Advanced Materials Research Vols. 503-504

Abstract: While nano-hydroxyapatite (nano-HAP) has been well known for series of amazing properties in chemical or physical, the controversy on the risks of its applications has also been existed. The worries of nano-HAP applications in preclinic and clinic indicate the blank researches of nano-HAP pharmacodynamics. It is important and necessary to trace and clarify the localizations of HAP nanoparticles in vivo. In the present paper, 18F is used as radiotracer for Positron Emission Tomography (PET) imaging of HAP nanoparticles. Through the transverse plane slices and three-dimensional reconstruction pictures, it is very clear to observe the localization of nano-HAP in vivo at real time. Most nano-HAP particles were noted in organs lump, liver, spleen, stomach and existed for period of time. Therefore, PET can be a new powerful technique for tracing nano-biomaterial and their pharmacodynamics researches.

Abstract: ZnO thin films were prepared by DC magnetron sputtering. The effects working pressures on the microstructure, optical properties and the photoluminescent properties were studied. The results show that ZnO thin films were successfully prepared with preferred orientation growth, showing structure of single crystal. The transmission of all the ZnO thin films kept above 85%. With increasing the working pressure, the surface of ZnO thin film became coarse, the intensity of X-ray diffraction peak decreased and the transmission of the film decreased and then increased. The intensity of the two photoluminescence peak of ZnO thin films one ultraviolet peak at 400 nm and one blue peak at 466 nm increased with increasing the working pressure. The ultraviolet peak was originated from the transition emission of the electrons from the conduction band to the valence band while the blue peak was originated from the defects in ZnO thin films.

Abstract: The interface of two low-density materials is bent in the forming process, which decreases the performance of materials. The theoretical analysis of the interface state in the forming process was taken to solve this problem, and the results indicated that the viscosity of the low-density material was very important to the interface state. The finite element simulation was also used to investigate the factors that affect the interface state. The results revealed the viscosity of material and the pressure were the main factors that affected the interface state; the stress and displacement at the interface could be accurately predicted by the finite element models. The ultimate aim was to modify the relevant parameters in a way that could obtain the required interface states.

Abstract: This paper makes road test on two kinds of engine lubricant, one contains nano-ceramic additives, and one does not. Results show that the lubricant containing nano-ceramic additives can fully meet the requirements of automotive engine, and nano-ceramic lubricant is superior in anti-wear properties to other lubricant in experiment, and nano-ceramic additives can improve the anti-wear properties of lubricant.

Abstract: After the horseradish peroxidase (HRP) was treated with different dose of N+ ion beam, the effect of N+ ion beam on the secondary structure of HRP was studied by FTIR(Fourier-transformation infrared spectroscopy). The results have shown that different dose ranging from 1015 to 1016 ions/cm2 has different effects on the secondary structure contents the HRP. The N+ implantation induce the mutual change in the secondary structure unit of HRP. It was suggested that N+ ion beam was bound to result in conformational change.

Abstract: The idea of generalized stress increment testing method which contains both the stress free method and the stress superimposing method for the residual stress determination is developed. The research development of full and partial stress free testing methods is reviewed. Different testing methods are characterized according to the different working conditions. The stress superimposing testing method of residual stress is different from the stress free one. A new stress field is introduced adding on the initial state. The residual stress is indentified by the strain increment differences of the material detected in the stress superimposing process. The traditional stress superimposing testing method including hardness and indentation method are reviewed. The principal and application of two new type of stress superimposing testing methods of residual stress are introduced, their disadvantages are also indicated.

Abstract: In this paper, the ultrasonic fatigue machine which works at frequency of 20kHz is utilized to conduct the ultrasonic fatigue tests on a high strength welding structural steel with symmetric cycle stress R=－1 at room temperature. Two typical specimen geometries are tested: smooth specimen and notch specimen. The fatigue tests of smooth specimen are also carried out on the electromagnetic resonance equipment at conventional frequency. A comparison is made between the fatigue test results at the ultrasonic and conventional frequency.

Abstract: The finish machining test is using the ultrasonic vibration turning, and a lot of experimental researches have done on the factors which influence the finishing surface roughness, It is determined a reasonable cutting parameters by comparing test and orthogonal test, analyzed some of the factors which influence the surface quality, and made a test analysis and verification for promoting the use of finishing technology of ultrasonic vibration turning, and in the same time analyzes the superiority and regularity of finish machining technology using ultrasonic turning.

Abstract: On the basis of the analysis of special demand of helical gear of automotive transmission, gear precision modeling and finite element analysis of flexural strength were carried out in this paper. In UG three-dimensional modeling environment, helical gear model was generated and imported into ANSYS software through data exchange interface. Then meshed on the geometric model, discussed the tooth contact area and the detrimental loading position, and compared the influence on gear strength with different tooth root fillet radius. The paper provided certain methods to guide the gear parametric design, strength analysis and improving optimization design efficiency of transmission gear parts.

Abstract: This paper studies the cylindrical acoustic emission signal generation, propagation and attenuation. Acoustic emission signal is a form of elastic waves and mechanical waves also. The large finite element physics simulation software COMSOL is used to simulate the propagation of acoustic emission signals coursed by the oil tank bottom corrosion. Simulation is divided into two parts，they are separately two-dimensional simulation and three-dimensional simulation. The bottom part of oil tank is two-dimensional simulation and the entire tank is three-dimensional simulation. Two-dimensional simulation is achieved in different situations. Strength of point source are the same in different positions, and the same point source position has different intensity. Acoustic emission wave propagation has a greater relationship with the media of dissemination, the point source position and the different interfaces.