ball-on-disc for deposited CrN films on tool steel (JIS SKD11). Three dimensional profile instruments were used to measure the wear scar trace for variations of numerical data of two dimensional profiles. By using numerical algorithms, the wear volume measurements of wear profiles are to save considerable time and economical. A new mathematical method is issued for determining wear volumes in this study. The estimated results were precisely fitted as compared with other calculations for three dimensional estimations of wear volumes.
Embrittlement of Ti-23Al-17Nb Alloy Laser Welded Joint at 650°C
Authors: Song Zhi Hua , Wu Ai Ping , Wang Guo Qing , Zou Gui Sheng , Ren Jia Lie
Published: February 2011

The tensile ductility of the Ti-23Al-17Nb (at.%) alloy laser welded joints is very low at 650°C, so the embrittlement of the joints at high temperature was investigated. The metastable coarse B2 phase of the as-welded metal transformed into coarse O phase in the weld zone when the joints were heated up to 650°C. This type of phase transformation was based on shear transformation. Coarse orthorhombic O phase has lower ductility compared with body-centered cubic B2 phase. Meanwhile, the shear transformation from B2 to O phase could induce stress-strain concentrations in the grain boundary, which seriously weakened the grain boundary of the columnar grains and led to the brittle fracture characteristics in the weld zone during tensile test at 650°C.
Mechanical Properties of Nanocrystalline Diamond Film Prepared by HFCVD
Authors: Xu Feng , Zuo Dun Wen , Lu Wen Zhuang , Mang Min
Published: February 2011

Nanocrystalline diamond film was deposited on silicon by double bias hot filament chemical vapor deposition (HFCVD) system. The effect of substrate temperature on the microstructure and mechanical properties of the film were investigated systematically. More defects and non-diamond contents were found as the decrease of grain size, which cause the decrease of hardness and elastic modulus. It is shown that the proper substrate temperature is in the range of 720~760 . The excessively high substrate temperature leads to the °C dramatic increase of nondiamond content and the decrease of mechanical properties.
The Thermal Conductivity Analysis of Sip/Al Base Composites
Authors: Li Ming , Hao Hai , Song Ying De , Zhang Xing Guo
Published: February 2011

Aluminum base composites with particles reinforced have high thermal conductivity, low thermal expansion coefficient, low density, and excellent working ability. On one hand the Sip/Al composites are prepared by pressure-less infiltration in experiments and take advantage of the finite element analysis to establish the models of Sip/Al composites. On the other hand, the Sip/Al composites morphology, the particles size, the volume fraction and the ratio between different Si particles have been discussed in the experiments. In experiments how they affect the thermal conductivity of the composites also has been explained. The thermal conductivity of Sip/Al composites is around 100 W/(m.k) at 50°C. When the Si volume fraction is definite, the thermal conductivity of the composites is little affected by the morphology, the size and the ratio between different Si particles. The study also showed that with the element Si content increasing, the thermal conductivity will decrease.
Fabrication of SS316L/Ni25 Functionally Gradient Materials Using Laser Engineered Net Shaping
Authors: Wu Dong Jiang , Liang Xiao Kang , Li Qian , Jiang Li Jia
Published: February 2011

Functionally gradient materials(FGMs) were successfully fabricated with compositions gradually changed from 100% stainless steel 316L to 100% Ni25 alloy using laser engineered net shaping(LENS) technology. The microstructure characterization, composition analysis and microhardness along the gradient direction are investigated. Meanwhile, the defects in the sample such as cracks and pores are analyzed. The results indicated that the microstructure evolves from columnar dendrite to cellular-crystal or equiaxed dendrite.
Roll Casting of Al-SiCp Strip
Authors: Haga Toshio , Nakamura Teppei , Kumai S. , Watari H.
Published: February 2011

The strip casting of Al-SiCp alloy was operated by a high speed twin roll caster. The content of SiCp was 20Vol% and 30Vol%. Both of Al-20Vol%SiCp and Al-30Vol%SiCp strips could be cast continuously at the speed up to 90m/min. The SiCp particle distributed uniformly. This was the effect of fine grain of the strip. The as-cast strip of Al-20Vol%SiCp could be cold rolled after homogenization. The as-cast strip of Al-30Vol%SiCp could be cold rolled after once hot rolling and annealing. The as-cast strip of Al-20Vol%SiCp could be coiled at the diameter of 460mm.
Deformation Mechanism Analysis of Hydro-Drawing Parabola Workpieces Based on DYNAFORM
Authors: Kuang Wei Hua
Published: February 2011

A three-dimensional finite element model of hydro-drawing parabola workpieces was built in this study. By finite element analysis, the deformation was obtained. Based on simulation, the changing trends of stress and strain were obtained. In addition, thinning and FLD were studied. These results might provide useful reference on design improvement of the hydro-drawing process.
Experiment Research on Removing Metal Impurities of the Pot Material in Vacuum Directional Solidification
Authors: Ma Wen Hui , Mei Xiang Yang , Wei Kui Xian , Tang Shao Yu
Published: February 2011

The pot material of Sb-doped n-type mono-crystal silicon was purified by our selfassembled vacuum directional solidification furnace. In the experimental, the pulling rate was 7μm/s, 10μm/s, 20μm/s, 30μm/s and 40μm/s, respectively. The experimental concentration of Sb, Al and Fe at 0.3 proportion of silicon ingot bottom to the top is detected and the theoretical concentration is calculated. The experimental results show that the pulling rate causes a great effect to concentration of Sb and a small effect to concentration of Fe. At the same time, the theoretical distribution concentration and experimental distribution concentration were compared. The experimental route provided a promising idea for complex utilization of the pot material.
Functionalized Silica Fume for Chromium (VI) Removal from Wasterwater
Authors: Zhou Yang , Wang Shi Xing , Xie Ke Qiang , Dai Yong Nian , Ma Wen Hui
Published: February 2011

Chemical modified silica fume by polyaniline was studied as a sorbent for removal of chromium (VI) determined by flame atomic absorption spectrometer. TEM analysis confirmed that the mean diameter of silica fume before and after treatment was of the order of 120 nm. The functionalized nanoparticles showed an extremely high efficiency towards chromium (VI) in the pH range of 4-5. Adsorption of chromium (VI) from water using functionalized silica fume was both a simple and efficient approach compared to the traditional adsorbents from the angle of integrated utilization of the secondary resources.
Finite Element Simulation of Microstructural Evolution during Inertia Friction Welding Process of Superalloy GH4169
Authors: Xu Wei , Zhang Li Wen , Yue Chong Xiang
Published: February 2011

During the inertia friction welding (IFW) process of superalloy GH4169, the main mechanism for microstructural evolution is dynamic recrystallization (DRX). In order to investigate the microstructural evolution during the process, a finite element (FE) model coupled with the DRX model of the alloy was developed on the platform of MSC.Marc. Equivalent strain was introduced into the DRX model to improve the computational precision. As a result, the IFW process with microstructural evolution was simulated. Simulated results reveal that DRX region is very small. Fully recrystallized region and fine grains appear near the weld line. Dynamically recrystallized fraction (DRXF) decreases and grain size increases with the increase of the distance from the weld line. Predicted results of microstructural distribution agree well with experimental ones.
Modeling Nucleation of Hydrogen Induced Cracking in Steels during Sour Service
Authors: Liu W.J.
Published: February 2011

A model, which can be used to illustrate the process of nucleation of hydrogen induced cracking (HIC) in steels during sour service, was developed with the aid of Gibbs theory. A set of criteria for crack nucleation were then derived from the model. Metallurgical parameters influencing the criteria and thusly the susceptibility of the material to HIC, which are measurable and controllable in industrial processing, were also advanced in the present article.
Numerical Simulation of Solidification Process for a Machine Tool Bed
Authors: Tang Ling , Wang Xu Dong , Zhao Hai Jing , Yao Man
Published: February 2011

In this paper, the flow, heat transfer and stress during solidification process of the machine tool bed weighed about 2.5ton that has been optimized by structural topologymethod, was calculated with ProCAST software, and the causes of the crack forming in the casting of the machine tool bed was analysed. According to the calculation results, the structural design of the local part where cracks tends to form has been improved, and the heat transfer and the stress are calculated again. By comparing the temperature field with filling of molten cast iron and without filling, it has been found that there was little effect of filling on the results of temperature distribution of the cast, therefore the effect of filling can be ignored in the following temperature field calculation to save computation time. The model has been simplified in the stress field calculation with considering the complexity of the machine tool bed and the cost of computation. Then, the merits and demerits of the original design and the improved design are compared and analyzed depending on the calculated temperature and stress results. It is suggested that the improved one could get a more uniform temperature distribution and then the trend of the crack occurring can be greatly reduced. These results could provide a guide for the actual casting production, achieving the scientific control of the production of castings, ensuring the quality of the castings.
Sheet Material Property Effects upon Dynamic Behavior in Self-Pierce Riveted Joints
Authors: He Xiao Cong
Published: February 2011

Self-pierce riveting (SPR) technology offers an alternative to resistance spot welding (RSW) for joining sheet materials. It has been found that the SPR technology produced a much stronger joint than the RSW in fatigue test. For efficient design of SPR structures, the knowledge of dynamic characteristics of the SPR beams is essential. In this paper, the free transverse vibration characteristics of single lap-jointed cantilevered SPR beams are investigated in detail. The focus of the analysis is to reveal the influence on the natural frequency and natural frequency ratio of these beams caused by variations in the material properties of sheet materials to be jointed. It is shown that the transverse natural frequencies of single lap jointed cantilevered SPR beams increase significantly as the Young’s modulus of the sheet materials increases, but change slightly corresponding to the change in Poisson’s ratio. It is also found that the material density of the sheets have significant effects on the free transverse vibration characteristics of the beams.
Genome-Wide Expression Profiling Identifies an Impairment of Negative Feedback Signals in the Crohn’s Disease-Associated NOD2 Variant L1007fsinsC
Authors: Billmann-Born Susanne , Till Andreas , Arlt Alexander , Lipinski Simone , Sina Christian , Latiano Anna , Annese Vito , Häsler Robert , Kerick Martin , Manke Thomas , Seegert Dirk , Hanidu Adedayo , Schäfer Heiner , van Heel David , Li Jun , Schreiber Stefan , Rosenstiel Philip
Published: February 2011

NOD2 is an intracellular receptor for the bacterial cell wall component muramyl dipeptide (MDP), and variants of NOD2 are associated with chronic inflammatory diseases of barrier organs (e.g., Crohn’s disease, asthma, and atopic eczema). It is known that activation of NOD2 induces a variety of inflammatory and antibacterial factors. The exact transcriptomal signatures that define the cellular programs downstream of NOD2 activation and the influence of the Crohn-associated variant L1007fsinsC are yet to be defined. To describe the MDP-induced activation program, we analyzed the transcriptomal reactions of isogenic HEK293 cells expressing NOD2wt or NOD2L1007fsinsC to stimulation with MDP. Importantly, a clear loss of function could be observed in the cells carrying the Crohn-associated variant L1007fsinsC, whereas the NOD2wt cells showed differential regulation of growth factors, chemokines, and several antagonists of NF-κB (e.g., TNFAIP3 [A20] and IER3). This genotype-dependent regulation pattern was confirmed in primary human myelomonocytic cells. The influence of TNFAIP3 and IER3 in the context of NOD2 signaling was characterized, and we could validate the predicted role as inhibitors of NOD2-induced NF-κB activation. We show that IER3 impairs the protective effect of NOD2wt against bacterial cytoinvasion. These results further our understanding of NOD2 as a first-line defense molecule and emphasize the importance of simultaneous upregulation of counterregulatory anti-inflammatory factors as an integral part of the NOD2-induced cellular program. Lack of these regulatory events due to the L1007fsinsC variant may pivotally contribute to the induction and perpetuation of chronic inflammation.
Strongyloides ratti Infection Induces Expansion of Foxp3+ Regulatory T Cells That Interfere with Immune Response and Parasite Clearance in BALB/c Mice
Authors: Blankenhaus Birte , Klemm Ulrike , Eschbach Marie-Luise , Sparwasser Tim , Huehn Jochen , Kühl Anja A. , Loddenkemper Christoph , Jacobs Thomas , Breloer Minka
Published: February 2011

To escape expulsion by their host’s immune system, pathogenic nematodes exploit regulatory pathways that are intrinsic parts of the mammalian immune system, such as regulatory T cells (Tregs). Using depletion of Treg mice, we showed that Foxp3+ Treg numbers increased rapidly during infection with the nematode Strongyloides ratti. Transient depletion of Tregs during the first days of infection led to dramatically reduced worm burden and larval output, without aggravation of immune pathology. The transient absence of Tregs during primary infection did not interfere with the generation of protective memory. Depletion of Tregs at later time points of infection (i.e., day 4) did not improve resistance, suggesting that Tregs exert their counterregulatory function during the priming of S. ratti-specific immune responses. Improved resistance upon early Treg depletion was accompanied by accelerated and prolonged mast cell activation and increased production of types 1 and 2 cytokines. In contrast, the blockade of the regulatory receptor CTLA-4 specifically increased nematode-specific type 2 cytokine production. Despite this improved immune response, resistance to the infection was only marginally improved. Taken together, we provide evidence that Treg expansion during S. ratti infection suppresses the protective immune response to this pathogenic nematode and, thus, represents a mechanism of immune evasion.
Piecing Together the Puzzle of Graduate Employment
Authors: Parris Melissa A. , Saville Kerrie
Published: February 2011

Providing graduates with a set of skills and attributes relevant to their future employment remains a key topic in both higher education policy and research. This paper reports findings from a pilot study of human resource management (HRM) students' perceptions of the graduate work experience. Specifically, it focuses on how these perceptions are shaped, driven by a concern for the uncertainty – and even fear – expressed by the study's participants in relation to their future workplace experiences. The influences of three key factors in shaping participants' expectations are discussed: the graduate recruitment experience, previous work experiences and ‘graduate work folklore’ from the stories of family and friends. With these influences not always providing students with a realistic picture of their future work experience, we conclude that educators need to improve the opportunities for practical experience and industry knowledge through work placements, stronger links with industry and increased exposure to the practicalities of work within the curriculum.
Organic Light‐Emitting Diodes: Organic Light‐Emitting Diodes with a White‐Emitting Molecule: Emission Mechanism and Device Characteristics (Adv. Funct. Mater. 4/2011)
Authors: Kim Se Hun , Park Sanghyuk , Kwon Ji Eon , Park Soo Young
Published: February 2011

The unique and unprecedented electroluminescence behavior of the white‐emitting molecule 3‐(1‐(4‐(4‐(2‐(2‐hydroxyphenyl)‐4,5‐diphenyl‐1H‐imidazol‐1‐yl)phenoxy)phenyl)‐4,5‐diphenyl‐1H‐imidazol‐2‐yl)naphthalen‐2‐ol (W1), fluorescence emission from which is controlled by the excited‐state intramolecular proton transfer (ESIPT) is investigated. W1 is composed of covalently linked blue‐ and yellow‐color emitting ESIPT moieties between which energy transfer is entirely frustrated. It is demonstrated that different emission colors (blue, yellow, and white) can be generated from the identical emitter W1 in organic light‐emitting diode (OLED) devices. Charge trapping mechanism is proposed to explain such a unique color‐tuned emission from W1. Finally, the device structure to create a color‐stable, color reproducible, and simple‐structured white organic light‐emitting diode (WOLED) using W1 is investigated. The maximum luminance efficiency, power efficiency, and luminance of the WOLED were 3.10 cd A−1, 2.20 lm W−1, 1 092 cd m−2, respectively. The WOLED shows white‐light emission with the Commission Internationale de l′Eclairage (CIE) chromaticity coordinates (0.343, 0.291) at a current level of 10 mA cm−2. The emission color is high stability, with a change of the CIE chromaticity coordinates as small as (0.028, 0.028) when the current level is varied from 10 to 100 mA cm−2.
Back of house/under the house: some psychoanalytic aspects of the acquisition and exhibition of art by survivors of the holocaust
Authors: Koh Eugen , Halasz George
Published: February 2011

The phrase “back of house” often refers to art gallery processes that are rarely seen by visitors. These include the processes of acquisition, cataloging, conservation, the development and production of exhibitions, and the planning of related public programs. This paper proposes that a psychoanalytic consideration of “back of house” art gallery processes can provide important insights into the nature of trauma that is manifested through creative efforts. It explores some of the psychoanalytic aspects of a unique project concerning the art by survivors of the Holocaust. It highlights transgenerational trauma and how a thoughtful process of acquisition and exhibition can facilitate the working through of a collectively painful experience in a traumatized community. Copyright © 2011 John Wiley & Sons, Ltd.
A uniform asymptotic expansion for stochastic volatility model in pricing multi‐asset European options
Authors: Ma Yansheng , Li Yong
Published: February 2011

In this paper, we consider a stochastic volatility model for pricing multi‐asset European options that are widely used in the real world, under the assumption that the volatilities are driven by different OU processes. Using the singular perturbation method for multi‐parameter and the boundary layer theory, we derive a uniform asymptotic expansion for the option prices, as well as the uniform error estimates. Copyright © 2011 John Wiley & Sons, Ltd.