bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Nb on Microstructure Evolution of Coarse-Grained Heat-Affected Zone with Large Heat Input Welding
Authors: Tao Xue Li , Wu Kai Ming , Wan Xiang Liang
Published: July 2011

The effect of Nb microalloying on microstructure transformation of coarse-grained heat-affected zone of high strength low alloy steels were investigated utilizing different heat input welding simulation. For the low-Nb steel, the microstructures of coarse-grained heat-affected zone mainly consisted of acicular ferrite, bainite and grain boundary ferrite for small heat input welding; the amount of acicular ferrite decreased whereas grain boundary ferrite, polygonal ferrite and pearlite increased with increasing heat input. In constrast, for the high-Nb steel, granular bainite was the dominant microstructure. The formation of granular bainitic microstructure was associated with the solid solution of Nb, which suppressed ferrite transformation and promoted the formation of granular bainite. The hardness of coarse-grained heat-affected zone increased with increasing Nb content, and decreased with decreasing heat input, which was attributed to the microstructural change.
Enhanced Room Temperature Magnetoresistance in La0.7Ca0.2Sr0.1MnO3/BN Composites
Authors: Zuo An You , Zhu Yong Dan , Liao Hong Hua , Tan Juan Jun
Published: July 2011

The effect of added BN on the electro-magnetic properties and enhanced room temperature magnetoresistance in (1-x)La0.7Ca0.2Sr0.1MnO3 (LCSMO)+x(BN)composites has been studied systematically. The results of X-ray diffraction (XRD) and SEM show that BN and LCSMO coexist in the composites and BN mainly goes into the grain boundary region without any chemical reaction with LCSMO. The results of electronic measurements show that the intrinsic insulator-metal transition temperature (TP) does not change, which is in accordance with the results for the Curie temperature TC. It is interesting to note that an enhanced magnetoresisitance (MR) effect for the composites is found over a wide temperature range from low temperature to room temperature in an applied magnetic field of 3 kOe. These phenomena can be explained by considering that BN, which segregated at the grain boundaries or surfaces, does not change the intrinsic structure of LCSMO. We argue that the introduction of BN gives rise to magnetic disorder and hence an enhanced tunnelling effect, which is responsible for the MR enhancement.
Optimizing of Flow Control Devices in a Single Strand Continuous Casting Tundish
Authors: Zhang Lei Lei , Chen Deng Fu , Liu Qiang , Zhang Min , Xie Xin , Luo De Hong
Published: July 2011

Flow control devices (weir and dam) in a continuous casting tundish are very important to the flow field, which influences the temperature uniform and the inclusion floating. In this work, the weir and dam were firstly optimized through numerical simulation and water simulation synthetically by orthogonal optimization tests. And the optimal parameters showed that the distance from upper weir to inlet was 1000 mm, the distance of upper weir to tundish bottom was 150 mm, the distance from upper weir to dam was 600 mm, and the height of the dam was 320 mm. Then the effect of different arrangement holes on the dam was discussed through RTD curve and velocity field under the optimum flow control device. And it revealed that the hole influenced the flow pattern in that area obviously, a dam with two holes could get a better flow field.
Study on Thermal Deformation and Recrystallization Behavior of Cu-P Weathering Steel
Authors: Zhang Xin , Xiong Yi , He Rong Hui , Li Zhi Qiang , Lin Ya Wei
Published: July 2011

Under different deformation temperatures and strain rates, the thermal deformation process of Cu-P weathering steel was studied using Gleeble1500D-type thermal simulator. After the high temperature rheopectic curves at different conditions and thermal deformation equation was got, the dynamic recrystallization diagram of the steel was plotted. The results show that the thermal deformation activation energy of the steel is 345kJ/mol, and the dynamic recrystallization diagram of the steel consisits of three parts as completely dynamic recrystallization zone, partially dynamic recrystallization zone and non-dynamic recrystallization zone.
Effects of B-Mg Additive on Metallurgical Properties of Oxidized Pellets
Authors: Wang Zhao Cai , Chu Man Sheng , Chen Shi Qiang , Liu Zheng Gen , Tang Jue , Xue Xiang Xin
Published: July 2011

The metallurgical properties of oxidized pellets are of great importance to achieve high efficiency and smooth running of blast furnace and gas-based direct reduction shaft furnace. In this study, the new method of adding B-Mg compound additive has been put forth to improve metallurgical properties of pellets. The effects of adding B-Mg additive on the strength of green balls, cold compressive strength, reduction swelling, and the strength after reduction and cooling of oxidized pellets are investigated through the experiments and microstructure analysis. The results revealed that, the B-Mg additive has not-so-remarkable effects on the properties of green balls. The rational addition amount of B-Mg additive is 0.6 %, and B-Mg additive make it feasible to reduce roasting temperature of the pellets. High temperature properties show remarkable improvement with the increase of B-Mg additive amount, the RSI decrease from 14.7% to 7.17%, and the strength of pellets after reduction and cooling increase from 162.5 N to 650.8 N when the addition amount increases from 0 to 0.6%.
Study of Low Carbon Steel on Microstructe of Slag Film
Authors: Han Xiu Li , Li Chang Cun , Liu Li Na , Feng Run Ming
Published: July 2011

Researched on the low carbon steel by mineral component ore phase structure of mould powder and its slag film under optical microscope. The result shows that the glass phase, quartz, and pyroxene in the mould powder helped to the slag film turn into glass. The melilite and wollastonite in the mould powder can promote the formation of melilite, and wollastonite can promote the formation of cuspidine in the slag film. The structure of the slag film is even and the main structure is glass phrase, the rate of crystallization is low, the crystallized mineralogical phases was melilite, the cuspidine did not appeared, which is good for lubrication. The content of glass phase, quartz and pyroxene in the mould powder of the low carbon steel should be increased, the content of wollastonite and fluorite should be reduced.
Three Dimensional Simulations on Stress Distribution and Fatigue Damage Life of Wheel/Rail Contact Region
Authors: Akeel Norie , Sajuri Zainuddin , Ariffin Ahmad Kamal , M. Abdulrazzaq Mohamed
Published: July 2011

This paper discusses the effect of different loading analysis on crack initiation life of wheel/rail in the contact region. A simulated three dimensional (3D) elastoplastic model of a wheel/rail contact is modelled using the fine mesh technique in the contact region by using Finite Element Method FEM code ANSYS 11.0 software. Different loads of approximately 70, 80, 90, 100, 110, 120, 130 and 140 KN were applied to the wheel tread during the running surface of the railhead to simulate stress distribution (Von Mises) and a life prediction of the crack initiation. Stress analysis is performed and the fatigue damage to the railhead surface is calculated numerically by using a multi-axial fatigue life of crack initiation model. Results obtained from previous researches are compared with this research.
Experimental Study on Tundish Flux System for High Al-Containing TRIP Steel’s Slab Casting
Authors: Li Feng Gong , Wang Bo , Zhan Dong Ping , Jiang Zhou Hua , He Sheng Ping , Wang Qian
Published: July 2011

In this paper, tundish flux system for high Al TRIP steel’s slab casting was studied. Firstly the thermodynamical calculation of Al-SiO2 reaction was carried out. Secondly 27 groups of chemical compositions of tundish flux were designed using orthogonal method on the basis of thermodynamical results and slag phase diagram. Thirdly the melting point and the viscosity of each group of chemical composition were tested. Then, regression equations of melting point and viscosity were obtained according to experimental data as well as the analysis of the effect of single-factor and double-factors variation on the regression equations. Finally, the optimal design of tundish flux is w(CaO)/w(Al2O3)=1.1-1.2, w(SiO2)<5%, w(MgO)=4%-7%, w(CaF2)=7%-10% and w(Na2O)=5%, which has a relatively low melting point and viscosity, and its physicochemical performance is relatively stable.
Metallographic Analysis of Non-Orientation Silicon Steel W20 in Different Shearing Deformation Area
Authors: Liu Ji Xiong , Huang Tao , Guan Yun , Feng Da Jun
Published: July 2011

In order to further understand the relationship between technology and metallographic microstructure for the large-scale production of non-orientation silicon steel, hot assembles rolling mill samples at different shearing deformation strip were selected and analyzed. The results show that the surface microstructure in finishing section at the first meeting to the fourth-pass is band-shape deformed ferrite plus equiaxed recrystallization ferrite, while the center is deformed ferrite. With the increase of shearing deformation, number of rheological ferrite increase, and become more slender.
The Effect of Yb2O3 Addition on Sintering of MgO Ceramic
Authors: Wang Sen , Li Zhi Hui , Liu Xin , Zhang Huan
Published: July 2011

The effect of Yb2O3 addition on sintering of MgO ceramics was studied in this work. Increasing of Yb2O3 addition is helpful to densification and grain growth. The effect of Yb2O3 amount on densification decreased when the sintering temperature was increased from 1400°C to 1550°C. Quick densification and rapid grain boundary mobility in Yb2O3 doped samples come from the point defect because the dopant mainly located at the grain boundary, and this is meaningful for grain growth and densification. The results also illustrate that sintering time and sintering temperature would noticeably affect grain growth and densification process, which is not related to the amount of Yb2O3 addition.
The Research for Bitmap and Vector Conversion Methods
Authors: Han Min , Guo You Ming
Published: July 2011

This paper analyzes the characteristics of bitmap and vector, introduce based on Photoshop, CorelDraw, Flash, Streamline and other software methods for bitmap conversion vector. Still introduce based on AutoCAD for vector conversion bitmap method.
The Effect of Bending Radius on Thickness Distribution in Hydroforming of Conical-Cylindrical Cups
Authors: Nourouzi Salman , Gorji Abdolhamid , Bakhshi-Jooybari Mohammad , Hosseinipour S. Jamal , Mohammad-Alinejad Ghorban
Published: July 2011

Conical parts forming is one of the complex and difficult fields in sheet metal forming processes; because of the low contact area of the sheet with the punch in the initial stages of forming, too much tension is applied to the sheet causing bursting occurrence. Furthermore, since the major part of the sheet surface between the blank holder and punch tip is free, wrinkles appear on the wall of the drawn parts. Therefore, these parts are normally formed in the industry by spinning, explosive forming or multi-stage deep drawing processes. In this paper, the effect of punch tip radius and conical- cylindrical radius on formability and thickness distribution of the conical parts for three different punch angles were studied.
Preparation of Porous Silica by Acid Dissociation of Thermally Activated Kaolinite
Authors: Li Guang Hui , Cheng Wei , Jiang Tao , Sun Na , Ai Ling Feng
Published: July 2011

Preparation of porous silica from thermally activated kaolinite was investigated by using acid dissociation process, and the relationship between structural transformation and acid dissociation properties of aluminium were elucidated. AlVI transfers into AlV and AlIV when kaolinite changes into metakaolinite during thermal activation. AlV is dissoluble in acid, while AlVI, AlIV are difficult to be dissolved into acid, therefore, the coordinations of aluminium affect acid dissociation of alumina markedly. Mesoporous silica is made by acid dissociation alumina of metakaolinite, and the specific surface area of porous silica is determined by acid dissociation ratio of alumina. The dissociation ratio of aluminum is up to 97% when kaolinite is activated at 900°C for 15 min. Specific surface area of the porous silica material is 357 m2/g, the pore volume is 0.43 cc/g, and BJH pore diameter is 2.18 nm. The pore is found to be in the worm-like shape by high resolution TEM analysis.
Alumina Gelcasting by Using Glutin-Urea System
Authors: Wang Jin Feng , Wang Xiao Qing , Zhao Wei
Published: July 2011

Glutin-urea system was used in alumina gelcasting. And alumina suspension with 53vol% solid loading was prepared. Urea was decomposed by using urease therefore it was possible that hydrogen bond could be rebuilt. Alumina greenbodies with 8.26MPa bending-strength were prepared when the dose of urease was 20 iu per milimole urea.
Preparation of Glass-Ceramics Using Molybdenum Tailings
Authors: Zhang Jin Rui , Wang Ru
Published: July 2011

In order to utilization the molybdenum tailings which be deposited in large quantities. Test used it to prepare glass-ceramics as main raw material, TiO2 as nucleation agents and CaO-Al2O3-SiO2 system and wollastonite as the principal crystalline phase. Heat treatment system of glass-ceramics was based on the differential thermal analysis. The crystalline phase, microstructure and characteristics of glass-ceramics were analysis by XRD, SEM and physical, chemical properties test. The result shows that the performance of glass-ceramics was superior to the other types of building decoration stone.
Phase Stability and Dielectric Properties of Low Temperature Fired BaTi4O9 Microwave Material with Copper Electrodes in Reducing Atmosphere
Authors: Chen Cheng Sao , Chen Pin Yi , Chou Chen Chia , Feng Kuei Chih , Chu Li Wen
Published: July 2011

In this study we report sintering behavior and microstructures of glass-added BaTi4O9 microwave dielectric ceramics with copper paste in reducing atmosphere. Experimental results show a buffer layer may form at the interface of Cu-electrode and BaTi4O9 microwave dielectric ceramics if the glass did not diffuse smoothly during sintering, and therefore materials exhibited different colors. X-ray results indicate that Cu reacted with Ba seriously to form complicated reaction products, and some BaTi4O9 transformed to barium titanate with various ration of Ba/Ti, which may degrade the dielectric properties of materials.
Evaluation of Sulfide Capacity Models and Application in Steelmaking Slags
Authors: Tang Hai Yan , Li Jing She , Guo Han Jie
Published: July 2011

The sulfide capacity (CS) and equilibrium distribution ratio of sulphur (LS) are important indicators to measure desulfurization capacity of slag system. The sulfide capacities of CaO-SiO2-MgO-Al2O3-FetO slags are calculated by optical basicity model and KTH model, and compared with measured values in literature. The results show that the values calculated by KTH model are nearer to measured values than by optical basicity model, so the former can be used to predict CS of different slag compositions. The factors affecting CS are also studied in detail. The results show that CS increases with increasing slag basicity and temperature and decreases with increasing MgO and Al2O3 contents in slag.
Synthesis of ZrTiO4 and MgAl2O4 Powders via Non-Hydrolytic Sol-Gel Route Using Alcohol as Oxygen Donor
Authors: Wei Heng Yong , Wang Rui Sheng , Zhao Jun Hong , Bu Jing Long , Wang Rong Lin , Wang Zhi Fa , Yu Li Xue , Wei Ying Na
Published: July 2011

Zirconium titanate and magnesium aluminate spinel precursors were prepared by non-hydrolytic sol-gel method using ethanol as oxygen donor. The gels and calcined powders were investigated by differential thermal analysis (DTA), thermogravimetry analysis (TG), X-ray diffraction (XRD). The results show that the ZrTiO4 and MgAl2O4 crystallized at low temperature of 550 °C and 700 °C, respectively. It indicated that the highly homogeneous zirconium titanate and magnesium aluminate gels were aslo obtained by nonhydrolytic sol-gel process using ethanol as oxygen donor. The particle size distribution measured by laser scattering exhibit that ZrTiO4 and MgAl2O4 powders were large soft agglomerates which could be broken through milling process.
The Wear and Drag Prediction of the 2D Micro-Asperities on Textured Wall
Authors: Traore Moussa Magara , Wang Li
Published: July 2011

This study presents a numerical simulation, using the flow simulation of solidworks 2010; the results showed the flow speed trajectory, the variation of the shear stress and the flow pressure on different faces of the micro-asperities in relation with the face length. The simulation was done in steady state and with the no- slips condition in contact with the upper surface. The flow characteristics were found also with different flow speed. The turbulence area due to the micro-asperity geometry is localized. The flow characteristics (variation of shear stress and flow pressure) are analyzed for the prediction of the maximum wear area due to the skin friction or drag.
Effect of Conventional Cold Rolling on Wear-Resisting Performance of High Manganese Steel
Authors: Wang Yan Feng , Qiu Chang Ming , Lu Chun Guang , Zhang Lina
Published: July 2011

By taking cold conventional rolling technique on austenitic high manganese steel specimens, their hardness increase. The microstructure is studied to analyze the reason why cold conventional rolling technique can create work hardening and improve wear-resisting performance of austenitic high manganese steel with the increase of deformation. The research will make great significance to theory and practice.
A Channelized Deadlock Prevention Policy for Flexible Manufacturing Systems Using Petri Net Models
Authors: Huang Yi Sheng , Row Ter Chan
Published: July 2011

Deadlock prevention, deadlock detection and deadlock avoidance strategies are used to solve the deadlock problems of flexible manufacturing systems (FMSs). The conventional prevention policies were always attempt to prevent the system entering the deadlocked situation by using a few control places. On can know that one prohibits the deadlocked markings, some dead markings will be sacrificed. Therefore, the reachability states will become less than the initial net. However, our goal is to preserve all the reachability states of the initial net. Under our control policy, the deadlocks or deadlock zone will be channelized to live markings such that all the dead markings in reachability states will be conserved. Finally, an example is performed and can obtain the maximal permissiveness of a Petri net model. The other examples are all getting the same result. To our knowledge, this is the first work that employs the channelized method to prevent the deadlock problem for FMSs.
A Practical and Selective Method for the Analysis of Molybdenum in Grade T91 Tube and P91 Pipe Intended for Power Plants
Authors: Li Ying , Huang Wan Qi , Chang Xu Hong , Cao Song Yan , Qi Bao Tong
Published: July 2011

ASME SA-213 T91 tubes and SA-335 P91 pipes were widely used in combined-cycle steam systems due to their greater increased temperature strength and creep behavior. In this paper, a practical and selective spectrophotometric method for the determination of molybdenum in ASME SA-213 T91 tube and SA-335 P91 pipe samples has been presented. This method was based on the chromogenic reaction between molybdenum(V) and sodium thiocyanate. Employing stannous chloride as a reductant, molybdenum(VI) was reduced to molybdenum(V) at the room temperature. The obtained molybdenum(V) formed an orange-red-colored (1:5) ligand complex with thiocyanate. The absorbance of the complex was measured at 470nm, and the molar extinction coefficient is 1.75´104L·mol-1·cm-1. Under the optimum reaction conditions the absorption value was proportional to the concentration of molybdenum in the range of 0.40~1.21%, and the relative standard deviation was less than 3.0%. The proposed method was free from the interference from a large number of analytical important elements and has been applied satisfactorily to the determination of molybdenum in grade T91 tube and P91 pipe samples with the improved accuracy and precision.
Study on Thermal Simulation of a New Al-Mg-Si-Cu Alloy
Authors: Zhao Zhi Hao , Meng Yi , Cui Jian Zhong
Published: July 2011

The new Al-Mg-Si-Cu aluminum alloy has been developed for application in cold and hot extrusion and forging. Its nominal composition is 1.37%Mg、0.85%Si、0.82%Cu、0.11%Cr and 0.15%V. In this paper, The hot deformation behaviors of the new Al-Mg-Si-Cu aluminum alloy were studied by means of compression deformation tests on MMS-200 multifunctional materials simulation machine at strain rates ranged between 0.1~0.5s-1 and deformation temperature between 350~550°C. The laws of the flow stress dependent both on thedeformation temperature and strain rates were discovered, and then the relationship between the first peak-stress σp and strain rates was obtained through one-dimensional linear regression.
Effects of the Vibration and Low Pressure on Solidification Microstruction of Zinc-Aluminum Alloy
Authors: Zhang Ying , Han Jing Xiao , Xie Xian Jiao , Xie Shui Sheng , He Jin Yu , Sun Wen Sheng , Li De Fu , Geng Mao Peng
Published: July 2011

The zinc alloy samples were prepared under the condition of the vibration and ordinary pressure, 0.4Mpa pressure and 0.7Mpa pressure. The photos of the microstructure morphology were obtained by optical microscopy. The analysis result shows that the crystalline microstructure of solidification by the band edge changes from dendrite-shaped to oval, spherical grains. The internal grains havealso been refined.
Correlation of Dynamic Response with Adiabatic Shearing Behavior in Ti–10V–2Fe–3Al Alloy
Authors: Ding Qing Wen , Ren Yu , Tan Cheng Wen , Zhang Jing , Yu Xiao Dong
Published: July 2011

A Split Hopkinson Pressure Bar system was employed to investigate the compressive dynamic mechanical behaviors of Ti-10V-2Fe-3Al (Ti-1023) alloy with lamellar microstructure, over a broad strain rates ranging from 1500/s to 5100/s. The results reveal that the strain rate has a significant effect on the flow stress of Ti-1023 alloy, and there exists serious thermal softening as the strain rate exceeds 3200/s. The critical strain rate of fracture for this alloy is 2300/s. The microstructure examination indicated that adiabatic shear bands (ASBs) bifurcate more intensely with the increasing of strain rate. Micro-voids nucleate either in the ASB or interface between shear band and matrix bulk. Finally, fracture of this alloy proceeds through the nucleation, growth and coalescence of these voids and cracks along the ASBs.
Influence of Fe on the Formation of Nucleation in Carbon-Inoculated Mg-3%Al Alloy
Authors: Du Jun , Wang Ming Hua , Fan Ting , Li Wen Fang
Published: July 2011

The Mg-3% Al melt was treated by carbon inoculation and Fe addition. The influence of Fe on the formation of nucleation was investigated. That Fe inhibited the grain refinement of the carbon-inoculated Mg-3%Al alloy or not was closely associated with the operating sequence of carbon inoculation and Fe addition. Under the condition of Fe addition firstly and then carbon inoculation, the Al4C3 particles and the particles with duplex phase structure of Al4C3 coated on Al-C-Fe or Al-Fe could be observed. Both kinds of particles should act as nucleating substrates for a-Mg grains, resulting in no obvious effect of Fe on refining efficiency of carbon inoculation. Under the contrary condition, the potency of Al4C3 nucleating substrates was poisoned by transforming Al4C3 into Al-C-Fe-rich intermetallic particles, resulting in grain-coarsening.
Study on the Law of Phrase Transformation of High-Carbon Matrix Steel 4Cr-3Mo-3V-2W
Authors: Na Shun Sang , Chen Jian Sha , Fu Chao , Zhang Guo Tao , Xu Qian
Published: July 2011

The study on the phase transformation law of High-Carbon Matrix steel 4Cr-3Mo-3V-2W-Ni-Nb, which is processed in different heat treatment, is conducted by means of metallographic observation, hardness determination and phase analysis conducted with the help of X-ray diffraction. The results indicate what is as follow: through quenching at 970°C, the main precipitations of alloy carbide are V4WC5, Cr7C3 and Fe3W3C at 200~300°C, V4WC5 and Cr7C3 at 400°C, V4WC5 and Cr7C3 at 500°C, V4WC5, Cr7C3 and Mn23C6 at 600°C. The transformation of residual austenite is thorough completed above 400 °C and the cause of secondary hardening is the precipitation of V4WC5 and V4C2.67.
On the Oxidation Behaviors of MoSi2 at 673 – 873 K
Authors: Zhang Hou An , Gu Si Yong
Published: July 2011

On the basis of analysis of thermodynamics and kinetics on the oxidation behavior of MoSi2 at 673 – 873 K, an oxidation kinetics model is established. The kinetics model gives a well explanation that the very severe oxidation rate of MoSi2 at 773 K is because of the maximum oxidation reaction constant near this temperature.
Effect of Melting Process on Zr Content and Grain Refinement in ZE41A Alloy
Authors: Liu Hong Hui , Ning Zhi Liang , Cao Fu Yang , Zhang Yu Chen , Sun Jian Fei
Published: July 2011

The effects of melting process on Zr content and grain size in ZE41A alloy were investigated in this study. The results show that the soluble Zr increases with the increased addition content of Mg-Zr master, up to 0.87%. The ratio of Zr addition content to soluble Zr content changes within 3.86-4.8. The melt temperature has little effect on soluble Zr content. Grain size grows and both soluble Zr and total Zr decrease with the prolonged isothermal holding of the melt.
Influence of the Strain Rates on Tensile Properties and Fracture Interfaces for Mg-Al Alloys Containing Y
Authors: Liang Hao , Pan Fu Sheng , Chen Yong Mei , Yang Ji Jun , Wang Jing Feng , Liu Bo
Published: July 2011

The tensile properties at strain rates of 0.001/s, 0.1/s and 0.6/s for Mg-3Al1-Zn-2Y, Mg-3Al-2Zn-2Y and Mg-3Al-6Zn-2Y were researched, which showed great difference on the mechanical sensitivity to strain rate. The fractal behavior of the alloys’fracture interface is remarkable. The brittleness, plasticity and the appearance of fracture interface can be related through the fractal dimension D.
Study on Corrosion Behavior of Al-Zn-In and Al-Zn-Ga Alloys in NaCl Solution
Authors: Ma Jing Ling , Wen Jiu Ba , Li Gao Lin
Published: July 2011

The corrosion behavior of Al-5Zn-0.03In and Al-5Zn-0.03Ga alloys in 3.5 % NaCl solution has been examined by electrochemical methods, scanning electron microscopy, X-ray microanalysis, electrochemical impedance spectroscopy. The results demonstrate that the alloys differ in the microstructure, corroded morphology and electrochemical properties. For Al-5Zn-0.03In alloy, the precipitates enriched in Al and Zn initiates pitting. For Al-5Zn-0.03Ga alloy, corrosion occurs more uniformly, the corrosion of the alloy occurred via the formation of a surface Ga-Al amalgam alloy. The EIS of Al-5Zn-0.03In alloy contains a capacitive loop and an inductive loop; the inductive loop can be attributed to the presence of the pitting. The EIS of Al-5Zn-0.03Ga alloy contains only a capacitive loop.
Structural Characteristics of Pheomelanin-Like Pigment from Lachnum singerianum
Authors: Ye Ming , Chen Xiao , Li Guang Wei , Guo Geng Yi , Yang Liu
Published: July 2011

Melanin was isolated from the mycelium of Lachnum singerianum YM-292 (LSM) by alkaline extraction, acid hydrolysis, and repeated precipitation with a yield of 8.85 g/100 g (dry weight basis). Scanning electron microscopy showed that LSM had a blocky crystal structure with an irregular surface. The percentages of C, H, N, O and S in LSM measured by the elemental analyzer were 54.44%, 6.65%, 8.25%, 24.24% and 6.42%, respectively. Infrared spectroscopy indicated that LSM had a typical indole structure, and 1H-NMR spectroscopy revealed signal peaks in the aliphatic and aromatic regions. It was concluded that LSM had a structural model of pheomelanin-like pigment.
A Review on Synthesis and Property of Polyurethane-Imide
Authors: Sang Xiao Ming , Wang Run Zeng , Chen Xing Gang , Zhang Lei , An Man , Shen Yi
Published: July 2011

Polyurethane-imide is a novel kind of po lymer with excellent heat-resistant and mechanical properties. This overview embracing microstructure, synthesis and properties of polyurethane-imide is given and provided representative examples to reflect the state of the research for polyurethane-imide. The microstructure includes molecular structure and phase structure. Synthesis of linear PUI and network PUI is given in next and, Mechanical properties, Thermal performance and other properties is also recommended. The shortages of PUI research is imperfection of synthesis and the theoretical analysis, so the prospect of the study on polyurethane-imide is also displayed.
The Influences of Double Modification on Carbon Fiber Surface and Microorganism Immobilization Behavior
Authors: Bao Yan Ling , Dai Guang Ze , Huang Xing Min , Han Jing , Zhao Jun Wen , Ni Qing Qing
Published: July 2011

As a biofilm carrier for wastewater treatment, PAN-based carbon fiber (CF) was usually modified with different ways. The double modification treatment composed of surface oxidation and maleic anhydride (MA) graft was used in current research and it’s regarded to be a favorable surface treatment for CF carrier. The consequent CF surface morphology and natures were then characterized by laser confocal microscopy (LCM), X-ray photoelectron spectroscopy (XPS) and the degree of moisture. In addition, biocompatibility of CF was discussed through immobilization behavior of microorganisms. The results indicated that the immobilization ability of microorganisms will be improved if the CF surface is modified to better hydrophilicity by producing oxygen-based functionalities. Furthermore, the configurations and the adhesion forms of cells were affected by the properties of CF surface.
Synthesis and Characterization of the Water-Soluble Oleoyl Acetyl Chitosan
Authors: Ke Wei Chang , Chen Yi Kun , Xiong Guo Xi , Peng Xiang Hong , Zhu Chao , Yang Xiao Qiu
Published: July 2011

Oleoyl chloride was synthesized by oleic acid and thionyl dichloride (SOCl2), and then reacted with chitosan in dichloromethane to obtain the oleoyl chitosan. Novel water-soluble oleoyl acetyl chitosan (OACh) was synthesized using oleoyl chloride reacted with acetic anhydride in pyridine. The chemical structure of the OACh was characterized by FT-IR, 1H and 13C NMR. There existed the peaks at 1743.9 cm-1 (C=O) and 1658.1 cm-1(C=C) in FT-IR spectrum, and the peaks at 170.8, 171.6 and 172.5 ppm which were assigned to the C=O of the oleoyl and acetyl groups in 13C NMR spectrum. The results indicated that OACh had oleoyl as hydrophobic moieties and acetyl as hydrophilic moieties.
Thermal and Mechanical Properties of Bagasse Microcrystalline Cellulose Reinforced PLA Composites
Authors: Li Chun Guang , Peng Wei Gong , Li Yun Xia , Xu Peng Fei , Tian Wei , Zhang Rui
Published: July 2011

The biodegradable composite films were prepared from bagasse microcrystalline cellulose as filler and polylactic acid (PLA) as polymeric matrix. The crystallinity, the tensile properties and the thermal properties of the composites were tested. The results show that the tensile properties and thermal properties were improved with the addition of bagasse microcrystalline cellulose. When bagasse microcrystalline cellulose mass fraction was 5%, the initial decomposition temperature was raised by 30.73°C, and the tensile strength increased by 50.98%, and the elongation at break increased by 16.25% compared to those of pure PLA.
Assembly of Type I Collagen on PVA Film Induced by Glutaraldehyde Vapor
Authors: Wang Yu Lu , Liao Xue Pin , Shi Bi
Published: July 2011

Type I collagen was isolated from calf skin and its assembly on PVA film induced by glutaraldehyde vapor was investigated. It was found that the collagen molecules were firstly orientationally assembled into collagen fibers under the inducement of glutaraldehyde vapor. Then the collagen fibers could be further aggregated into novel network structure in proper conditions of the induced reaction. The morphology of the assembled collagen fibers was depended on induced time and concentration of collagen. The network arrangement could be obtained after being induced for 72h when collagen concentration was 2.5mg/ml. At higher concentration of collagen (5 mg/ml), the collagen fibers with larger dimension were obtained, but the growth of fibers was almost in one direction.
Study on the Preparation, Property and Drug Release Carrier of Chitosan-Based Nanoparticles for Cancer Treatment
Authors: Chou Chih Wei , Kuo Yueh Hsiung , Hseu You Cheng , Chen Yung Shiu , Wu Te Hsing
Published: July 2011

In this paper, the effective nanocompoties (EFNCs) as drug carriers are prepared by grafting reaction of cationic chitosan (CS) and anionic tripolyphosphate (TPP) to encapsulate cancer therapeutic agents such as berberine (BB), KCY-24B…etc. These EFNCs were featured by ultra violet–visible-near infrared spectrophotometer (UV-VIS-NIR spectrophotometer), fourier transform infrared spectrophotometer (FT-IR), zetasizer, transmission electron microscope (TEM) and field-emission scanning electron microscope (FESEM). So we can obtain here the synthetic method, characterization, and functionality of these effective nanoparticles.
Directing Human Chondrocytes Cell Behavior by Fabrication of Protein Micropattern on Polystyrene Surfaces
Authors: Pan Chang Jiang , Nie Yu Dong , Dong Yun Xiao
Published: July 2011

In the present study, three BMP-2 (bone morphogenetic protein-2) micropatterns were produced on polystyrene (PS) surface by microcontact printing in order to investigate the effect of protein micropattern on biomaterials surface on human chondrocytes behavior. The excellent BMP-2 micropatterns from fluorescent observation were successfully obtained. Cell adhesion and immunohistochemical assay were utilized to explore cell behavior. The results indicated that the protein micropatterns have significant influence on cell adhesion, spread, alignment and protein expression. The cells preferentially adhered on protein micropattern zones. The cells tend to spread towards micropattern direction, leading to better spread. The spread cells could excreted more type II and VI collagen than that of non-spread or poor-spread cells. The results of this paper suggested that extracellular matrix (ECM) protein micropatterns can effectively regulate human chondrocytes behavior, which may be helpful for development of new cartilage tissue.
S-Scan of Ultrasonic Phased Array Testing for Electrofusion Joints of Polyethylene Pipes
Authors: Fu Yang , Lin Kai Ming , Huang Hui , Zhang Wei Feng
Published: July 2011

Electrofusion joint is used widely for PE pipes; the quality of the joint influences the safety of gas distribution system. Proven and reliable NDT technology of the joint is immature. The attenuation of ultrasound in PE is higher than for metals. Defects Include voids, cracks, bad fusion interfaces, dislocations of heating wires, could find be ultrasonic phased array testing. Examination time, surface of specimen, transducer, calibration block, resolution, examination range and couplant are recommend.
Effect of Cross-Linking Degree on Hydrogels using Surfactant Detergent as Template
Authors: Chen Kun , Zhang Qing Song , Chen Li
Published: July 2011

To avoid the formation of layer-pore structure and flocculation caused by the excessive introduction of nonionic surfactant detergent polyoxyethylene 20 cetyl ether (Brij58) into poly N-isopropylacrylamide/inorganic nanoclay hectorite hydrogels network (PLH hydrogels), inorganic nanoclay hectorite content, severed as physical cross-linker, was increased from 1wt% to 3wt%. The morphology, temperature- responsibility, capacity of water absorption and swelling kinetics of resulting PHL hydrogels were investigated by SEM, DSC and Gravimetric method, respectively. It was found that PLH hydrogels would keep well honeycomb-like pore with increasing hectorite content. Furthermore, PLH hydrogels exhibited good temperature sensitivity regardless of physical cross-linker content.
Preparation and Properties of PS/PSEG Composite Materials
Authors: Wang Jue , Hou Gui Xiang
Published: July 2011

Polystyrene(PS)/Polystyrene-expanded graphite(EG)(PS/PSEG) composites were prepared by melt blending, using a variety of PSEG. The electrical and mechanical properties of the PS/PSEG were measured. Mechanical property measurements of composites indicated higher impact strength and lower tensile strength with increasing content of PSEG. Exfoliated graphite has seen a significant reduction for composites in electrical resistivity.
Effect of Peroxide Content on Morphology and Properties of Thermoplastic Vulcanizates Based on PP and NR
Authors: Wang Rui , Peng Zheng , Fan Peng Peng
Published: July 2011

Thermoplastic vulcanizates (TPVs) of natural rubber (NR) and polypropylene (PP) (60:40) containing various dosages (0.5-5.5phr) of peroxide were prepared using a Haake Rheocord. The effects of peroxide content on the crosslink density, thermal behaviors, morphology, mechanical and rheological properties of NR/PP TPVs were studied. The crosslink density of TPVs increased with increasing of peroxide content. However, the tensile strength, tear strength and elongation at break obtained the maximum values when 2.5phr peroxide was added, which was ascribed to the presence of smallest particle size of crosslinked rubber phase at this peroxide content. It was proposed that the effect of DCP, which not only initiated crosslink reaction in NR phase, but also degraded the polypropylene molecules, played an important role in determined the morphology and properties of TPVs. The viscosity of TPVs decreased with shear stress, indicating pseudoplastic nature of the TPV samples. The elastic modulus of the samples gradually increases with the increase in DCP content.
Synthesis of Poly(Aryl Sulfone Benzimidazole) Sulfone
Authors: Chang Guan Jun , Zhang Lin , Lin Run Xiong
Published: July 2011

Sulfoned aromatic acid and o-phenylenediamine as the monomers, sulfoned-benzimidazole was obtained by condensation reaction. Poly(aryl sulfone benzimidazole) sulfone (PSBIS) as novel heat-resistant polymer was obtained by the condensation polymerization via Palladium-catalyzed aryl amination reaction of sulfoned-benzimidazole and aromatic dibromide. Differential scanning calorimetry (DSC) and thermal analysis (TG) measurements showed that the polymer synthesized possessed high glass transition temperature (Tg>321°C), good thermal stability with high decomposition temperature (TD>540°C) and good solubility.
Analysis of Performance of PR.S Asphalt Mixture and Application
Authors: Peng Yu Hua , Liu Hui Xing , Shi Lin Kai
Published: July 2011

In order to study the performance of asphalt mixture with PR.S, Marshall test and rutting, low temperature bending, water stability test were done. The results indicated that the additive PR.S played an important role in improving high-temperature anti-rutting performance of asphalt mixture because of the cementation, reinforcement, inter-lock and adsorption function. With the amount of PR.S increasing, high-temperature performance of asphalt mixture increased gradually and low-temperature performance declined a little. In order to decide the appropriate amount of the additive PR.S, the low-temperature anti-cracking performance should be mainly considered when asphalt mixture was designed. The other performance of asphalt mixture with the amount of 0.45% PR.S could also meet the requirements of the specification. Considering its great contribution to anti-rutting, PR.S asphalt mixture was more properly adopted in the middle layer of asphalt pavement.
Study on Preparation and Properties of Polystyrene/Styrene-Ethylene/Butylene-Styrene Composites
Authors: Sang Xiao Ming , Zhang Lei , Wang Run Zeng , Chen Xing Gang , An Man , Shen Yi
Published: July 2011

The polystyrene/styrene-ethylene/butylene-styrene composites were prepared by melt blending process in this paper. The mechanical properties of PS/SEBS composites were analyzed. The results showed that the impact strength of PS/SEBS composites could be increased with the content increasing of SEBS, meanwhile the tensile strength was lower than pure polystyrene. When the content of SEBS increased to 13 wt.%, the impact strength of PS/SEBS composites was 2.4 times higher than that of pure PS. The fractured surfaces of the specimens were characterized by scanning electron microscopy(SEM). The results showed that the impact fractured surfaces produced a lot of sliding along with the addition of SEBS. The particles of SEBS could be well dispersed in polystyrene matrix. From rheological properties studies and the values of the torque, it was suggested that the maximum torque of PS/SEBS composites decreased drastically.
Ultrafine Pd Nanoparticles Synthesis and Catalytic Performance in Methane Partial Oxidation
Authors: Fu Bao Song , Liu Hu , Xiao Guo Min
Published: July 2011

Narrow size distribution Palladium nanoparticles was synthesized by adding Pd precursor into a modified PMHS polymer solution, and then jelled by aluminium. The multi-functional polymer was characterized by NMR; Pd nanoparticle samples were characterized by TEM and catalytic activity was tested in methane partial oxidation reaction.
Thermal Degradation Kinetics of Poly(Arylene Ether Nitrile) and its Crosslinked Polymer
Authors: Zhong Jia Chun , Yang Jian , Tang Hai Long , Liu Xiao Bo
Published: July 2011

The kinetics of the thermal degradation of Polyarylene ether natriles (PEN) (crosslinked and uncrosslinked) were investigated by thermogravimetric analysis (TGA). The corresponding kinetic parameters of PEN were determined using Flynn–Wall–Ozawa method and Friedman method, respectively. Satava method was also used to discuss the probable degradation mechanisms of PEN. The results showed that the activation energy obtained from Flynn–Wall–Ozawa method was in good agreement with the value obtained from Friedman method. The solid-state decomposition mechanisms of PEN and crosslinked PEN were A2 type (nucleation and growth) and R2 type (phase boundary controlled reaction), respectively. The activation energy and initial decomposition temperature of crosslinked PEN were higher than that of PEN, which indicates that crosslinking treatment is effective to enhance the thermal stability of PEN.
Research on Al2TiO5-Si3N4 Composites Fabricated by Reaction Method
Authors: Wang Rui Sheng , Wei Jun Cong , Yao Shao Wei
Published: July 2011

Al2TiO5-Si3N4 composites were fabricated by mixing 75-95% premixed powder, composed of titanium dioxide, α-Al2O3 powder, and suitable amount of stabilizing agents such as MgO, SiO2 and ZrO2, and 5-25% α-Si3N4 and being sintering at 1450-1550°C in nitrogen atmosphere. The effects of Si3N4 content, sintering temperature and soaking temperature on the properties of Al2TiO5-Si3N4 composites were investigated. The results showed that the optimum formula for Al2TiO5-Si3N4 composites was 90% premixed powder and 10% α-Si3N4. The optimum technological parameter was that sintering time was 1550°C for 2h.
Effect of Calcium Stearate Concentration on Cure Properties of Epoxidized Natural Rubber
Authors: Yang Chang Jin , Peng Zheng , Luo Yong Yue , Liao Shuang Quan , Zhong Jie Ping , He Can Zhong , Wang Yue Qiong
Published: July 2011

Two grades of epoxidized natural rubber (ENR), namely, ENR 25 and ENR 40 were mixing through adding 0-5 phr calcium stearate. The effect of calcium stearate concentration on cure characteristics of ENR was studied. The cure properties were determined by Moving Die Rheometer (MDR 2000) at 150°C. It showed that the scorch time (TS1) for ENR 25 and ENR 40 increased to a maximum value at 1 phr of calcium stearate, and further addition of calcium stearate maked it decrease. The cure time (T90), maximum torque (MH) and torque difference (MH﹣ML) of ENR decreased with increasing calcium stearate loading. For a fixed calcium stearate concentration, the scorch time (TS1) and cure time (T90) of ENR 40 were shorter than that of ENR 25, which is attributed to the activation of an adjacent double bond by the epoxide group in ENR. The results indicate that the effect of calcium stearate concentration on the cure characteristics of epoxidized natural rubber is remarkable.
QSPR Study on Electric Spark Sensitivity of Nitro Arenes
Authors: Wang Rui , Jiang Jun Cheng , Pan Yong
Published: July 2011

A quantitative structure-property relationship (QSPR) model was proposed for predicting electric spark sensitivity of 39 nitro arenes. The genetic function approximation (GFA) was employed to select the descriptors that have significant contribution to electric spark sensitivity from various descriptors and for fitting the relationship existed between the selected 8 descriptors and electric spark sensitivity. The correlation coefficients (R2) together with correlation coefficient of the leave-one-out cross validation (Q2CV) of the model are 0.924 and 0.873, respectively. The model is highly statistically significant, and the robustness as well as internal prediction capability of which is satisfactory. The results show that the predicted electric spark sensitivity values are in good agreement with the experimental data.
Elastic Properties and Electronic Structure of L12 (Al,Si)3Sc
Authors: Yao Qiang
Published: July 2011

The method of ultrasoft pseudopotential within the generalized gradient approximation has been employed to study the elastic constants and electronic structure of (Al,Si)3Sc precipitate with L12 structure in Al-base alloys. Based on the calculated results, the elastic properties of (Al,Si)3Sc precipitate were investigated. The Young’s and shear modulus of the polycrystals for (Al,Si)3Sc precipitate were calculated using Voigt-Reuss-Hill averaging scheme. The calculated results of elastic properties showed that the (Al,Si)3Sc precipitate has a strengthening effect in the Al matrix, owing to the larger shear modulus differences between (Al,Si)3Sc and Al matrix. The calculated results also showed that (Al,Si)3Sc precipitate is brittle in nature.
Light Yield Non-Proportionality and Energy Resolution of Lu1.8Y0.2SiO5:Ce and LaCl3:Ce Scintillation Crystals
Authors: Wanarak Chalerm , CHEWPRADITKUL WEERAPONG , Phunpueok Akapong
Published: July 2011

The scintillation response of Lu1.8Y0.2SiO5:Ce (LYSO:Ce) and LaCl3:Ce scintillators were compared under g-ray excitation using photomultiplier tube (PMT) readout. For 662 keV g-rays (137Cs source), energy resolution of 4.5±0.2% obtained for LaCl3:Ce coupled to XP5200B PMT is much better than that of 8.2±0.4% for LYSO:Ce. The non-proportionality of the light yield and energy resolution versus g-ray energy were measured and the intrinsic resolution of the crystals was calculated. Special attention was devoted to the correlation between intrinsic resolution and non-proportional response of scintillators.
Comparison of Lu0.7Y0.3AP:Ce and Bi4Ge3O12 Scintillators in Gamma Ray Spectrometry
Authors: Phunpueok Akapong , CHEWPRADITKUL WEERAPONG , Limsuwan Pichet , Yu Bing Kun , Wanarak Chalerm
Published: July 2011

The scintillation response of Lu0.7Y0.3AP:Ce and Bi4Ge3O12 scintillation crystals have been compared using photomultiplier tube readout for photon energies ranging from 22.1 to 1274.5 keV. Lu0.7Y0.3AP:Ce showed a light yield non-proportionality of about 20% upon lowering energy from 1,274.5 to 22.1 keV, which is better than that of about 39% obtained for Bi4Ge3O12. Lu0.7Y0.3AP:Ce showed the light yield of 13,400 ph/MeV and energy resolution of about 8 % for 662 keV gamma rays from a 137Cs source. The photofraction of Bi4Ge3O12 is better than that of Lu0.7Y0.3AP:Ce. The intrinsic resolution of the crystals versus energy of gamma rays has been determined after correcting the measured energy resolution for photomultiplier tube statistics.