bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Balanced Fertilization on Phyllostachys heterocycla cv. pubescens Yield, Quality and Mechanical Properties
Authors: Guo Xiao Min , Chen Fang , Zhang Wen Yuan , Lu Shun Bao , Zhang Guo Shi , Niu De Kui , Luo Zhi Jian
Published: November 2010

Field experiments were carried out to study the effect of balanced fertilization on Phyllostachys heterocycla cv. Pubescens quality in Jiangxi and Hubei province. The results showed that the diameter breast height (DBH) and quality of bamboo shoots could be significantly increased under balanced fertilization The relative increment was best and reached to 11.17 % by N2P2K2, while there was after-effects of fertilizer. The Zn content of bamboo shoots under K fertilizer was lower than one of CK. The effects of fertilization were complex on mechanical properties of bamboo, which are slightly higher than the control by K fertilization, but the difference is not significant. Therefore, measures of balanced fertilization to improve forest productivity and quality, a significant increase in economic and ecological protection.
Effects of Soil NPK on Mechanical Properties of Culm-Wood of Ph. pubescens
Authors: Lu Shun Bao , Zhang Wen Yuan , Niu De Kui , Guo Xiao Min
Published: November 2010

The mechanical properties of Ph. Pubescens were an important index to measure quality of bamboo. We research effects of soil available N (AN), available P (AP) and available K (AK) on mechanical properties of Ph. Pubescens in Jiangxi province. The results showed that there was no obvious regular between soil NPK content and mechanical properties of Ph. Pubescens. The anti-bending strength (ABS), anti-extension strength (AES) and anti-shears strength (ASS) of Ph. Pubescens were 148MPa, 98MPa and 15.6MPa, respectively, the maximum shear-force (MSF) was 2.0KN, and the anti-pressure strength (APS) was 59Mpa. The APS of all samples were higher than that of the middle timber. The APS was high why the vascular bundle of Ph. Pubescens arranges rules. The effect of AK on APS was larger than that of AN and AP. The MPF was 10.1 KN, The internal structures of bamboo determined their mechanical properties, so the anatomy of bamboo could also affect the mechanical properties of bamboo.
Simulation of Stainless Steel Drilling Mechanism Based on Deform-3D
Authors: Gao Xing Jun , Li Huan , Liu Qing , Zou Ping , Liu Feng
Published: November 2010

An emulation study of the drilling mechanism by general purpose twist drills is conducted by using FEM analysis software Deform-3D. Application of finite element software Deform-3D, some characteristic parameters of the work piece and the cutting tool material are combined. The load boundary conditions and the friction between tool rake face and chip are analyzed and defined. The chip separation criteria are chosen. The finite element analysis simulation of pretreatments is completed. By the finite element simulation analysis, the three-dimensional FEM model of twist drill is build. The scraps forming process and the distributed situation of cutting force，cutting temperature in the drilling process are analyzed. The effect of cutting variables on drilling forces of stainless steel is analyzed. The drilling temperature and the drill wear condition are discussed. The effect of the main geometric parameters on the stainless steel twist drill drilling performance is studied.
Research on the Temperature Stress Field of Interface End between Asphalt Concrete Overlay and Concrete Pavement
Authors: Zhang Yu Wei , Yang Qing Guo , Tu Zhi Zhong
Published: November 2010

For the interface end formed after paving asphalt overlay on cement concrete pavement, the stress field of interface end is very important for both structural analysis and interface design when the temperature drops. The stress field of interface end can be gotten with the crack-tip field theory that consider displacement continuation and stress equality on each side of interface, but it needs further verification to prove whether the initial stress field can satisfy far field boundary condition when temperature dropping. In conditions of different material properties, different plane dimension and different thickness of asphalt overlay the stress field is calculated with the finite element method (FEM), and the results show that the forms of theoretical solution can exactly describe stress field of the interface end when temperature dropping. The stress field of interface end indicates that when the elastic modulus of asphalt overlay becomes lager, the stress singularity’s degree of interface end will reduce. As for the interface end formed after paving asphalt concrete overlay on the concrete pavement, improving the elastic modulus of asphalt overlay is beneficial.
Microstructures and Wear Properties of Micro-Nanostructure Coating on Cast Iron Rolls by Electro-Spark Deposition
Authors: Gao Yu Xin , Zhao Cheng , Fang Zhi Gang , Yi Jian
Published: November 2010

Micro-nanostructure coatings have been attempted to prepare by Electro-spark deposition (ESD) on cast iron substrate. The microstructures and properties of the coating were investigated by X-ray diffractometer (XRD), scanning electron microscopy (SEM) and microhardness tester. The results show that micro-nanosized particles and fine equiaxed structures prevail in the coating. The primary phases of the coating contain Fe3W3C, Co3W3C, Fe7W6 and W2C. Its average microhardness reaches 1290.1 HV. The results of abrasive test demonstrated that the coating had an excellent sliding wear resistance because the superfine particles distributed dispersedly in the coating increased the resistance to micro-cutting and plowing during the wear test, which effectively improves the surface performance of cast iron substrate.
Investigation of Square Wave Pulsed Currents on Solidification Behavior of Al-Cu Alloys
Authors: Yang Xiao Tian , Li Xia , Li Wen Sheng
Published: November 2010

Al-(4-5)%Cu alloy was served as experiment material，the effect of pulsed currents on the solidification structure was investigated. During the solidification process of Al-Cu alloys, pulsed currents was added into the melted alloy in the crucible .The change of temperature curve and microstructure about the alloy was investigated in such conditions by temperature-recording instrument and optical microscope.The results showed that pulsed currents can shorten the temperature region of crystallization and refine the grains of the alloy,which crush the dendrite and make the solidification structure non-dendrite, presenting columnar and equiaxed grains which are distributed evenly and whose space between crystals are reduced. This investigation firstly started to study the relations between the temperature region of crystallization and organization structure of solidification. Finally, the mechanism of metal solidification affected by square wave pulsed currents was discussed.
Study on the Kinetics of Adsorption of Cadmium by Chitosan
Authors: Bi Qiang , Xue Juan Qin , Guo Ying Juan , Wang Yu Jie , Xue Yun Feng
Published: November 2010

The adsorption of cadmium in simulated wastewater by chitosan was investigated. The influence of temperature, contact time and pH on adsorption efficiency of cadmium was examined. Some related mathematical models were used in the fitting of experimental data. The results showed that at room temperature, the optimum pH of adsorption is between 4 and 7. At lower pH values, a strong competition existed between cadmium ions and protons for sorption sites and the sorption efficiency was decreased. After 60 minutes the adsorption equilibrium can be achieved. Chitosan is very effective at removing cadmium with the maximum adsorption capacity is 112.05mg•g-1. The adsorption kinetic curves agree with the pseudo-second-order adsorption kinetic equations and the adsorption isotherms could be well described by Langmuir isotherm equations.
Chemical Composition and Microstructure of Metal Doped Graphite-Like Carbon Films by Closed Field Unbalanced Magnetron Sputtering
Authors: Chen Di Chun , Jiang Bai Ling , Fu Yang Hong
Published: November 2010

The addition of metal atoms within the matrix of the graphite-like carbon films lead to the improvement of their mechanical properties. In this paper, metal (Cr, Al, Zr, W) doped graphite-like carbon(GLC) films were deposited on silicon substrates by closed field unbalanced magnetron sputtering from pure metal target and pure graphite target. Chemical composition and chemical states of films were measured by X-ray photoelectron spectroscopy (XPS) and show that mainly sp2 bond existing in all the metal doped films, and sp2/sp3 ratios are not depend on the doped metal. Cross-section micrographs were observed by high resolution transmission electron microscopy (HRTEM) and revealed a structure of composite that metal or metal carbides embedded in amorphous carbon matrix. The relationship between microstructure and chemical composition was discussed.
Effect of Compound Modification on Structure of Hypereutectic Al-Si Alloy
Authors: Liu Niu Can , Li Jun Qing , Liu Zhong Xia
Published: November 2010

Double compound modification was carried out for hypereutectic Al-24Si alloy. The experiment showed that double modification with phosphorus and rare earth can fine the structure of alloy. The complex modifications of phosphorus and rare earth make the coarse block primary silicon obviously refined and the large needle eutectic silicon modified to the fine fibrous or lamella ones. Phosphorus mainly refines the primary silicon. Rare earth can well refine the primary and eutectic silicon, but its modification effect on the eutectic silicon is more obvious. The alloys with the additions of 0.10% phosphorus and 0.9% rare earth have the optimal microstructure. Compared with the unmodified alloy, the primary silicon of alloys can be refined from 93.5 μm to 24.1 μm and the eutectic silicon can be refined from 8.5 μm to 5.3 μm. Mechanism of double compound modification with phosphorus and rare earth is discussed as well.
Influence of Bias Voltage on the Structural Properties and Adhesive Performance of ZnO Thin Films Deposited by Cathodic Vacuum Arc Deposition on Polyimide Foil Substrates
Authors: Hu Chang Ji , He Zhen Hui
Published: November 2010

ZnO thin films were deposited on polyimide foil substrates using cathodic vacuum arc deposition technique. X-ray diffraction was used to investigate the influence of bias voltage on the structure of ZnO thin films. The results show that all the samples have (002) preferred orientation. The internal stress of the films is compressive stress which increases with the bias voltage. Fragmentation test shows that the intrinsic interfacial shear strength of ZnO thin film without bias voltage is slightly lower than the shear yield strength of polyimide substrate; the intrinsic interfacial shear strength of ZnO thin film increases with the bias voltage from -50V to -200V, which indicates that bias voltage is beneficial to the enhancement of the adhesion between ZnO films and polyimide substrates. Further increase of the bias voltage to -300V leads to surface damage of the polyimide substrates.
A New Pair of Cumulative Fatigue Damage Models for Composite Materials
Authors: Mu Peng Gang , Wan Xiao Peng , Zhao Mei Ying
Published: November 2010

Fatigue damage growth can be described by the gradual reduction of the stiffness and strength, and damage expressed by the two degradation methods are equivalent. According this assumption, a pair of cumulative fatigue damage models based on residual stiffness and residual strength is proposed, and then the connection between the two damage indices is established. The two damage models follow equation with the same form, but the parameters in them are not equal. Each of the two models contains three unknown parameters which have pertinent effect on the damage growth rates, in addition, the models also take into account of the effects of stress levels and stress ratios. By fitting the experimental data, it is observed that the parameters in damage functions obey the linear relation well, and the unknown constants are deduced with finite tests easily. Finally, the models are found to give a good description of fatigue damage evolutions of different stacking sequence for both of the stiffness and strength.
Optimization Design of Microwave Absorbing Composites Containing Activated Carbon Fibers
Authors: Zou Tian Chun , Feng Zhen Yu
Published: November 2010

Microwave absorbing materials (MAMs) is a key component for weapon systems such as aircrafts, warships, and missiles to achieve the stealth performance by absorbing electromagnetic waves incident on. In this work, activated carbon fibers (ACFs) with average length of 1-3mm were prepared, and ACFs dielectric properties were investigated. The results show that ACFs have the frequency response effect, which is helpful for broadening the absorbing bands. According to ACF permittivity, the optimal design is carried out for four-layer microwave absorbing composites with thickness of 4mm based on the impedance matching design method. Following the optimization results the four-layer absorbing material was prepared, and it obtains a reflection loss below -10dB over 8GHz and the minimum value reaches -39.3dB in 2-18GHz.
Surface Yield Strength Gradient versus Residual Stress Relaxation of 7075 Aluminum Alloy
Authors: Hu Yong Hui , Wu Yun Xin , Wang Guang Yu , Guo Jun Kang
Published: November 2010

Different distributed residual stresses were introduced by quenching and two shot-peening treatments on 7075 aluminum alloy. The residual stress distributions and micro-hardness profiles in surface layers were measured. Pre-stress coefficient characterizing contribution of local residual stresses to local yield strength is introduced to analyze residual stress relaxation under cyclic loading. Load testing shows that re-distribution of residual stresses and proportional decrease of the pre-stress coefficient would occur in the non-uniform structural residual stresses introduced by quenching, while great stress relaxation and non-linear decrease of the pre-stress coefficient would occur in the uniform surface residual stresses introduced by shot-peening. Additionally, advantages of surface compressive residual stress and micro yield strength on anti-fatigue property and on restraining initiation and propagation of surface micro cracks should be considered in the usually conservative engineering design.
Numerical Simulation of Two-Dimensional Turbulent in T-Tube Tee about Two Kinds of Angle
Authors: Xiong Mo You , Tang Zhong Hua
Published: November 2010

Due to T-tube tee is used mostly to connect ducts of the central air conditioning system, different angles of branch pipes caused different local resistance changes. This paper studied two-dimensional turbulent numerical simulation about inter flow of two kinds T-tube by numerical calculation software (CFD),in the method of implicit separation and standard k- ε two equations model, it is clear known that two kinds of forms tee fitting Angle of the internal flow field, Through the contrastive analysis of flow characteristics, it is obvious that local resistance of the oblique angled T-tube tee is much smaller than the common T-tube tee, and also is much more homogeneous.
Calculation of Nature Frequency for Ship’s Tail Shaft Flexural Vibration Based on Genetic Algorithm
Authors: Jia Xiao Jun
Published: November 2010

Analysis of the nature frequency of flexural vibration is vital to be able to provide effective shock absorption for a ship’s tail shaft. The paper built mathematic model of ship’s tail shaft flexural vibration by transfer matrix method, and put forward an effective method for calculating the natural frequency of vibration system: a genetic algorithm (GA). Through example calculation compared with Prohl method under conditions bearing isotropic supporting, the result showed that the method can meet the requirements of engineering calculation, and overcome the disadvantage that initial value of calculation is difficult to be obtained with other methods. Then the method has advantage especially when the degrees of frequency equation increase.
Fabrication of Single-Negative Metamaterials Based on Coplanar Waveguide
Authors: Feng Tuan Hui , Zhang Yuan Min , Li Yun Hui
Published: November 2010

The fabrication of the single-negative (SNG) metamaterials involving the tunable SNG metamaterials based on coplanar waveguide is investigated. First, the SNG metamaterials are fabricated by periodically loading lumped-element series capacitors and shunt inductors on coplanar waveguide. Moreover, based on it, the tunable SNG metamaterials in which the center frequency and frequency region of the SNG gap can be tuned conveniently is also realized through loading the varactor diodes in place of the lumped-element capacitors.
Preparation of Three Different Sphere-Like Au/CeO2 Catalysts and their Activity for the CO Oxidation
Authors: Wang Lei , Guo Guang Sheng , Gu Fu Bo , Wang Zhi Hua
Published: November 2010

Three different CeO2 sphere nanomaterials (hollow sphere, flowerlike sphere, spherical cluster) were controllably synthesized by carbon sphere template method, hydrothermal and solvothermal method respectively. Then 2.5 wt% Au was doped on the supports by the deposition precipitation method and Au/CeO2 catalysts with three different morphologies were obtained. Composition, morphology and structure of these catalysts were characterized by the techniques of XRD, Raman, TPR, SEM and TEM, and the activity for CO oxidation of the catalysts was investigated. The catalytic test results indicated that the addition of Au could remarkably improve catalytic performance on CO oxidation. The activities of the three catalysts differ largely, the flowerlike Au/CeO2 catalyst had the highest activity for CO oxidation and its T100% was 29°C. The mechanism for the different activity of the catalysts was investigated. H2-TPR result indicated flowerlike had a more intensive peak at 125°C than others and it implied more reducible Au species in this case, that plays a vital role in the CO oxidation.
Laser Cladding of Zr55Al10Ni5Cu30/SiC Amorphous Composite Coatings on AZ91D Magnesium Alloy for Improvement of Wear Resistance
Authors: Huang Kai Jin , Tan Chao Dong , Zhou Chang Rong
Published: November 2010

To improve the wear property of magnesium alloys, Zr-based amorphous composite coatings have been fabricated on AZ91D magnesium alloy by laser cladding using mixed powders Zr55Al10Ni5Cu30/SiC. The microstructure of the coating was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The wear resistance of the coatings was evaluated under dry sliding wear test condition at room temperature. The results show that the coatings mainly consist of amorphous and different crystalline phases. The coatings exhibit excellent wear resistance due to the recombination action of amorphous and different crystalline phases. The main wear mechanism of the coatings and the AZ91D sample are different, the former is abrasive wear and the latter is adhesive wear.
Research on a Navigating Hierarchy Model of Aircraft Manufacturing Supply Chain
Authors: Liu Li Lan , Tian Shuai , Sun Xue Hua , Yu Tao
Published: November 2010

Aircraft is a complex product, and the Supply-Chain System of Aircraft Manufacturing has many characters which containing hierarchy structure, wide contents in each level, complex relationship between providers etc. So it has a great significance to do research on this. After studying the Kleinberg model and analyzing the characters of providers’ data in Aircraft Manufacturing industry, advanced changes of the Kleinberg model are made, and also the data of Supply-Chain of Aircraft Manufacturing is projected to circle structure, base on these two factors a advanced hierarchical navigable Kleinberg model is proposed, it is more suitable for the Aircraft Manufacturing Supply Chain and its structure is corresponding with the structure of Aircraft Manufacturing Supply Chain. From this advanced model we can do easier research on Supply-Chain System of Aircraft Manufacturing than Kleinberg model.
Three Critical Technologies of Simulation Analysis on Thermal-Loads of the Radome in Flight
Authors: Zhang Juan , Wang Zhen Feng , Zhang Lie , Tian Zhong Qiang
Published: November 2010

Three critical technologies of simulation analysis on thermal-loads of radome in flight are selected to study in this paper. Section 2 analyzes the first critical technology, which is modeling of the radome and the antenna. And the computational fluid dynamics software FLUENT is used to analyse the radome, so as to calculate the temperature distribution of its outer surface. Section 3 analyzes the second critical technology, which is to establish the multi-cavity thermal radiation model of the radome so that to get the temperature distribution of the inner surface. A kind of interpolation method, which is the third critical technology, is used to transfer the temperature of flow field and the space heat radiation to the corresponding thermal-stress analysis model of radome.
Synthesis and Microwave Electromagnetic Property of Nano-Sized Mn0.5Zn0.5Fe2O4 Spinel-Type Ferrite
Authors: Zhang Li Li , Sun Jie , Tan Yong
Published: November 2010

The nano-sized Mn0.5Zn0.5Fe2O4 spinel-type ferrite was synthesized by sol-gel auto-combustion method using citric acid as the chelating agents. The analysis methods of FT-IR, XRD, wave-guide were used to character the gel and the products after calcining. From the results, it was shown that the homogeneous organic complex base salts were formed in the process of gelation formation. The crystalline sizes of as-synthesis powders, calcined at 700°C for 2h and calcined at 1000°C for 2h were 15nm, 21nm and 25nm, respectively. The nanocrystalline had both dielectric loss and magnetic loss in the frequency range of measurement. The electron transportation of Fe2+↔Fe3+ can make the resistivity reduce to result in a certain amount of dielectric loss.
Numerical Solution of Bending Problem of a FGM Cantilever Beam with Large Deformation
Authors: Li Qing Lu , Li Shi Rong
Published: November 2010

Nonlinear bending problem of FGM cantilever beam under distributed load are discussed in this paper. Based on the large deformation theory and considering the axial extension of the beam, the equilibrium equations with geometric nonlinearity of a FGM beam subjected to distributed load are established. They consist of a boundary value problem of ordinary differential equations with strong non-linearity, in which seven unknown functions are included and the arc length of the deformed axis is considered as one of the basic unknown functions. By using shooting method and analytical continuation, the nonlinear boundary-value problem is numerically solved as well as the non-linear bending characteristic curves of the deformed beam versus the load are presented.
A New Concept for Material Fragmentation Simulation – Nodes Separation
Authors: Zhang Xiao Tian , Jia Guang Hui , Huang Hai
Published: November 2010

A method for material fragmentation based on Lagrangian FEM with the concept of nodes separation is proposed. This method is consisted of nodes separation mechanism and elements distortion erosion. In the simulation the nodes of failure elements are separated to form crack and distorted elements are detected and eliminated to prevent singularity. Nodes separation method can greatly improve the energy loss disadvantage in the failure erosion method. Based on LS-dyna secondary development the method is implemented. Hypervelocity impact problem of satellite protective structure is simulated and compared to experimental data for calibration. The performance of multi layer aluminum mesh shield under hypervelocity impact is also evaluated. The results show the high efficiency and applicability of nodes separation method in practical problems.
Characterization on Propylene Oxide Polymerization with In Situ FT-IR
Authors: Yang Peng Fei , Li Jun Ying , Li Tian Duo
Published: November 2010

In-situ FT-IR technique is used to investigate the polymerization of propylene oxide with potassium t-butoxide as initiator. The epoxy absorbance at 828 cm-1 is the most useful peaks to monitor the reaction. The absorbance of C-O-C stretching vibration at 1107 cm-1 is very strong and also very useful. Yet, the absorbance of C-H stretching vibration in 3000~2800 cm-1 region is very weak and not reliable for In-situ FT-IR analysis. By monitoring the consumption of propylene oxide, the polymerization rate constant k at 33°C was calculated out and an interesting auto acceleration phenomenon was discovered. Moreover, the chain-transfer process was analyzed by measuring the formation of C=C double bonds, which clarified a former confusion about the course of propylene oxide rearrangement.
Supporting Effect and Economic Benefit Analysis on New Type Concrete-Filled Steel Tube Supports
Authors: Wang Qi , Jiang Bei , Li Shu Cai , Wang Han Peng , Li Wei Teng , Li Zhi
Published: November 2010

The finite element contrast model such as concrete filled steel tube support, U-steel support and hollow steel tube support were established with ANSYS software, combining with engineering practice and relative design scheme of concrete filled steel tube test, respectively analysis their influencing factors and mechanical properties such as support effect, bearing capacity and so on. The economic benefit of each support was been analysised by comprehensive comparison of the material using condition and mechanical performance. The results show that, comparing with traditional U-steel support, retractable concrete filled steel tube support is a new style support with high bearing capacity, a large variety of sizes, higher economic benefit, and hence fit to support the deep soft rock broken jointed rock mass.
Quantum Spectra and Classical Orbits in Nano-Microstructure
Authors: Lu Jun , Wang Xue Mei
Published: November 2010

A kind of new classical-quantum correspondence principle is proposed using the idea of closed-orbit theory. The quantum spectrum function is introduced by means of the eigenvalues and the eigenfunctions in the system of one-dimensional nano-microstructure. The Fourier transformation of the quantum spectrum function is found corresponding with the classical orbits in the system. These results give new evidence about the classical-quantum correspondence. All the methods and results can be used in a lot of other systems, including some two-dimensional and three-dimensional systems. The researches about these systems are very important in the field of applied science, for example, molecular reaction dynamics and quantum information.
Transparent Conducting ZnO:Ga Epitaxial Films Prepared on Epi-GaN/Al2O3 (0001) by MOCVD
Authors: Yu Qiao Qun , Ma Jin , Luan Cai Na , Kong Ling Yi , Zhu Zhen
Published: November 2010

High-quality Gallium-doped zinc oxide (ZnO:Ga) films have been prepared on epi-GaN/sapphire (0001) substrates by the metalorganic chemical vapour deposition (MOCVD) method. The relative amount of gallium doping was varied from 0 to 8% (atomic ratio). The structural, electrical and optical properties of the ZnO:Ga films have been investigated in detail, as a function of Ga content. All the prepared samples have the wurtzite structure of pure ZnO with a strong (0002) preferred orientation. The microstructure for the surface of films was markedly influenced by the amount of Ga doping. The resistivity decreases continuously with adding Ga content and reaches to the value of 8.4×10-3 Ω•cm at 8%. The average transmittance for the deposited ZnO:Ga samples in the visible range was over 75%.
Fabrication and Mechanical Properties of Wood-PMMA Composite
Authors: Li Yong Feng , Lv Duo Jun , Jiang Chi , Liu Yi Xing , Zhang Hong Yue
Published: November 2010

A new composite, wood-polymer composite, was fabricated by formation of poly (methyl methacrylate) in wood cellular structure. Methyl methacrylate (MMA) monomer and a few of 2,2'- azobisisobutyronitrile (AIBN) as an initiator, as well as several drops of pyrimidine as catalyst were first impregnated into wood porous structure under a pressure condition, and then initiated for thermal polymerization through a catalyst-thermal treatment. The mechanical properties of the composite were tested, and the composite was also analyzed by SEM and DSC to further correlate its performance. The results indicated that the modulus of rupture, modulus of elasticity, compression strength and hardness of Wood-PMMA Composite were improved by 68.28%, 110.27%, 62.43%, 357% over those of Untreated Wood, respectively. The SEM observations showed that PMMA generated and filled up wood pores under the employed conditions, and thus reinforced the mechanical properties of wood. DSC analysis suggested that Wood-PMMA Composite was more thermal stability than Untreated Wood as the formation of PMMA within wood pores.
Study on Characteristic and Compressive Property of Porous NiTi Alloys Fabricated by Thermal Explosion Method
Authors: Li Qiang , Yu Jing Yuan , Sun Xu Dong
Published: November 2010

Porous NiTi shape memory alloys were fabricated by thermal explosion method using different Ti and Ni powder as initial materials. The effect of process parameters including heating rate, and particle size of Ti on pore characteristic and phase composition was analyzed. Microstructure, phase composition, and mechanical properties were studied by SEM, XRD, and compression test, respectively. The mechanism of thermal explosion reaction was studied. The results show higher heating rate and smaller Ti particle size result in higher porosity and bigger pores. The thermal explosion reaction starts with the melting of a eutectic between β-Ti(Ni) and Ti2Ni and the main phases of as-reacted products are TiNi phase which are the desired phases. NiTi2 and TiNi3 phases are also present in small amounts. The content of TiNi phase increases with increasing heating rate or decreasing Ti particle size. The compressive strength and Young’s modulus of compacts decrease with the increase of the porosity.
Electrochemical Performance of La0.7Sr0.3Cu1-xFexO3-δ as Cathode Material in IT-SOFCs
Authors: Zheng Min Zhang , Liu Xiao Mei
Published: November 2010

To obtain more detail information about the cathode of La0.7Sr0.3Cu1-xFexO3-δ（x= 0.1,0.3,0.5,0.7,0.9）in IT-SOFCs, the cathode material La0.7Sr0.3Cu1-xFexO3-δ（x=0.1, 0.3, 0.5, 0.7, 0.9）was synthesized by a sol-gel method. X-ray diffraction revealed it to be form a single phase of perovskite. The high temperature electrical conductivity was measured by using the four-point dc technique, and cathodic overpotential with SDC（Sm0.15Ce0.85O1.925） electrolyte support was measured by using a current-interruption technique. The investigation of electrocheimical properties suggested that La0.7Sr0.3Cu0.7Fe0.3O3-δ has the highest electrical conductivity and the lowest cathodic polarization. Using La0.7Sr0.3Cu0.7Fe0.3O3-δ as cathode and 65%NiO/SDC as anode based on SDC electrolyte one can obtain higher current density and power density at intermediate temperatures, La0.7Sr0.3Cu0.7Fe0.3O3-δ is considered to be a possible cathode adapted to IT-SOFCs.
Preparation and Properties of Biodegradable Sodium Lignosulfonate/Poly(Vinyl Alcohol) Blend Films
Authors: Li Xian Fa
Published: November 2010

A biodegradable films were prepared by blending sodium lignosulfonate (LS) with poly(vinyl alcohol) (PVA) and with borax as cross-linking agent, in an aqueous system. The suitable process conditions of preparing the blend films with good water-resistance and mechanical properties were determined by single-factor experiments. SEM, FT-IR, TGA and DSC analysis were performed to examine the contribution of LS and borax to the properties of the blend films. The results indicated that the introduction of a moderate LS mass ratios to PVA from 1/8 to 4/8 in the blend films could simultaneously enhance the tensile strength of blend films up to 43.98MPa. SEM showed that the intermiscibility of blend films was satisfactory with appropriate LS. Studies of the water sorptive capacity of the materials suggested that the water sorptive capacity at equilibrium less than 17% and water-resistance improved. The results of TGA indicated blend films have greater thermal stability than the pure polymers.
A Welding Method for Carbon Nanotubes
Authors: Zhang J.W. , Luo Zhen , Li Y.L. , Zhu J.D. , Hao J.
Published: November 2010

A simple and reliable welding method was developed to weld carbon nanotubes with the power supply here. The carbon nanotubes were synthesized chemical vapor deposition method and Multi-walled carbon nanotubes was uesd here. Firstly, apply less than 5 V voltages between carbon nanotubes when they were in close proximity under direct view of optical microscope. Then, let carbon nanotube contact with each other and increase the external voltage to 7–8V until carbon nanotube was attached to the end of the other, the two carbon nanotube join into a carbon nanotube. Furthermore, some experiments were implemented to analyze the reliability, the images of the weld joint and the weld strength all indicted this method were reliable.
Electrode Classification and Retrieval Using Supported Vector Machine
Authors: Wang Hua Chang , Lv Zhu Qing , Li Zhi Gang
Published: November 2010

Due to the similarities between electrode model and their CNC machining process, process design could be finished efficiently using the electrode automatic classification system as well as the existed standard process template. This study developed an automatic classification retrieval system of electrode model by applying a statistical approach, namely SVM model, to the classification of electrode model, where 3D Polar-Radius Surface Moment was used to extract the feature vector of the electrode model. Experiments showed a promising result with an average classification accuracy up to 85.72% in addition to the high efficiency and usability. Most important, the developed approach is capable of reusing existing knowledge and experience and as a result it makes the CNC programming process easier.
Model Test Study on Embankment Instability Induced by Rapid Drawdown of Water Level at Yellow River Downstream
Authors: Zhao Yu Kun , Yang Ji Hong , Li Qing An
Published: November 2010

Rapid drawdown of water level is one of the most important factors that influencing the embankment stability. Based on the principle of geomechanical model test and hydroaulic model test methods, the model test was performed to study Yellow River downstream embankment instability induced by rapid drawdown of water level. The slope models with geometric scale of 1:25, 1:45, 1:62.5 were constructed in the transparent plexiglass model box with 1.6m long, 0.8m wide and 0.6m high. Changes on the slope were recorded during water level decline at different velocity by digital camera and slope tracer etc. The model test results showed that during the rapid drawdown process, there was only small cracks and not slippage in advance; when the water level dropped to a certain height, the sliding distance increased suddenly, which showed that the rate of water level decline was behind the river water, and the slope weight and downslope hydrodynamic pressure by the saturation line in slope body were higher than water lever exceeds the sliding force in a very short period of time, which caused landslide; after the sliding body appearing, slide was continuous and not mutation.
Microstructure and Properties of Mold Steel 3Cr2W8V by Electron Beam Surface Alloying
Authors: Chen Yuan Fang , Peng Xiao Dong , Hu Jian Jun , Xu Hong Bin , Hao Chan
Published: November 2010

Ti coating was deposited on mold steel 3Cr2W8V by PVD and then processed with electron beam surface alloying process. The microstructure, surface roughness and microhardness of electron beam surface alloying treated specimens were investigated by using metallurgical microscope, SEM , XRD, micro hardness tester and roughness tester. It is shown that the electron beam surface alloying treated specimens have a rapidly solidified microstructure consisting of the uniformly distributed TiC phases and fine VCrFe8 intermetallic phases.The coating has a strong metallurgical boning with substrate, and the coating has high hardness, excellent wear resistance. The coating layer has an average microhardness of approximately HV600, 35% higher than the substrate’s. So it is used widely. Furthermore the need for further research is discussed as well.
First Principles Calculations of Phase Stabilities of MgH2 and Mg7XH16(X=Nb,V,Ti)
Authors: Niu Jian Gang , Xie Fei , Jia Ke Jun , Guan Li , Dong Xiao Ping
Published: November 2010

First-principles calculations were performed to study the relative stabilities of MgH2 and Mg7XH16(X=Nb,V,Ti).The calculated results show that MgH2 has the higher stability than Mg7XH16. The density of states of MgH2 and Mg7XH16 were obtained and analysized. It shows that the extinction of the gap at 0~4eV interval , the increment of N(EF) and the weakening of Mg-H bonds impaired the stability of Mg7XH16.
Electronic Structure and Bonding Characteristic of LaMgNi4H4
Authors: Wang Bao Jun , Zhu Lu Jia
Published: November 2010

We performed first-principles calculations to the electronic structure and bonding characteristic of LaMgNi4H4. The calculation results show that the H—Ni units are formed by the covalent H—Ni bonds, the surrounding Mg and La atoms provide electrons to the H—Ni units, and the Ni-Ni bonds between the different H—Ni units are covalent, making the H—Ni units not isolated. These bonding characteristics show that LaMgNi4H4 is similar with interstitial metal hydride in some aspects, and similar with complex metal hydrides in other aspects, indicating LaMgNi4H4 is the intermediate between interstitial metal hydrides and complex metal hydrides.
The Role of NADH in the PHB Synthesis Mechanism in Methanotroph
Authors: Zhang Ying Xin , Xin Jia Ying , Dong Jing , Xia Chun Gu
Published: November 2010

To complete the explanation on the mechanism of the Poly-3-hydroxybutyrate (PHB) synthesis intracellular in methanotrophs, the role of nicotinamide adenine dinucleotide (NADH) in the PHB synthesis mechanism in Methylosinus trichosporium IMV 3011, which can utilize methane and methanol as source of carbon and energy to synthesize PHB, was studied. The study carried on by using carbon monoxide (CO) as NADH consumption substrate or using sodium formate as NADH production substrate. The results showed that NADH influenced the synthesis and accumulation of PHB intracellular to some extent. Especially, the yield of PHB would decrease to 13.5% (compared to normal yield of 21.3%) under NADH deficiency condition caused by CO at content of 20%. During the flask fermetation process of Methylosinus trichosporium IMV 3011, adding CO with certain centent (10%, v/v) or at right time (72h) into gas mixture would keep the NADH intrcelluar at appropriate concentration, which will be avialable for cell growth and PHB accumulation. The findings on the NADH will greatly contribute to the less expensive production of PHB by methanotrophs and promote the application in this field.
Synthesis and Microwave Absorption Properties of Co2Z Barium Ferrite by Salt-Molten Method
Authors: Zhang Jun Li , Wang Bo Chong , Li Zhi Wei , Qiao Liang , Wang Tao , Li Fa Shen
Published: November 2010

In this work, the Z-type barium ferrite of single phase was prepared by the salt-molten method which was a novel, economical and environmentally friendly method. The results showed that the salt was helpful to get single phase and could effectively modify the shape of the powder. Based on the microwave measurement, reflection losses exceeding −20 dB of Co2Z composite were obtained in the frequency range of 4.1–14.5 GHz for absorber thicknesses of 2.1–3.5 mm and the minimum value of the reflection loss was -42.9 dB at 4.9 GHz for the thickness of 2.9 mm. For those unique properties, Co2Z could be a good candidate for electromagnetic (EM) materials and other practical applications at the high frequency.
Study of Processing Parameters of Preparation of Wood-Polymer Composite by Synthesis of Terpolymer in Wood Porous Structure
Authors: Li Yong Feng , Liu Yi Xing , Wang Feng Hu , Lv Duo Jun , Jiang Chi
Published: November 2010

Inspired from the natural porous structure of wood, a novel wood-polymer composite combining both advantages of wood with high strength-to-weight ratio as a natural renewable resource and polymer as a reinforcer was manufactured by synthesis of terpolymer of methyl methacrylate (MMA), Styrene (St) and Vinyl Acetate (VAc) inside wood. The three kinds of monomers with a few of 2,2'- azobisisobutyronitrile (AIBN) as an initiator, as well as some additives were first impregnated into wood porous structure under a pressure condition, and then initiated for terpolymerization through a catalyst-thermal treatment. The impregnating conditions containing pressure value and pressure time, and polymerizing crafts including heating temperature and heating time, as well as additive content were confirmed according to rate of monomer loading and rate of polymer loading inside wood. Results indicate that among these influencing factors, pressure and temperature were the significant influencing factors; and the rate of monomer loading and rate of polymer loading linearly positive correlated to them, respectively. SEM observation shows that the terpolymer fully filled in wood porous structure under the optimum manufacturing craft.
The Mechanochemistry of Synthetic Phosphate Oil under High Pressure
Authors: Song Bao Yu , Yang Qing Xiang , Qi Yu Lin , Su Dai Zhong
Published: November 2010

The pressure-viscosity relationships of phosphate synthetic oil and other two kinds of similar atmospheric viscosity synthetic oils were studied using ultra-high pressure capillary viscometer. The pressure-viscosity relationship of phosphate synthetic oil is much better than the other two kinds of synthetic oils. The impact of pressure on viscosity is not limited to purely physical factors. The pressure can cause a variety of chemical reactions in some cases. The investigation results of mechanochemistry of phosphate synthetic oil at high pressure reveal that the physical state of phosphate synthetic oil changed from liquid into glassy amorphous state under high pressure, and the color varied from transparent into milky white. The mechanochemistry of phosphate synthetic oil was analyzed using the infrared spectroscopy and gel permeation chromatography, and the results indicate that under high pressure, the oxidation reaction of phosphate synthetic oil occurred, and the molecular weight distribution changed with the increase of the low molecular weight region. The reason of the mechanochemistry phenomena was that phosphate synthetic oil molecular chain disconnects to inform great radical. The great radical has strong activity, and reacts with other free radicals acceptor (oxygen, etc).
Study on Laser Cladding Coatings of Ni-Based Alloy/TiC/Nickel-Coated Graphite on Steel Substrate
Authors: Ying Li Xia , Jiang Li Dong , Kong Fan Kai , Yang En Xia
Published: November 2010

In order to improve the antiwear and antifriction performances of tribological metal surfaces for the extreme conditions, the composite coating has been fabricated on metal surfaces by the technology of laser cladding. In the experiment, Ni-based alloy, TiC and Nickel-coated graphite are used as the main ingredients of composite. The cross-sectional macrographs, microstructure, compositions, microhardness, tribological properties and the forming mechanism of the coating was tested and analyzed. Results show that laser cladding Ni60A/TiC/Nickel-coated graphite composite can obtain excellent coating with fully compact and uniform microstructure, and good interface with the substrate. The microhardness of the clad coating is over HV1000, which is five times higher than that of the steel substrate. The friction coefficient is reduced to about 0.4-0.5 in comparison with that of the steel substrate (about 0.7-0.8). At the same time, the wear resistance of the clad coating is also improved greatly.
On the Development of Complex Products Containing Sub-Assemblies
Authors: Mirica Radu Florin , Dobre George , Vladu Mihai Robert
Published: November 2010

The paper analyzes aspects regarding the product development process of a complex product containing sub-assemblies. The sub-assembly is considered as an independent product integrated in a general assembly. The paper proposes new ideas, adding to the state of art in this field. Thus, a proposed scheme of the product development process is applied with new considerations in the case of a complex product containing sub-assemblies. This scheme contains distinct stages for the main developer, aiming with the general coordination and even the development of sub-assemblies, and third-parties, which develop other sub-assemblies (whether manufactured or not by the main developer).
Study of Monitoring for Oil Film Thickness of Elastic Metallic Plastic Pad Thrust Bearing
Authors: Li Yong Hai , Yu Xiao Dong , Li Chuang , Meng Xiu Li
Published: November 2010

On-line monitoring method of structural characteristics and traditional performance parameters of babbitt metal pad thrust bearing is analyzed. Based on deformation characteristics of elastic metallic plastic(EMP) pad thrust bearing, an oil film thickness measuring system is applied to set up a new kind of optical fiber reflective sensor model, the outputs of the sensor are independent of the characteristics of the light source, the losses in the ambient medium and the target reflectivity. Additionally, the distance information is averaged over several points on the target surface, which reduces signal fluctuations due to inhomogeneities. An optical fiber sensor model of correcting static error based on BP artificial neural network (ANN) is set up also. According to the actual operation in thrust bearing test board, the designed system shows better performance.
Assembly of Nanostructures by Using a Mechanical Nanomanipulator
Authors: Chang Ming , Chen Po Cheng , Lin Chung Po , Chang Yu Han
Published: November 2010

A mechanical nanomanipulation system has been developed for the assembly and fabrication of nano-devices inside a scanning electron microscope (SEM). The mechanical manipulator is made up of commercially available actuators and positioning stages which consists of three individual operation units each having three linear stages and one rotational stage. Experiments were performed to construct 2D and 3D nanostructures with Au nanowires. Versatile manipulations including shape modification, length amendment, and connection of nanowires were carried out. An electron beam induced deposition (EBID) technique was used to grasp nano-materials and assemble them, enabling 2D and 3D manipulation to be easier to conduct. Experimental results show that this manipulator is possible to play an important role in enabling the technology of assembling nano-scale mechanical and electronic devices from prefabricated nano-scale components.
Evaluation of Component Reliability Using Data Derived from Infrared Thermography
Authors: Redgate John , Al-Habaibeh Amin , Su Dai Zhong , Wilmshurst Tim , Rudd Jon
Published: November 2010

Condition monitoring of components is commonly required to evaluate integrity, manage maintenance and predict impending failure. The condition of many electrical and mechanical components is revealed by their thermal signature which can be reliably monitored by infrared camera. Thermal data obtained optically has the advantage of being non-contact so that moving mechanical parts and high voltage electrical components, including those located in hazardous environments or with difficult access, can be readily monitored. This paper proposes that data obtained by such methods is processed within a model in order to identify the imminent failure of a component or to estimate the probability that a component may exceed its operating tolerances at any given time within the remainder of its expected life.