Advanced Materials Research Vols. 415-417

Abstract: The most difficult form of its periodicity is one of the conditions of the elements which traversing the entire results of the corresponding operations, when the fuzzy numbers in the use of traditional methods of operation principle of extension to express problems. The operation to fuzzy analysis of the process of application of the theory has brought great difficulty, and which making the actual operation can not proceed. Fuzzy parameters of the reliability of the system had been studied, and it had been compared with the traditional fuzzy reliability analysis. We proposed a new reference to the reliability of fuzzy membership function and its form of expression. And it reached a more precise definition of fuzzy reliability of confidence interval type. It solved some problems such as the traditional fuzzy reliability analysis in the mass caused by the calculation of fuzzy computing complexity and low-precision. Hydraulic systems as an example of fuzzy parameters based on the reliability of the information model have proved that the model has good application value.

Abstract: In order to study the effects of laser fluence on silver nanoparticles colloid, the silver nanoparticles colloid was prepared by pulsed laser ablation of silver target for 10min in distilled water at different laser fluence. The particles size，morphologies and absorption spectroscopy of the obtained nanoparticles colloid were characterized by ultraviolet to visible (UV-Vis) spectrometer and transmission electron microscopy (TEM), the average diameter and its distribution were analyzed by Image-ProPlus software. The results shown that the average diameter of the silver nanoparticles prepared at the laser fluence of 4.2J/cm² was the smallest (D=17.54nm), also, the distribution of particle size was narrowest (=36.86nm) and the morphologies were more homogeneous. It was confirmed that the nanoparticles size and shape could be controlled by pulsed laser ablation parameters.

Abstract: In the protecting inert gas, Aluminum nanoparticles were successfully prepared by anodic arc discharge plasma method. The morphology, particle size, crystal microstructure and specific surface area of the particles by this process were characterized via X-ray powder diffraction (XRD), Brunauer–Emmett–Teller(BET) adsorption equation, transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED). The experimental results indicate that the crystal structure of the samples is face centered cubic (fcc) structure as same as the bulk materials, the particle size distribution ranging from 20 to 70 nm, with an average particle size about 44 nm obtained by TEM and confirmed by XRD and BET results. The specific surface area is 41 m²/g, the nanopowders distributed uniformly in spherical chain shapes with uniform size and monodisperse particles.

Abstract: La_0.8Sr_0.2MnO₃ (LSMO) films with SrMnO₃ (SMO) diffusion barrier layers were deposited on (100) Si substrates at 600oC by RF magnetron sputtering. From X-ray diffraction patterns (XRD), (110) peak of LSMO has been greatly enhanced in LSMO/SMO/Si, which may result from small lattice mismatch between SMO and LSMO Rutherford backscattering spectrometry spectra (RBS) measurements clearly show that there is a sharp interface between SMO and Si and small diffusion between LSMO and SMO after introducing SMO diffusion barrier layer. Small lattice mismatch is also considered to play an important role in deciding good interface quality. The current-voltage measurement shows a good rectifying property of LSMO/SMO/Si when the thickness of SMO is 50 nm. On further increasing SMO thickness, the junction currents are depressed at the same applied positive voltage. We attribute the results to the bigger junction resistance caused through introducing thicker barrier layer.

Abstract: The vibrational characteristics of cantilever beams with initial axial tension were studied using a nonlocal continuum Euler-Bernoulli beam model. Small size effects are essential to nanotechnology and it can not be ignored in micro or nano scale. Nonlocal elasticity theory has been proved to work well in nanomechanics and it is considered into the governing equation which can be transformed into a fourth-order ordinary differential equation together with a dispersion relation. Boundary conditions are applied so as to determine the analytical solutions of vibrational mode shape and transverse deformation through a numerical method. Relations between natural frequency and the small scale parameter are obtained, including the fundamental and the second order frequencies. It is found that both the small scale parameter and dimensionless initial axial tension play remarkable roles in dynamic behaviors of micro cantilever beams and their effects are analyzed and discussed in detail.

Abstract: ZrO₂-Al₂TiO₅ composites were finally prepared with synthetic powders by coprecipitation or solid method phase.we compared with their properties. The results show that the sintering properties and thermal shock resistance of ZrO₂-Al₂TiO₅ composites prepared by coprecipitation method are superior to solid phase method.

Abstract: SnO₂/TiO₂ composite material was prepared by use of microwave deposition method, on basis of tetrabutyl titanate(C₁₆H₃₆O₄Ti) and tin tetrachloride(SnCl₄) were used as source material and carbamide (CO(NH₂)₂) as precipitator. The characteristics of composite material were investigated by means of X-ray diffraction (XRD), scanning electron microscope(SEM) and Fourier transform infrared(FTIR). The result showed that optimization mol ratio of carbamide and metal elementary( Sn & Ti) was 2:1. SnO₂ adulteration counterworked TiO₂ crystal transformation and restrained rutile nucleation. Anatase TiO₂ grew up easily. SnO₂ content had been influence on composite material average emissivity at 8~14 waveband. Mix proportion of composite material was achieved which emissivity was 0.3185.

Abstract: Base on robot D-H method, the features of three-DOF cylindrical industrial manipulator are analyzed, the motion equation of robotic mechanisms are deduced by using coordinate transformation method and symbolic method. Then three-DOF cylindrical industrial manipulator inverse kinematics solving analytic formula is found. That provides a basis for the position and speed control of actual three-DOF cylindrical industrial manipulator.

Abstract: In the present paper effect of post deformation cooling rates on microstructure of ER70S-6 steel was investigated by using Gleeble1500 simulator. From the results, a controlling cooling process for obtaining dual phase (DP) microstructure was designed to produce hot rolled wire rod with a diameter of 6.5mm in a continuous no-twist and high-speed wire rolling mill, and the microstructures and the tensile properties of the wire rod were analyzed. The results showed that ER70S-6 steel deformed at 845°C and cooled at a rate of faster than 10°C/s had a DP microstructure with grain size of less than 8.3μm and martensitic volume fraction of 9-11%. The hot rolled wire rod cooled by blowing air had a DP microstructure with a grain size of 8.2μm and martensitic volume fraction of 11.5%. The present wire rod was superior to that of the same steel with ferrite plus pearlite microstructure in tensile properties, with yield strength level of 335-345MPa, ultimate tensile strength level of 600-620MPa, plastic elongation of 26.5-31.5% and strain hardening exponent of 0.221, respectively. ER70S-6 steel wire rod with DP microstructure showed promise of meeting the requirements for grade 8.8 fastener.,In the present paper steel wire rod with DP microstructure showed promise of meeting the requirements for grade 8.8 fastener.

Abstract: The effect of cold working on semiconducting properties of passive film and pitting corrosion resistance of 19Cr-18Mn-2Mo-0.9N high nitrogen austenitic stainless were investigated by anodic polarization, AC impedance and capacitance measurement methods. With increasing the cold rolling deformation ranging from 0% to 60%, the passive region of high nitrogen austenitic stainless steel decreases, and the corrosion potential, EIS radius and polarization resistance all decreases. The Mott-Schottky result indicates that the pitting corrosion resistance deteriorates with increment of cold rolling deformation. The results show that the passive films formed on high nitrogen austenitic stainless steel with different cold rolling deformation behave as n-type semiconductors. With increasing the cold rolling deformation grade, the donor density (ND) increases, but the thickness of the space-charge layer (W) decreases. The decreasing of the thickness of space-charge layer with increment of cold rolling deformation is attributed to the inceasing defect which deteriorates the stability of the passive film.