Applied Mechanics and Materials Vols. 26-28

Abstract: During the silicon wafer grinding, the different process parameters could cause the silicon wafer shape greatly different. Based on the rotational coordinate principle of kinematics, a theoretical model of the ground wafer shape in rotational grinding process is developed, in which many critical factors are considered in this paper. These factors mainly include the parameters of the dressing vacuum chuck and wafer grinding etc. And the mathematical equation of the ground wafer shape is derived. Moreover, as one of the important indexes, TTV(total thickness variation) is researched and analyzed. The equation of TTV is given. The built model can offer a theoretical foundation for further experimental researching. The research results are significant to effectively control the ground wafer shape in a certain.This paper applied the Autonomous Intelligent System(AIS) to deal with the intelligent activities intelligently and automatically, and thereof provided a new method for the Supply Chain Management(SCM) on MC manufacture. First, a new supply chain model based on E-HUB was presented according to the requirements of MC manufacture, and then the structure and operation of AIS were designed to support that SCM. Finally, the development technology of AIS was discussed.

Abstract: Recast layer is an inherent defect commonly associated with holes produced with laser drilling. The defect is likely to limit the extent of aero industrial application. In order to solve the problem, a new processing of laser drilling assisted with neutral salt solution (SALD) has been developed to improve the overall quality of laser-drilled holes. The process bases on the application of a fluid neutral salt solution, which is being on the workpiece surface with the focused laser beam at the same time. The effects of the neutral salt solution during the process mostly consist of thermal chemical reaction and continuing cooling effect of materials. Because of green laser being weakly absorbed underwater, the experiments of SALD have been performed on 0.5mm thickness 321 stainless steel with pulsed Nd:YAG laser at second harmonic wavelength. The optical microscope is used to detect the experimental results. It is found that the recast layer has been effectively removed during the SALD compared with laser drilling in ambient atmosphere conditions. It is confirmed that the principle of SALD is right and the new process can obtain good hole quality without recast layer.

Abstract: Subdivision surfaces have become a standard technique for free shape modeling. But tradition subdivision scheme does not adjust the shape of subdivision results. In this paper, We introd uce adjustable adaptive subdivision as a new adaptive subdivision method for triangle meshes. This method applied to the method of adaptive subdivision constructs a new subdivision rule by introducing adjustable parameter to the traditional Loop scheme. The experiment shows that this method not only use fewer meshes to obtain the performance good surface but also can adjust the hape of subdivision surface to satisfy the actual need.

Abstract: For describing and resolving the process of chromium ore smelting reduction preferably, the coupling dynamic model was established using metallurgical thermodynamics, dynamics and reaction engineering. The different influencing factors were investigated and discussed. The results of the model show that the mass transfer of Cr2O3 in the slag phase is rate-determining step. The initial hot metal should contain definite chrome metal and the yield of chromium in slag should be controlled properly at 1560°C so as to decrease refining time considerably and improve production efficiency for producing stainless steel crude melts in a converter. A reference and basis for the constitution of rational processing route in a practical converter steelmaking have been afforded.

Abstract: The grid resources scheduling problem is one of the key problem in manufacturing grid. After studying on manufacturing grid resource property and requirement on scheduling, the scheduling method based on multi-agent and genetic algorithm is put forward. Contract Net Protocol is adopted to the multi-agent cooperation and negotiation system. The communication and interaction mechanism are guarantee on the JADE and JGAP platform. Simulation result shows that the method is effective to the negotiation and scheduling problem in manufacturing grid.

Abstract: The paper first demonstrates some relevant concepts with virtual maintenance, and further discusses the concepts and connotations of virtual maintenance. As the key techniques, virtual maintenance model and simulation method are studied in the paper. Virtual maintenance model (VMM) is present, and the model is based on Petri Net and can describe the relations of maintenance resources. In addition, virtual maintenance simulation rules are built in the paper. Finally, a case study of the LRU repair of an aircraft is conducted, and the result confirms the validation and feasibility of all the studies, which can become a new technique means for maintainability engineering.

Abstract: High-pure and single-phase PbI2 polycrystal was synthesized by Pb and I elements (99.9999%) according to the stoichiometry of PbI2 with excess of 0.3% Pb through modified two-zone vapor-transporting method (MTVM). The synthesis reaction was carried in a special quartz ampoule to prevent the ampoule exploding by controlling the temperature. With presynthesized polycrystal, an integral PbI2 single crystal with 15 mm in diameter and 25 mm in length was grown by vertical Bridgman method (VBM). The as-grown crystal was characterized by X-ray diffraction (XRD), ZC36 megger and Infrared (IR) spectrophotometers. XRD analysis indicated the structure of PbI2 crystal is 2H with hexagonal space group of , the lattice constants of a and c are 0.4560 nm and 0.6979 nm, respectively. The IR transmittance of a sample of 2.5 mm thickness is about 40% in the range from 4000 to 400 cm-1. Resistivity of the crystal is about 1013 Ωcm magnitude. These results demonstrate that the quality of the as-grown crystal is high enough for applications of room temperature nuclear radiation detectors.

Abstract: The resource-constrained project scheduling is an important problem for enterprise resource planning. We herein propose a differential evolution with scatter search structure (named by DESS hereinafter) to tackle resource-constrained project scheduling problem. DESS follows the scatter search structure but uses differential evolution (DE) to generate new solutions of SS, and applies 3-opt local search algorithm as the improvement method of SS to transform each trial solution into enhanced trial solution. The proposed DESS is compared with the state-of-the-art algorithms on a set of standard problems available in the literature. The experimental results validate the effectiveness of DESS.

Abstract: With the development of times, industry has been making great progress, which varies from primitive manual labor to machines in the age of steam. Then, machines and factories have taken the place of more and more manual labors with the development of mechanical design and relative theory. However, it still fails to reach the stage of full automation. Owing to the birth of computer and development of artificial intelligence, the robot factory is no longer a fresh topic. Undoubtedly, those are linked with graphic and computer’s development. There must be a more advanced theory and technology coming into being as graphic & image reach a higher stage. Then, it was named as the virtual realism technology. This new technology has been widely applied to various fields, such as, automatic production line, air quality automatic detector, war-simulating in army, “simulating space environment” on the earth, virtual laboratories building in the education and etc. Now, here are two basic concepts involved in the long-term development: graphics and image.

Abstract: The 3D physical model of the electrical water heater was built. The water-heater performance of two kind structures was resolved by computer fluid dynamics simulation (CFD). The heater performance is characterized by a new method rather than that the discharge efficiency, extraction efficiency and fraction of heat recoverable. The new method is based on the constant discharge water temperature and rate for end user, 5L/min and 43°C that include the hot water from EWH and cold water from outside EWH. But the water discharge rate from EWH was variable as the water temperature discharge from EWH was variable. The discharge efficiency of conventional EWH was 79.312%, and the discharge efficiency of improved EWH was 84.97%. Compared with the traditional method, it is more close to the user using reality condition.