Applied Mechanics and Materials Vol. 678

Abstract: The matching status of wheel/rail affect the driving stability and safety directly. It could improve the dynamic behaviors by optimizing the matching status of wheel/rail. Taking the wheel rim tread named LMa as an object, the wheel diameter curve method was used to optimize the profile of tread LMa. Then the dynamic behaviors of the optimized profile (LMa-G) were obtained by the dynamic analysis. The results obtained indicate that the profile of tread LMa - G showing better contact performance.

Abstract: The Ni-Nd₂O₃ nanocomposite coatings were prepared by electrodeposition under combination ultrasound field. The Nd₂O₃ content and surface morphology of coatings were analyzed by scanning electron microscopy (SEM). And the microhardness of coatings was tested. The results showed that ultrasound power is a great influence on Nd₂O₃ content in coatings. The Nd₂O₃ content of the nanocomposite coating prepared by electrodeposition using combination ultrasound was high at 3.48%, when bath-type ultrasound power was 240W and probe-type ultrasound power was 30W. And the surface morphologies of nanocomposite coating showed better smooth surface, finer grain and more compact microstructure.

Abstract: The effect of electrode wear is significant on machining quality, in order to ensure the processing precision of micro-EDM milling, need to give reasonable compensation for the tool electrode. In this paper, based on the model of fixed length compensation method to machining the micro groove with micro-EDM by layered milling experiment, moreover, adopted the orthogonal machining path and the machine vision technology to obtain the stable end of the electrode image after processing, and then determine the reasonable path of trajectory overlap. The experimental results show that, the electrode compensation model can availably compensate the electrode wear, and the processing time is shortened by 50% with the machining method of orthogonal trajectories, and the method can make the residual cut remove obviously, gained good machining precision. We observe the bottom section linearity of micro groove is very good and the processing error of the micro groove depth is about 2 μm by the optical microscope.

Abstract: Ni-CeO₂ nanocomposites were electrodeposited using rotating cylindrical cathode in ultrasonic field. The surface morphologies and the CeO₂ contents in the nanocomposite were examined by the Scanning Electron Microscopy and the Energy Disperse Spectroscopy. The microhardness of nanocomposites were also evaluated by digital microscopical Weis Sclerometer. The effect of ultrasonic power and cathode rotating speed on the CeO₂ nanoparticles contents and the distribution condition of the nanocomposites were investigated. The results indicate that both the ultrasonic power and cathode rotating speed effect the microstructure and property of the nanocomposites remarkably. Prepared under the technology parameters of cathode current density 4A/dm², cathode rotating speed 1200rpm, CeO₂ nanoparticles addition 40g/L and ultrasonic power 300W, the Ni-CeO₂ nanocomposites present refined crystal grains, compact microstructure, smooth surface morphology and high microhardness.

Abstract: COREX and COSRI smelting reduction iron-making process could directly use coal as reductant. So it is necessary to contrast the development and technology of two kinds smelting reduction iron-making process. Due to lack of funds, COSRI smelting reduction iron-making process has not been fully developed. And the COREX has completed the transformation to the industrial production. But on the whole, COSRI has good prospects for development as COREX.

Abstract: The research status of physical simulation on LF furnace refining ladle is introduced in this paper.Since 1970, the research on the gas-liquid two-phase region has begun. 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.The establishment of physical model should include similarity principle and flow field measurement technique

Abstract: The research status of numerical simulation on LF furnace refining ladle is introduced in this paper.Since 1970, the research on the gas-liquid two-phase region has begun.Szekely began to be simulated by mathematical model and physical experiment method of flow phenomena in ladle in early 1975. It is the first time that the numerical model is introduced to study the refining process of steel. The plume model is presented by Xiao Zeqiang in 1980, then the numerical simulation began to develop rapidly.

Abstract: Theory of Machines and Mechanism as a major technology foundation course of mechanical engineering plays an important role in connecting professional education. From the perspective of inspiring mechanical design thinking, put forward the idea of classroom teaching reform for the curriculum. The knowledge of the curriculum is combed; the target ability of the curriculum is specified; the teaching plans are designed to inspire design thinking; the teaching mode is reformed, and the extracurricular learning mode is enhanced. This paper provides a reference for the classroom teaching reform in the other mechanical course.

Abstract: Among the one of most interesting and challenging theoretical and practical problems in describing pedestrians behavior are evacuating tactics preference. Compared to other modes of transports, the features of pedestrian route preference are that everyone has a different decision-making ability based on differentiating spatial recognition. This article focused on the correlative issues between pedestrian characteristic and their routing choice behavior in special event. As the data collected from a field survey conducted in a large market exposed, we analyzed the difference of individual strategy behavior, which showed that different pedestrians held different preferences and probabilities of choosing a particular road for evacuation due to diversity of spatial cognition. They searched their corresponding personalized spatial cognitive road network to find some roads which maybe a route to the destination. According to the questionnaire, it was the fact that 62% of people would choose the most familiar paths parts of which may be shortest one. Each pedestrian derived his own road network from the roads selected from different levels consisted with personal characteristics. Through this paper, the author expected to make a step that the pedestrian behavior simulation will advance on integrating the human cognition from theoretical precision and managers can realize the importance of spatial knowledge and correct strategy for evacuation.

Abstract: Massive Online Open Course which based on Open Educational Resource might be the most effective method to large-scale quality education, which can realize passive learning to active learning. Analyzing the status and shortages of Intelligent Answering System, propose and design an intelligent question answering system based on agent-model. System use software agents to implement and improve MOOC system’s Intelligent Answering System performance, which has capacity of natural language processing, and good versatility. It can provide an efficient online problem answer environment for thousands of learners, and can effectively promote students' autonomous learning and self-development.