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11.
Incorporation of nano-Al2O3 particles into a Ni–Co alloy by electrodeposition influences the corrosion properties, morphology, and structure of the layers. The resistance against corrosion of Ni–Co/Al2O3 composite films deposited on stainless steel was investigated in a 0.1-M NaCl solution by potentiodynamic polarization. The presence of nanoparticles improves the corrosion resistance of Ni–Co/nano-Al2O3 deposits when compared to pure Ni–Co alloy. Moreover, by increasing the pH of the electrodeposition bath and the content of Co in the alloy, the resistance against corrosion is furthermore improved. The morphology of the deposits before and after their corrosion was analyzed by scanning electron microscopy. The presence of the embedded alumina particles in the Ni–Co alloys was one of the key factors that limited further propagation of corrosion on the metallic surface. Preferential corrosion attack, in the form of a pitting corrosion, was located mainly at the grain boundaries. 相似文献
12.
M. Benoit S. Ispas P. Jund R. Jullien 《The European Physical Journal B - Condensed Matter and Complex Systems》2000,13(4):631-636
A Car-Parrinello (CP) molecular dynamics simulation of vitreous silica, combined with classical molecular dynamics, is presented.
The equilibration of the liquid, quench and relaxation of the glass are performed classically using the van Beest, Kramer
and van Santen (BKS) potential [12] and the resulting configuration (coordinates and velocities) is used as input for the
CP simulation. A remarkable stability of the CP dynamics is observed justifying this procedure and validating the BKS potential.
Several structural and electronic properties are calculated and compared with experiments.
Received 23 March 1999 and Received in final form 15 July 1999 相似文献
13.
The authors of the presented paper are propose to relief the calculus, modelling and construction of the translation module of an industrial robot which possess in his cinematic chain five degrees of freedom, type TTRTR. It is propose a choosing variant of the direct current driving engine of the translation module, knowing the output momentum and calculating the input momentum. This is realized by equalize of an equation which results from dynamic modeling of the robot with a designing equation which keep in view the component elements of the structure of the module. The robot is composed by: module of translation on horizontal to the base of the robot (MTB-Sil), module of translation on vertical (MTV-Sil), module of rotation round the vertical axis from the robot's arm, module of translation from the structure of the robot's arm (MT-Sil) and module of orientation assembled with clamping device. In the paper, also is presented an economic study regarding the implementation of the analyzed robot in a manufactural cell concerning the manufacturing and assembling of some types of car radiators. (© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
14.
The authors want to conceive and to model a structure of a 6R serial modular industrial robot with six freedom degrees. Some specific points are followed: the direct geometric modelling of the robot using the matrix of rotation method, the given in 3D modelling of the robot, the presentation of its components having some possible applications in the processes of production in the spaces with noises and vibrations. The direct geometrical modelling will be determinate the relative orientation matrices, which express the position of each system Ti, (i=1-6), according to the system Ti–1, also expressing the vectors of relative position of origin Oi of the systems Ti. They will be expressed the orientation of each system Ti in account to the fixed system To attached to the robot base, the set of independent parameters of orientation then are obtained the final equation of the column vector of the generalized coordinates, which express the position and the orientation of the clamping device. The paper presents the two possible applications of the studied robot implementation in a flexible manufacturing cel for the manipulation operations of parts. The robot will be used on the other side for the execution of weld in a points applied to the car carcases. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献