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11.
Polycrystalline Cu(In,Ga)Se2 (CIGS) films with various ratios of Cu, In, and Ga were grown by codeposition of all elements in vacuum. The X-ray diffraction
study showed that the films are single-phase and possess a chalcopyrite structure with predominant [112] orientation. The
films exhibited a mirror smooth surface and had a close-packed structure composed of crystallites with clear faceting and
a transverse size of 0.1–0.3 μm. Related surface barrier structures of the (In,Ag)/Cu(In,Ga)Se2 type were obtained and their spectra of the quantum efficiency of photoconversion were studied. The obtained structures can
be used for optimization of the CIGS film technology. 相似文献
12.
Examination of the wreckage of a light aircraft revealed that approximately 20 cm was missing from one tip of the aluminum
alloy propeller. Fractographic and metallographic examination of the remaining portion of the propeller revealed extensive
grain-boundary separation in the vicinity of the fracture, and grain edges and corners rounded by corrosion on the fracture
surface. Energy dispersive X-ray analysis (EDXA) revealed fluorine on, and in the vicinity of, the fracture surface. In the
ensuing litigation, it was asserted that the crash occurred because the propeller fractured in flight as the result of intergranular
attack caused by the use of a fluorine-bearing cleaner. 相似文献
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14.
The purpose of this paper is to evaluate two methods of assessing the productivity and quality impact of Computer Aided Software Engineering (CASE) and Fourth Generation Language (4GL) technologies: (1) by the retrospective method; and (2) the cross-sectional method. Both methods involve the use of questionnaire surveys. Developers' perceptions depend on the context in which they are expressed and this includes expectations about the effectiveness of a given software product. Consequently, it is generally not reliable to base inferences about the relative merits of CASE and 4GLs on a cross-sectional comparison of two separate samples of users. The retrospective method that requires each respondent to directly compare different products is shown to be more reliable. However, there may be scope to employ cross-sectional comparisons of the findings from different samples where both sets of respondents use the same reference point for their judgements, and where numerical rather than verbal rating scales are used to measure perceptions. 相似文献
15.
Jan van Eijck 《Formal Aspects of Computing》1994,6(1):766-787
Presuppositions of utterances are the pieces of information you convey with an utterance no matter whether your utterance is true or not. We first study presupposition in a very simple framework of updating propositional information, with examples of how presuppositions of complex propositional updates can be calculated. Next we move on to presuppositions and quantification, in the context of a dynamic version of predicate logic, suitably modified to allow for presupposition failure. In both the propositional and the quantificational case, presupposition failure can be viewed as error abortion of procedures. Thus, a dynamic assertion logic which describes the preconditions for error abortion is the suitable tool for analysing presupposition. 相似文献
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18.
Three interesterified vegetable oils (IVOs) prepared from palm, cottonseed, and olive oil, respectively, have been studied for application to Frankfurters. Beef fat (10%) was replaced by one of the IVOs at 20, 60 or 100%. Fatty acid composition of the lipid fraction in the Frankfurters and saturated/unsaturated ratios were established for all batches. We found that total or partial replacement of beef fat by IVOs did not lead to significant changes in appearance, colour, texture, flavour or sensory score. We conclude that IVOs may be successfully applied as beef fat substitutes in Frankfurters. 相似文献
19.
The behavior of two series of concrete slabs exposed to sulfate-bearing soils was investigated by a numerical model called
STADIUM. In addition to the diffusion of ions and moisture, the model also accounts for the effects of dissolution/precipitation
reactions on the transport mechanisms. The simulations yielded by the model were compared to the actual degradation of the
slabs after 8 years of exposure. The microstructural alterations of concrete resulting from the penetration of magnesium,
chloride and sulfate ions were studied by backscatter mode scanning electron microscope observations and energy-dispersive
X-ray analyses. The comparison of both series of data indicates that the model can reliably predict the various features of
the microstructural alterations of concrete.
Editorial Note Laval University (Canada) is a RILEM Titular Member. Prof. J. Marchand was awarded the 2000 Robert L'Hermite Medal. He is Editor in Chief for Concrete Science and Engineering and Associate Editor for Materials and Structures. He participates in RILEM TC 186-ISA ‘Internal Sulfate attack’. 相似文献
Résumé Le comportement de deux séries de dalles sur sol en béton exposées à des sols chimiquement agressifs a été étudié à l'aide d'un code de calcul numérique appelé STADIUM. Ce modèle permet de décrire le transport couplé de l'eau et des ions dans des matériaux poreux non-saturés en prenant en considération l'influence des réactions chimiques. Les résultats des simultations de la dégradation du béton après huit ans d'exposition à des ions chlore, sulfate et magnésium. Les observations ont été réalisées par microscopie électronique à balayage. Des analyses par dispersion des rayons X ont également été effectuées. Les données démontrent clairement que le modèle perment de prédire avec précision le comportement du béton soumis à différents types d'agression chimique.
Editorial Note Laval University (Canada) is a RILEM Titular Member. Prof. J. Marchand was awarded the 2000 Robert L'Hermite Medal. He is Editor in Chief for Concrete Science and Engineering and Associate Editor for Materials and Structures. He participates in RILEM TC 186-ISA ‘Internal Sulfate attack’. 相似文献
20.
J-M Choe 《欧洲信息系统杂志》2002,11(2):142-158
This study empirically examined the organisational learning effects of the nonfinancial performance information provided by management accounting information systems (MAISs) under advanced manufacturing technology (AMT). In this study, a target costing system and the frequent and quick reporting of information were considered the facilitators of learning. First, we examined the relationships between AMT level and the amount of nonfinancial performance information produced by MAISs. The empirical results showed that there are significant positive relationships between the level of AMT and nonfinancial performance information. With a systems approach, we also proved the impact of the relationships among AMT levels, nonfinancial performance information and learning facilitators on the organisational performance of a firm. The results of our research suggest that under a high level of AMT, for the provision of information to result in an increase of performance through organisational learning, a target costing system must be introduced and a large amount of information should be provided frequently and quickly. The results of this study also showed that although AMT level may be low, fairly well-arranged facilitators and a moderately large amount of information may be necessary for the improvement of performance. In conclusion, effective organisational learning depends on the provision of relevant information as well as efficient learning support mechanisms. 相似文献