bluuebunny/crossref_metadata_2025 huggingface dataset:
The Research of Spraying SiC/Cu Electronic Packaging Composites
Authors: Hu Ming , Gao Jing , Zhang Yun Long
Published: July 2011

The SiC/Cu electronic packaging composites with excellent performance were successfully prepared by the chemical plating copper on the surface of SiC powders and high-speed flame spraying technology. The results showed that the homogeneous dense coated layers can be obtained on the surface of SiC powder by optimizing process parameters. The volume fraction of SiC powders in the composites could significantly increase and figure was beyond 55vol% after spraying Copper. The SiC and Cu were the main phases in the spraying SiC/Cu electronic packaging composite, at the same time Cu2O can be tested as the trace phase. The interface combination properties of SiC/Cu in the hot-pressed samples can obviously improve. The thermal expansion coefficient and thermal conductivity of SiC/Cu electronic packaging composite basic can satisfy the requirements for electronic packaging materials.
Properties of Waterborne Polyurethanes: Effect of NCO/OH Ratio
Authors: Jiu Yong Bin , Zeng Xin Miao , Ji Jun Hui , Zhai Yu , Wang Lian Cai
Published: July 2011

Waterborne polyurethanes(WPUs) based on isophorone diisocyanate(IPDI), Polybutylene adipate (PBA) and dimethylolproprionic acid(DMPA) were synthesized by prepolymer mixing process. Effect of NCO/OH ratio on the properties of the dispersions was studied. The structure of the WPUs was studied by FT-IR. Besides the mechanical properties and water swelling of the films, the number average diameters of the dispersions and the viscosity of WPUs were characterized, results showed that all WPUs had higher solid content (over 45%). With higher NCO/OH ratio, WPUs had bigger dispersion size and lower dispersion viscosity; the casting film had higher water swelling, lower tensile strength, and more water-soluble substance.
Composite Behavior of Concrete Slab with Steel Decking under Flexural Loading
Authors: Kan Yu Cheng , Chen Li Huai , Wu Chung Hao , Yen Tson , Liao Hui Wen
Published: July 2011

In this study, mechanical behavior and failure pattern of composite concrete deck were investigated. A unique dimension of steel concrete deck was fabricated and tested in four-point bending. Two series of decking were also designated with bolts at a spacing of 15 cm and 30 cm, used to compare with those without bolt. Totally, 9 composite concrete decks were tested in a close-loop servo-hydraulic testing system (MTS) using displacement control. Load versus displacement curves as well as failure patterns of the specimens were studied to figure out the mechanical behavior of this type of composite structure.
Numerical Simulation Research of Flexible Shield Support Lateral Caving Technology
Authors: Zhao Tong Bin , Yin Yan Chun , Sun Qing , He Shu Dong
Published: July 2011

The arrangement and caving order of the mouths after the shield are the key technological problems of lateral caving in flexible shield support face of steep inclined coal seam,and restrict the production.Based on the geological and production conditions of Muchengjian Mining 5113 flexible shield support face in Beijing mining area,lateral caving was simulated by using PFC2D.Single mouth caving and double mouth caving in different orders were researched.It showd that double mouth caving discharged more coal than the single one.When opening two mouths,caving from the upper to the lower had discharged the most coal.Open the third mouth between the two mouths could discharge more coal.The best technology of caving was caving from the upper mouth to the lower one.It increased the rate of recovery and decreased the workload.
Effect of TiO2 on Mechanical Properties and Microstructure of Magnesium Aluminate Spinel Refractories
Authors: Wei Jun Cong , Han Xiao Cui , Gao Chun Hui , Huang Jian Kun , Tu Jun Bo
Published: July 2011

MgO-Al2O3-TiO2 composite refractories were prepared by using magnesium aluminate spinel (MgAl2O4) and titanium dioxide as main starting materials and being sintered at high temperature. The influences of titanium dioxide additions on the room temperature physical properties, phase composition and microstructure were investigated. The phase composition and microstructure were tested by means of XRD and SEM. The results revealed that with increasing TiO2 content, the densification of the composites first increased sand then decreased and maximized at 4% TiO2 loading. This showed appropriate amount of TiO2 could contribute to the sintering of the composites due to the solid solution of TiO2 in magnesium aluminate spinel.
Two-Step Green Hydrothermal Synthesis of ZnO Powders
Authors: Liu Ling , Wang Tian Xi , Zhang Yong Cai , Zhang Ming
Published: July 2011

ZnO2 nanoparticles were synthesized via hydrothermal reaction between Zn5(CO3)2(OH)6 powder and 30 mass% H2O2 aqueous solution at 80 °C for 24 h, and ZnO powders with granular and rodlike morphologies were synthesized via hydrothermal decomposition of the as-synthesized ZnO2 nanoparticles in water at 150-170 °C for 24 h. The obtained products were characterized by X-ray diffraction, Raman and Field emission scanning electron microscopy.
Molecular Dynamics Simulation on Micro Couette Flow of Nanofluids
Authors: Cui Wen Zheng , Bai Min Li , Lv Ji Zu , Li Xiao Jie
Published: July 2011

This research applied molecular dynamics method to micro Couette flow of nanofluids, in order to examine the absorption layer near solid surfaces, and propose mechanisms of heat transfer enhancement due to flow. The model of nanofluids consisted of 4 nm Cu nanoparticles and liquid argon as base liquid, Lennard-Jones potential function was adopted to deal with the interactions between atoms. Through visual observation and analysis, it was found that the even-distributed liquid argon atoms near solid surfaces could be seemed as a reform to base liquid and had contributed to heat transfer enhancement. In the process of Couette flow, nanoparticles were rotating and vibrating besides moving translationally. The micro-motions of nanoparticles could disturb the continuity of fluid and strengthen partial flow nearby nanoparticles, and enhance heat transfer in nanofluids.
MoB/CoCr Coating by Low Pressure Plasma Spraying against Erosion by Molten Al-12.07wt.%Si Alloy
Authors: Chen Xiao
Published: July 2011

MoB/CoCr, a novel material for thermal spraying, with high durability is used to resist erosion by molten Al-12.07wt.%Si alloy. The durability of the MoB/CoCr coating prepared by low pressure plasma spraying (LPPS) has been investigated using a molten-metal immersion tester. The test revealed that the MoB/CoCr coating has much higher durability without dissolution in the molten Al-12.07wt.%Si alloy. Little change of crystal structure, mainly composed of ternary borides of Co2MoB2 and CoMoB, is observed after the immersion test, suggesting that the ternary borides have much higher durability.
Preparation of α-Ni(OH)2 with Flowerlike Hierarchical Architectures via Homogeneous Precipitation Method
Authors: Li Chang Yu , Liu Li Li , Liu Shou Xin
Published: July 2011

Without using any templates or surfactants, flowerlike α-nickel hydroxide (Ni(OH)2) was successfully synthesized by homogeneous precipitation method. The prepared products were characterized by X-ray powder diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and N2 adsorption-desorption. The prepared Ni(OH)2 is α-phase with specific surface area of 245.0 m2/g and shows flowerlike structure with 4-6 um in diameter.
Effect of Particle Size on Oxidation Reaction Kinetics Parameter of Cu2O Powders
Authors: Li Zai Yuan , Zhai Yu Chun , Pang Myongil
Published: July 2011

The 0.4mol•L-1CuSO4 liquor and 5mol•L-1NaOH liquor were prepared by CuSO4·5H2O and NaOH as raw materials. The Cu2O powders were prepared by dextrose reducer and PVP dispersant. The Cu2O oxidation reaction DTA-TG-DTG curves were obtained by SDT 2960 simultaneous DSC-TGA analysis apparatus. The mensuration condition were that rise temperature velocity 15°C·min-1 and deoxidize gas air. The Cu2O oxidation reaction kinetics was calculated by DTA-TG-DTG curves data. The results indicate that the cuprous oxide powders shape were spherical, their particle’ sizes were 100,200,1000nm. Their apparent activation energy were 164.38, 175.54, 282.65 KJ·mol-1, the apparent activation energy increase with Cu2O particle’ size. Their frequency factors were 1.22×1013, 1.40×1013, 2.88×1020, the frequency factors increase with particle’ size Cu2O. Their reaction progressions were 1.02, 1.00, 0.96, the reaction progression increase with Cu2O particle’ size decreased.
Synthesis of Nano-Crystalline Magnesium Chromate Spinel by Citrate Sol-Gel Method
Authors: Li Su Ping , Jia Xiao Lin , Qi Ya Fang
Published: July 2011

Nanocrystalline MgCr2O4 with a crystal size of about 20nm is synthesized by citrate sol-gel process, which is characterized by X-ray diffraction (XRD), thermogravimetry coupled with differential thermal analysis (TG-DTA) and field emission scanning electron microscopy (FE-SEM). The initial crystallization temperature of MgCr2O4 spinel was at about 550°C, whereas that of the fully crystallized magnesium chromate spinel appeared at about 600°C. The crystal grain size increases with the annealing temperature and holding time.
Morphology of ZnO Controlled by Anion of Simple Zinc Salt
Authors: Hu Han Mei , Deng Chong Hai , Zhang Ke Hua
Published: July 2011

In this paper, three kinds of morphologies of ZnO crystals including particle-based lotus-like, hexagonal bipod-like (dumbbell-like) and rod-based chrysanthemum-like microstructures were controllably synthesized by using simple zinc salts (Zn(CH3COO)2·2H2O, ZnSO4·7H2O and Zn(NO3)2·6H2O) and ethanolamine as raw materials in microwave-assisted aqueous solution. The crystal structure, composition and morphology of the as-prepared products are characterized by X-ray diffraction (XRD), energy dispersive X-ray spectrometry(EDX), field-emission scanning electron microscopy(FESEM). It was found that anion of zinc salt is a dominative factor in determining the morphology of the obtained ZnO crystals. The possible formation mechanism of ZnO microstructures was simply discussed.
Step-Scan DSC Study on the Melting Behavior of Polypropylene/Attapulgite Nanocomposites
Authors: Sun Li Li , Hu Kun , Chen Lin , Zheng Kang , Tian Xing You
Published: July 2011

Attapulgite(AT) was modified by grafting with butyl acrylate(BA) via polymerizations initiated by Gamma radiation. The polypropylene(PP)/AT nanocomposites were synthesized via melting extrude in a twin-screw extruder. The thermogravimetry(TG) and scanning electron microscopy (SEM) were used to assess the graft ratio of the hybrid materials and the dispersion of AT, respectively. Step-scan differential scanning calorimetry(SSDSC) was used to study the influence of AT on the crystallization and subsequent melting behavior. The results indicated that PP and PP/AT nanocomposites underwent multiple melting and secondary crystallization processes during heating. The melting behaviours of PP and PP/AT nanocomposites varied with the variation of crystallization temperature and AT content.
Research on Pollution-Free Separation of Wheat Straw Cellulose by Ethanol/Acetic Acid Solvent System
Authors: Li Jin Bao , Zhang Mei Yun , Yang Ya Ling , Jia Ling Ying
Published: July 2011

Agriculture wastes-- wheat straw is used as raw material to take place of cotton and wood pulp in this research. In order to separating of the crude cellulose, non-polluting ethanol/acetic acid binary solvent system is utilized to dissolve lignin. Then pure cellulose is obtained by refining processing. Finally, microcrystalline cellulose is obtained by acid hydrolysis, grinding and the subsequent process. The paper focuses on the effect of the dosage of acetic acid in the binary solvent system on separating efficiency of wheat straw cellulose, and analyzing the effects of acetic acid dosage on kappa number, yield, α-cellulose content and crystallinity of the wheat straw crude cellulose. The results indicated that acetic acid can promote the removal of lignin and hemicellulose degradation, and is conducive to improve the purity of crude fiber. The lignin removed mainly adsorbed and deposited onto the surface of crude cellulose. The optimum dosage of acetic acid in the thermal decomposition system of wheat straw is 2%. Under the optimum condition, the crystallinity of crude cellulose is the highest, the yield and α-cellulose content are both rather high, but a low Kappa number.
Investigation of Morphology of Vetier (Vetiveria zizanioides) Cellulose Micro/Nano Fibrils Isolated by High Intensity Ultrasonication
Authors: Wang Xin , Wu Yan , Huang Jin Tian
Published: July 2011

The Vetier (Vetiveria zizanioides) cellulose micro/nano fibrils (VCMNFs) were isolated by high intensity ultrasonication (HIUS). The morphology and diameter distribution of cellulose fiber and micro/nano fibrils were investigated by optical microscopy, scanning electric microscopy (SEM) and laser diameter analysis instrument. The range of diameter distribution of micro/nano fibrils was from 0.24 μm to 426 μm. With the variation of treating amplitude and time by HIUS, the extent of fibrillation and diameter distribution were different. There were significant changes of diameter distribution treated at amplitude of 90% and 30 min or 60 min and the diameter distribution was showed from 7.0 to 80 μm.
Selective Oxidation of Cyclohexane to Cyclohexanone and Cyclohexanol over Au/Co3O4 Catalyst
Authors: Wan Jun , Zhao Jing , Zhu Ming Qiao , Dai Huan , Wang Lei
Published: July 2011

Au/Co3O4 catalysts were prepared by a co-precipitation method and characterized by inductively coupled plasma-atomic emission spectrometry (ICP-AES), transmission electron microscope (TEM) and X-ray diffraction (XRD). The selective oxidation of cyclohexane to cyclohexanone and cyclohexanol was investigated over Au/Co3O4 catalysts using molecular oxygen as oxidant. These catalysts showed higher activities as compared to the pure Co3O4 under the same reaction conditions.
Research on Solvothermal Synthesis of Phase Composition Controllable Nanocrystalline TiO2 Powders
Authors: Li Mei Jun , Cao Wen Bin
Published: July 2011

N-doped TiO2 powders have been prepared by solvothermal synthesis using TiCl3 aqueous solution as precursor. The as-synthesized powders are composed of anatase and rutile and show light-yellow in color. The grain size is ranged from 10.3 nm to 19.1 nm by Scherrer's method and the specific surface area is ranged from 21 m2/g to 122 m2/g. X-ray photoelectron spectroscopy (XPS) results indicate that N atoms have been doped into the lattice of TiO2. Ti-N bonding and radical groups such as ×OH were detected on the surface of the powders. The synthesized N-doped TiO2 powders shows excellent visible-light photocatalytic activities and their absorption edge have been red-shifted to 560 nm.
Periodic Changes Effects of Distance between Magnetic Barriers on Electron Transport in Nanostructure
Authors: Bamshad Zahra
Published: July 2011

I theoretically investigate the spin Polarization and transmission of the electrons in a nanostructure consisting barriers with periodic, parallel and also anti parallel magnetization .also I investigate polarization when distance between barriers is constant, or is increased, or is decreased periodically. These observable quantities are found to be strongly affected by both the magnetic configuration and the number of the periodic magnetic barriers. When the number of periods increases, in parallel magnetization for periodic increasing distance the polarization is enhanced so in parallel configuration it is better that distance between barriers to be increasing periodically. I investigate Polarization in these configuration in both delta function approximation and modulated magnetic barriers in x direction. This Polarization can be used in spintronics device.
Micro-Stress Transfer of CNT and CNT-Interface in CNT Reinforced Mg-Matrix Composites
Authors: Qing Li , Chao Yu
Published: July 2011

The aim of the present paper is that, utilizing finite element method, considering the influence of different length of CNTs and different strength of interface to investigate the micro stress distribution of CNT reinforced magnesium matrix composite. When analyzing, the material character of magnesium is regarded as anisotropic. Utilizing the primary theory to calculate the anisotropic elasticity modulus; Define the reasonable length of CNTs; Considering the influence on the micro stress distribution of different interface strength.
Experimental Research on the Relationship between Dielectric Constant and Compressive Strength of Cement Concrete Materials
Authors: Zhang Bei , Zhong Yan Hui , Wang Tao , Wang Fu Ming
Published: July 2011

Dielectric constant is the most important material property which ground penetrating radar(GPR) data reflects. Based on experiment, through the determination of the compressive strength during concrete mixture ages and the real part and imaginary part of dielectric constant, the relationship between dielectric constant and the compressive strength of cement concrete material is studied. It is shown from the achievements that there has feasibility to non-destructively test the cement concrete material compressive strength by using GPR.
Microstructure and Magnetic Behavior of One-Dimensional Co0.5Zn0.5Fe2O4 Nanofibers
Authors: Xiang Jun , Zhou Guang Zhen , Chu Yan Qiu , Shen Xiang Qian
Published: July 2011

One-dimensional Co0.5Zn0.5Fe2O4 nanostructures (nanofibers) with an average diameter of 154 nm were fabricated by electrospinning. These nanofibers were characterized by X–ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy. Magnetic hysteresis loops were measured for randomly oriented and aligned Co0.5Zn0.5Fe2O4 nanofibers, in comparison with the corresponding powder sample synthesized using the conventional sol-gel process. The differences in magnetic properties are observed between the Co0.5Zn0.5Fe2O4 nanofibers and powders, and these differences mainly arise from the grain size and morphological variations between these two materials. In determining the magnetization ease axis for the aligned Co0.5Zn0.5Fe2O4 nanofibers the shape anisotropy is slightly dominant competing with the magnetocrystalline anisotropy.
Investigation on Cleansing the if Molten Steel with the Dispersed In Situ Phase Induced by the Composite Ball Explosive Reaction in RH Ladles
Authors: Li Zhen , Wang Xiao Feng , Lin Yang , Fei Peng , Jiang Mao Fa
Published: July 2011

A novel fine inclusion removal technology due to the dispersed in-situ phase induced by the composite ball explosive reaction was put forward. A composite ball with this function has been designed and prepared using a laboratory model batch type balling disc (at 12 rpm) and the composite ball has been fed at the end of RH refining. The results indicate that feeding composite ball in RH ladle is a novel technology and the inclusion in the IF molten steel can be removed effectively. Compared with conventional inclusion removal technology, the number of the oxide inclusion can be decreased to a lower level and the inclusion size becomes finer. Using this novel technology, the total oxygen in the as-cast slab can approach to 5ppm and the steel production cost for per ton can be reduced by 5 ~12 RMB.
Simulation of Electron Transport in Silicon using Monte Carlo Method
Authors: Wang Zan , Quan Lei , Ruan Yi Wu
Published: July 2011

A Monte Carlo method is employed to investigate the properties of electron transport with considerations of electron-phonon scattering including intervalley scattering and intravalley scattering. Under different electric fields, the coupling relations between electrons and phonons are studied, and the behaviors of absorbing and releasing phonons from electrons are also analyzed. The results show the scattering events of absorbing phonons from electrons decrease with the increasing simulation time. At the same temperature, the mean free path of electron increases initially and then decreases with the increasing electric field intensity, and finally approaches an asymptotic value.
The Microstructure and Mechanical Properties of ZrAlN/Cu Coating
Authors: Du Jun , Zhang Ping , Zhu Xiao Ying , Cai Zhi Hai
Published: July 2011

ZrAlN/Cu coating has been deposited onto Ti-6Al-4V substrates by reactive magnetron sputtering. The morphology of films was investigated by FESEM, the microstructure was studied by XRD, XPS and TEM. The plastic deformation characteristic of thin films were analysised from loading/unloading curves measured by nano-indentation method. Erosion tests were conducted to evaluate anti-erosion ability. Erosion rates were measured and characteristic damage features were identified on the surface of eroded specimens. The mechanisms of erosion are discussed in order to explain the promising performance of materials in erosive conditions. It was found that there is an significant increase of erosion resistance because of the increase of hardness and toughness.
Comparison of Reactively Sputtered HfO2 and HfSixOy Dielectrics for High Density Metal-Insulator-Metal Capacitor Applications
Authors: Xu Hui , Zhang Li Feng , Zhang Qiu Xiang , Ding Shi Jin , Zhang Wei
Published: July 2011

The reactively sputtered HfO2 and HfSixOy dielectrics have been investigated comparatively for metal-insulator-metal (MIM) capacitor applications. X-ray photoelectron spectroscopy analyses reveal the presence of Hf-O, Hf-O-Si and Si-O chemical bonds in the HfSixOy films as well as lots of oxygen vacancies. The relative concentrations of Hf-O-Si and Si-O bonds increase with an increment of the power applied to the Si target. Further, it is found that the quadratic voltage coefficient of MIM capacitor decreases with increasing the Si content in the HfSixOy dielectric in despite of a decrease in the resulting capacitance density. The HfSixOy dielectric MIM capacitors with a capacitance density of ~8.4fF/μm2 exhibit a quadratic voltage coefficient of 1840 ppm/V2 at 100kHz, which is much smaller than 2750 ppm/V2 for the HfO2 dielectric MIM capacitors with a density of ~11.8fF/μm2.
Influence of Rolling Reduction Ratio on Continuous Confined Strip Shearing Deformation Procedure Using Finite Element Analysis
Authors: Zhao Zi Hao , Xu Xiao Jing , Zhou Hai , Zhu Xin Dong , Cheng Cheng , Fei Zhen Dan
Published: July 2011

The severe plastic deformation (SPD) procedure designated continuous confined strip shearing (CCSS/C2S2) technique based on rolling, equal channel angular pressing (ECAP) and Conform principle was simulated numerically by using finite element code DEFORM-3D. The influences of rolling reduction ratio on restoration ratio of work-piece geometry, effective strain, output velocity of processed work-piece, torque of rollers, and energy consumption feature for the C2S2 procedure were investigated. The results show that rolling reduction ratio has significant influences on C2S2 procedure. With the increase of rolling reduction ratios (5%, 10% and 20%), the restoration ratio of work-pieces geometry reduced, the magnitude of effective strain kept almost unchanged, the output velocity of processed work-piece increased, the total torque of rollers decreased, and the energy consumption used for making unit volume work-piece subjected to unit straining reduced considerably. It was found that the optimal rolling reduction ratio was about ~10 %, where the energy consumption reduced by 8.16 %, whereas the restoration ratio of work-piece geometry was almost the same as constrasting with the rolling reduction ratio of 5 %.
Morphology and Properties of Carbon Nanotubes Modified Epoxy
Authors: Hu Xiao Lan , Wang Wen Hao , Yu Rong Lu , Liu Gang , Lu Teng Fei
Published: July 2011

Multi-walled carbon nanobutes (MWNTs) reinforced epoxy resin nanocomposites were fabricated by functionalizing the MWNTs with amino group. The functionlization of MWNTs was characterized by FTIR, elementary analysis, and TEM, and the MWNTs dispersion was characterized by optical microscopy and SEM. MWNTs functionalization with ethylene diamine improved the nanotube dispersion in the epoxy matrix composites. The dynamic mechanical thermal properties and thermal properties of MWNTs/epoxy nanocomposites are briefly discussed in terms of the MWNT loading and dispersion.
Gas-Electrospun Degradable PEG/PBT-HA: Potential Scaffold for Tissue Engineering
Authors: Yang Xiao Zhan , Wang Bing , Li Zhen Sheng , Feng Wen Lin
Published: July 2011

In this work, the composite nanofibers of polybutylene terephthalate/polyethylene glycol (PEG/PBT) with difference intrinsic viscosity and different ratio of the hard-segment to the soft-segment were obtained by gas-electrospun. The PEG/PBT-HA composite nanofibers were also obtained by gas-electrospun. PEG/PBT and PEG/PBT-HA composite nanofibers were characterized using scanning electron microscopy (SEM), horizontal attenuated total reflectance for Fourier transformation infra-red spectrometer (HATR-FTIR), dynamic contact angle measurement and differential scanning calorimetry (DSC). The results strongly suggest that this synthetic matrix combines with the advantages of synthetic biodegradable polymers, nanometer-scale dimension mimicking the natural ECM, may represent an ideal tissue engineering scaffold, especially for soft tissue, such as skin and cartilage tissue engineering scaffold.
Research on Fault Diagnosis System for Mine Hoist
Authors: Wang Cheng Long , Zeng Qing Liang , Zhou Guang Yu , Zhao Wen Ming
Published: July 2011

Basing on the analysis of Mine Hoist working condition, Research on fault diagnosis system for Mine Hoist was introduced, including detailed introduction of its functions, composition and work principles. According to its application, it shows that fault diagnosis and monitoring technology to ensure that the equipment can run in good conditions so as to reduce unplanned downtime and help to reduce maintenance costs.
Study on the Preparation of Ultramicro Molybdenum Nitride Powder and Wear Properties of Its Coating
Authors: An Geng
Published: July 2011

Using the specially designed mechanochemical ball-mill equipment, the ultramicro molybdenum nitride powders were prepared from pure molybdenum powders in ammonia atmosphere at room temperature by high-energy ball milling. The results show that the mass ratio of grinding media to powder was 4:1 and after milling for 30 h, the Mo2N of fcc structure was obtained, and the average particle size of powders was around 100 nm. It is found that the chemisorption of ammonia onto the fresh molybdenum surfaces created by milling was the predominant process during solid–gas reaction，and the change of Mo electronic undersaturation induced by the grain refining also accelerated the bonding between Mo and N. The coating was formed on the 40Cr steel base using plasma spray method by mix Ni60 alloy powders and ultramicro Mo2N powders of 5wt%, 10wt% and 15wt%, respectively. Coating abrasion test under the condition of dry-grinding , 2h wear time and 300N test load showed that the wear-resisting property of coating added with ultramicro Mo2N powders could be improved greatly, and the wear-resisting property of coating increased with the increase of Mo2N content. In the abrasion process, the evenly distributed ultramicro Mo2N particles play the dispersion strengthening and self-lubricating role in the coating.
Growth and Photoluminescence Properties of ZnO Microrods
Authors: Guo Xing Yuan , Ding Zhan Hui , Zhou Jing , Feng Guan Lin , Shen Hong Zhi , Xu Da Peng
Published: July 2011

Zinc oxide (ZnO) microrods were grown by the floating zone method, the as-grown ZnO microrods have uniform size. Scanning electron microscope image reveals that the ZnO microrods are grown with a hexagonal structure, well faceted ends and side surfaces. Most of ZnO microrods have diameters of about 20-30 mm and lengths of about 1-2 mm. Polarizing microscopy image of ZnO microrods shows that they have high crystal quality. The X-Ray diffraction pattern shows that microrods have vertical orientation and the crystal structure of ZnO is wurtzite type. At low exciting intensity, ultra violet range emission was found and the growth process of ZnO microrods was discussed.
Synthesis of Nanocrystalline Silver by Warm-Vacuum-Compaction Method
Authors: Liu Wei , Zhou Qiong Hua
Published: July 2011

The nano-sized silver particles were prepared by flow-levitation technique firstly, and then the particles were compacted with warm-vacuum-compaction method to fabricate the nanocrystalline silver with average grain size of 18.5 nm. The influences of experimental parameters, such as pressure, temperature and pressure duration, upon the density and microhardness of the nanocrystalline silver were investigated in detail. The experimental results show that both the density and microhardness of the nanocrystalline silver increase significantly with higher pressure or elevated temperature, while the duration of pressure has a little effect to the density. The average microhardness of the as-prepared nanocrystalline silver is 1.25 GPa, which is 3 times higher than that of coarse-grained silver.
Preparation of Spheric and Hollow TiO2 Electrophoretic Nanoparticles
Authors: Tan Ting Feng , Qi Peng , Li Xiang Gao , Wang Shi Rong , Zhao Shang Gang
Published: July 2011

The inorganic electrophoretic particles easily sedimentate and are not preferably dispersed in medium because their density is relatively big. Spheric and hollow TiOB2B particles were prepared against the core-shell polymer latex particles via a simple wet-chemistry route, using Ti(OBu)B4B as a precursor. The particles¢ morphology was observed by atom force microscopy (AFM) images, scanning electron microscope (SEM) and transmission electron microscopy (TEM). The products were characterized by X-ray Diffraction (XRD) and TEM. TEM showed spheric and hollow particles with a diameter around 290 nm. The density (in the atmospheric pressure, 20°C) of TiOB2 Bwas 2.21 g∙mLP-1P. Results showed that hollow framework could reduce the density of particles. The Zeta potentials were determined by micro-electrophoresis apparatus. TiOB2B particles had good electrophoretic property, and the Zeta potential was 5.25 mV.
Preparation And Photoelectric Properties Of CuCr2O4 Nanopowders
Authors: Hu Zhi Qiang , Qin Ying , Zhou Hong Ru , Kang Jiao , Zhai Shang Ru , Gao Hong
Published: July 2011

CuCr2O4 nanopowders were successfully prepared by co-precipitation technique from alcohol-aqueous system and applied for photo-anodes of dye-sensitized solar cells (DSSCs). The synthesized CuCr2O4 particles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–vis diffuse reﬂectance spectrum (UV-vis) and thermo-gravimetric/differential Scanning Calorimetry (TG-DSC). It was shown that, with the sintering temperature of 1000 °C and the amount of PEG-400 of 1.5 wt % , the size of primary crystal grain was about 48 nm. The CuCr2O4/TiO2 composite exhibit high absorption ability in the spectral range 600 ~ 900 nm, which leading to a much higher conversion efficiency (η) of the solar cell in comparison with the pure TiO2 film electrode.
Experimental Study on Strengthened Bridge Structures with Carbon Fiber Plate
Authors: Zou Lan Lin , Zhou Xing Lin
Published: July 2011

In order to analyze the impact of anchor length, ends anchorage measures, strength of concrete, shear-span ratio, reinforcement ratio and the amount of carbon fiber plate on the bearing capacity of strengthened bridge structures with carbon fiber plate, 11 pieces of rectangle beams are fabricated for flexural experimental study. The experimental results show that the ultimate bearing capacity of the specimens increase different degree as different strengthened schemes: the bearing capacity of rectangle beams with plate end anchorage has increased remarkably; The beams have greater bearing capacity with more anchorage length in contrast to those without any anchorage measure; The ultimate bearing capacity enhanced more prominent for those specimens with low shear-span ratio and low reinforcement ratio.
The Development and Experimental Study on High Strength and Toughness Drill Pipe Steel
Authors: Hu Feng , Han Li Hong , Wang Hang , Feng Yao Rong , Li He Lin
Published: July 2011

With the development of oil industry, the high strength-toughness drill pipe suited to the task of sour environment and ultra deep wells would be considered more and more important. A new drill pipe steel, which was designed with the proper decrease of C content and increase of Cr, Ni, Mo, Nb and V alloy element, was developed and studied in this study. Large deformation hot rolling technology was used to obtain ultrafine grains microstructure. The results showed that the yield strength of this new drill pipe steel had reached 150ksi with the impact toughness more than 150J, which can perfectly meet the “leak-before-break” crack principle. The new low-alloy carbon steel drill pipe in the controlled yield strength grade 150ksi showing excellent sulfide stress cracking resistance and strength-toughness have been developed. Based on the observation of scanning electron microscopy and transmission electron microscopy, several kinds of carbide particles including (Nb, Mo, V)C with nanometer scale, were distributed in tempered sorbite matrix. The objective of this work was to study the relationship between carbide precipitation and strength-toughness by optimizing element design, thermo mechanical control process and heat treatment of drill pipe steel.
Oxidation Behavior of Fe-Y Coatings Deposited by Magnetron Sputtering
Authors: Fu Guang Yang , Tang Xiao Peng , Liu Qun , Su Yong , Yang Ning Ning
Published: July 2011

By means of magnetron sputtering, the Fe-Y coatings containing 15.4%, 20.7% and 32.7% Y (atom fraction), were deposited on stainless steels. The sputtered coatings were investigated by discontinuous weigh measurement. The results indicate that the oxidation kinetics can be divided into three stages, of which the first and second stages obey the parabolic rate law, while the oxidation kinetic curves of the last stage nearly exhibits horizontal lines. With the increase of the content of Y, the oxidation rate obviously increases. The external scale of the three kinds of alloys is substantially similar. After 24-h oxidation at 800 °C under 1 atm of air, the surface of sputtered coating is mainly transformed into three types of oxide scales, of which the thin outermost layer was Fe2O3, the innermost is YFeO3 mixed with double oxides including FeO or Fe3O4. Single Y2O3 layer was not formed on the surface or in the alloys. The results were disscussed by taking into account the defects in the metal oxide, the self-diffusion of the elements in the alloys, and the low diffusion of yttrium in iron.
Microstructure and Properties and Wear Resistant of Carbide Free Bainitic Casting Steel
Authors: Liu Zhi Xue , Cheng Ju Qiang
Published: July 2011

The microstructure and properties and wear resistant of carbide free bainitic casting steel were studied by using of OM, TEM, XRD, impact test and abrasion test. The results showed that after normalizing at 1080°C and tempering at low temperature the microstructures consisted of bainitic ferrite, remaining austenite and no carbides with combination properties of strength and toughness. After tempering at 250°C the tensile strength was 1667MPa, Rockwell hardness HRC49 and impact ductility AKU 36J, respectively. This new casting steel by normalizing at 1080°Cand tempering at 200°C had better wear resistance than that of high manganese steel under the same test conditions, moreover the reason was analyzed.
Test and Application on New Synchronous Grouting Materials for Earth Pressure Balance Shield
Authors: Qiao Guo Gang , Yuan Da Jun , Wang Dao Gang , Wang Quan Hua
Published: July 2011

The type and properties of the grouting materials contribute great impact on the grouting effect. The new grout with hydrated lime, fly ash, bentonite, sand, water and water reducer as materials was developed, and the raw material requirements and performance requirements of the new grout were ascertained. Some experimental results were illustrated on the fineness modulus of sand and water reducer dosage impact on the properties of the new grout. The preliminary application results in Shanghai and Soochow metro showed that the new grout played a very good role on the surface subsidence control both in fine clay soil and sand strata.
Optimization and Analysis for Coke Consumption Based on Clustering
Authors: Zhang Jun Hong
Published: July 2011

In order to reduce the coke consumption of Blast Furnace（BF），a relevance analysis is carried out for operation parameters and fuel rate of BF，and a prediction method that is combining clustering analysis and artificial neural network for coke rate is proposed. The data cluster is divided into several classes by clustering analysis，the data similarity is high，and the neural network model is used to realize the prediction of coke rate. By combining the neural network with clustering analysis，the data in one BF is simulated，and the results are compared with the traditional neural network model. The result shows that the improved neural network has a higher accuracy, the average absolute error can be decreased by 3.13kg/t, and the average relative error can be decreased by 5.19%, it will have a good using foreground.
The Microstructure Research on Interfacial Transition Zone of Filling Material Containing FA and Coal Gangue
Authors: Yao Yan , Wu Hao , Wang Ling
Published: July 2011

Interfacial transition zone (ITZ) is the weakest part in concrete structure because of the interrelation between its special characters and the performance of concrete, and adding mineral admixture in concrete is a feasible and effective way to improve ITZ. The workability, mechanical and durability performance of filling materials with Fly ash and Coal gangue has been invesitgated, and the interrelation has been research in a micro view by means of SEM and EDS.
The Effect of Pretreatment and Homogenization on the Precipitation of Spherical Al3Zr Phase in Aluminium Alloy Containing Trace of Zr
Authors: Guo Zhan Ying , Zhao Gang , Liu Yue , Tian Ni
Published: July 2011

The number and size of the precipitation of spherical Al3Zr particles, in aluminium alloy containing trace of Zr which subjected to different heat treatments, have been investigated by transmission electron microscopy. The results show that, the number of spherical Al3Zr particles is determined by the pretreatment, and that the size is determined by the homogenization. The number of spherical Al3Zr particles increases with prolonging the time of pretreatment between 0h to 48h and rising the temperature of pretreatment between 200°C to 400°C, and the size of spherical Al3Zr particles turn out to be the same. The size of spherical Al3Zr particles increases with prolonging the time of homogenization between 0h to 48h and rising the temperature of homogenization between 470°C to 500°C.
Research on the Application of Recycled PE in High Modulus Asphalt Mixture
Authors: Huang Shao Long , Shen Fan , Ding Qing Jun
Published: July 2011

In this paper, recycled PE was added directly to the asphalt mixture to prepare high modulus asphalt mixture. To study the influence of the dosage and molecular weight of recycled PE on the performance of asphalt mixture, three kinds of recycled PE with different molecular weight and three asphalt binders (Conventional, SBS Modified and PE Modified) were used to prepare eight kinds of asphalt mixture. Various tests, including dynamic modulus, wheel tracking and Lottman test, were conducted to evaluate the performance of them. The results showed that 1) the dynamic modulus of asphalt mixture modified by recycled PE is higher than the normal mixture and mixture prepared with SBS modified asphalt binder; 2) adding recycled PE directly into the asphalt mixture during mixing is more effective than preparing asphalt mixture with PE modified asphalt binder in making high modulus asphalt mixture; 3) the recycled PE used to produce high modulus asphalt mixture should have certain big molecular weight, more than 27,000, and the dosage of recycled PE should be no less than 0.4% of the total weight of asphalt mixture. The performance tests indicted the good high temperature deformation resistance property of asphalt mixture modified by recycled PE.
Feasibility of Basalt Fiber Reinforced Inorganic Adhesive for Concrete Strengtening
Authors: Ding Zhu , Lu Zhan Xi , Li Yuan
Published: July 2011

Phosphate based binders are high early strength materials with a short setting time. Usually, they are used as rapid repair material for concrete structures. The feasibility of a basalt fiber reinforced inorganic binder for strengthening concrete was studied. We successfully compounded suitable phosphate binder (PB) for concrete strengthening. In the current paper, phosphate binder was to adjusted to has excellent workability, suitable setting time and fluidity. Compressive strength of phosphate binder mortar, bonding strength between PB and Portland cement mortar, and strengthening effect of PB sticked basalt fiber on concrete beam were measured. Results showed that PB has excellent adhesion with Portland cement mortar. The strengthening effect of basalt fiber reinforced PB composite on concrete beam is evident. It is feasible that concrete strengthening by basalt fiber reinforced inorganic adhesive.
Proposal of a Simplified Prediction Formula for Compressive Strength of Fly Ash Concrete
Authors: Zhang Wen Bo , Yoshitake Isamu , Saitoh Tadashi
Published: July 2011

To propose a prediction formula of compressive strength of concretes containing fly ash (FA concrete), over 1600 strength data are collected from previous studies and discussed in this study. In particular, the study focuses on developing strengths of FA concrete. The study deals with test data of concrete with wide range of FA replacement, namely 0-50% by mass of cement. Compressive strength at age of 7 days has strongly relation to the cement-water ratio, so the strength can be predicted by using only water and cement contents. In addition, early age strengths within 7 days can be estimated by using the Goral curve based on strength ratio. Strength after the age of 7 days can be predicted by using replacement ratio of fly ash because the strength ratios are proportional to the replacement ratio. Based on the findings, a simplified formula for predicting compressive strength at various ages is proposed in the paper.
The Research Status and Prospect of the Fiber Reinforced Concrete
Authors: Sun Jie
Published: July 2011

Fiber reinforced concrete is a commonly used special concrete. As enhancing the tensile and compressive strength and improving the durability of concrete, fiber reinforced concrete was used widely around the world. The characteristics and categories of the fiber reinforced concrete were introduced and the application status of that at home and abroad was presented. Some problems during the research and application were proposed and the application prospect of the fiber reinforced concrete was forecast.
Energy Calculation Model of Concrete Based on Life Cycle Assessment
Authors: Gong Ping
Published: July 2011

The energy consumption of concrete is considered as the research object,and the life cycle theory is applied in the energy consumption analysis of concrete. the life cycle energy consumption inventory analysis of concrete is set up,the concrete’s whole life cycle is divided into four stage. Each stage’s energy consumption is carried out a detailed analysis. Based on the inventory analysis, an energy calculation model of concrete is established .
The Effect of Super-Absorbent Polymer as a Self-Curing Admixture on the Performance of Mortars
Authors: Yu Fa Qi , Sun Na , Deng Chao , Zhang Jin , Pei Mei Shan
Published: July 2011

Super-absorbent polymer (SAP) was used as a self-curing admixture for cement-based materials. Two types of super-absorbent polymer and effect of super-absorbent polymer on fluidity and mechanical properties of mortars were investigated. The performance of the mortars cured for different ages was tested. The results showed that SAP could play a role of reserving water and reserving water of SAP particles A with an average diameter of 180 mm was more effective than that of SAP particles B with an average diameter of 80 mm, the optimal performance of reserving water was obtained at 0.07 wt.% of SAP particles A; Mechanical properties of hardened mortars with SAP particles A were better than those with SAP particles B, the favorably experiment ratio was 0.05 wt.% of SAP particles A.
Synthesis and Properties of Chemically Cross-Linked Poly(Vinyl Alcohol)/quaterized Hydroxyethylcellulose Ethoxylate (PVA/QHECE) as Novel Alkaline Anion-Exchange Membrane
Authors: Liu Ling Ling , Xu Li , Xie Juan , Ding Lei , Qiao Jin Li , Li Guang
Published: July 2011

A new type of chemically cross-linked polymer blend membranes consisting of poly(vinyl alcohol) (PVA) and quaterized hydroxyethylcellulose ethoxylate (QHECE) have been prepared and evaluated as OH--conducting polymer electrolytes. The OH--conductivity (s) of the membranes was investigated as a function of cross-linking time, blending composition and water uptake. Membrane swelling decreased with cross-linking time, accompanied by an improvement in mechanical properties and a small decrease in OH--conductivity due to the reduced water absorption. The OH--conductivities in the range of 2.7 ×10-4－1.52 ×10-3 S cm-1 were obtained at room temperature (19±2°C), depending on the polymer composition and the content of cross-linking agent. TG analysis showed that the membranes exhibited the thermal stability high up to 350°C when incorporating 75% QHECE. In addition, the membranes displayed a high alkaline stability without losing their integrity and OH--conductivity after conditioning in 6M KOH at 60°C for one week.
Preparation and Characterization of Low-Methoxyl Pectin/Bletilla Striata Composite Membranes
Authors: Lou Ching Wen , Hu Jin Jia , Lu Chao Tsang , Huang Chao Chiung , Sie Ming Yuan , Lin Jia Horng
Published: July 2011

The skin is the largest organ in the body composed of the epidermis, dermis, and subcutaneous tissue through the latter it is integrated with deeper tissues. The major function of the skin is to shield out attacks, acting as a barrier. The skin can trigger a series of self-healing procedure when it is damaged. The healing process can be divided into three phases: inflammatory, tissue hyperplasia, and tissue reconstruction. Particularly during tissue hyperplasia, fibroblast proliferation and collagen deposition play important roles in the healing. The healing could be accelerated if wound dressing can be properly applied. An ideal wound dressing is capable of absorbing tissue fluid, keeping the wound moistured, stopping bleeding, attaching to the wound surface properly without sticking to the wound tissues, protecting the wound from infection, and accelerating the wound recovery. In this study, the composite membranes was made by adding mixed solutions of low-methoxyl pectin and Bletilla striata, which is a traditional Chinese medicine, into calcium chloride solution. The low-methoxyl pectin is cross-linked with calcium ions, forming a hydrogel. Membranes of varying ratio of the low-methoxyl pectin and Bletilla striata were prepared seeking for the optimal manufacturing parameters to use to investigate its effects on the water stability, water retention, contact angle and degree of swelling of the composite membranes. The results showed that when the ratio of low-methoxyl pectin solutioin (2 wt%) and Bletilla striata extract is 80/20 was added into 40 ml of 0.3 wt% calcium chloride solution, the composite membrane had the optimal performance in terms of the water stability, water retention, and swelling.