bluuebunny/crossref_metadata_2025 huggingface dataset:
Transient Thermo-Elastohydrodynamic Lubrication of Rough Surface in Soft Material
Authors: Wongseedakaew Khanittha
Published: March 2013

This paper presents the effects of transient rough surface thermo-elastohydrodynamic lubrication (TEHL) of rollers for soft material with non-Newtonian fluid base on power law model. The time independent modified Reynolds equation, energy equation and elasticity equation were solved numerically using finite different method, Newton-Raphson method and multigrid multilevel method to obtain the film pressure profiles, film thickness profiles and friction coefficient in the contact region. The simulation results show surface roughness has effect on film thickness but its effect on film temperature is insignificant. The minimum film thickness decreases while the coefficient increases when the amplitude of surface roughness increases. Meanwhile, increasing applied loads causes the friction coefficient to decrease.
Three-Dimensional Flexible Polyimide Based Probe Array with Stiffness Improvement by Using Biodegradable Polymer
Authors: Cheng Ming Yuan , Tan Kwan Ling , Yee Tack Boon , Je Mink Yu
Published: March 2013

This work presents a three-dimensional flexible polyimide (PI) probe array with biodegradable polymer that offers desirable insertion capability. In order to avoid the recording sites position shifts slightly and damage neuron cells when the body moves, the flexible neural probes are more preferable than traditional Si-based neural probes. A sufficient buckling strength of flexible probe is critical for inserting flexible probe into the brain. Here, we used a biodegradable polymer, polyethylene glycol (PEG), to improve the mechanical stiffness of flexible probe. PEG, which is solid state at room temperature and dissolves when immersing in water, was coated onto the flexible probe and the mechanical stiffness of the flexible probe was increased before insertion into the biological tissue. The buckling strength of different probes was simulated using finite element analysis and measured by compression tester. The coated PEG flexible probe maintains sufficient stiffness to facilitate tissue penetration with solid PEG elastic modulus of 660±19 MPa but loses its strength within 25 minutes once immersed in saline. A microassembly method of three-dimensional flexible probe array was also proposed to integrate the flexible probe and their interconnections. In vitro test, the coated PEG flexible probe regained their original impedance of 12.8 kΩ at 1 kHz within 30 minutes of immersing in saline via water absorption and polymer’s biodegradable response.
Application of a Newly Developed Thermally Induced Volumetric Error Compensation Model in Improving Dimensional Accuracy of Parts
Authors: Lu Yu Xia , Islam M.N.
Published: March 2013

The thermally induced volumetric error of a machine tool has been recognised as a major contributor to the dimensional and geometric errors of component parts produced by that tool. Therefore, considerable research has focused on ways to compensate for this type of error. The traditional model of compensation for the thermally induced volumetric error of a three-axis machine tool requires the measurement of 21 geometric error components and their variations with temperature, which is difficult and time-consuming to conduct. In our previous research, we developed a simplified and economical method of compensation of thermally induced volumetric error by modeling the positioning error as functions of ball-screw nut temperature and travel distance. This paper describes the application of this newly developed compensation model in improving the dimensional accuracy of parts. The model was applied to reduce the positioning error of a number of drilled holes. The results showed an average reduction of absolute and relative errors by 30.44 μm and 77%, respectively.
Hydrothermal Synthesis and Photocatalytic Hydrogen Generation of Cr3+ Doped Porous ZnIn2S4 Photocatalysts
Authors: Wu Wei , Bai Xue Feng
Published: March 2013

A series of Cr3+doped porous ZnIn2S4photocatalysts were synthesized via a facile hydrothermal method using cetylpyridiniumbromide (CPBr) as template. The above-prepared photocatalysts were characterized by XRD, FESEM, DRS and XPS. The effects of different Cr3+doping concentration on the morphology and photocatalytic activity of ZnIn2S4photocatalysts were investigated. It is demonstrated from the experimental results that Cr3+doping in the ZnIn2S4photocatalyst had significantly influence on the crystal structure, electron-hole recombination and photocatalytic activity. The highest rate of hydrogen evolution of 3115.2 μmol/(h•g) over Cr3+(0.5%)- ZnIn2S4photocatalyst was observed.
Thermoelectric Heat Pipe-Based Refrigerator: System Development and Comparison with Thermoelectric, Absorption and Vapor Compression Refrigerators
Authors: Putra Nandy , Ardiyansya H. , Irwansyah Ridho , Septiadi Wayan Nata , Adiwinata A. , Renaldi A. , Benediktus K.
Published: March 2013

Thermoelectric coolers have been widely applied to provide cooling for refrigerators in addition to conventional absorption and vapor compression systems. To increase heat dissipation in the thermoelectric cooler’s modules, a heat pipe can be installed in the system. The aim of this study is to develop a thermoelectric heat pipe-based (THP) refrigerator, which consists of thermoelectric coolers that are connected by heat pipe modules to enhance heat transfer. A comparative analysis of the THP prototype and conventional refrigerator with vapor compression, absorption and thermoelectric systems is also presented. The prototype system has a faster cooling down time and a higher coefficient of performance than the absorption system but still lower than vapor compression system
Design of a Novel Photocatalytic Gypsum Plaster: with the Indoor Air Purification Property
Authors: Yu Q.L. , Brouwers H.J.H.
Published: March 2013

This article addresses the design of a new photocatalytically active gypsum plaster. A hemihydrate in beta type is used as binder to design this material and a carbon modified TiO2 that can be activated by visible light is used as photocatalyst. An own developed test setup to assess the indoor air purification capacity of the developed material is presented. The new product possesses the indoor air pollutants removal capacity. The air pollutants removal ability is related with not only the dosage of the applied photocatalyst but also strongly with the physical property of the resulting matrix such as the porosity.
Investigation of Dual-Wavelength Erbium-Doped Fiber Laser Intra-Cavity Absorption Sensor
Authors: Lu Ying , Huang Xiao Hui , Wu Bao Qun , Jing Lei , Musideke Mayilamu , Hao Cong Jing , Duan Liang Cheng , Yao Jian Quan
Published: March 2013

We propose a dual-wavelength intra-cavity absorption sensor based mode competition. The sensitivity of output power to relative cavity loss in different pump current is studied experimentally by defining a sensitivity enhancement factor (SEF). A measurement sensitivity of 158.5 times that of a single-pass absorption sensor is achieved.
Method to Detect SQL Injection Attacks for Complex Network Environment
Authors: Pan Wu Min
Published: March 2013

SQL injection has become a serious security risk among all the attacks against Web application. The SQL injection attack allows an attacker to access the underlying database unrestrictedly, and furthermore, retrieves the confidential information of the corporation and the network user. We found that most of the existing researches are able to detect most of the attacks, but they do not consider the complexity involved in using the defense system and the eventual cost of modification of the original program. For this reason, we conducts an in-depth research on SQL injection and defense: requires no modification of the web application code,and can be adapted to different usage scenarios,involving also different operating systems and server applications,and can be able to detect all the known injection points for the test application
A Decorrelation-Based Nonnegative Matrix Factorization Algorithm for Face Recognition
Authors: Zhou Dan , Gao Hai Yan , Zhang Yun Jie
Published: March 2013

Nonnegative Matrix Factorization (NMF) is among the most popular subspace methods, widely used in a variety of image processing problems. However, this approach is very time-consuming in face recognition due to the extreme high dimensionality of the original matrix. To remedy this limitation, this paper presents a Decorrelation-based NMF (DNMF) method. The proposed algorithm first takes into account the dimension reduction of the original matrix by preprocessing of decorrelation in spatial domain, and then uses nearest neighbor classifier on the reduced subspace. The developed algorithm has been applied for the ORL standard face image database. Experimental results demonstrate the validity of this method.
Short-Term Power Load Forecasting Based on EMD and ESN
Authors: Luo Yong , Jia Xue , Chen Shu Wei
Published: March 2013

With the continuous development of power market, the precision requirement for short-term power load forecasting is constantly being improved. In order to obtain higher prediction accuracy, this paper put forward a method of combining empirical mode decomposition (EMD) with echo state network (ESN) for short-term power load forecasting. First, original data had been decomposed into several independent components, whose features were obvious. A corresponding echo state network was built for each component. Then, each component should be trained and predicted by its corresponding echo state network. The experimental results showed that this method has a better prediction accuracy compared with traditional neural network method.
Dynamic Surface Neural Control for a Class of Nonlinear Time-Varying Delay Systems Preceded by Unknown Hysteresis
Authors: Zhang Xiu Yu , Liu Cui Ping , Sun Yan
Published: March 2013

In this paper, a new robust adaptive neural dynamic surface control is proposed for a class of time-varying delay nonlinear systems preceded by backlash-like hysteresis. Compared with the present schemes of dealing with time-varying delay and hysteresis input, the main advantages of the proposed scheme are that the prespecified transient and steady state performance of tracking error can be guaranteed for the first time when using DSC to deal with the time-varing delays; the computational burden can be greatly reduced and the explosion of complexity problem inherent in backstepping control can be eliminated. It is proved that the new scheme can guarantee all the closed-loop signals semi-globally uniformly ultimate bounded. Simulation results are presented to demonstrate the validity of the proposed scheme.
Matrix Structure and Cryptographic Properties of Rotation Symmetric H Boolean Functions
Authors: Huang Jing Lian , Wang Zhuo , Zhang Jing
Published: March 2013

Use the derivative of the Boolean function and the e-derivative defined by ourselves as research tools, Cryptographic properties such as structural features, and the balance, correlation immunity of diffused rotation symmetric H Boolean functions is studied. Then we get the results of the relationship of a matrix structure, correlation immunity, dimension and balance of rotationally symmetric H Boolean functions, etc. As well as the result of algebraic immunity and the algebraic immunity orders that related with the Third Order completely pure rotation symmetric Boolean functions.
The Evolution of Deuterium Bubbles in Iron under Electron Irradiation
Authors: Jiang Shao Ning , Long Yi , Sun Jin Xiu
Published: March 2013

To investigate the interaction between Reduced Activation Ferritic Martisitic steel (RAFMs) and deuterium produced by the plasma in Tokamak, iron was implanted deuterium ions at RT, then aged at 773K for 1h. Finally it was irradiated with 1250keV electrons in high voltage electronic microscope (HVEM) at 773K. The result shows that dense small bubbles appeared on surface of iron in the form of convex lens after aged. The bubbles have tended to distribute along some line in grain body. Electron irradiation at 773K resulted in a greater size and a smaller density of bubbles with the increasing dose. Bubbles continued to grow up and broke. Lateral stress drive theory indicates the evolution of bubbles on surface in iron is mainly attributed to lateral stress caused by irradiation.
The Divacancy Formation Energy for B2 FeAl Alloy Simulated with Finnis-Sinclair many-Body Interatomic Potential
Authors: Wang Yue Hua , Liu Yan Xia , Wang Xun
Published: March 2013

The Finnis-Sinclair many-body potential was fitted for binary FeAl alloy with B2 structure. As the examination to the acquired potential function, some properties were calculated, and the results agree with the experiments well. Further, properties of point defects, such as divacancies were studied as an application.
An Investigation on Grain Refinement Mechanism of Master Alloys Al-Ti, Al-TiC and Al-Ti-C Toward Pure Aluminum
Authors: Ding Wan Wu , Zhu Jiang Tao , Zhao Wen Jun , Xia Tian Dong
Published: March 2013

The grain refining effects of Al-Ti, Al-TiC and Al-Ti-C master alloys on commercially pure aluminum were compared, and the grain refinement mechanism of TiAl3 and TiC among master alloys was discussed. The results show that: the grain refinement of the master alloys Al-TiC and Al-Ti toward pure aluminum mainly stems from the heterogeneous nucleation role of TiC and TiAl3 particles, but with the extension of heat preservation time of fused mass, its role of heterogeneous nucleation will decline due to dissolution of TiAl3 and aggregation and precipitation of TiC. The preferable grain refinement effects of Al-Ti-C master alloys toward pure aluminum are mainly due to the fact that when TiAl3 and TiC particles are acted commonly as heterogeneous nucleation particles, the heterogeneous nucleation effect of TiC particles will be enhanced because of the presence of TiAl3.
Effect of Heat Treatment on Microstructure and Properties of Ti-6.5Al-1.5Mo-2.5V-2Zr Titanium Alloy
Authors: Zhou Bing , Zhang Shang Zhou
Published: March 2013

The relationship of microstructure and properties of Ti-6.5Al-1.5Mo-2.5V-2Zr titanium alloy heat-treated in the α+β phase field was studied. It was found that globular or bimodal microstructures were obtained for alloy annealed at 400-950°C. Ductility decreased with increasing annealing temperature, while the strength showed a minimum at 800°C. The properties at the center of billet are lower than that at the edge due to the low cooling rate after forging. With the increase of test temperature, the strength decreased and ductility increased.
Research on Corrosion Rate Prediction of Aluminum Alloys in Typical Domestic Areas Based on BP Artificial Neural Network
Authors: Li Li , Qiu Peng , Xing Shi Bo , Su Xiao
Published: March 2013

By analyzing the climatic factors and aluminum alloys corrosion data in 10 atmospheric corrosion sites, the aluminum alloy atmospheric corrosion prediction model was built. The reasonableness of the corrosion model was verified by using the BP artificial neural network to learn, train, simulate, and compare with the corrosion test results of aluminum alloy samples in 10 typical atmospheric corrosion test stations. The results show that a stable forecasting model can be built based on the BP artificial neural network, which well predicted the corrosion rates of aluminum alloys in 10 typical atmospheric corrosion test stations.
Prediction of Electrical Conductivity of Cu-15Ni-8Sn-XSi Alloys Using the Physical Model and Artificial Intelligence Model
Authors: Fang Shan Feng , Han Yuan Shan , Wang Ming Pu
Published: March 2013

The kinetics of phase transformation in Cu-15Ni-8Sn-XSi alloys alloy was studied through the measurement of the relationship between electric conductivity and volume friction of the new phase. The phase transformation kinetics equation was deduced from the Avrami empirical formula based on the linear relationship between the electrical conductivity and the volume fraction of the phase transformation. The electrical conductivity calculated by the physical model was also obtained. As comparisons, a new model based on least square support vector machines (LSSVM) and capable of forecasting electrical property of Cu-15Ni-8Sn-XSi alloys has been proposed and tested on the same data. The present calculated results of both the physical and artificial intelligence models are in very good agreement with the experimental values. Two models are feasible and efficient to forecast the electrical conductivity of Cu-15Ni-8Sn-XSi alloys.
The Inhibiting Effect of Monoethanolamine on 6063 Aluminum Alloy in Sodium Chloride Solution
Authors: Yu Hui Cheng , Wei Yi Chun , Huang Xue Yi , Lei Fu Hou
Published: March 2013

Monoethanolamine (MEA) was investigated as corrosion inhibitors of a 6063 aluminum alloy in 3.5 % solution using polarization and electrochemical impedance spectroscopy techniques and weight loss. The polarization curves show that monoethanolamine (MEA) can increase corrosion potential (Ecorr) and pitting corrosion potential (Epit), and decrease corrosion current density (icorr) of the 6063 aluminum alloy. EIS results indicate that monoethanolamine (MEA) can increase impedance of the 6063 aluminum alloy. The results show that monoethanolamine exhibits better inhibitor properties for the 6063 aluminum alloy. Electrochemical test results show monoethanolamine (MEA) can improve corrosion resistance and the inhibition action depends on the concentration of the inhibitor. The weight-loss experiment also proves that monoethanolamine (MEA) can improve the corrosion resistance of the 6063 Al alloy.
Studies on Curing Kinetics of Epoxy Resin / Modified Amine System
Authors: Guan Dong Bo , Cai Zhong Yi , Zhai Xiao Jie , Yao Wei Guo , Wang Shou Jun , An Hui , Qiu Xiao Ming
Published: March 2013

In this paper, E51 epoxy resin with 1050B modified polyamine and 1055B Modified polyamide was studied by non-isothermal DSC, and then we use Kissinger and Ozawa methods to calculate the activation energy and reaction order n, obtained its curing reaction kinetic model, and the reaction is a complicated reaction, at last we determine the E51 epoxy resin and 1050B modified polyamine / 1055B Modified polyamide curing conditions.
Vibrating Mixing and the Improvement of Concrete Performance
Authors: Zhang Liang Qi , Feng Zhong Xu , Zhao Li Ping
Published: March 2013

Velocity gradient and low efficiency zone exist in the common forced mixing. The linear velocity of mixing is low, and the mixing time is long. The concrete has poor micro uniformity. The interface bonded strength and the durability are low. Based on the deficiency of common forced mixing, we put forward vibrating mixing technology and have successfully developed a device. The device adopts the method of forced mixing and vibrating mixing combined, which makes the material particle own certain vibrating frequency and present in vibrating status not only to destroy the sticky connection of mixture, but also reduce friction in materials to promote materials from clusters into uniform distribution. Meanwhile, the device improves micro uniformity and interface connection strength of concrete, and air content of concrete can reach above 3%. The mixing time is shorter and the cement dosage is fewer under the condition of invariable concrete strength.
Analysis of Indentation Size Effect of Vickers Hardness Tests of Steels
Authors: Budiarsa Nyoman , Norbury Andrew , Su Xiao Xiang , Bradley Gareth , Ren Xue Jun
Published: March 2013

In this work, the indentation size effect (ISE) in Vickers hardness tests of steel with selected heat treatments (annealed or tempered) has been investigated and analysed. Systematical hardness tests were performed within a commonly used micro-load range. The experimental data was analysed according to the Meyer power-law and the proportional specimen resistance (PSR) models and the link between ISE and material properties was discussed. The results showed that the experimental data fitted well with the Mayers power-law (P = A.dn) and the PSR (P/d = al + a2d) models. The ISE index (n) showed a good correlation with the hardness-elastic modulus ratio (H/E), which potentially could be used to predict the relative contributions of the elastic and plastic deformation contact area under indentation load and to normalize the hardness values for inverse material properties .
Integrity Assessment on Natural Gas Transmitting Pipe Based on the Finite Element Analysis
Authors: Chen Mei Bao , Jiang Yu Rong , Tian Yuan , Xu Chun Bi , Cai Zhi Yong
Published: March 2013

Recently, the intelligent inspection data of one natural gas transmitting pipeline showed that lots of the blistering was found in the pipe inner surface. In this paper, the method of finite element analysis was carried out to simulate and calculate the effect of blistering to the pipe strength. The results show that the max vonmises stress of the pipe with blistering was close to the yield strength and the max vonmises stress of the pipe increased with the increase of the press in the blistering. The minimum safety factor in the pipe with blistering was 0.99 which was reduced by the blistering. The sulfide stress corrosion (SSCC) and the manufacturing technology of hot rolling compound accelerated the growth of the blistering in the pipe.
Influence of Point Defects on Band Gaps of Fe-Epoxy in Two-Dimensional Phononic Crystal
Authors: He Jiao , Fan Guang Hui , Zhao De Xun , Liu Ying Kai
Published: March 2013

The band gap of a new two-dimensional phononic crystal was studied by the plane-wave expansion method. The two-dimensional phononic crystal is formed by square-shape array geometry of iron cylinders with square cross section inserted in an epoxy resin. The band gaps of different structures were calculated such as defect-free, single cavity crystal point defect states, crystal point defect states with (10) direction coupling, crystal point defect states with (10) direction next-nearest-neighbor coupling, and crystal point defect states with (11) direction next-nearest-neighbor coupling. Compared with that of defect-free, it is conclude that point defect is beneficial to the production of band gaps. The bandwidth of point defect is about 5 times larger than that of the defect-free crystal with the filling fraction F=0.4. In addition, the maximum number of band gap is in the crystal point defect states with (10) direction next-nearest-neighbor coupling. It will provide a theoretical reference for the manufacture of phononic crystal.
A Fretting Damage Analysis of Railway Axle
Authors: Zhang Yue Jun , Peng Jin Fang , Cai Zhen Bing , Zhu Min Hao
Published: March 2013

A railway axle operated over 6×105 km has been detected by varied micro-examination methods in detail. The examination of Leeb hardness tester results showed that the hardness of the press-fit seats presented higher hardness than that of other sites. According to the micro morphological analyses by optical microscope (OM), scanning electron microscope (SEM), energy dispersive X-ray spectrum (EDX), and proﬁlometer on the surface at different press-fit seats, the most severe damage band was occurred at the inner edge of wheel seat near the gear seat. The transmission electron microscope (TEM) results indicated that the dislocation density of subsurface, beneath the axle surface about 20 μm, was much higher with a great deal of dislocation tangles, pile-ups and cellular structure formation. However, when the examination depth increased to 100 μm, no cellular structure can be founded, the dislocation density was very low, so the damage depth was less than 100 μm.
Effect of Carbon Doped in BN on Electronic Structures and Mechanical Properties
Authors: Ao Jing , Li Chun Mei , Chen Zhi Qian , Wang Jin
Published: March 2013

The structural properties and elastic constants of (B1-xCx)(N1-xCx) (x=0.0, 0.2, 0.4 and 0.6) are calculated by the ultra-soft pseudo-potentials within the generalized gradient approximation and local density approximation in frame of density functional theory with virtual crystal approximation. The elastic constants, the aggregate elastic modulus, poisson’s ratio, energy gap and hardness are computed too. The energy band structure, DOS, and Hellmann-Feynman stresses are also examined in details.
The Qualitative Analysis of Far-Infrared Fiber by Near-Infrared Spectroscopy
Authors: Guan Yu , Zhang Yi
Published: March 2013

Using Near-infrared Spectroscopy developed a complete set of method of qualitative analysis for far-infrared fiber.It is able to do a qualitative analysis for the far-infrared fiber quickly and accurately. Experiments using Near-infrared Spectroscopy, a total of 10 samples were collected from different varieties of polypropylene, polyester, far-infrared polypropylene and far-infrared polyester. This experiment created the far-infrared polypropylene qualitative model and the far-infrared polyester qualitative model.They can correctly identify the polypropylene and far-infrared polypropylene, polyester and far-infrared polyester.
Surface Activity Research of Cationic Gemini Surfactants
Authors: Fan Zhen Zhong , Li Lan Lan , Zhang Li Feng , Liu Qing Wang
Published: March 2013

Cationic Gemini surfactant concentration, the inorganic salts added and the pH value of surface tension obtained cationic gemini surfactant critical micelle concentration is 0.4mmol / L;by adding three kinds of inorganic salts NaCl, MgCl2, and Na2SO4 ,which Na2SO4 has the greatest impact on surface tension, followed by MgCl2.The surface minimum tension of the pH ranged from 9 to 11 , indicating that the surface activity of cationic gemini surfactants achieved the highest.
Dynamic Stress and Deformation of Non-Homogeneous Poroelastic Moderately Thick Shells of Revolution Saturated in Viscous Fluid
Authors: Gonda Takeshi , Otsuka Shigeru , Yakabe Masaki , Tao Katsumi
Published: March 2013

This paper describes an analytical formulation and a numerical solution of the elastic dynamic problems of non-homogeneous poroelastic moderately thick shells of revolution saturated in viscous fluid. The porosity and porous diameter of the material are assumed to be continuously varied along the shell thickness. The equations of motion and the relations between strains and displacements are derived from the Reissner-Naghdi shell theory. As the constitutive relations, the consolidation theory of Biot for models of fluid-solid mixtures is employed. The flow of viscous fluid through a porous elastic solid is governed by Darcy's law. In the numerical analysis of the fundamental equations an usual finite difference form is employed for the spatial derivatives and the inertia terms are treated with the backward difference formula proposed by Houbolt. As a numerical example, the simply supported cylindrical shell under a semi-sinusoidal internal load with respect to time is analyzed. Numerical computations are carried out by changing porosity and mean void radius along the shell thickness, and the variations of pore pressure, displacements and internal forces with time are analyzed.
Numerical Analysis of a New Test Method for Evaluating the Mechanics Characteristics of Steel Deck Pavement
Authors: Li Xing Hai , Ma Wang Yu , Brown Ray
Published: March 2013

In order to utilize Overlay Tester to evaluate the crack resistance of Hot Mixture Asphalt (HMA) of steel deck pavement, three-dimensional finite element (FE) models of local steel deck pavement, composite beam and Overlay Tester specimen were established by Abaqus Software. The results show that the characteristic tensile stress in three FE models are similar, and the tensile stress of composite beam’s steel plate is much larger than that of composite beam’s HMA layer, hence the steel plate undergoes the major external force in the composite beam fatigue test, while the HMA layer seems not to be tested. To reduce this problem, FE models of Overlay Tester in three different displacements: 0.63mm, 0.063mm and 0.01mm, were analyzed. The results indicate that the stress in the 0.63mm displacement condition is much larger so that the asphalt mixture will be broken, and the stress in the 0.01mm displacement condition is similar to that of local steel deck pavement. In consideration of testing cycles and other factors, the 0.063mm displacement is recommended to test the HMA of steel deck pavement.
Role of Multiwalled Carbon Nanotube on Mechanical Reinforcement of High-Density Polyethylene
Authors: Miao Xia Ran , Qi Yuan Jiang , Li Xiao Yun , Wang Yu Zhu , Li Xiao Long , Tian Feng , Li Hui , Bian Feng Gang , Wang Jie , Li Xiu Hong
Published: March 2013

The high density polyethylene (HDPE) nanocomposites were prepared by melt mixing HDPE with multi-wall carbon nanotubes (MWCNTs). In this work, the morphological, nucleation, crystallization and mechanical properties of the HDPE nanocomposites were studied by scanning electron microscopy, different scanning calorimetry, small-angle X-ray scattering and tensile testing. It was found that the tensile strength and Young’s modulus is increased by 42.4% and 116.5% at 3.wt% MWCNT loading compared to the pure HDPE. According to SEM results combined with SAXS, well-defined nanohybird shish-kebab (NHSK) entities exist in the composites, and in the shish-kebab structures fibrillous carbon nanotubes (MWCNTs) act as shish while HDPE lamellae act as kebab. The crystallization behavior, probed by DSC, suggests that MWCNTs have strong nucleation ability and shear stress plays an important role in polymer crystallization process. The mechanical properties demonstrated that the formation of the Shish-kebab structures improved the interfacial adhesion and brought obvious mechanical enhancement for the HDPE/MWCNTs nanocomposites.
Analysis of Structural Parameters for Unbonded Flexible Pipes
Authors: Li Zhi Bo , Xu Hui , Zhang Gui Zhen
Published: March 2013

Due to the complex structure and nonuniform material of unbonded flexible pipes, an elastic thin-walled cylinder model and a helical steel strip model were established respectively to simulate different layers based on the specific structure form and parameters. Quasi-static incremental load was adopted to identify the structural parameters which had significant effects on the axial, radial and bending behavior of the pipes during the complex deformation. Sensitivity of these parameters were also analysed. The conclusion in this paper could provide guaidance for the design of unbonded flexible pipe.
Catalytic Hydrolysis of CCl2F2 over Solid Base CaO/ZrO2
Authors: Liu Tian Cheng , Ning Ping , Wang Hong Bin , Guo Jun Ming
Published: March 2013

Catalytic hydrolysis decomposition of dichlorodifluoromethane (CCl2F2) in the presence of water vapor and oxygen was studied over a series of solid base that have different ZrO2 content using a fixed-bed reactor. CO2 and CClF3 were the main-products and no CO was detected as by-product. The decomposition activity depended on the calcination temperature and the Zr:Ca. Calcined at 650 °C and Zr:Ca=1:0.35 were the best catalyst preparation conditions. Adopting low concentration of oxygen and CCl2F2 and high concentration of water vapor is preferable to the achievement of high conversion of CCl2F2 and selectivity for CO2. The catalytic activity of CaO/ZrO2 remained steady for 20 h on stream.
Preparation and Characterization of Alginate/Polyvinyl Alcohol Composite Fibers Containing Copper Ions
Authors: Guo Jing , Chen Qian He , Zhang Yu Yan , Gong Yu Mei , Zhang Hong
Published: March 2013

Alginate/polyvinyl alcohol (PVA) composite fibers containing copper ions were prepared by wet spinning. The spinning solution and manufacturing process were researched. The composite fibers were characterized by Tensile Strength Tester, SEM and TGA. This report shows that the spinning solution is a typical kind of pseudoplastic fluid. Adding boric acid to coagulation bath and putting Cu ions into composite fibers can improve the strength. The structure of composite fibers with Cu ions is denser and there are grooves on the fiber surface. In addition, the thermal property of composite fibers is steady.
QSAR Study of the Adsorption Mechanism of Ascorbic Acid towards Iron in Alkaline Media
Authors: Tian Hui Wen , Li Wei Hua , Hou Bao Rong
Published: March 2013

A significant correlation was obtained between corrosion inhibition efficiency and the molecular structure of ascorbic acid, using the Quantitative Structure Activity Relationship (QSAR) approach based on a multivariate nonlinear regression technique. It is proposed that inhibitor molecules attach to iron surface by means of chemical adsorption. The considerations leading to this assumption were confirmed by ATR FTIR spectroscopy.
The Preparation and Characterization of Starch Oxidized by Nitric Acid and its Properties of Calcium Complexing Capacity
Authors: Wang Xue Chuan , Li Fei Hu , Qiang Tao Tao
Published: March 2013

The primary hydroxyl groups of Starch Oxidized by nitric acid to the corresponding carboxylic acids has been investigated. The structure of the Oxidized-Starch(OS) was characterized by FT-IR, 1HNMR and GPC. The predicated product was obtained from the results. Its application in calcium complexing capacity has been discussed. The calcium complexing capacity of OS may up to 119.39 mg/g. The data confirmed that the starch oxidized by nitric acid had excellent capacity of calcium complexing.
Use of Rice Husk Ash to Treat Simulated Agricultural Cultivation Wastewater
Authors: Liu Jun Xia
Published: March 2013

This laboratory-scale study explored the use of rice husk ash (RHA) as absorbent to stabilize and solidify the simulated agricultural cultivation wastewater. Various factors including the shaking time, solution pH, the dosage of absorbents and the temperature of the heating were taken into account and promising results obtained. The results showed that the RHA at 300°C of heating temperature has a better efficiency on the removal of COD and NH3-N. The initial solution PH of 5~6 was most favorable for COD and NH3-N removal. The removal rate of COD and NH3-N is nearly 25% and 18% respectively under the conditions of the pH=5.5, shaking time of 30 minutes and quality of RHA of 6.0g. The results suggested that absorption treatment of simulated agricultural cultivation wastewater with RHA is an effective method to remove the COD and NH3-N.
Effects of Recycling Ladle Lining Materials on Sintering Performance of Al2O3-SiC-C Castable for Iron Runner
Authors: Wang Li Ren , Wang Rong Lin , Cui Yi , Bu Jing Long
Published: March 2013

In this experiment, preparation of samples were based on original ratio of bauxite matrix Al2O3-SiC-C castable for iron runner, and partial bauxites of size 8-5 mm, 5-3 mm, 3-1 mm and 2O3-MgO-C materials from spent ladle bricks, respectively. Effects of particle size and content of the recycled materials on sintering performance of the castable were investigated. The sintering performance was analyzed by measuring apparent porosity, room temperature flexural strength, room temperature pressure strength and high temperature flexural strength. The results showed that the apparent porosity of the samples overall tended to increase with content of the recycling materials increasing, while room temperature flexural strength, room temperature pressure strength and high temperature flexural strength of the samples reduced gradually. 8-5mm and 5-3 mm particle of 5%-15% the recycling Al2O3-MgO-C materials was more suitable for the preservation of high temperature flexural strength and room temperature strength of the samples than 3-1 mm and < 0.074 mm particle.
Spatial Distribution in Forest Soil Nutrients and its Relationship with Ecological Factors on the up Stream of Taihu Lake Basin
Authors: Yang Yan Gang , Shen Yi , Shao She Gang , Li Xue Fei
Published: March 2013

To examine the role of the forest in non-point source pollution control in the Taihu lake region, the soil profile nutrients including nitrate, hydrolyze nitrogen(HN), available phosphorus(AP), total nitrogen(TN), total phosphorus(TP) concentration of 26 forest sample plots along the Xitiaoxi River from upstream to downstream were measured through July to August 2009, the relationship between vegetation type and topographic factors and soil nutrients was analyzed. results show that: (1) All of five soil nutrients concentration decreased with increasing soil depth; (2) Soil nutrients of different soil depth is intermediate variability, the coefficient of variation of AP, TN, HN, TP were increased with the increasing of soil depth, and the coefficient of variation of nitrate was decreased with the increasing of soil depth. (3)Soil HN content under plots with an average tree height above 10m was significantly higher than plots with an average tree height less than 10m; (4) Soil AP, HN, TN, TP content was first decreased and then increased with the increasing of elevation. .In summary, the soil nutrients of different soil depth was found to be closely related to vegetation type, community age, structure, fertilization and topographic features in the upstream of Taihu lake basin.
Investigation on the Electrochemical Behaviors of Phenol Oxidation on GCE (Glassy Carbon Electrode)
Authors: Wang Yan , Zuo Shao Qing , Zhu Huai Gong
Published: March 2013

Cyclic voltammograms were carried out to track the process of phenol electro-oxidation on GCE, understand the course and further guide the use in dealing with waste water. The effect of supporting electrolyte, phenol concentration, and scan rate were all tested. The results show that phenol oxidation contains several steps, and the first step is a mass transport process, while the following steps are not. What’s more, alkaline solution facilitates the first step, but the produced polymer can foul GCE and hinder the oxidation reaction in turn.
Study on Preparation of Iron-Based Flocculant by Hydrogen Peroxide Oxidation Process
Authors: Chen Long , Zheng Gui Fu , Ran De Chao
Published: March 2013

Coagulation-flocculation process as an important water treatment technology has been widely used in the water treatment plant. The technology has been applied to the wastewater treatment, in general, by addition of a certain amount of chemical into the aquatic environment to make colloids destabilization and aggregation based on neutralization and adsorption bridging role. The conventional aluminum-based coagulant has been extensively studied. As a viable opinion, iron-based coagulant has attracted a wide attention. The objective of this research was aimed to investigate the preparation process of the iron-based coagulant using hydrogen peroxide as oxidizing agent. Parameters such sulfate dosage and hydrogen peroxide were analyzed. The results showed that a flocculant with the total iron mass percentage of 9.47 % and density of 1.43 g/mL was obtained. The flocculation test showed better performance.
Comparative Study of the Cyclic Oxidation Resistance of NiCrAlY and NiCoCrAlY Coatings
Authors: Liu Jian Ming , Yu Yue Guang , Ren Xian Jing , Zhang De Ming , Shen Jie
Published: March 2013

The free standing NiCrAlY and NiCoCrAlY coating samples were prepared by HVOF. The cyclic oxidation resistance of the coatings was evaluated and the coating surface morphology was investigated by SEM. The MCrAlY coating CTE was tested. The results show that the NiCoCrAlY coating exhibits better oxidation resistance than the NiCrAlY coating and the difference in MCrAlY CTE curve shape is considered as the main reason.
A Porous TiO2 Coating with Vermiform Morphology Formed on Ti through Micro-Arc Oxidation
Authors: Liu Zhen Fei , Wang Wei Qiang , Qi Min
Published: March 2013

A porous titania (TiO2) coating with vermiform slots was prepared on the Ti substrate through micro-arc oxidation (MAO) treatment using sodium tetraborate as electrolyte. Morphologies and phase structure were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. Results show that the rutile phase increases and anatase decreases gradually with increasing MAO time. The electrolyte of sodium tetraborate has significant influence on the formation of vermiform coatings, which determine the corrosive patterning in the first stage during MAO processing. The evolution of vermiform morphology is proposed as followed: some corrosive pores appear on the surface before arcing; afterward, the adjacent micropores in the dense regions link each other due to the high temperature result from continuous arc action; then, the micropores grow up to big pits and combine with each other with increasing MAO treating time; finally, the vermiform morphology forms on the surface of Ti metal.
Effect of Atmosphere Composition on Lifetime and Oxidation Behavior of EB-PVD TBC with NiPtAl Bondcoats
Authors: Song Peng , Lu Jian Sheng
Published: March 2013

NiPtAl coatings are widely used as bondcoats for thermal barrier coating (TBC) systems during high temperature exposure. Pt modified aluminide coatings on the CMSX-4 Ni-base alloy were oxidized at 1150°C in different atmospheres. Cross-section oxide layer morphologies on the NiPtAl coatings after TBC failure were similar in air with that in air+15%H2O. The surface morphologies of as-received low and high-Pt bondcoats showed great effect on the oxide layer growth and morphologies due to the different compositions within the two bondcoats. The irregular alumina surface on the low-Pt bondcoat was showed due to the slipping of the NiPtAl grains. Raman spectroscopy illustrated that the alumina mainly consisted θ and α-Al2O3 during the Ar+20%O2 exposure, however, only α-Al2O3 could be found in Ar+4%H2+2%H2O during short time exposure. Low oxygen partial pressure of Ar+4%H2+2%H2O perhaps is the reason that spinel and θ-Al2O3 can not formed, and directly promotes the α-Al2O3 formation.
Evolution of Microstructure and Properties of a Disk Cutter Ring Material during Carburization and Heat Treatment
Authors: Lin Guo Biao , Zhang Zhong Jian , Wang Mao Qing , Zhu Su Min
Published: March 2013

This paper presents the research on the influence of carburizing and heat treatment on the properties and microstructure of a new medium carbon alloy steel Fe-0.39C-0.99Si -0.37Mn -5.06Cr-1.21Mo-0.75V (wt.%) used for disk cutter ring. The carburized case has secondary cementite besides those appeared in core such as pearlite and some carbides of Cr, Mo and V. Microstructure of the case is coarse and there are more and larger carbide particles than in core. After quenching and tempering, the carburized case and the core transformed into the microstructure comprised mostly of troostite and fully precipitated tiny carbide particles of Cr, Mo and V. The grains in the carburized case are still larger and the quantity of carbide precipitations including cementite is larger compared with that in the core. Finally, the case depth of about 1mm can be obtained; the surface hardness is above 60HRC; the core hardness is above 55HRC; and the impact toughness reaches 16.9 kJ/cm2.
Synthesis and Surface Properties of SiO2 Modified Fluorosilicone Acrylic Copolymer Hybrids
Authors: Yang Xiao Yu , Chen Yi Chi
Published: March 2013

SiO2 modified fluorosilicone acrylic copolymer hybrids were synthesized via seeding emulsion polymerization in the presence of conventional nonionic and anionic surfactants, in which methyl methacrylate (MMA) and butyl acrylate (BA) were used as main monomers, small amount of methacrylic acid (MAA) and 2-hydroxyethyl methacrylate (HEMA) were used as functional monomers to confer adhesion, hardness and strength upon the latex film, while trifluoroethyl methacrylate (TFMA) and vinyl triethoxy silane (VTES) were used as fluorine- and silicon- containing monomers respectively. Meanwhile, tetraethoxysilane (TEOS) used as the precursor to prepare in-situ SiO2 nanoparticles, was added during the polymerization process, which resulted in SiO2 enhanced fluorosilicone acrylic copolymer latexes. SiO2 nanoparticles were produced in-situ during the polymerization. The nanocomposite latex film revealed better thermal resistance and wear resistance properties as compared with the counterpart free of SiO2 nanoparticles prepared under similar polymerization conditions.
Interfacial Failureof SiN/GaAs Film/Substrate BilayersInduced by Nanoscratch
Authors: He An Shun , Huang Han
Published: March 2013

The failure characteristics of silicon nitride thin film deposited on GaAs substrate were investigated by use of nanoscratch. It was found that the film started to failvia delamination or buckling, which should beattributed to interfacial shear stress. The cracks were then formed and propagated around the edge of the delaminated film before it was chipped away by the moving tip. A normal load of 6.5 mN, corresponding to a depth of 150 nm, was found to be the critical threshold for theinterfacial failure. The fracture energy release rateof the film/substrate interface, or the work of adhesion, was calculated as 2.90 J/m2.
Electrochemical Corrosion Behavior of Corrosion-Resistant Steel for Cargo Oil Tank
Authors: Xu Jing , Yang Jian Wei , Cao Jian Ping
Published: March 2013

Electrochemical corrosion behavior of corrosion-resistant steel for cargo oil tank were studied under different immersion corrosion time, and tests were carried in the PH=0.85, 10% NaCl solution, which temperature were 30°C. The electrochemical tested by the electrochemical polarization curve and electrochemical impedance spectroscopy (EIS), and the corrosion morphology and distribution of corrosion pit were observed under the metallography. The results indicate that along with the time extending, the corrosion potential of material moved from positive to negative, and then moved to positive. The corrosion current density also first reduced, then followed by the increasing and then decreasing, which indicated that the corrosion products of sample surface experienced a growth - dissolution - growth process, and presented a periodic corrosion rule. The position of corrosion pit mainly occurred around the pearlite.
Fabrication of YBa2Cu3O7-δ Superconducting Film on NiW Alloy Using Electrophoretic Deposition
Authors: Luo Qing Wei , Li Ying Nan , Li Feng Hua , Fan Zhan Guo
Published: March 2013

This work reported on exploring a low cost preparation technology for coated conductor. The epitaxial of La0.4Sr0.6TiO3 conductive buffer layer on NiW substrate was achieved by metal organic deposition. Excellent in-plane and out of plane alignment is confirmed via XRD. YBCO film was fabricated by electrophoretic deposition (EPD). We used buffered (LSTO) Ni-W substrate and Ni plate as cathode and anode respectively. The critical current density of YBCO coating is more than 1000A/cm2 (0T, 77K).
Effect of Laser Cladding Al3Ti-Based Coatings on the Wear and Corrosion Resistances of AA6063 Aluminum Alloy
Authors: He Huan , Guo Wei Hua , Xiao Min , Pang Xing Zhi , Shen Xiao Ming , Fu Yue Chun , Zeng Jian Min
Published: March 2013

Al3Ti-based intermetallic compound coatings were formed on AA6063 aluminum alloy by laser cladding. The microstructure, wear and corrosion behaviors were investigated. The results showed that, the laser cladding coatings were made up of Al3Ti dendrites, interdendritic α-Al and uniform distribution of TiC particles, and showed good bonding to the substrate. The microhardness, wear and corrosion resistances of the laser cladding coatings greatly increased compared to the substrate. And with the addition of TiC particles to the coating, the superficial properties are improved simultaneously.