bluuebunny/crossref_metadata_2025 huggingface dataset:
Degradation in Fatigue Crack Propagation Resistance of a Gas Turbine Vane after Long Term Service
Authors: Okazaki Masakazu , Sakaguchi Motoki , Sasaki Yosuke , Namba Koichi
Published: July 2011

Degree of long term degradation damage of a retired gas turbine vane made of a Ni-based superalloy which had been operating for about 20000 hrs in a land-based gas turbine, was experimentally evaluated, through an assessment on the change in fatigue crack propagation resistance. For the purpose, a new testing apparatus has been developed to measure the local area fatigue crack propagation resistance, by extracting the miniature size compact tension specimens from the vane, where the specimens were extracted from the leading and the trailing edge, respectively. It was shown, the propagation rate of the crack that grew at the trailing edge part was significantly higher that that at the leading edge part. It was also shown that the crack propagation rates in the miniature specimen were generally higher than those in the standard size specimen. In order to explore an possibility to recover the degradation damage, the effect of a simple reheat treatment on the fatigue crack propagation resistance was also investigated
Evaluation of Mechanical Properties of a Superalloy Disk with a Dual Microstructure
Authors: Tao Yu , Liu Jian Tao , Zhang Yi Wen
Published: July 2011

The main purpose of this paper is to evaluate the mechanical properties of a FGH96 alloy disk with a dual microstructure. FGH96 is a powder metallurgy (P/M) processed disk alloy, which was developed in the 1990s in China. The manufacturing processes used to produce the FGH96 disk with a dual grain structure consisted of atomization by plasma rotating electrode process (PREP), hot isostatic pressing (HIP), isothermal forge, special heat treatment for obtaining dual grain struc-ture and final heat treatment. The disk was cut up and completely evaluated. Mechanical properties, including tensile, stress rupture, plastic creep, low cycle fatigue, fatigue crack growth rate, fracture toughness, impact and hardness, were tested at room and higher temperatures. In addition, a detailed grain characterization of the disk, from rim to bore, was also presented.
Transient Liquid Phase Bonding of Pairings of Parent Superalloy Material with Different Composition and Grain Structure
Authors: Steuer Susanne , Piegert Sebastian , Frommherz M. , Singer Robert F. , Scholz Alfred
Published: July 2011

Joining of different nickel-base superalloys could simplify the manufacturing of turbine blades. The used technique of choice is transient liquid phase bonding, which is an established repair technology for high temperature components. Two nickel-base superalloys with distinct composition and grain structure are bonded and the joints are analysed regarding the microstructure. To quantify the mechanical properties of these joints, tensile and short term creep rupture tests were performed at room and elevated temperatures.
Effect of Nitrogen on Microstructure and Properties of a Cast Cobalt-Base Superalloy
Authors: Yuan Chao , Guo Jian Ting , Zhou Lan Zhang
Published: July 2011

The effect of the nitrogen on the microstructure and properties of a cast Co-based superalloy K640S was investigated with the different level ranged from 24 ppm to 85 ppm. The results indicate that almost all nitrogen exist in the form of nitride precipitation in the vacuum induction melting. It is found that high N level would extend the solidification window during the solidification process, and then increase the quantity of the carbide eutectic phases and led to the distribution in the network form of the eutectics in the interdendritic regions. High nitrogen content (more than 40 ppm) can reduced the mechanical properties of the testing alloy. So, it is suggested that the nitrogen in the recycled Co-based superalloys should be controlled at a suitable level in order to avoid the degradation of their properties.
Intermetallic Ti-Al-Cr Based Layers and Zirconia Topcoats Deposited on Gamma Titanium Aluminides for Environmental Protection
Authors: Braun Reinhold , Fröhlich Maik , Leyens Christoph
Published: July 2011

. Intermetallic Ti-Al-Cr layers with small additions of Si, Zr, W, and Y were deposited on γ-TiAl specimens using magnetron sputtering. The oxidation behaviour of the coated γ-TiAl alloy was studied in the temperature range between 950 and 1000°C under cyclic oxidation conditions in air. Compared to the bare substrate material, the coatings exhibited higher oxidation resistance. During prolonged exposure the intermetallic layers degraded losing their capability to form a protective alumina scale. On coated γ-TiAl samples zirconia topcoats were deposited by electron beam physical vapour deposition. These thermal barrier coating systems exhibited lifetimes exceeding the maximum exposure length of 1000 1 h cycles at 950°C, but failed at 1000°C. Failure was caused by degradation of the bond coats resulting in spallation of the thermally grown oxides.
Structure of NiCrAlY Coatings Deposited on Oriented Single Crystal Superalloy Substrates by Laser Cladding
Authors: Vilar Rui , Santos Edson Costa
Published: July 2011

In the present work single and multiple layer NiCrAlY coatings were produced by laser cladding on (100) single-crystalline substrates of SRR99 Ni-based superalloy. Detailed structural characterisation and texture analysis by optical microscopy, scanning electron microscopy, X-ray diffraction and Rutherford backscattering showed that the NiCrAlY coatings consisted essentially of gamma phase with yttrium oxide (Y2O3) and a small proportion of yttrium–aluminium garnet (Al5Y3O12) precipitated in the interdendritic regions. The coatings presented a columnar dendritic structure grown by epitaxial solidification on the substrate and inherited the single-crystalline nature and the orientation of the substrate. The coating material also showed a mosaicity and a defect density similar to those of the substrate. It can be expected that the protective effect of these coatings against oxidation is greatly enhanced compared with polycrystalline coatings because high diffusivity paths, such as grain boundaries, are eliminated in single-crystalline coatings, thus reducing mass transport through the coating.
Laser Shock Adhesion Test (LASAT) of Electron Beam Physical Vapor Deposited Thermal Barrier Coatings (EB-PVD TBCs)
Authors: Fabre Gregory , Guipont Vincent , Jeandin Michel , Boustie M. , Cuq-Lelandais J.P. , Berthe L. , Pasquet A. , Guédou Jean Yves
Published: July 2011

Damage prediction, adhesion strength and remaining lifetime of TBC are highly important data for understanding and preventing TBC spallation on blades. LAser Shock Adhesion Test (LASAT) is a powerful method to measure adhesion of coating due to its rapidity, simplicity and capabilities to distinguish different strength levels and the easy damage observation in case of TBCs. A new protocol of LASAT has been introduced in order to measure the adhesion level of the ceramic coating from the exploitation of the two-dimensional effects that promotes a shock wave pressure-dependent size of the damage. Finite element modeling, taking into account the TBCs dimensions, showed the edges effect on interfacial stress applied by laser shock.
Tin Addition to Improve the Oxidation Behaviour of NbSs/Nb5Si3 Based In Situ Composite
Authors: Knittel Stephane , Mathieu Stéphane , Vilasi Michel
Published: July 2011

This work focuses on the effect of tin additions (2, 5 and 8%) to the MASC alloy (Nb-25Ti-8Hf-2Cr-2Al-18Si) on the microstructure and the oxidation behaviour at 815°C in air. The alloys are mainly constituted of a niobium solid solution plus the () Nb5Si3 silicides. For the higher Sn additions (5 and 8%), a fourth phase is evidenced: it is enriched in Sn and has a crystal structure close to Nb3Sn. The oxidation resistance of these alloys is clearly improved by tin additions: the oxygen inward diffusion is hindered and consequently the fragmentation of the silicides is avoided. Cracks in silicides are no longer observed for the MASC containing 8%Sn. This effect is not attributed to a better efficiency of the oxide scales but rather to the reduction of the niobium solid solution fraction with tin additions.
Dislocation Mechanisms during High Temperature Creep Experiments on MC2 Alloy
Authors: Touratier Fabienne , Viguier Bernard , Siret Christophe , Lesterlin Sandrine , Andrieu Eric
Published: July 2011

The creep behaviour of MC2 single crystal superalloy has been studied at 1150°C/80 MPa, with an applied load along [001] axis. The resulting dislocation microstructures were examined by transmission electron microscopy. The occurrence of a[010] type dislocations (with a zero Schmid factor) within the ordered γ' precipitates is often observed. It is shown that those dislocations moved by a climb process, based on a mechanism involving two dislocation systems and vacancy exchanges, as proposed in the literature. We calculate the vacancy fluxes associated with such a mechanism and show that the vacancy transportation can be easily insured by a simple diffusion process. This calculation shows that the diffusion and climbing steps do not seem to be the creep rate controlling mechanisms for those situations in MC2 alloy.
Effect of the Particle Size of γ’ Phase on the Mechanical Properties of Ni Base Superalloy
Authors: Razumovskii Igor M. , Bykov Yuriy G. , Beresnev A.G. , Poklad V.A. , Razumovskiy V.I.
Published: July 2011

The effect of γ’ particle size upon the mechanical properties of Ni base superalloy EP741NP obtained by powder metallurgy was investigated. The particle size of γ’ phase in γ-γ’ microstructure was varied by changing the cooling rate V from the temperature of the solid solution treatment at 1200 °C (V = 80, 200 and 400 °C \ min.). After solid solution treatment billets were subjected to aging in the standard mode. It was established that as V increases from 80 to 200 °C \ min., the average particle’s size of γ’ phase decreases from 0.54 microns to 0.22 microns in the aged state. This improves the characteristics of creep and low cycle fatigue at 650°C: time to rupture under load 1000 MPa increased from 132 hours to 416 hours and low cycle fatigue increased from 42,215 to 82,016 cycles.
Effect of Quenching Temperature on Microstructures and Tensile Properties of PM Ti-23Al-17Nb Alloy
Authors: Lang Ze Bao , Zhang Xu Hu , Wang Liang , Jia Wen Jun
Published: July 2011

After treated with different quenching processes near transition temperature of orthorhombic phase, PM Ti-23Al-17Nb alloys with different microstructures were obtained. Microstructures of the alloy were observed by optical microscope, and tensile properties were also tested. In order to analyze the relationship between microstructures and tensile properties at room temperature, fractures of broken test bars obtained in tensile tests were characterized by SEM. The results show that quenching process below transition temperature of orthorhombic phase has few effects on improvement of size and morphology of crystal grain. However, it may lead to an abnormal growth of partial crystal grain, which results in low tensile strength and poor ductility; Quenching process above transition temperature of orthorhombic phase can cause recrystallization of B2 phase, which make a remarkably improvement on size and morphology of crystal grain. Moreover, the alloy performs the max tensile strength of 1026 MPa and the max ductility of 5.8% after quenched at the temperature of 1020
Crystal Structure and Resistance-Temperature Characteristic of the Boron-Doped Diamonds Synthesized from Fe-Ni-C-B System
Authors: Gong Jian Hong , Lin Shu Xia , Gao Jun
Published: July 2011

In the present paper, boron-doped diamond was synthesized by static pressure method using Fe-Ni-C-B system catalyst, whose resistance-temperature characteristic curve was studied. Experiments results proved that the boron-doped diamond has different ionization energy in different temperature interval and the reasons were analyzed. The maximum operating temperature is about 773K for such boron-doped diamond. The research provides experimental basis for high-temperature semiconductor diamond.
The Effect of Microstructure on Properties of Fe-Cr-C-Nb/Ti Hardfacing Alloy
Authors: Tang Wen Bo , Guo Yun Gang , Wang Hon Grui
Published: July 2011

Hardfacing is one of the most useful and economical ways to improve the performance of components submitted to severe wear conditions. In this paper, a new kind of alloy called Fe-Cr-C-Nb/Ti alloy system for wear resistant successfully with the shielded metal arc welding (SMAW) method has been studied. The microstructure and wear resistant of hardfacing alloys reinforced with primary carbides were compared in this study. Meanwhile, the average hardness, the abrasion weight loss and microstructure of deposited metal were systematically studied by optical microscopy, scanning electronic microscopy and energy dispersive spectrum analysis. The results showed that the microstructure of the best optimizing hardfacing layer was the mixed martensite and little retained austenite, and NbC/TiC particles distributing dispersively in the matrix. The amount of low-carbon martensite and high-carbon martensite was identical. The alloy system showed high wear resistance due to the formation of dispersed MC type carbides and good toughness due to the exist of low carbon martensite in the matrix. The hardfacing alloy reinforced with complex carbides was also investigated, the microstructure was analyzed and its hardness and wear resistance were evaluated. In conclusion, the distribution, the chemical composition and the amount of the carbides, as well as the matrix microstructure are all factors to influence the crack resistance, hardness and wear resistance of the hardfacing alloys.
New Technology Research of Nondestructive Testing for Aero Aircraft Composite Materials
Authors: Shan Ning , Heng Guo
Published: July 2011

Composite materials have many advantages such as big specific strength, high specific stiffness, good disrepair safety characteristic, large area molding conveniently and easy to forming complex shape. It becomes important structural materials of aero aircraft equipment necessarily and is used widely in aviation industry. Composite materials components of aero aircraft with complex and delicate structure chronically work in harsh environment. Early testing of its key component’s minute defects has been an urgent and necessary task. In this paper, its damage model and characteristic are analyzed and studied. Considering the limitation of composite materials structure’s detection methods at present, a number of existing problems are presented and development directions are pointed out. Laser ultrasound detection technique, continuous distribution sensing technique and optical fiber sensing technique are studied. The method of damage detection of aero aircraft’s composite materials components is put forward based on the organic combination of the three techniques. The results show that the system can be used to detect multi-ultrasound signals of large composite materials structure. Its structure is simple. It has small bulk and low cost. It is characterized by easy realization.
Study on the Adsorption Capability of Nano-Barium-Strontium Titanate Immobilized on Aluminum Oxide for Zinc Ion
Authors: Zhang Dong , Zhang Yan Li
Published: July 2011

Zinc ion was adsorbed and enriched by nano-barium-strontium titanate immobilized on aluminum oxide(ABST). The adsorption and elution conditions were investigated. The results showed that ABST had strong adsorption ability for zinc ion in water in the medium at pH more than 4.0. The maximum adsorption capability was up to 16.38 mg/g. The adsorbed zinc on ABST could be eluted and reclaimed with 0.5 mol/L of HNO3. Zinc was determined by flame atomic absorption spectrophotometry (FAAS). The detection limit of this method for zinc ion was 2.5 μg/L. The method had been applied to the determination of trace zinc in surface water and tap water samples with recovery of 92.5%-98.7%. The results were found to be in agreement with the method of dithizone spectrophotometry.
Fabrication and Characteristics of Elliptical-Holes and near Elliptical Core Hexangular Lattice Photonic Crystal Fibers Based on Polymer
Authors: Liu Fei , Gao Hong Yan , Xu Qiang , Zhang Ya Ni
Published: July 2011

The polarization properties of a new structure of high birefringence polarization maintaining photonic crystal fibers were explored, which were consisted of elliptical-holes and near elliptical core triangle lattice of hexangular structure based on polymer. The optical birefringence and the first order polarization mode dispersion were studied based on a full-vector localized basis function method. The numerical results show that the polarization properties are strongly dependent on structural parameters of the PCF. Furthermore, the proposed fiber was fabricated based on MMA monomer polymerization method in situ. So the proposed PCFs may be useful in the field of high birefringence polarization-maintaining optical communication.
Photoluminescence of ZnO Whiskers with Various Excitation Intensity at Room Temperature
Authors: Guo Xing Yuan , Zhou Jing , Ding Zhan Hui , Xue Yan Feng , Yao Bin
Published: July 2011

Hexagonal ZnO whiskers were prepared by using an optical floating zone furnace. Most of the as-grown whiskers have diameters of about 20-30 µm and lengths of about 2~3 mm. The characteristic peaks of X-ray diffraction (XRD) verify that the as-grown ZnO whiskers have excellent hexagonal wurtzite phase and (001) orientation. The room-temperature photoluminescence spectra show a near-UV emission band located at 380 nm and a green light emission band centered at 515 nm. The threshold of near-UV emission and lasing were observed.
Preconcentration and Separation Capabilities of Nano-Barium-Strontium Titanate Powder Coated by Dithizone for Trace Cobalt in Water
Authors: Zhang Dong
Published: July 2011

A new method for the preconcentration and separation of cobalt ion in water was described. The methodology combines determination using a flame atomic absorption spectrometry (FAAS) with adsorption and desorption of cobalt on the nano-barium-strontium titanate powder coated by dithizone (BST-dithizone). The operation conditions for the pre-concentration and separation of the cobalt, including pH, contact time, eluent condition and co-existing ions have been investigated. The result showed that the cobalt ion could be adsorbed by BST-dithizone. The adsorption quantity was affected by the pH value of medium and shaking time. In the medium of pH 6.0, the adsorption capacity of BST-dithizone to cobalt ion was 8.92 mg·g-1 when the shaking time was more than10 min. The cobalt adsorbed on the adsorbent could be completely eluated and recovered using 10 g·L−1 ethylene diamine tetraacetic acid (EDTA) solution. The enrichment factor was 100. The detection limit of cobalt was 0.53 ng·L−1. The purposed method has been applied to the pre-concentration and separation of cobalt in the water sample with satisfied results.
Investigation of Photo-Induced C-H Bond Activating by CpRh(CO)2 Complex Using Density Functional Theory
Authors: Liu Qing Liong , Wang Shu Wei , Lv Li , Wang Xiao Jing
Published: July 2011

The charge transfer and structural distortions that occurred in the complex CpRh(CO)2 upon excitation with an light irradiation were studied by density functional theory (DFT). The calculations showed that the electrons transferred from Cp to CO ligands with the transition of CpRh(CO)2 from ground state to the first excited state. Accompanying with this transfer process, CpM(CO)2 became distorted and the linear bond of M-CO became bent upon excitation. The second excitation is the strongest excitation which is identified to be metal to ligand CO charge transfer (MLCT) excitations. We also found the lowest excited state has little effect for the M-CO bond photoactivation while the photodissociation of CO from CpM(CO)2 can be achieved in the second excited state.
Numerical Simulation of Thermoplastic Composite Material by ANSYS
Authors: Zhao Guo Hua , Shu Qing Lian , Huang Bo Sheng
Published: July 2011

This paper proposes a material model of AS4/PEEK, a typical thermoplastic composite material, for the general purpose finite element code—ANSYS, which can be used to predict the mechanical behavior of AS4/PEEK composite structures. The computational result using this model has a good agreement with the test result. This investigation can lay the foundation for the numerical simulation of thermoplastic composite structures.
Shape Control for Composite Structures of Photostrictive Actuators Using Topology Optimization Method
Authors: Wang Yu , Luo Zhen
Published: July 2011

This paper aims to present an alternative design method for remote wireless shape control of laminated composite structures using topology optimization. The photostrictive material is introduced to implement the active control of the structure by making use of its photostriction mechanism, which is actually the superposition of photovoltaic effect and converse piezoelectric effect when exposed to the illumination of near ultraviolet light. The finite element formulation including multiphysics effects of photovoltaic, pyroelectric and thermal expansion is developed to model composite structures of ferroelectric materials, based on the Mindlin plate theory of first-order shear deformation. The topology optimization method is used to seek the optimal topologies for material layouts of both the smart actuation and elastic host layers. A typical numerical example is used to demonstrate the feasibility of this method in shape control of composite structures.
A Four-Node Hybrid-Trefftz Plane Elasticity Element with Fundamental Analytical Solutions
Authors: Wang Ke Yong
Published: July 2011

A new four-node hybrid-Trefftz element is developed for plane elasticity problems. From the Airy stress function, the fundamental analytical solutions of the governing equation are derived as Trefftz functions for the intra-element (Trefftz) displacement field. Together with an independent frame displacement field along the element boundary, the element formulation is then constructed following the modified variational functional. Several numerical examples indicate that the proposed element exhibits good performance.
Investigation of TIG Dressing and Chilling Treatment for Improving the Fatigue Strength of Welded Joints
Authors: Zhu Ping , Shi Chun Yuan , Jin Cheng , Zhang Xiu Juan
Published: July 2011

The negative temperature field with a certain strength is exerted on the TIG dressing zone in welding toes, which could decrease and offset the residual stress. When the temperature of TIG dressing zone is or above 450 °C, the chilling treatment could produce the stress field of biaxial compression. The chilling treatment is performed when the temperature of dressing zone is 550 °C. The fatigue strength of joints can be increased more than twice comparing with those after welding.
Acoustic Performance Analysis of Impedance Compound Muffler with Aluminum Foam
Authors: Bao Huai Qian , Wang Chang Tian , Li Jun
Published: July 2011

The common reactive muffler has poor acoustic properties in high frequency, so aluminum foam is applied to the reactive muffler and the impendence compound muffler is designed. The acoustic performance of the muffler is analyzed; the interior sound field of the muffler is modeled and meshed in the ANSYS, then they are imported into SYSNOISE, and imposed reasonable boundary conditions to carry out the analysis of acoustic performance of the muffler. The results show that, compared to reactive muffler, the muffler with aluminum foam has a higher amount of noise reduction and a wider frequency band in middle and high frequency.
A New Hydraulic Excitation Mode with Liquid-Filled Pipe
Authors: Kou Zi Ming , Lu Chun Yue , Wu Juan , Zhang Hui Xian
Published: July 2011

The current vibration modes, whether inertial vibration or hydraulic vibration, have some problems such as large power consumption and low energy utilization rate. A new low energy hydraulic excitation mode is presented. This mode takes the high-pressured pipe as the new excitation source. Periodic pressure pulsation generated by wave exciter makes the pipe vibrating. The vibration mode of pipe with fluid-structure interaction is established and solved with numerical method. The modal analysis and the simulation of the vibration have been carried out. An experimental platform is built to verify that the new hydraulic vibration can be exploited.
A New Method for Hardened Gears Machining - Ausform Finishing Process
Authors: Li Yan Bin , Jiang Tong , Zheng Peng
Published: July 2011

Ausform finishing process plastically deforms the surface of a steel component, generates compressive residual stresses in the surface layer, and imparts added strength and durability to the component. It integrates heat treatment, roll finishing and hardening of steel components into a single in-line manufacturing operation. The gear steel 20CrMo is introduced to determine various operation parameter of this process. The experiment results shown that ausform finished gears have the advantages of improved surface finish and profile accuracy.
Dielectric Properties of Graphite Nanosheets Doped Poly(vinylidene Fluoride)/Silicon Carbide Hybrid
Authors: Li Yu Сhao , Ge Xiang Сai , Tjong Sie Chin
Published: July 2011

Binary poly(vinylidene fluoride)/silicon carbide (PVDF/SiC) composites and its graphite nanosheets (GN) doped ternary hybrids were fabricated using simple solution mixing and hot compression molding process. The dielectric behavior of such hybrids was studied over a wide frequency range. Additions of graphite nanosheets with their concentrations close to the percolation threshold were found to be very effective to enhance the dielectric permittivity of PVDF/SiC system. The dielectric constant for PVDF/SiC/GN 80/20/2 system was ~ 200, being twenty times higher than that of neat PVDF. Furthermore, the dielectric behavior of such hybrid displayed strong frequency dependence.
Analysis on Transmission of UV Radiant Energy in Rapid Prototyping
Authors: Yu Dian Hong , Li Lin , Zhao Kai
Published: July 2011

Based on the optical-wave’s theory, focusing energy transmission of UV radiation in rapid prototyping technology has been analyzed in depth. The reflecting focusing theory that continuous spherical wave radiated by point light source is reflected from concave ellipsoidal surface has been enucleated and the axial and lateral optical energy distribution of the reflecting optical wave field has been showed up. The analysis indicates that distribution of the intensity in optical axis is approximately Gauss distribution. And by means of experimentation, the research educes that the UV radiant energy being coupled by optical fiber and being focused by lens is approximately Gauss distribution, too. For effectively utilizing the UV radiant energy and improving the prototyping precision in rapid prototyping, the research supplies sufficient academic basis and has important guidance on the optical design of rapid prototyping.
Extraction Feature of Spindle Unbalance of Machine Tool Based on the Wavelet Transform
Authors: Chen Dong Ju , Fan Jin Wei , Zhang Fei Hu
Published: July 2011

A new method for extracting spectrum feature of spindle unbalance of machine tool is proposed. The flatness error of workpiece surface includes much errors information, and the information contains high frequency signal and low frequency signal. For these errors information, a new identification method of turning errors of workpiece based on the wavelet transform and power spectral density analysis is proposed. According to the focal variation character of wavelet and the energy value of power spectral density analysis, the feature of spindle unbalance from the measured flatness error of workpiece is extracted and identified.
Dynamic Analysis of Elbow Joint in the Stroke of Tennis
Authors: Han Liang , Tian Meng Qian , Gui Jing Liang
Published: July 2011

The paper presents a multi-rigid model of arm for an impact between a tennis ball and racket, and makes dynamic analysis of it. The input to the model is the impact force caused by a tennis ball and racket. Its value comes from the deflection of the racket stringbed detected by a high speed camera and the stiffness of the racket stringbed is measured by a force gage. The effect of the impact force on the elbow is analyzed in order to research the pathogenesis of tennis elbow.
CuCr1 Alloy Surface Hardening via Ultrasonic Assisted Electro-Spark Deposition
Authors: Xu Yong , Guo Z.N. , Wang Guan , Zhang Y.J.
Published: July 2011

Resistance Spot Welding (RSW) is a widely used technology. And the rapid wear is the main reason for the short life of RSW electrodes. To improve electrode life during RSW, a novel ultrasonic-aided electro-spark deposition technology (UESD) and device are proposed in this paper. The WC metallurgical bond coating was fabricated on the surface of CuCr1 electrodes by UESD, and some experimental results were also analyzed. Moreover, the surface morphology of WC coating was studied by SEM and the quality of coating wear resistance was analyzed through experimental method. This study provides a novel way to extend the life of common moulds and RSW electrodes.
Experimental Study of Automotive Aerodynamics in Headlamp Effect
Authors: Jiang Lan Fang , Liu Hong , Li Ai Qi
Published: July 2011

The effect of headlamp modeling on automotive aerodynamics was studied by wind tunnel tests. Firstly, the effect of Reynolds number on drag coefficient of automotive scaled down models was studied under different velocity of flow to verify the rationality of selecting scale for scaled down model and setting inlet boundary condition. Secondly, drag coefficient of automotive scaled down models with different headlamp modeling design were measured. Thirdly, the distribution of surface pressure on central symmetry plane and headlamp was measured and analyzed. It also validated the validity of preceding numerical simulation. It is of importance to guide the headlamp modeling design and automotive modeling design.
Study on Parameters Configuration for Ant Colony Optimization
Authors: Gan Yi , Lan Lian Wang , Li Sheng
Published: July 2011

To find the parameters’ configuration relationship of the Ant Colony Algorithm, based on the ecological actions about ants, the distributing multiformity of ant colony pheromone, the pheromone updating strategy and the mutant of information difference were applied to Microhabitat Ant Colony Optimization (MACO). The parameters, α0, β0, kα and kβ of MACO were configured by the orthogonal experiment to enhance the performance of the algorithm, in which the interactions of α0 and β0, kα and kβ, α0 and kα, β0 and kβwere also analyzed. Some benchmarks of TSP and JSSP were solved by MACO which showed significant optimize performance with configured parameters.
Analysis of Lower Leg Injury of Occupant in Frontal Crash Tests Based on China NCAP Protocol
Authors: Liu Zhi Xin , Wan Ren Jun , Shi Yong Wan
Published: July 2011

With the popularization of passenger vehicle safety devices such as safety belt, airbag and so on, the chance that occupant’s upper limbs were injured seriously was decreased significantly in frontal impact. However, the injury of occupant’s lower limbs became more and more severe, especially on lower leg injury. 37 groups of test data of China NCAP crash tests including full-frontal rigid crash and 40% offset deformable barrier crash were investigated in this paper, and lower leg injury distributing characteristic of drivers and passengers in these two kinds of crash configurations were obtained. Finally the effect rules of characteristic parameters on lower leg injury were summarized.
A Method about Load Distribution of Rolling Mills Based on RBF Neural Network
Authors: Liu Dong Dong
Published: July 2011

Rolling mills process is too complicated to be described by formulas. RBF neural networks can establish finishing thickness and rolling force models. Traditional models are still useful to the neural network output. Compared with those finishing models which have or do not have traditional models as input, the importance of traditional models in application of neural networks is obvious. For improving the predictive precision, BP and RBF neural networks are established, and the result indicates that the model of load distribution based on RBF neural network is more accurate.
Effect of Sulfosalicylic Acid on Kinetics of Ce3+/Ce4+ Electrode Reaction
Authors: Xie Zhi Peng , Xiong Feng Jiao , Zhou De Bi
Published: July 2011

The effect of sulfosalicylic acid (SSA) on the electrochemical behaviour of Ce3+/Ce4+ redox couple was studied using voltammetry at stationary electrode and rotating disc electrode (RDE). When the SSA was added to the Ce3+/Ce4+ electrolyte there was change to the peak current and peak potential, i.e. the increase of peak current and the decrease of peak potential difference. The diffusion coefficient of Ce3+ is 6.5 × 10-6 cm2 s-1 and the standard rate constant of the Ce3+/Ce4+ redox reaction is 3.2 × 10-4 cm s-1 in the presence of SSA, which are all larger than that in the absence of SSA (3.6 × 10-6 cm2 s-1, 2.0 × 10-4 cm s-1). Therefore, the SSA as the additive in the supporting electrolyte for a cerium redox flow battery (RFB) application will result in a high voltage efficiency and will satisfy an important requirement for a RFB electrolyte.
Isothermal Dielectric Relaxations of Poly(vinylidene Fluoride) Filled with Silicon Carbide Nanoparticles
Authors: Li Yu Сhao , Ge Xiang Сai , Tjong Sie Chin
Published: July 2011

The dielectric relaxation behavior of poly (vinylidene fluoride) based composites filled with beta silicon carbide nanoparticles were investigated over a wide frequency range and temperature intervals. The composites exhibited dielectric relaxations in the tested frequency range and the relaxations of composites can be well described via the modulus formalism of dielectric spectroscopy. Further, activation energy determined from the isothermal dielectric relaxations tended to decrease with increasing SiC indicating the promotion of SiC to the dipole relaxations of PVDF.
Effect of Laser Ablation on Ba0.5Sr0.5Co0.8Fe0.2O3-δ Membrane for Methane Conversion
Authors: Shen Zi Gang , Guo Xiao Rui , Zhang Wu Qing , Pan Li Jun
Published: July 2011

A cross-shaped pattern was formed on the surface of Ba0.5Sr0.5Co0.8Fe0.2O3−δ oxygen permeation membrane by laser ablation in order to increase the specific surface area of the membrane. The membrane was used to assemble a reactor for partial oxidation of methane (POM) to syngas in the present of Ni/ZrO2 catalyst. The CH4 conversion and CO selectivity of the membrane reactor can reach 98.8% and 91.5%, respectively, and the oxygen permeation flux through the membrane was 11.0 ml/cm2 min at 850°C. The effect of space velocity (SV) on CH4 conversion rate and CO selectivity in such reactor was discussed.
Visible-Light Driven LaNiO3 Nanosized Photocatalysts Prepared by a Sol-Gel Process
Authors: Tang Pei Song , Sun He , Cao Feng , Yang Jin Tian , Ni Sheng Liang , Chen Hai Feng
Published: July 2011

The LaNiO3 nanoparticles were prepared by a sol-gel process. The LaNiO3 nanoparticles were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-Vis diffuse reflectance spectroscopy (DRS). XRD and SEM demonstrate the successful synthesis of single phase perovskite LaNiO3 and an average grain size of 80 nm in diameter. It was found that the as-prepared LaNiO3 shows strong visible-light absorption with absorption onset of 545 nm, indicating a narrow optical band gap of 2.28 eV. Consequently, LaNiO3 nanoparticles show high visible-light photocatalytic activity for decomposition of methyl orange in comparison with the commercial Degussa P25. The photocatalytic experiment shows the high photocatalytic activity for the decomposition of methyl orange under visible-light irradiation, which is attributed to the strong visible-light absorption.
The Field Emission of Globe-Like Diamond Microcrystalline Aggregate Films
Authors: Gao Jin Hai , Zhang Wu Qing , Li Zhen
Published: July 2011

The globe-like diamond microcrystalline aggregates films were fabricated by microwave plasma chemical vapor deposition method. The field emission properties and emission stability of the films were tested using a diode structure in vacuum. It was found that the globe-like diamond microcrystalline aggregates films exhibited good electron emission properties and stability. The turn-on field of 0. 55 V /μm and the current density of 11mA/cm2 at the electric fields of 2.73V/μm were obtained. At the successive operator circles, the turn-on field tends to stabilize at 1. 08V /μm and the current density of 6.6 mA/cm2 is obtained.
Effects of K2HPO4 on Fermentative Biohydrogen Production of Biohydrogenbacterium R3 Sp.nov.
Authors: Lin Yong Bo , Chen Hong , Yue Li Ran
Published: July 2011

This study has investigated the effects of K2HPO4 to the cell growth and hydrogen production ration to Biohydrogenbacterium R3 sp.nov.. The results found that: K2HPO4 can promote the cell growth and hydrogen production effectively and it can maintain the pH value stably in culture. The biogas yield, hydrogen production yield and specific hydrogen production ration(SHPR) had the maximum of 4960 ml/L, 2107.5 ml/L and 1.93 mol H2/mol glucose respectively when the concentration of K2HPO4 was 1.5g/L. The final pH in the culture was always kept at 3.0~5.0.
Building Energy Consumption Prediction Evaluation Model
Authors: Li Nan , Zhao Jing , Zhu Neng
Published: July 2011

Building energy consumption prediction provides the possibility for regulating running condition of equipments in advance. Then the equipments will keep good movement and building energy consumption will reduce obviously. This paper built an energy consumption prediction evaluation model according to Matlab Artificial Neural Network Toolbox. The model was trained and simulated by operation data in June-September of 2008 and 2009 of a case building. Then it can be used to predict this building energy consumption by special data, such as meteorological characteristics of prediction year, operation load, operation time and energy consumption of last year. With more building samples, the model will be used in wide range of building energy consumption prediction.
Synthesis of N-(3-Rosin Acyloxy-2-Hydroxyl) Propyl-N,N Diethanolamine and its Anti-Fungal Activity
Authors: Liang Tao , Li Shuang Yue , Li Shu Jun , Zhang Li Jun
Published: July 2011

Rosin was used as a raw material to prepare N-(3-rosin acyloxy-2-hydroxyl) propyl-N,N diethanolamine. First, rosin was modified with epoxy chloropropane. Then the modified rosin reacted with diethanolamine and N-(3-rosin acyloxy-2-hydroxyl) propyl-N, N diethanolamine was produced under the following conditions: modified rosin and diethanolamine mole ratio of 1:2, reaction temperature of 78°C, and reaction time of 2.5 h. The chemical structure of the product as a rosin amide derivative was identified by Fourier transform infrared spectroscopy (FTIR) and liquid chromatography-mass spectrometry (LC-MS) method. The anti-fungal activity of this rosinyl tertiary amine was determined in vitro against wood decay fungi, Trametes versicolor, Gloeophyllum trabeum and mould fungi, Aspergillus niger and Paecilomyces variot Bainier. The anti-fungal experiment results signified that N-(3-rosin acyloxy-2-hydroxyl) propyl-N,N diethanolamine was active to these fungi at a certain concentration.
Application on the Stratified Air Conditioning System with Low Velocity in the Main Hall of the Temple
Authors: Huang Yi Yun , Zhang Ling , Han Xiao Hong
Published: July 2011

This paper presents a design scheme of the stratified air conditioning system, in accordance with the temple hall’s large space and function characteristics. The indoor stratified air conditioning environment is formed by the low velocity air supply of fan coil units embedded below the Buddha statue. The interface of stratified air is only 1.7m high, because the large amount of air unavoidably penetrates the room due to the prohibition of closing the door. From the tested results, the design not only meet the temple hall’s operational requirements for decoration and the open front door, but also greatly reduces the energy consumption of the air conditioning at the cost of the comfortable feeling of air conditioning. In this work, some suggestions are also given in order to further improve the comfort and lower the energy use.
Experimental Study on Frost Resistance Durability of Concrete with Intensified Recycled Aggregates
Authors: Chai Wen Ge , Li Wen Li , Gao Wen Xia
Published: July 2011

In order to study high performance recycled concrete, the recycled concrete is prepared through the double admixing technology, i.e. mixing of high-quality mineral admixture and high-efficient water reducer. It is modified with the recycled aggregates soaked in and intensified by chemical grouts. The mass loss rate and relative dynamic elastic modulus of the recycled concrete are measured through fast freeze-thaw test, and a model for predicting the life of the recycled concrete under freeze-thaw conditions is built. The experiment results show that it is an efficient way to intensify recycled aggregates through being soaked in chemical grouts. The recycled concrete prepared with recycled aggregates intensified by chemical grouts, high-quality mineral admixture and the high-efficient water reducer feature favorable frost-resistance.
Discuss on Green Building Materials and Related Issues
Authors: Wang Shi Jin
Published: July 2011

Green building materials as an important factor plays important role in the promote sustainable development. However, at present a unified understanding on the green building materials in China have not been formed,the evaluation system of green building materials is not perfect.In this paper,the concept and features of green building materials are discussed deeply,and life cycle model is used to evaluate the green building materials.The status and future trend of green building materials are discussed too.
Spatial Analysis of Continuous Rigid Frame High Pier under Completed Bridge State
Authors: Yang Ya Xun , Sun Lei
Published: July 2011

The continuous rigid frame bridge was taken as a typical background, considering the horizontal alignment curvature of the continuous rigid frame bridge space by the force, by selecting a different radius of curvature and height of piers, using the finite element program to the completed bridge state into the curve of the high continuous rigid frame bridge pier stress and deformation analysis, focused on the effects of curvature and height of piers. Analysis of it, provided the design suggestions for the curve corresponding rigid frame bridge.
Dynamic Performance Analysis on High-Speed Railway Continuous Girder Bridge
Authors: Song Shou Tan , Zhang Ji Wen , Yuan Xin
Published: July 2011

The dynamic performance of continuous girder under the train in a series of speed is studied through examples, and the main conclusions are given in the following. The resonance mechanism of continuous girder is similar to simply supported beam. The vehicle wheel load forms regular moving load series, which induces periodical action and resonance of the bridge. The damping ratio of bridge itself has less effect on the amplitude at the loading stage, but significant effects appear when the load departs from the bridge. The count of continuous spans also has less impact on the dynamic coefficients, so three continuous spans can be adopted for calculation and analysis. Span and fundamental frequency have significant influence on dynamic coefficients of bridge structures. To extend the span of the bridge structure can reduce the dynamic coefficient while keeping its frequency invariant. The fundamental frequencies of different bridges are corresponding to certain resonant speeds, which calls for the attention in the design.
Preparation of Lignocellulose Aerogel from Wood-Ionic Liquid Solution
Authors: Chen Cheng , Li Jian
Published: July 2011

This paper reports a new method to prepare a new lignocellulose aerogel that is made from two kinds of wood powder through dissolution/regeneration of cellulose in ionic liquids. The obtained gel was washed with ethanol, liquid carbon dioxide and ﬁnally dried by releasing the carbon dioxide from the net structure at supercritical temperature to obtain the aerogel wood. All aerogels were compressible and consisted of nanoﬁbrillar biomaterial network with open-pore structure. The range of density meets a criterion with aerogel density. Infrared spectrum shows that the pre-and post-treatment characteristic absorption peak of wood powder remained unchanged, and the ionic liquid played a mesomeric role among the physical reaction.
The Current Construction Situation and Future Development Strategy of Rural Primary Boarding Schools in Jiangxi Province
Authors: Nie Lu , Zhao Zhi Qing , Wu Zhi Yun
Published: July 2011

The current primary and secondary schools in China's rural areas and the readjustment of the distribution mechanism to ensure funding for rural compulsory education in the context of the reform of the province is pushing forward rural boarding schools project key projects. This paper elaborates the development of rural primary school’s construction actualities and summed up the design strategies outlook and principle of primary school building about function, standardization and regulation.
Neural Network Architecture Based on the Production Process of Ceramic Classification System of Environmental Factors
Authors: Hong Chao , Zhang Ru , Huang Xiao Hua
Published: July 2011

This article is about a green product in the ceramic industry that is not mature in the context of production. we make use of new neural network approach to the accurate classification of general building ceramics, to facilitate the construction of ceramic materials to handle the production line of various ceramic the proportion of environmental factors, so the decision on the most environmentally friendly way of energy production technology. To this end, we have introduced a BP neural network model and parameters proposed the concept of porcelain, porcelain shape parameters from the correlation analysis, discussing the porcelain the determination of parameters. Finally, we create the required network, and it trained until getting the training error of the training requirements.
Application of a New Asphalt Pavement Maintenance Agent on Yuhe Road of Chongqing
Authors: Qin Li Ping , Huang Wei Rong
Published: July 2011

In this paper, the abilities of recovery and regeneration for aged asphalt of a new type of asphalt pavement maintenance agent are studied. The agent is applied in the construction of test section of Yuhe Road, and the pavement performances before and after the construction are compared. The test indicates that after the maintenance agent is added into aged asphalt, the penetration and ductility are effectively improved, the softening point is lowered. When the penetration depth of agent reaches 6 mm，the texture depth , friction coefficient and antiskid value are improved to some extent ,the water permeability coefficient is reduced, and the appearance of pavement is improved as well，The paper provided reference for the applying curing agent of asphalt pavement to the preventive maintenance system.
The Holistic Urban Planning Approach of Urban Sustainable Development
Authors: Xu Hong
Published: July 2011

The lacking of holistic analysis in urban planning is urgent in China. This paper start from complexity theory to analyze and study the urban development patterns in urban planning of China cities. This paper analyzes the need of holistic analysis in the process of urban planning. This need is very important for the current process of urban modernization and the building of harmonious society in China. As discussed in this paper, we must make an effort to improve urban planning by virtue of choosing a very clear direction according to the nature of urban planning. From the perspective of different disciplines to understand the city and urban planning, we can able to make a complex system of our city and complex understanding of things deviation reduced, and finally effectively promote the development of the city.