Applied Mechanics and Materials Vol. 696

Abstract: The relationship between the location of gate oxide breakdown in n-MOSFETs and its electrical characteristics has been studied by using TCAD software. The comparison of device terminal current with gate oxide breakdown at different locations suggests that the variation of the source and the drain currents can be directly correlated to the breakdown location in the ultra thin gate oxide. The results provide a fundamental understanding to the experimental results observed in our devices.

Abstract: At present, China's IF steel production has get a certain scale. But IF steel production is still in the primary stage of development. Therefore, the process control of inclusions in IF steel have become a pressing matter of the moment. This has important theoretical value and practical significance for further development of IF steel production in China. According to the size, the inclusions can be divided into super micro inclusions, micro inclusions and micro inclusions in the steel. According to the deformation capacity, inclusions can be divided into plastic inclusions, semi plastic inclusion and brittle inclusion.

Abstract: The process of LF Refining is introduced in this paper. Because the LF ladle furnace has the advantages are widely used and developed in many companies. The argon is blown into the ladle, so the purpose of refining is achieved. The argon stirring can accelerate the chemical reaction between slag and steel. In the circulation process, large inclusion and deoxidation product in the lower region transfer into the slag. The material transfer between steel and slag can be accelerated. At the same time, argon stirring can make molten steel composition and temperature uniformity. Thus, the ladle of blowing argon can be roughly divided into three important flow region has been introduced. Two-phase region, the top horizontal flow zone and recirculation zone exists in the ladle.

Abstract: Laser cladding is an effective mean to repair the damaged components in remanufacture industry. The iron-based alloy coating was obtainment by laser cladding on grey cast iron (HT250). The microstructure and morphology of laser cladding were observed by using scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). The micro hardness of laser cladding coating was tested. The wear properties of grey cast iron and laser cladding coating at room temperature without lubrication were evaluated by sliding wear tests. The distribution regularity of surface residual stress of substrate and cladding coating was obtained. It was shown that the laser cladding coating on grey cast iron has a homogeneous and dense microstructure. It was observed that the laser cladding coating presents a great hardness and excellent wear resistance. Tensile stress was generated in the surface of laser cladding coating.

Abstract: A digital mask microlithography system is designed and constructed, which employs a 405nm semiconductor laser diode as light source, and uses a DMD (Digital Micro-mirror Device) as high-precision digital mask. The microstructure array with logo and optical grating has been obtained successfully on this system. Lithography results have been evaluated carefully with the aid of microscope and white light scanning profiler. The feasibility of the microlithography system has been further proved.

Abstract: A basic experiment study with a simplified wing model was carried out to introduce a opposite wake vortex by different sizes of spoilers. A PIV measurement was employed to obtain a two dimension wing wake vortex velocity field data of different spoilers in a water towing tank and confirm the existence of Reyleigh-Ludwieg instability in aircraft wake vortex. The image preprocessing is useful in PIV post-processing by comparing the three kinds of image preprocessing results with normal PIV image processing results.

Abstract: Aiming at infrared images' disadvantages such as low contrast and blur edges, an infrared image enhancement algorithm using lateral inhibition of human visual system (HVS) is proposed. The algorithm makes use of the rapid decline properties of exponential function to reconstruct lateral inhibition coefficient distribution model based on exponential function, which could provide an obvious inhibition function and produce strong contrast between sharp edge and even part. The experimental results show that image edges are obviously highlighted, and the edge enhancement is 2 times compared with traditional balanced spacing density of gray-scale, and the PSNR is 2 times compared with traditional histogram equalization method.

Abstract: With the development of modern aviation technology, the structure of aircraft engine as the heart of the plane is more and more complicated. The problem of people’s concern is how to monitor engine condition and realize the fast fault diagnosis of engine. In this paper, the method of support vector machine (SVM) combing evidence theory decides whether a signal is a fault signal on the base of researching the engine vibration mechanism and the characteristics of rotor fault vibration signals. This method avoids the defects giving the single information though the traditional method which is unable to predict the tendency of the engine safety. Evidence theory meets weaker conditions than Bayesian probability theory. It can express "uncertain" and "unknown" directly. Therefore the paper makes information fusion in combination with evidence theory in different measuring points and different working conditions of engine. This method not only can identify small sample and nonlinear system, but also fuse information which gets more evidence samples effectively. At the same time, the posterior probability diagnosis results can predict the development trend of the fault accurately. Output in the form of probability can deepen the cognition about the present situation of the engine and better observe the safety of the trend of engine simultaneously. It can facilitate the management and protection in time.

Abstract: Because of the powerful data processing ability of FPGA, the fast interpolation algorithm is used for Bayer format data which comes from CMOS sensor MT9M011 to convert to RGB image format. In the RGB color space to YCbCr space conversion stage,using color space conversion formula, combined with the characteristics of FPGA, realize the conversion of RGB to YCbCr. Finally, correctness is verified by the experimental results which use SignalTap II embedded logic analyzer.

Abstract: On the basis of the analysis of characteristics, application occasion, and limitations, comparison simulations are performed with the combined methods by means of AT&T face database. The paper present the method based on PCA and FLDA which can improve the recognition precision and shorten the recognition time, and show the comparative results of the three combined methods based on PCA respectively combined with FLDA, SVM, and Bayes.