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The 4H-SiC(000-1)C and (0001)Si surface reconstructed structures and the oxidation processes of these surfaces are investigated using a first-principles calculation method. The most stable reconstructed 4H-SiC(000-1)C and (0001)Si surfaces have p-bonded chains. In the topmost SiC bilayer, half of Si and C atoms exchange their positions and C-C or Si-Si bonds formed densely below the surfaces. When we place a SiO2 layer on the p-bonded chain (000-1)C surface, C-C bonds are formed more densely below the interface. We simulate a sequence of O2 molecules arrivals at an interface of tridymite-phase-SiO2 and 4H-SiC(000-1)C. Dissociated O atoms at the interface tended to make bonds with Si atoms. The C-C bonds in the SiC substrate break easily and a local C surface occasionally appears. We have examined how the surface structure changes through an O2 molecule exposure by using a classical molecular dynamics simulation program and confirmed the formation of C-C bonds below the surface and the interface.

Abstract:Permeability is one of important factors for a reservoir simulation model because flow in a model is affected a lot by this parameter.Whether "reservoir characterization" method or conventional reservoir evaluating method would be taken to construct a simulation model, permeability distribution along the wells is important, because the distribution is used as a base to predict field-wide permeability distribution.In this study, two permeability prediction methods were evaluated for estimating uncored well permeability from wire line well logs. One is method using artificial neural network (ANN), which is suitable to analyze complicated non-linear problem. The other is multiple linear regression analysis (MLRA) method. Also classical empirical porosity-permeability relationship method was evaluated to compare the accuracy or validity of ANN and MLRA methods.ANN showed little improvement and MLRA showed no improvement, compared to conventional porosity-permeability relationship result. Especially, better results were seen when all data were fed in to the ANN system, assuming that no geological information was provided. However, even ANN, which showed the best result, is not recommendable method for this reservoir because of lower quality than required. In conclusion, these trials showed difficulty of estimating uncored well permeability in this reservoir because of poor log quality and the nature of this complicated carbonate reservoir.

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The development of the high performance computer and network ， and accumulation of information contents ， such as data and software attained development of the advanced design system ． However ， in order to make this possibility actual ， development oflarge − scale and complicated software is indispensable ， and the new architecture of the software for a design is needed ． In this paper， the new architecture ， which integrates the existing information contents on a high perf ( ｝rmance computer and network enVironment ， is proposed ． This new architecture ． is called taskflow． While establishing the concept of a task flow ， the task且ow was applied to the materials design， and the virtual experiment system for materials design was developed ． The conceptoftask 且ow and Virtua1 experiment system are explained ． The efficiency of the new architecture of the software fbr a design was confirmed ．